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<title>nativeGen/RegAlloc/Graph/SpillClean.hs</title>
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<pre><a name="line-1"></a><span class='hs-comment'>{-# OPTIONS -fno-warn-missing-signatures #-}</span>
<a name="line-2"></a><span class='hs-comment'>-- | Clean out unneeded spill\/reload instrs</span>
<a name="line-3"></a><span class='hs-comment'>--</span>
<a name="line-4"></a><span class='hs-comment'>-- * Handling of join points</span>
<a name="line-5"></a><span class='hs-comment'>--</span>
<a name="line-6"></a><span class='hs-comment'>-- B1: B2:</span>
<a name="line-7"></a><span class='hs-comment'>-- ... ...</span>
<a name="line-8"></a><span class='hs-comment'>-- RELOAD SLOT(0), %r1 RELOAD SLOT(0), %r1</span>
<a name="line-9"></a><span class='hs-comment'>-- ... A ... ... B ...</span>
<a name="line-10"></a><span class='hs-comment'>-- jump B3 jump B3</span>
<a name="line-11"></a><span class='hs-comment'>--</span>
<a name="line-12"></a><span class='hs-comment'>-- B3: ... C ...</span>
<a name="line-13"></a><span class='hs-comment'>-- RELOAD SLOT(0), %r1</span>
<a name="line-14"></a><span class='hs-comment'>-- ...</span>
<a name="line-15"></a><span class='hs-comment'>--</span>
<a name="line-16"></a><span class='hs-comment'>-- the plan:</span>
<a name="line-17"></a><span class='hs-comment'>-- So long as %r1 hasn't been written to in A, B or C then we don't need the</span>
<a name="line-18"></a><span class='hs-comment'>-- reload in B3.</span>
<a name="line-19"></a><span class='hs-comment'>--</span>
<a name="line-20"></a><span class='hs-comment'>-- What we really care about here is that on the entry to B3, %r1 will always</span>
<a name="line-21"></a><span class='hs-comment'>-- have the same value that is in SLOT(0) (ie, %r1 is _valid_)</span>
<a name="line-22"></a><span class='hs-comment'>--</span>
<a name="line-23"></a><span class='hs-comment'>-- This also works if the reloads in B1\/B2 were spills instead, because</span>
<a name="line-24"></a><span class='hs-comment'>-- spilling %r1 to a slot makes that slot have the same value as %r1.</span>
<a name="line-25"></a><span class='hs-comment'>--</span>
<a name="line-26"></a>
<a name="line-27"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>RegAlloc</span><span class='hs-varop'>.</span><span class='hs-conid'>Graph</span><span class='hs-varop'>.</span><span class='hs-conid'>SpillClean</span> <span class='hs-layout'>(</span>
<a name="line-28"></a> <span class='hs-varid'>cleanSpills</span>
<a name="line-29"></a><span class='hs-layout'>)</span>
<a name="line-30"></a><span class='hs-keyword'>where</span>
<a name="line-31"></a>
<a name="line-32"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>RegAlloc</span><span class='hs-varop'>.</span><span class='hs-conid'>Liveness</span>
<a name="line-33"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Instruction</span>
<a name="line-34"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Reg</span>
<a name="line-35"></a>
<a name="line-36"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>BlockId</span>
<a name="line-37"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Cmm</span>
<a name="line-38"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>UniqSet</span>
<a name="line-39"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>UniqFM</span>
<a name="line-40"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Unique</span>
<a name="line-41"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>State</span>
<a name="line-42"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Outputable</span>
<a name="line-43"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Util</span>
<a name="line-44"></a>
<a name="line-45"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span> <span class='hs-layout'>(</span> <span class='hs-varid'>find</span><span class='hs-layout'>,</span> <span class='hs-varid'>nub</span> <span class='hs-layout'>)</span>
<a name="line-46"></a>
<a name="line-47"></a><a name="Slot"></a><span class='hs-comment'>--</span>
<a name="line-48"></a><a name="Slot"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>Slot</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Int</span>
<a name="line-49"></a>
<a name="line-50"></a>
<a name="line-51"></a><a name="cleanSpills"></a><span class='hs-comment'>-- | Clean out unneeded spill\/reloads from this top level thing.</span>
<a name="line-52"></a><span class='hs-definition'>cleanSpills</span>
<a name="line-53"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Instruction</span> <span class='hs-varid'>instr</span>
<a name="line-54"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>LiveCmmTop</span> <span class='hs-varid'>instr</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>LiveCmmTop</span> <span class='hs-varid'>instr</span>
<a name="line-55"></a>
<a name="line-56"></a><span class='hs-definition'>cleanSpills</span> <span class='hs-varid'>cmm</span>
<a name="line-57"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>evalState</span> <span class='hs-layout'>(</span><span class='hs-varid'>cleanSpin</span> <span class='hs-num'>0</span> <span class='hs-varid'>cmm</span><span class='hs-layout'>)</span> <span class='hs-varid'>initCleanS</span>
<a name="line-58"></a>
<a name="line-59"></a><a name="cleanSpin"></a><span class='hs-comment'>-- | do one pass of cleaning</span>
<a name="line-60"></a><span class='hs-definition'>cleanSpin</span>
<a name="line-61"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Instruction</span> <span class='hs-varid'>instr</span>
<a name="line-62"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Int</span>
<a name="line-63"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>LiveCmmTop</span> <span class='hs-varid'>instr</span>
<a name="line-64"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CleanM</span> <span class='hs-layout'>(</span><span class='hs-conid'>LiveCmmTop</span> <span class='hs-varid'>instr</span><span class='hs-layout'>)</span>
<a name="line-65"></a>
<a name="line-66"></a><span class='hs-comment'>{-
<a name="line-67"></a>cleanSpin spinCount code
<a name="line-68"></a> = do jumpValid <- gets sJumpValid
<a name="line-69"></a> pprTrace "cleanSpin"
<a name="line-70"></a> ( int spinCount
<a name="line-71"></a> $$ text "--- code"
<a name="line-72"></a> $$ ppr code
<a name="line-73"></a> $$ text "--- joins"
<a name="line-74"></a> $$ ppr jumpValid)
<a name="line-75"></a> $ cleanSpin' spinCount code
<a name="line-76"></a>-}</span>
<a name="line-77"></a>
<a name="line-78"></a><span class='hs-definition'>cleanSpin</span> <span class='hs-varid'>spinCount</span> <span class='hs-varid'>code</span>
<a name="line-79"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-80"></a> <span class='hs-comment'>-- init count of cleaned spills\/reloads</span>
<a name="line-81"></a> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span>
<a name="line-82"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>sCleanedSpillsAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0</span>
<a name="line-83"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sCleanedReloadsAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0</span>
<a name="line-84"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sReloadedBy</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>emptyUFM</span> <span class='hs-layout'>}</span>
<a name="line-85"></a>
<a name="line-86"></a> <span class='hs-varid'>code_forward</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>mapBlockTopM</span> <span class='hs-varid'>cleanBlockForward</span> <span class='hs-varid'>code</span>
<a name="line-87"></a> <span class='hs-varid'>code_backward</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>mapBlockTopM</span> <span class='hs-varid'>cleanBlockBackward</span> <span class='hs-varid'>code_forward</span>
<a name="line-88"></a>
<a name="line-89"></a> <span class='hs-comment'>-- During the cleaning of each block we collected information about what regs</span>
<a name="line-90"></a> <span class='hs-comment'>-- were valid across each jump. Based on this, work out whether it will be</span>
<a name="line-91"></a> <span class='hs-comment'>-- safe to erase reloads after join points for the next pass.</span>
<a name="line-92"></a> <span class='hs-varid'>collateJoinPoints</span>
<a name="line-93"></a>
<a name="line-94"></a> <span class='hs-comment'>-- remember how many spills\/reloads we cleaned in this pass</span>
