Optimize branches to non-weak symbols with visibility

Branches to global non-weak symbols defined in the same segment with
non-default visibility can be optimized the same way as branches to
local symbols.

gas/

	* config/tc-i386.c (elf_symbol_resolved_in_segment_p): New.
	(md_estimate_size_before_relax): Use it.

gas/testsuite/

	* gas/i386/i386.exp: Run relax-3 and x86-64-relax-2.
	* gas/i386/relax-3.d: New file.
	* gas/i386/relax-3.s: Likewise.
	* gas/i386/x86-64-relax-2.d: Likewise.
This commit is contained in:
H.J. Lu
2015-05-07 09:13:39 -07:00
parent 1c56a84d9b
commit b084df0b8d
7 changed files with 137 additions and 4 deletions

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@ -1,3 +1,8 @@
2015-05-07 H.J. Lu <hongjiu.lu@intel.com>
* config/tc-i386.c (elf_symbol_resolved_in_segment_p): New.
(md_estimate_size_before_relax): Use it.
2015-05-06 Jose E. Marchesi <jose.marchesi@oracle.com> 2015-05-06 Jose E. Marchesi <jose.marchesi@oracle.com>
* config/tc-sparc.c: Typo in comment fixed. * config/tc-sparc.c: Typo in comment fixed.

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@ -8772,6 +8772,25 @@ i386_frag_max_var (fragS *frag)
return TYPE_FROM_RELAX_STATE (frag->fr_subtype) == UNCOND_JUMP ? 4 : 5; return TYPE_FROM_RELAX_STATE (frag->fr_subtype) == UNCOND_JUMP ? 4 : 5;
} }
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
static int
elf_symbol_resolved_in_segment_p (symbolS *fr_symbol)
{
/* STT_GNU_IFUNC symbol must go through PLT. */
if ((symbol_get_bfdsym (fr_symbol)->flags
& BSF_GNU_INDIRECT_FUNCTION) != 0)
return 0;
if (!S_IS_EXTERNAL (fr_symbol))
/* Symbol may be weak or local. */
return !S_IS_WEAK (fr_symbol);
/* Global symbols with default visibility in a shared library may be
preempted by another definition. */
return ELF_ST_VISIBILITY (S_GET_OTHER (fr_symbol)) != STV_DEFAULT;
}
#endif
/* md_estimate_size_before_relax() /* md_estimate_size_before_relax()
Called just before relax() for rs_machine_dependent frags. The x86 Called just before relax() for rs_machine_dependent frags. The x86
@ -8795,10 +8814,7 @@ md_estimate_size_before_relax (fragS *fragP, segT segment)
if (S_GET_SEGMENT (fragP->fr_symbol) != segment if (S_GET_SEGMENT (fragP->fr_symbol) != segment
#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF) #if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
|| (IS_ELF || (IS_ELF
&& (S_IS_EXTERNAL (fragP->fr_symbol) && !elf_symbol_resolved_in_segment_p (fragP->fr_symbol))
|| S_IS_WEAK (fragP->fr_symbol)
|| ((symbol_get_bfdsym (fragP->fr_symbol)->flags
& BSF_GNU_INDIRECT_FUNCTION))))
#endif #endif
#if defined (OBJ_COFF) && defined (TE_PE) #if defined (OBJ_COFF) && defined (TE_PE)
|| (OUTPUT_FLAVOR == bfd_target_coff_flavour || (OUTPUT_FLAVOR == bfd_target_coff_flavour

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@ -1,3 +1,10 @@
2015-05-07 H.J. Lu <hongjiu.lu@intel.com>
* gas/i386/i386.exp: Run relax-3 and x86-64-relax-2.
* gas/i386/relax-3.d: New file.
* gas/i386/relax-3.s: Likewise.
* gas/i386/x86-64-relax-2.d: Likewise.
2015-05-06 Jose E. Marchesi <jose.marchesi@oracle.com> 2015-05-06 Jose E. Marchesi <jose.marchesi@oracle.com>
* gas/sparc/natural-32.d: Test ldn, ldna, stn, stna, slln, srln, * gas/sparc/natural-32.d: Test ldn, ldna, stn, stna, slln, srln,

