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>RegAlloc.Graph.SpillClean</TITLE
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>ghc-6.12.3: The GHC API</TD
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>RegAlloc.Graph.SpillClean</FONT
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><TD CLASS="section1"
>Description</TD
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><P
>Clean out unneeded spill/reload instrs
</P
><UL
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> Handling of join points
</LI
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><P
>B1: B2:
... ...
RELOAD SLOT(0), %r1 RELOAD SLOT(0), %r1
... A ... ... B ...
jump B3 jump B3
</P
><P
>B3: ... C ...
RELOAD SLOT(0), %r1
...
</P
><P
>the plan:
So long as %r1 hasn't been written to in A, B or C then we don't need the
reload in B3.
</P
><P
>What we really care about here is that on the entry to B3, %r1 will always
have the same value that is in SLOT(0) (ie, %r1 is _valid_)
</P
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>This also works if the reloads in B1/B2 were spills instead, because
spilling %r1 to a slot makes that slot have the same value as %r1.
</P
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>Synopsis</TD
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><A HREF="#v%3AcleanSpills"
>cleanSpills</A
> :: <A HREF="Instruction.html#t%3AInstruction"
>Instruction</A
> instr => <A HREF="RegAlloc-Liveness.html#t%3ALiveCmmTop"
>LiveCmmTop</A
> instr -> <A HREF="RegAlloc-Liveness.html#t%3ALiveCmmTop"
>LiveCmmTop</A
> instr</TD
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>Documentation</TD
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><TD CLASS="decl"
><A NAME="v:cleanSpills"
><A NAME="v%3AcleanSpills"
></A
></A
><B
>cleanSpills</B
> :: <A HREF="Instruction.html#t%3AInstruction"
>Instruction</A
> instr => <A HREF="RegAlloc-Liveness.html#t%3ALiveCmmTop"
>LiveCmmTop</A
> instr -> <A HREF="RegAlloc-Liveness.html#t%3ALiveCmmTop"
>LiveCmmTop</A
> instr</TD
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>Clean out unneeded spill/reloads from this top level thing.
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>Produced by <A HREF="http://www.haskell.org/haddock/"
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