<a name="line-95"></a> <span class='hs-varid'>spills</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>gets</span> <span class='hs-varid'>sCleanedSpillsAcc</span>
<a name="line-96"></a> <span class='hs-varid'>reloads</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>gets</span> <span class='hs-varid'>sCleanedReloadsAcc</span>
<a name="line-97"></a> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span>
<a name="line-98"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>sCleanedCount</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>spills</span><span class='hs-layout'>,</span> <span class='hs-varid'>reloads</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>sCleanedCount</span> <span class='hs-varid'>s</span> <span class='hs-layout'>}</span>
<a name="line-99"></a>
<a name="line-100"></a> <span class='hs-comment'>-- if nothing was cleaned in this pass or the last one</span>
<a name="line-101"></a> <span class='hs-comment'>-- then we're done and it's time to bail out</span>
<a name="line-102"></a> <span class='hs-varid'>cleanedCount</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>gets</span> <span class='hs-varid'>sCleanedCount</span>
<a name="line-103"></a> <span class='hs-keyword'>if</span> <span class='hs-varid'>take</span> <span class='hs-num'>2</span> <span class='hs-varid'>cleanedCount</span> <span class='hs-varop'>==</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-num'>0</span><span class='hs-layout'>,</span> <span class='hs-num'>0</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <span class='hs-layout'>(</span><span class='hs-num'>0</span><span class='hs-layout'>,</span> <span class='hs-num'>0</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-104"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>return</span> <span class='hs-varid'>code</span>
<a name="line-105"></a>
<a name="line-106"></a> <span class='hs-comment'>-- otherwise go around again</span>
<a name="line-107"></a> <span class='hs-keyword'>else</span> <span class='hs-varid'>cleanSpin</span> <span class='hs-layout'>(</span><span class='hs-varid'>spinCount</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span><span class='hs-layout'>)</span> <span class='hs-varid'>code_backward</span>
<a name="line-108"></a>
<a name="line-109"></a>
<a name="line-110"></a><a name="cleanBlockForward"></a><span class='hs-comment'>-- | Clean one basic block</span>
<a name="line-111"></a><span class='hs-definition'>cleanBlockForward</span>
<a name="line-112"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Instruction</span> <span class='hs-varid'>instr</span>
<a name="line-113"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>LiveBasicBlock</span> <span class='hs-varid'>instr</span>
<a name="line-114"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CleanM</span> <span class='hs-layout'>(</span><span class='hs-conid'>LiveBasicBlock</span> <span class='hs-varid'>instr</span><span class='hs-layout'>)</span>
<a name="line-115"></a>
<a name="line-116"></a><span class='hs-definition'>cleanBlockForward</span> <span class='hs-layout'>(</span><span class='hs-conid'>BasicBlock</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>instrs</span><span class='hs-layout'>)</span>
<a name="line-117"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-118"></a> <span class='hs-comment'>-- see if we have a valid association for the entry to this block</span>
<a name="line-119"></a> <span class='hs-varid'>jumpValid</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>gets</span> <span class='hs-varid'>sJumpValid</span>
<a name="line-120"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>assoc</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>lookupUFM</span> <span class='hs-varid'>jumpValid</span> <span class='hs-varid'>blockId</span> <span class='hs-keyword'>of</span>
<a name="line-121"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>assoc</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>assoc</span>
<a name="line-122"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>emptyAssoc</span>
<a name="line-123"></a>
<a name="line-124"></a> <span class='hs-varid'>instrs_reload</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>instrs</span>
<a name="line-125"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>BasicBlock</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>instrs_reload</span>
<a name="line-126"></a>
<a name="line-127"></a>
<a name="line-128"></a><a name="cleanBlockBackward"></a><span class='hs-definition'>cleanBlockBackward</span>
<a name="line-129"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Instruction</span> <span class='hs-varid'>instr</span>
<a name="line-130"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>LiveBasicBlock</span> <span class='hs-varid'>instr</span>
<a name="line-131"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CleanM</span> <span class='hs-layout'>(</span><span class='hs-conid'>LiveBasicBlock</span> <span class='hs-varid'>instr</span><span class='hs-layout'>)</span>
<a name="line-132"></a>
<a name="line-133"></a><span class='hs-definition'>cleanBlockBackward</span> <span class='hs-layout'>(</span><span class='hs-conid'>BasicBlock</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>instrs</span><span class='hs-layout'>)</span>
<a name="line-134"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>instrs_spill</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>cleanBackward</span> <span class='hs-varid'>emptyUniqSet</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>instrs</span>
<a name="line-135"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>BasicBlock</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>instrs_spill</span>
<a name="line-136"></a>
<a name="line-137"></a>
<a name="line-138"></a>
<a name="line-139"></a>
<a name="line-140"></a><a name="cleanForward"></a><span class='hs-comment'>-- | Clean out unneeded reload instructions.</span>
<a name="line-141"></a><span class='hs-comment'>-- Walking forwards across the code</span>
<a name="line-142"></a><span class='hs-comment'>-- On a reload, if we know a reg already has the same value as a slot</span>
<a name="line-143"></a><span class='hs-comment'>-- then we don't need to do the reload.</span>
<a name="line-144"></a><span class='hs-comment'>--</span>
<a name="line-145"></a><span class='hs-definition'>cleanForward</span>
<a name="line-146"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Instruction</span> <span class='hs-varid'>instr</span>
<a name="line-147"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>BlockId</span> <span class='hs-comment'>-- ^ the block that we're currently in</span>
<a name="line-148"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-conid'>Store</span> <span class='hs-comment'>-- ^ two store locations are associated if they have the same value</span>
<a name="line-149"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>LiveInstr</span> <span class='hs-varid'>instr</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- ^ acc</span>
<a name="line-150"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>LiveInstr</span> <span class='hs-varid'>instr</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- ^ instrs to clean (in backwards order)</span>
<a name="line-151"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CleanM</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>LiveInstr</span> <span class='hs-varid'>instr</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- ^ cleaned instrs (in forward order)</span>
<a name="line-152"></a>
<a name="line-153"></a><span class='hs-definition'>cleanForward</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>acc</span> <span class='hs-conid'>[]</span>
<a name="line-154"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varid'>acc</span>
<a name="line-155"></a>
<a name="line-156"></a><span class='hs-comment'>-- write out live range joins via spill slots to just a spill and a reg-reg move</span>
<a name="line-157"></a><span class='hs-comment'>-- hopefully the spill will be also be cleaned in the next pass</span>
<a name="line-158"></a><span class='hs-comment'>--</span>
<a name="line-159"></a><span class='hs-definition'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>acc</span> <span class='hs-layout'>(</span><span class='hs-varid'>li1</span> <span class='hs-conop'>:</span> <span class='hs-varid'>li2</span> <span class='hs-conop'>:</span> <span class='hs-varid'>instrs</span><span class='hs-layout'>)</span>