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@ -394,6 +394,8 @@ if [expr ([istarget "i*86-*-*"] || [istarget "x86_64-*-*"]) && [gas_32_check]]
run_dump_test "size-4" run_dump_test "size-4"
run_dump_test "note" run_dump_test "note"
run_dump_test "relax-3"
} }
# This is a PE specific test. # This is a PE specific test.
@ -748,6 +750,8 @@ if [expr ([istarget "i*86-*-*"] || [istarget "x86_64-*-*"]) && [gas_64_check]] t
run_dump_test "x86-64-size-4" run_dump_test "x86-64-size-4"
run_dump_test "x86-64-size-5" run_dump_test "x86-64-size-5"
run_list_test "x86-64-size-inval-1" "-al" run_list_test "x86-64-size-inval-1" "-al"
run_dump_test "x86-64-relax-2"
} }
set ASFLAGS "$old_ASFLAGS" set ASFLAGS "$old_ASFLAGS"

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@ -0,0 +1,30 @@
#objdump: -dwr
.*: +file format .*
Disassembly of section .text:
0+ <foo>:
[ ]*[a-f0-9]+: eb 1f jmp 21 <local>
[ ]*[a-f0-9]+: eb 19 jmp 1d <hidden_def>
[ ]*[a-f0-9]+: e9 fc ff ff ff jmp 5 <foo\+0x5> 5: (R_386_PC)?(DISP)?32 global_def
[ ]*[a-f0-9]+: e9 fc ff ff ff jmp a <foo\+0xa> a: (R_386_PC)?(DISP)?32 weak_def
[ ]*[a-f0-9]+: e9 fc ff ff ff jmp f <foo\+0xf> f: (R_386_PC)?(DISP)?32 weak_hidden_undef
[ ]*[a-f0-9]+: e9 fc ff ff ff jmp 14 <foo\+0x14> 14: (R_386_PC)?(DISP)?32 weak_hidden_def
[ ]*[a-f0-9]+: e9 fc ff ff ff jmp 19 <foo\+0x19> 19: (R_386_PC)?(DISP)?32 hidden_undef
0+1d <hidden_def>:
[ ]*[a-f0-9]+: c3 ret
0+1e <weak_hidden_def>:
[ ]*[a-f0-9]+: c3 ret
0+1f <global_def>:
[ ]*[a-f0-9]+: c3 ret
0+20 <weak_def>:
[ ]*[a-f0-9]+: c3 ret
0+21 <local>:
[ ]*[a-f0-9]+: c3 ret
#pass

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@ -0,0 +1,39 @@
.text
.global foo
foo:
jmp local
jmp hidden_def
jmp global_def
jmp weak_def
jmp weak_hidden_undef
jmp weak_hidden_def
jmp hidden_undef
.hidden hidden_undef
.global hidden_def
.hidden hidden_def
hidden_def:
ret
.global weak_hidden_def
.hidden weak_hidden_def
.weak weak_hidden_def
weak_hidden_def:
ret
.global global_def
global_def:
ret
.global weak_def
.weak weak_def
weak_def:
ret
local:
ret
.global weak_hidden_undef
.weak weak_hidden_undef
.hidden weak_hidden_undef

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@ -0,0 +1,32 @@
#source: relax-3.s
#objdump: -dwr
.*: +file format .*
Disassembly of section .text:
0+ <foo>:
[ ]*[a-f0-9]+: eb 1f jmp 21 <local>
[ ]*[a-f0-9]+: eb 19 jmp 1d <hidden_def>
[ ]*[a-f0-9]+: e9 00 00 00 00 jmpq 9 <foo\+0x9> 5: R_X86_64_PC32 global_def-0x4
[ ]*[a-f0-9]+: e9 00 00 00 00 jmpq e <foo\+0xe> a: R_X86_64_PC32 weak_def-0x4
[ ]*[a-f0-9]+: e9 00 00 00 00 jmpq 13 <foo\+0x13> f: R_X86_64_PC32 weak_hidden_undef-0x4
[ ]*[a-f0-9]+: e9 00 00 00 00 jmpq 18 <foo\+0x18> 14: R_X86_64_PC32 weak_hidden_def-0x4
[ ]*[a-f0-9]+: e9 00 00 00 00 jmpq 1d <hidden_def> 19: R_X86_64_PC32 hidden_undef-0x4
0+1d <hidden_def>:
[ ]*[a-f0-9]+: c3 retq
0+1e <weak_hidden_def>:
[ ]*[a-f0-9]+: c3 retq
0+1f <global_def>:
[ ]*[a-f0-9]+: c3 retq
0+20 <weak_def>:
[ ]*[a-f0-9]+: c3 retq
0+21 <local>:
[ ]*[a-f0-9]+: c3 retq
#pass