From d8699a0b89a3588ba049befa2249cd65f00fa195 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Sun, 10 Feb 2019 04:34:10 -0800
Subject: [PATCH] gas: Pass max_bytes to TC_FRAG_INIT
ommit 3ae729d5a4f63740ed9a778960b17c2912b0bbdd
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Mar 7 04:18:45 2018 -0800
x86: Rewrite NOP generation for fill and alignment
increased MAX_MEM_FOR_RS_ALIGN_CODE to 4095 which resulted in increase
of assembler time and memory usage by 5 times for inputs with many
.p2align directives, which is typical for LTO output. This patch passes
max_bytes to TC_FRAG_INIT so that MAX_MEM_FOR_RS_ALIGN_CODE can be set
as needed and tracked by backend it so that HANDLE_ALIGN can check the
maximum alignment for each rs_align_code frag. Wall time to assemble
the same cc1plus.s:
before:
423.78user 0.89system 7:05.71elapsed 99%CPU
after:
102.35user 0.27system 1:42.89elapsed 99%CPU
PR gas/24165
* config/tc-i386.h (MAX_MEM_FOR_RS_ALIGN_CODE): Set to
(alignment ? ((1 << alignment) - 1) : 1)
(i386_tc_frag_data): Add max_bytes.
(TC_FRAG_INIT): Track max_chars in max_bytes.
(HANDLE_ALIGN): Replace MAX_MEM_FOR_RS_ALIGN_CODE with
fragP->tc_frag_data.max_bytes.
(cherry picked from commit db22231044df03bbcb987496f3f29f0462b2e9ee)
---
gas/config/tc-i386.h | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/gas/config/tc-i386.h b/gas/config/tc-i386.h
index f10b00df9c..fcb87e83a8 100644
--- a/gas/config/tc-i386.h
+++ b/gas/config/tc-i386.h
@@ -206,7 +206,7 @@ if ((n) \
goto around; \
}
-#define MAX_MEM_FOR_RS_ALIGN_CODE 4095
+#define MAX_MEM_FOR_RS_ALIGN_CODE (alignment ? ((1 << alignment) - 1) : 1)
void i386_print_statistics (FILE *);
#define tc_print_statistics i386_print_statistics
@@ -251,6 +251,7 @@ struct i386_tc_frag_data
enum processor_type isa;
i386_cpu_flags isa_flags;
enum processor_type tune;
+ unsigned int max_bytes;
};
/* We need to emit the right NOP pattern in .align frags. This is
@@ -258,12 +259,14 @@ struct i386_tc_frag_data
the isa/tune settings at the time the .align was assembled. */
#define TC_FRAG_TYPE struct i386_tc_frag_data
+/* NB: max_chars is a local variable in frag_var_init. */
#define TC_FRAG_INIT(FRAGP) \
do \
{ \
(FRAGP)->tc_frag_data.isa = cpu_arch_isa; \
(FRAGP)->tc_frag_data.isa_flags = cpu_arch_isa_flags; \
(FRAGP)->tc_frag_data.tune = cpu_arch_tune; \
+ (FRAGP)->tc_frag_data.max_bytes = max_chars; \
} \
while (0)
@@ -280,7 +283,8 @@ if (fragP->fr_type == rs_align_code) \
offsetT __count = (fragP->fr_next->fr_address \
- fragP->fr_address \
- fragP->fr_fix); \
- if (__count > 0 && __count <= MAX_MEM_FOR_RS_ALIGN_CODE) \
+ if (__count > 0 \
+ && (unsigned int) __count <= fragP->tc_frag_data.max_bytes) \
md_generate_nops (fragP, fragP->fr_literal + fragP->fr_fix, \
__count, 0); \
}
--
2.20.1