<a name="line-160"></a>
<a name="line-161"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>SPILL</span> <span class='hs-varid'>reg1</span> <span class='hs-varid'>slot1</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>li1</span>
<a name="line-162"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RELOAD</span> <span class='hs-varid'>slot2</span> <span class='hs-varid'>reg2</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>li2</span>
<a name="line-163"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>slot1</span> <span class='hs-varop'>==</span> <span class='hs-varid'>slot2</span>
<a name="line-164"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-165"></a> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>sCleanedReloadsAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sCleanedReloadsAcc</span> <span class='hs-varid'>s</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span> <span class='hs-layout'>}</span>
<a name="line-166"></a> <span class='hs-varid'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>acc</span>
<a name="line-167"></a> <span class='hs-layout'>(</span><span class='hs-varid'>li1</span> <span class='hs-conop'>:</span> <span class='hs-conid'>Instr</span> <span class='hs-layout'>(</span><span class='hs-varid'>mkRegRegMoveInstr</span> <span class='hs-varid'>reg1</span> <span class='hs-varid'>reg2</span><span class='hs-layout'>)</span> <span class='hs-conid'>Nothing</span> <span class='hs-conop'>:</span> <span class='hs-varid'>instrs</span><span class='hs-layout'>)</span>
<a name="line-168"></a>
<a name="line-169"></a>
<a name="line-170"></a><span class='hs-definition'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>acc</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Instr</span> <span class='hs-varid'>i1</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-conop'>:</span> <span class='hs-varid'>instrs</span><span class='hs-layout'>)</span>
<a name="line-171"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>r1</span><span class='hs-layout'>,</span> <span class='hs-varid'>r2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>takeRegRegMoveInstr</span> <span class='hs-varid'>i1</span>
<a name="line-172"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>r1</span> <span class='hs-varop'>==</span> <span class='hs-varid'>r2</span>
<a name="line-173"></a> <span class='hs-comment'>-- erase any left over nop reg reg moves while we're here</span>
<a name="line-174"></a> <span class='hs-comment'>-- this will also catch any nop moves that the "write out live range joins" case above</span>
<a name="line-175"></a> <span class='hs-comment'>-- happens to add</span>
<a name="line-176"></a> <span class='hs-keyword'>then</span> <span class='hs-varid'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>acc</span> <span class='hs-varid'>instrs</span>
<a name="line-177"></a>
<a name="line-178"></a> <span class='hs-comment'>-- if r1 has the same value as some slots and we copy r1 to r2,</span>
<a name="line-179"></a> <span class='hs-comment'>-- then r2 is now associated with those slots instead</span>
<a name="line-180"></a> <span class='hs-keyword'>else</span> <span class='hs-keyword'>do</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>assoc'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>r1</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>r2</span><span class='hs-layout'>)</span>
<a name="line-181"></a> <span class='hs-varop'>$</span> <span class='hs-varid'>delAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>r2</span><span class='hs-layout'>)</span>
<a name="line-182"></a> <span class='hs-varop'>$</span> <span class='hs-varid'>assoc</span>
<a name="line-183"></a>
<a name="line-184"></a> <span class='hs-varid'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc'</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span> <span class='hs-conop'>:</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span> <span class='hs-varid'>instrs</span>
<a name="line-185"></a>
<a name="line-186"></a>
<a name="line-187"></a><span class='hs-definition'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>acc</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span> <span class='hs-conop'>:</span> <span class='hs-varid'>instrs</span><span class='hs-layout'>)</span>
<a name="line-188"></a>
<a name="line-189"></a> <span class='hs-comment'>-- update association due to the spill</span>
<a name="line-190"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>SPILL</span> <span class='hs-varid'>reg</span> <span class='hs-varid'>slot</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>li</span>
<a name="line-191"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>assoc'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>reg</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>SSlot</span> <span class='hs-varid'>slot</span><span class='hs-layout'>)</span>
<a name="line-192"></a> <span class='hs-varop'>$</span> <span class='hs-varid'>delAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SSlot</span> <span class='hs-varid'>slot</span><span class='hs-layout'>)</span>
<a name="line-193"></a> <span class='hs-varop'>$</span> <span class='hs-varid'>assoc</span>
<a name="line-194"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc'</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span> <span class='hs-conop'>:</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span> <span class='hs-varid'>instrs</span>
<a name="line-195"></a>
<a name="line-196"></a> <span class='hs-comment'>-- clean a reload instr</span>
<a name="line-197"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RELOAD</span><span class='hs-layout'>{</span><span class='hs-layout'>}</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>li</span>
<a name="line-198"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-layout'>(</span><span class='hs-varid'>assoc'</span><span class='hs-layout'>,</span> <span class='hs-varid'>mli</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>cleanReload</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>li</span>
<a name="line-199"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>mli</span> <span class='hs-keyword'>of</span>
<a name="line-200"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc'</span> <span class='hs-varid'>acc</span> <span class='hs-varid'>instrs</span>
<a name="line-201"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>li'</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc'</span> <span class='hs-layout'>(</span><span class='hs-varid'>li'</span> <span class='hs-conop'>:</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span> <span class='hs-varid'>instrs</span>
<a name="line-202"></a>
<a name="line-203"></a> <span class='hs-comment'>-- remember the association over a jump</span>
<a name="line-204"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Instr</span> <span class='hs-varid'>instr</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>li</span>
<a name="line-205"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>targets</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>jumpDestsOfInstr</span> <span class='hs-varid'>instr</span>
<a name="line-206"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>not</span> <span class='hs-varop'>$</span> <span class='hs-varid'>null</span> <span class='hs-varid'>targets</span>
<a name="line-207"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>mapM_</span> <span class='hs-layout'>(</span><span class='hs-varid'>accJumpValid</span> <span class='hs-varid'>assoc</span><span class='hs-layout'>)</span> <span class='hs-varid'>targets</span>
<a name="line-208"></a> <span class='hs-varid'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span> <span class='hs-conop'>:</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span> <span class='hs-varid'>instrs</span>
<a name="line-209"></a>
<a name="line-210"></a> <span class='hs-comment'>-- writing to a reg changes its value.</span>
<a name="line-211"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Instr</span> <span class='hs-varid'>instr</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>li</span>
<a name="line-212"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>RU</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>written</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>regUsageOfInstr</span> <span class='hs-varid'>instr</span>
<a name="line-213"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>assoc'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldr</span> <span class='hs-varid'>delAssoc</span> <span class='hs-varid'>assoc</span> <span class='hs-layout'>(</span><span class='hs-varid'>map</span> <span class='hs-conid'>SReg</span> <span class='hs-varop'>$</span> <span class='hs-varid'>nub</span> <span class='hs-varid'>written</span><span class='hs-layout'>)</span>
<a name="line-214"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>cleanForward</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc'</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span> <span class='hs-conop'>:</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span> <span class='hs-varid'>instrs</span>
<a name="line-215"></a>
<a name="line-216"></a><span class='hs-comment'>-- bogus, to stop pattern match warning</span>
<a name="line-217"></a><span class='hs-definition'>cleanForward</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span>
<a name="line-218"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>panic</span> <span class='hs-str'>"RegAlloc.Graph.SpillClean.cleanForward: no match"</span>
<a name="line-219"></a>
<a name="line-220"></a>
<a name="line-221"></a><a name="cleanReload"></a><span class='hs-comment'>-- | Try and rewrite a reload instruction to something more pleasing</span>
<a name="line-222"></a><span class='hs-comment'>--</span>
<a name="line-223"></a><span class='hs-definition'>cleanReload</span>
<a name="line-224"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Instruction</span> <span class='hs-varid'>instr</span>
<a name="line-225"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>BlockId</span>
<a name="line-226"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-conid'>Store</span>
<a name="line-227"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>LiveInstr</span> <span class='hs-varid'>instr</span>
<a name="line-228"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CleanM</span> <span class='hs-layout'>(</span><span class='hs-conid'>Assoc</span> <span class='hs-conid'>Store</span><span class='hs-layout'>,</span> <span class='hs-conid'>Maybe</span> <span class='hs-layout'>(</span><span class='hs-conid'>LiveInstr</span> <span class='hs-varid'>instr</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-229"></a>
<a name="line-230"></a><span class='hs-definition'>cleanReload</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>li</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>RELOAD</span> <span class='hs-varid'>slot</span> <span class='hs-varid'>reg</span><span class='hs-layout'>)</span>
<a name="line-231"></a>
<a name="line-232"></a> <span class='hs-comment'>-- if the reg we're reloading already has the same value as the slot</span>
<a name="line-233"></a> <span class='hs-comment'>-- then we can erase the instruction outright</span>
<a name="line-234"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>elemAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SSlot</span> <span class='hs-varid'>slot</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>reg</span><span class='hs-layout'>)</span> <span class='hs-varid'>assoc</span>
<a name="line-235"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>sCleanedReloadsAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sCleanedReloadsAcc</span> <span class='hs-varid'>s</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span> <span class='hs-layout'>}</span>
<a name="line-236"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>assoc</span><span class='hs-layout'>,</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>)</span>
<a name="line-237"></a>
<a name="line-238"></a> <span class='hs-comment'>-- if we can find another reg with the same value as this slot then</span>
<a name="line-239"></a> <span class='hs-comment'>-- do a move instead of a reload.</span>
<a name="line-240"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>reg2</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>findRegOfSlot</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>slot</span>
<a name="line-241"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>sCleanedReloadsAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sCleanedReloadsAcc</span> <span class='hs-varid'>s</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span> <span class='hs-layout'>}</span>
<a name="line-242"></a>
<a name="line-243"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>assoc'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>reg</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>reg2</span><span class='hs-layout'>)</span>
<a name="line-244"></a> <span class='hs-varop'>$</span> <span class='hs-varid'>delAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>reg</span><span class='hs-layout'>)</span>
<a name="line-245"></a> <span class='hs-varop'>$</span> <span class='hs-varid'>assoc</span>
<a name="line-246"></a>
<a name="line-247"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>assoc'</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varop'>$</span> <span class='hs-conid'>Instr</span> <span class='hs-layout'>(</span><span class='hs-varid'>mkRegRegMoveInstr</span> <span class='hs-varid'>reg2</span> <span class='hs-varid'>reg</span><span class='hs-layout'>)</span> <span class='hs-conid'>Nothing</span><span class='hs-layout'>)</span>
<a name="line-248"></a>
<a name="line-249"></a> <span class='hs-comment'>-- gotta keep this instr</span>
<a name="line-250"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span>
<a name="line-251"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-comment'>-- update the association</span>
<a name="line-252"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>assoc'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>reg</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>SSlot</span> <span class='hs-varid'>slot</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- doing the reload makes reg and slot the same value</span>
<a name="line-253"></a> <span class='hs-varop'>$</span> <span class='hs-varid'>delAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>reg</span><span class='hs-layout'>)</span> <span class='hs-comment'>-- reg value changes on reload</span>
<a name="line-254"></a> <span class='hs-varop'>$</span> <span class='hs-varid'>assoc</span>
<a name="line-255"></a>
<a name="line-256"></a> <span class='hs-comment'>-- remember that this block reloads from this slot</span>
<a name="line-257"></a> <span class='hs-varid'>accBlockReloadsSlot</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>slot</span>
<a name="line-258"></a>
<a name="line-259"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>assoc'</span><span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>li</span><span class='hs-layout'>)</span>
<a name="line-260"></a>
<a name="line-261"></a><span class='hs-definition'>cleanReload</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span>
<a name="line-262"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>panic</span> <span class='hs-str'>"RegSpillClean.cleanReload: unhandled instr"</span>
<a name="line-263"></a>
<a name="line-264"></a>
<a name="line-265"></a><a name="cleanBackward"></a><span class='hs-comment'>-- | Clean out unneeded spill instructions.</span>
<a name="line-266"></a><span class='hs-comment'>--</span>
<a name="line-267"></a><span class='hs-comment'>-- If there were no reloads from a slot between a spill and the last one</span>
<a name="line-268"></a><span class='hs-comment'>-- then the slot was never read and we don't need the spill.</span>
<a name="line-269"></a><span class='hs-comment'>--</span>
<a name="line-270"></a><span class='hs-comment'>-- SPILL r0 -> s1</span>
<a name="line-271"></a><span class='hs-comment'>-- RELOAD s1 -> r2</span>
<a name="line-272"></a><span class='hs-comment'>-- SPILL r3 -> s1 <--- don't need this spill</span>
<a name="line-273"></a><span class='hs-comment'>-- SPILL r4 -> s1</span>
<a name="line-274"></a><span class='hs-comment'>-- RELOAD s1 -> r5</span>
<a name="line-275"></a><span class='hs-comment'>--</span>
<a name="line-276"></a><span class='hs-comment'>-- Maintain a set of</span>
<a name="line-277"></a><span class='hs-comment'>-- "slots which were spilled to but not reloaded from yet"</span>
<a name="line-278"></a><span class='hs-comment'>--</span>
<a name="line-279"></a><span class='hs-comment'>-- Walking backwards across the code:</span>
<a name="line-280"></a><span class='hs-comment'>-- a) On a reload from a slot, remove it from the set.</span>
<a name="line-281"></a><span class='hs-comment'>--</span>
<a name="line-282"></a><span class='hs-comment'>-- a) On a spill from a slot</span>
<a name="line-283"></a><span class='hs-comment'>-- If the slot is in set then we can erase the spill,</span>
<a name="line-284"></a><span class='hs-comment'>-- because it won't be reloaded from until after the next spill.</span>
<a name="line-285"></a><span class='hs-comment'>--</span>
<a name="line-286"></a><span class='hs-comment'>-- otherwise</span>
<a name="line-287"></a><span class='hs-comment'>-- keep the spill and add the slot to the set</span>
<a name="line-288"></a><span class='hs-comment'>--</span>
<a name="line-289"></a><span class='hs-comment'>-- TODO: This is mostly inter-block</span>
<a name="line-290"></a><span class='hs-comment'>-- we should really be updating the noReloads set as we cross jumps also.</span>
<a name="line-291"></a><span class='hs-comment'>--</span>
<a name="line-292"></a><span class='hs-definition'>cleanBackward</span>
<a name="line-293"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>UniqSet</span> <span class='hs-conid'>Int</span> <span class='hs-comment'>-- ^ slots that have been spilled, but not reloaded from</span>
<a name="line-294"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>LiveInstr</span> <span class='hs-varid'>instr</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- ^ acc</span>
<a name="line-295"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>LiveInstr</span> <span class='hs-varid'>instr</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- ^ instrs to clean (in forwards order)</span>
<a name="line-296"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CleanM</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>LiveInstr</span> <span class='hs-varid'>instr</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- ^ cleaned instrs (in backwards order)</span>
<a name="line-297"></a>
<a name="line-298"></a>
<a name="line-299"></a><span class='hs-definition'>cleanBackward</span> <span class='hs-varid'>noReloads</span> <span class='hs-varid'>acc</span> <span class='hs-varid'>lis</span>
<a name="line-300"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>reloadedBy</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>gets</span> <span class='hs-varid'>sReloadedBy</span>
<a name="line-301"></a> <span class='hs-varid'>cleanBackward'</span> <span class='hs-varid'>reloadedBy</span> <span class='hs-varid'>noReloads</span> <span class='hs-varid'>acc</span> <span class='hs-varid'>lis</span>
<a name="line-302"></a>
<a name="line-303"></a><a name="cleanBackward'"></a><span class='hs-definition'>cleanBackward'</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>acc</span> <span class='hs-conid'>[]</span>
<a name="line-304"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varid'>acc</span>
<a name="line-305"></a>
<a name="line-306"></a><span class='hs-definition'>cleanBackward'</span> <span class='hs-varid'>reloadedBy</span> <span class='hs-varid'>noReloads</span> <span class='hs-varid'>acc</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span> <span class='hs-conop'>:</span> <span class='hs-varid'>instrs</span><span class='hs-layout'>)</span>
<a name="line-307"></a>
<a name="line-308"></a> <span class='hs-comment'>-- if nothing ever reloads from this slot then we don't need the spill</span>
<a name="line-309"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>SPILL</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>slot</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>li</span>
<a name="line-310"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>lookupUFM</span> <span class='hs-varid'>reloadedBy</span> <span class='hs-layout'>(</span><span class='hs-conid'>SSlot</span> <span class='hs-varid'>slot</span><span class='hs-layout'>)</span>
<a name="line-311"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>sCleanedSpillsAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sCleanedSpillsAcc</span> <span class='hs-varid'>s</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span> <span class='hs-layout'>}</span>
<a name="line-312"></a> <span class='hs-varid'>cleanBackward</span> <span class='hs-varid'>noReloads</span> <span class='hs-varid'>acc</span> <span class='hs-varid'>instrs</span>
<a name="line-313"></a>
<a name="line-314"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>SPILL</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>slot</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>li</span>
<a name="line-315"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>elementOfUniqSet</span> <span class='hs-varid'>slot</span> <span class='hs-varid'>noReloads</span>
<a name="line-316"></a>
<a name="line-317"></a> <span class='hs-comment'>-- we can erase this spill because the slot won't be read until after the next one</span>
<a name="line-318"></a> <span class='hs-keyword'>then</span> <span class='hs-keyword'>do</span>
<a name="line-319"></a> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span> <span class='hs-varid'>sCleanedSpillsAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sCleanedSpillsAcc</span> <span class='hs-varid'>s</span> <span class='hs-varop'>+</span> <span class='hs-num'>1</span> <span class='hs-layout'>}</span>
<a name="line-320"></a> <span class='hs-varid'>cleanBackward</span> <span class='hs-varid'>noReloads</span> <span class='hs-varid'>acc</span> <span class='hs-varid'>instrs</span>
<a name="line-321"></a>
<a name="line-322"></a> <span class='hs-keyword'>else</span> <span class='hs-keyword'>do</span>
<a name="line-323"></a> <span class='hs-comment'>-- this slot is being spilled to, but we haven't seen any reloads yet.</span>
<a name="line-324"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>noReloads'</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addOneToUniqSet</span> <span class='hs-varid'>noReloads</span> <span class='hs-varid'>slot</span>
<a name="line-325"></a> <span class='hs-varid'>cleanBackward</span> <span class='hs-varid'>noReloads'</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span> <span class='hs-conop'>:</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span> <span class='hs-varid'>instrs</span>
<a name="line-326"></a>
<a name="line-327"></a> <span class='hs-comment'>-- if we reload from a slot then it's no longer unused</span>
<a name="line-328"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RELOAD</span> <span class='hs-varid'>slot</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>li</span>
<a name="line-329"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>noReloads'</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>delOneFromUniqSet</span> <span class='hs-varid'>noReloads</span> <span class='hs-varid'>slot</span>
<a name="line-330"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cleanBackward</span> <span class='hs-varid'>noReloads'</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span> <span class='hs-conop'>:</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span> <span class='hs-varid'>instrs</span>
<a name="line-331"></a>
<a name="line-332"></a> <span class='hs-comment'>-- some other instruction</span>
<a name="line-333"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span>
<a name="line-334"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>cleanBackward</span> <span class='hs-varid'>noReloads</span> <span class='hs-layout'>(</span><span class='hs-varid'>li</span> <span class='hs-conop'>:</span> <span class='hs-varid'>acc</span><span class='hs-layout'>)</span> <span class='hs-varid'>instrs</span>
<a name="line-335"></a>
<a name="line-336"></a>
<a name="line-337"></a><a name="collateJoinPoints"></a><span class='hs-comment'>-- collateJoinPoints:</span>
<a name="line-338"></a><span class='hs-comment'>--</span>
<a name="line-339"></a><span class='hs-comment'>-- | combine the associations from all the inward control flow edges.</span>
<a name="line-340"></a><span class='hs-comment'>--</span>
<a name="line-341"></a><span class='hs-definition'>collateJoinPoints</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CleanM</span> <span class='hs-conid'>()</span>
<a name="line-342"></a><span class='hs-definition'>collateJoinPoints</span>
<a name="line-343"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span>
<a name="line-344"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>sJumpValid</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mapUFM</span> <span class='hs-varid'>intersects</span> <span class='hs-layout'>(</span><span class='hs-varid'>sJumpValidAcc</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-345"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sJumpValidAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>emptyUFM</span> <span class='hs-layout'>}</span>
<a name="line-346"></a>
<a name="line-347"></a><a name="intersects"></a><span class='hs-definition'>intersects</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Assoc</span> <span class='hs-conid'>Store</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-conid'>Store</span>
<a name="line-348"></a><span class='hs-definition'>intersects</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>emptyAssoc</span>
<a name="line-349"></a><span class='hs-definition'>intersects</span> <span class='hs-varid'>assocs</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldl1'</span> <span class='hs-varid'>intersectAssoc</span> <span class='hs-varid'>assocs</span>
<a name="line-350"></a>
<a name="line-351"></a>
<a name="line-352"></a><a name="findRegOfSlot"></a><span class='hs-comment'>-- | See if we have a reg with the same value as this slot in the association table.</span>
<a name="line-353"></a><span class='hs-definition'>findRegOfSlot</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Assoc</span> <span class='hs-conid'>Store</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Int</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Maybe</span> <span class='hs-conid'>Reg</span>
<a name="line-354"></a><span class='hs-definition'>findRegOfSlot</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>slot</span>
<a name="line-355"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>close</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>closeAssoc</span> <span class='hs-layout'>(</span><span class='hs-conid'>SSlot</span> <span class='hs-varid'>slot</span><span class='hs-layout'>)</span> <span class='hs-varid'>assoc</span>
<a name="line-356"></a> <span class='hs-layout'>,</span> <span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>reg</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>find</span> <span class='hs-varid'>isStoreReg</span> <span class='hs-varop'>$</span> <span class='hs-varid'>uniqSetToList</span> <span class='hs-varid'>close</span>
<a name="line-357"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>reg</span>
<a name="line-358"></a>
<a name="line-359"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span>
<a name="line-360"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Nothing</span>
<a name="line-361"></a>
<a name="line-362"></a>
<a name="line-363"></a><a name="CleanM"></a><span class='hs-comment'>---------------</span>
<a name="line-364"></a><a name="CleanM"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>CleanM</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>State</span> <span class='hs-conid'>CleanS</span>
<a name="line-365"></a><a name="CleanS"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>CleanS</span>
<a name="line-366"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>CleanS</span>
<a name="line-367"></a> <span class='hs-layout'>{</span> <span class='hs-comment'>-- regs which are valid at the start of each block.</span>
<a name="line-368"></a> <span class='hs-varid'>sJumpValid</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>UniqFM</span> <span class='hs-layout'>(</span><span class='hs-conid'>Assoc</span> <span class='hs-conid'>Store</span><span class='hs-layout'>)</span>
<a name="line-369"></a>
<a name="line-370"></a> <span class='hs-comment'>-- collecting up what regs were valid across each jump.</span>
<a name="line-371"></a> <span class='hs-comment'>-- in the next pass we can collate these and write the results</span>
<a name="line-372"></a> <span class='hs-comment'>-- to sJumpValid.</span>
<a name="line-373"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sJumpValidAcc</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>UniqFM</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>Assoc</span> <span class='hs-conid'>Store</span><span class='hs-keyglyph'>]</span>
<a name="line-374"></a>
<a name="line-375"></a> <span class='hs-comment'>-- map of (slot -> blocks which reload from this slot)</span>
<a name="line-376"></a> <span class='hs-comment'>-- used to decide if whether slot spilled to will ever be</span>
<a name="line-377"></a> <span class='hs-comment'>-- reloaded from on this path.</span>
<a name="line-378"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sReloadedBy</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>UniqFM</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>BlockId</span><span class='hs-keyglyph'>]</span>
<a name="line-379"></a>
<a name="line-380"></a> <span class='hs-comment'>-- spills\/reloads cleaned each pass (latest at front)</span>
<a name="line-381"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sCleanedCount</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-conid'>Int</span><span class='hs-layout'>,</span> <span class='hs-conid'>Int</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span>
<a name="line-382"></a>
<a name="line-383"></a> <span class='hs-comment'>-- spills\/reloads that have been cleaned in this pass so far.</span>
<a name="line-384"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sCleanedSpillsAcc</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span>
<a name="line-385"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sCleanedReloadsAcc</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span> <span class='hs-layout'>}</span>
<a name="line-386"></a>
<a name="line-387"></a><a name="initCleanS"></a><span class='hs-definition'>initCleanS</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>CleanS</span>
<a name="line-388"></a><span class='hs-definition'>initCleanS</span>
<a name="line-389"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>CleanS</span>
<a name="line-390"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>sJumpValid</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>emptyUFM</span>
<a name="line-391"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sJumpValidAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>emptyUFM</span>
<a name="line-392"></a>
<a name="line-393"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sReloadedBy</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>emptyUFM</span>
<a name="line-394"></a>
<a name="line-395"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sCleanedCount</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-396"></a>
<a name="line-397"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sCleanedSpillsAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0</span>
<a name="line-398"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>sCleanedReloadsAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0</span> <span class='hs-layout'>}</span>
<a name="line-399"></a>
<a name="line-400"></a>
<a name="line-401"></a><a name="accJumpValid"></a><span class='hs-comment'>-- | Remember the associations before a jump</span>
<a name="line-402"></a><span class='hs-definition'>accJumpValid</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Assoc</span> <span class='hs-conid'>Store</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>BlockId</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CleanM</span> <span class='hs-conid'>()</span>
<a name="line-403"></a><span class='hs-definition'>accJumpValid</span> <span class='hs-varid'>assocs</span> <span class='hs-varid'>target</span>
<a name="line-404"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span>
<a name="line-405"></a> <span class='hs-varid'>sJumpValidAcc</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addToUFM_C</span> <span class='hs-layout'>(</span><span class='hs-varop'>++</span><span class='hs-layout'>)</span>
<a name="line-406"></a> <span class='hs-layout'>(</span><span class='hs-varid'>sJumpValidAcc</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-407"></a> <span class='hs-varid'>target</span>
<a name="line-408"></a> <span class='hs-keyglyph'>[</span><span class='hs-varid'>assocs</span><span class='hs-keyglyph'>]</span> <span class='hs-layout'>}</span>
<a name="line-409"></a>
<a name="line-410"></a>
<a name="line-411"></a><a name="accBlockReloadsSlot"></a><span class='hs-definition'>accBlockReloadsSlot</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>BlockId</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Slot</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>CleanM</span> <span class='hs-conid'>()</span>
<a name="line-412"></a><span class='hs-definition'>accBlockReloadsSlot</span> <span class='hs-varid'>blockId</span> <span class='hs-varid'>slot</span>
<a name="line-413"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>modify</span> <span class='hs-varop'>$</span> <span class='hs-keyglyph'>\</span><span class='hs-varid'>s</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>s</span> <span class='hs-layout'>{</span>
<a name="line-414"></a> <span class='hs-varid'>sReloadedBy</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addToUFM_C</span> <span class='hs-layout'>(</span><span class='hs-varop'>++</span><span class='hs-layout'>)</span>
<a name="line-415"></a> <span class='hs-layout'>(</span><span class='hs-varid'>sReloadedBy</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-416"></a> <span class='hs-layout'>(</span><span class='hs-conid'>SSlot</span> <span class='hs-varid'>slot</span><span class='hs-layout'>)</span>
<a name="line-417"></a> <span class='hs-keyglyph'>[</span><span class='hs-varid'>blockId</span><span class='hs-keyglyph'>]</span> <span class='hs-layout'>}</span>
<a name="line-418"></a>
<a name="line-419"></a>
<a name="line-420"></a><a name="Store"></a><span class='hs-comment'>--------------</span>
<a name="line-421"></a><a name="Store"></a><span class='hs-comment'>-- A store location can be a stack slot or a register</span>
<a name="line-422"></a><a name="Store"></a><span class='hs-comment'>--</span>
<a name="line-423"></a><a name="Store"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Store</span>
<a name="line-424"></a> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>SSlot</span> <span class='hs-conid'>Int</span>
<a name="line-425"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>SReg</span> <span class='hs-conid'>Reg</span>
<a name="line-426"></a>
<a name="line-427"></a><a name="isStoreReg"></a><span class='hs-comment'>-- | Check if this is a reg store</span>
<a name="line-428"></a><span class='hs-definition'>isStoreReg</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Store</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-429"></a><span class='hs-definition'>isStoreReg</span> <span class='hs-varid'>ss</span>
<a name="line-430"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>ss</span> <span class='hs-keyword'>of</span>
<a name="line-431"></a> <span class='hs-conid'>SSlot</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>False</span>
<a name="line-432"></a> <span class='hs-conid'>SReg</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>True</span>
<a name="line-433"></a>
<a name="line-434"></a><span class='hs-comment'>-- spill cleaning is only done once all virtuals have been allocated to realRegs</span>
<a name="line-435"></a><span class='hs-comment'>--</span>
<a name="line-436"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Uniquable</span> <span class='hs-conid'>Store</span> <span class='hs-keyword'>where</span>
<a name="line-437"></a> <span class='hs-varid'>getUnique</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>r</span><span class='hs-layout'>)</span>
<a name="line-438"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RegReal</span> <span class='hs-layout'>(</span><span class='hs-conid'>RealRegSingle</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>r</span>
<a name="line-439"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mkUnique</span> <span class='hs-chr'>'R'</span> <span class='hs-varid'>i</span>
<a name="line-440"></a>
<a name="line-441"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>RegReal</span> <span class='hs-layout'>(</span><span class='hs-conid'>RealRegPair</span> <span class='hs-varid'>r1</span> <span class='hs-varid'>r2</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>r</span>
<a name="line-442"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mkUnique</span> <span class='hs-chr'>'P'</span> <span class='hs-layout'>(</span><span class='hs-varid'>r1</span> <span class='hs-varop'>*</span> <span class='hs-num'>65535</span> <span class='hs-varop'>+</span> <span class='hs-varid'>r2</span><span class='hs-layout'>)</span>
<a name="line-443"></a>
<a name="line-444"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span>
<a name="line-445"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>error</span> <span class='hs-str'>"RegSpillClean.getUnique: found virtual reg during spill clean, only real regs expected."</span>
<a name="line-446"></a>
<a name="line-447"></a> <span class='hs-varid'>getUnique</span> <span class='hs-layout'>(</span><span class='hs-conid'>SSlot</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>mkUnique</span> <span class='hs-chr'>'S'</span> <span class='hs-varid'>i</span>
<a name="line-448"></a>
<a name="line-449"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Outputable</span> <span class='hs-conid'>Store</span> <span class='hs-keyword'>where</span>
<a name="line-450"></a> <span class='hs-varid'>ppr</span> <span class='hs-layout'>(</span><span class='hs-conid'>SSlot</span> <span class='hs-varid'>i</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>text</span> <span class='hs-str'>"slot"</span> <span class='hs-varop'><></span> <span class='hs-varid'>int</span> <span class='hs-varid'>i</span>
<a name="line-451"></a> <span class='hs-varid'>ppr</span> <span class='hs-layout'>(</span><span class='hs-conid'>SReg</span> <span class='hs-varid'>r</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ppr</span> <span class='hs-varid'>r</span>
<a name="line-452"></a>
<a name="line-453"></a>
<a name="line-454"></a><a name="Assoc"></a><span class='hs-comment'>--------------</span>
<a name="line-455"></a><a name="Assoc"></a><span class='hs-comment'>-- Association graphs.</span>
<a name="line-456"></a><a name="Assoc"></a><span class='hs-comment'>-- In the spill cleaner, two store locations are associated if they are known</span>
<a name="line-457"></a><a name="Assoc"></a><span class='hs-comment'>-- to hold the same value.</span>
<a name="line-458"></a><a name="Assoc"></a><span class='hs-comment'>--</span>
<a name="line-459"></a><a name="Assoc"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>UniqFM</span> <span class='hs-layout'>(</span><span class='hs-conid'>UniqSet</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-460"></a>
<a name="line-461"></a><a name="emptyAssoc"></a><span class='hs-comment'>-- | an empty association</span>
<a name="line-462"></a><span class='hs-definition'>emptyAssoc</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span>
<a name="line-463"></a><span class='hs-definition'>emptyAssoc</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>emptyUFM</span>
<a name="line-464"></a>
<a name="line-465"></a>
<a name="line-466"></a><a name="addAssoc"></a><span class='hs-comment'>-- | add an association between these two things</span>
<a name="line-467"></a><span class='hs-definition'>addAssoc</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Uniquable</span> <span class='hs-varid'>a</span>
<a name="line-468"></a> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span>
<a name="line-469"></a>
<a name="line-470"></a><span class='hs-definition'>addAssoc</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-varid'>m</span>
<a name="line-471"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>let</span> <span class='hs-varid'>m1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addToUFM_C</span> <span class='hs-varid'>unionUniqSets</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span> <span class='hs-layout'>(</span><span class='hs-varid'>unitUniqSet</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-472"></a> <span class='hs-varid'>m2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addToUFM_C</span> <span class='hs-varid'>unionUniqSets</span> <span class='hs-varid'>m1</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-varid'>unitUniqSet</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-473"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>m2</span>
<a name="line-474"></a>
<a name="line-475"></a>
<a name="line-476"></a><a name="delAssoc"></a><span class='hs-comment'>-- | delete all associations to a node</span>
<a name="line-477"></a><span class='hs-definition'>delAssoc</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Outputable</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Uniquable</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-478"></a> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span>
<a name="line-479"></a>
<a name="line-480"></a><span class='hs-definition'>delAssoc</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span>
<a name="line-481"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>aSet</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>lookupUFM</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span>
<a name="line-482"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>m1</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>delFromUFM</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span>
<a name="line-483"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldUniqSet</span> <span class='hs-layout'>(</span><span class='hs-keyglyph'>\</span><span class='hs-varid'>x</span> <span class='hs-varid'>m</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>delAssoc1</span> <span class='hs-varid'>x</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span><span class='hs-layout'>)</span> <span class='hs-varid'>m1</span> <span class='hs-varid'>aSet</span>
<a name="line-484"></a>
<a name="line-485"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>m</span>
<a name="line-486"></a>
<a name="line-487"></a>
<a name="line-488"></a><a name="delAssoc1"></a><span class='hs-comment'>-- | delete a single association edge (a -> b)</span>
<a name="line-489"></a><span class='hs-definition'>delAssoc1</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Uniquable</span> <span class='hs-varid'>a</span>
<a name="line-490"></a> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span>
<a name="line-491"></a>
<a name="line-492"></a><span class='hs-definition'>delAssoc1</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-varid'>m</span>
<a name="line-493"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Just</span> <span class='hs-varid'>aSet</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>lookupUFM</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span>
<a name="line-494"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>addToUFM</span> <span class='hs-varid'>m</span> <span class='hs-varid'>a</span> <span class='hs-layout'>(</span><span class='hs-varid'>delOneFromUniqSet</span> <span class='hs-varid'>aSet</span> <span class='hs-varid'>b</span><span class='hs-layout'>)</span>
<a name="line-495"></a>
<a name="line-496"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>m</span>
<a name="line-497"></a>
<a name="line-498"></a>
<a name="line-499"></a><a name="elemAssoc"></a><span class='hs-comment'>-- | check if these two things are associated</span>
<a name="line-500"></a><span class='hs-definition'>elemAssoc</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Outputable</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Uniquable</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-501"></a> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-502"></a>
<a name="line-503"></a><span class='hs-definition'>elemAssoc</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span> <span class='hs-varid'>m</span>
<a name="line-504"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>elementOfUniqSet</span> <span class='hs-varid'>b</span> <span class='hs-layout'>(</span><span class='hs-varid'>closeAssoc</span> <span class='hs-varid'>a</span> <span class='hs-varid'>m</span><span class='hs-layout'>)</span>
<a name="line-505"></a>
<a name="line-506"></a><a name="closeAssoc"></a><span class='hs-comment'>-- | find the refl. trans. closure of the association from this point</span>
<a name="line-507"></a><span class='hs-definition'>closeAssoc</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>Outputable</span> <span class='hs-varid'>a</span><span class='hs-layout'>,</span> <span class='hs-conid'>Uniquable</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-508"></a> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>UniqSet</span> <span class='hs-varid'>a</span>
<a name="line-509"></a>
<a name="line-510"></a><span class='hs-definition'>closeAssoc</span> <span class='hs-varid'>a</span> <span class='hs-varid'>assoc</span>
<a name="line-511"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>closeAssoc'</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>emptyUniqSet</span> <span class='hs-layout'>(</span><span class='hs-varid'>unitUniqSet</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span>
<a name="line-512"></a> <span class='hs-keyword'>where</span>
<a name="line-513"></a> <span class='hs-varid'>closeAssoc'</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>visited</span> <span class='hs-varid'>toVisit</span>
<a name="line-514"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>uniqSetToList</span> <span class='hs-varid'>toVisit</span> <span class='hs-keyword'>of</span>
<a name="line-515"></a>
<a name="line-516"></a> <span class='hs-comment'>-- nothing else to visit, we're done</span>
<a name="line-517"></a> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>visited</span>
<a name="line-518"></a>
<a name="line-519"></a> <span class='hs-layout'>(</span><span class='hs-varid'>x</span><span class='hs-conop'>:</span><span class='hs-keyword'>_</span><span class='hs-layout'>)</span>
<a name="line-520"></a>
<a name="line-521"></a> <span class='hs-comment'>-- we've already seen this node</span>
<a name="line-522"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>elementOfUniqSet</span> <span class='hs-varid'>x</span> <span class='hs-varid'>visited</span>
<a name="line-523"></a> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>closeAssoc'</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>visited</span> <span class='hs-layout'>(</span><span class='hs-varid'>delOneFromUniqSet</span> <span class='hs-varid'>toVisit</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-524"></a>
<a name="line-525"></a> <span class='hs-comment'>-- haven't seen this node before,</span>
<a name="line-526"></a> <span class='hs-comment'>-- remember to visit all its neighbors</span>
<a name="line-527"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span>
<a name="line-528"></a> <span class='hs-keyglyph'>-></span> <span class='hs-keyword'>let</span> <span class='hs-varid'>neighbors</span>
<a name="line-529"></a> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>lookupUFM</span> <span class='hs-varid'>assoc</span> <span class='hs-varid'>x</span> <span class='hs-keyword'>of</span>
<a name="line-530"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>emptyUniqSet</span>
<a name="line-531"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>set</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>set</span>
<a name="line-532"></a>
<a name="line-533"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>closeAssoc'</span> <span class='hs-varid'>assoc</span>
<a name="line-534"></a> <span class='hs-layout'>(</span><span class='hs-varid'>addOneToUniqSet</span> <span class='hs-varid'>visited</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-535"></a> <span class='hs-layout'>(</span><span class='hs-varid'>unionUniqSets</span> <span class='hs-varid'>toVisit</span> <span class='hs-varid'>neighbors</span><span class='hs-layout'>)</span>
<a name="line-536"></a>
<a name="line-537"></a><a name="intersectAssoc"></a><span class='hs-comment'>-- | intersect</span>
<a name="line-538"></a><span class='hs-definition'>intersectAssoc</span>
<a name="line-539"></a> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Uniquable</span> <span class='hs-varid'>a</span>
<a name="line-540"></a> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Assoc</span> <span class='hs-varid'>a</span>
<a name="line-541"></a>
<a name="line-542"></a><span class='hs-definition'>intersectAssoc</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span>
<a name="line-543"></a> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>intersectUFM_C</span> <span class='hs-layout'>(</span><span class='hs-varid'>intersectUniqSets</span><span class='hs-layout'>)</span> <span class='hs-varid'>a</span> <span class='hs-varid'>b</span>
<a name="line-544"></a>
</pre></body>
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