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| author | H.J. Lu <hjl.tools@gmail.com> | 2015-12-04 08:43:45 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2015-12-04 09:03:04 -0800 |
| commit | 02e2aef89bb58e8e0cc4390db41c5f775e1b7c3e (patch) | |
| tree | 323891844d56806214ca3851131d40cea1d8fc68 /bfd | |
| parent | f27c5390b2fcff06b1e2199a4f051d543670aa03 (diff) | |
| download | gdb-02e2aef89bb58e8e0cc4390db41c5f775e1b7c3e.zip gdb-02e2aef89bb58e8e0cc4390db41c5f775e1b7c3e.tar.gz gdb-02e2aef89bb58e8e0cc4390db41c5f775e1b7c3e.tar.bz2 | |
Optimize R_386_GOT32/R_386_GOT32X only if addend is 0
Linker can't optimize R_386_GOT32 and R_386_GOT32X relocations if addend
isn't 0. It isn't valid to convert
movl foo@GOT+1(%ecx), %eax
to
leal foo@GOTOFF+1(%ecx), %eax
nor to convert
movq foo@GOTPCREL+1(%rip), %rax
to
leaq foo(%rip), %rax
for x86-64. We should check if addend is 0 before optimizing R_386_GOT32
and R_386_GOT32X relocations. Testcases are added for i386 and x86-64.
bfd/
* elf32-i386.c (elf_i386_convert_load): Skip if addend isn't 0.
(elf_i386_relocate_section): Skip R_386_GOT32X optimization if
addend isn't 0.
ld/testsuite/
* ld-i386/i386.exp: Run mov2a, mov2b and mov3.
* ld-i386/mov2.s: New file.
* ld-i386/mov2a.d: Likewise.
* ld-i386/mov2b.d: Likewise.
* ld-i386/mov3.d: Likewise.
* ld-i386/mov3.s: Likewise.
* ld-x86-64/mov2.s: Likewise.
* ld-x86-64/mov2a.d: Likewise.
* ld-x86-64/mov2b.d: Likewise.
* ld-x86-64/mov2c.d: Likewise.
* ld-x86-64/mov2d.d: Likewise.
* ld-x86-64/x86-64.exp: Run mov2a, mov2b, mov2c and mov2d.
Diffstat (limited to 'bfd')
| -rw-r--r-- | bfd/ChangeLog | 6 | ||||
| -rw-r--r-- | bfd/elf32-i386.c | 24 |
2 files changed, 17 insertions, 13 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index ab717ea..e810dbe 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2015-12-04 H.J. Lu <hongjiu.lu@intel.com> + + * elf32-i386.c (elf_i386_convert_load): Skip if addend isn't 0. + (elf_i386_relocate_section): Skip R_386_GOT32X optimization if + addend isn't 0. + 2015-12-04 Tristan Gingold <gingold@adacore.com> * elf.c (rewrite_elf_program_header): Remove useless loop. diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index ae3187d..300839b 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -2820,6 +2820,11 @@ elf_i386_convert_load (bfd *abfd, asection *sec, if (roff < 2) continue; + /* Addend for R_386_GOT32 and R_386_GOT32X relocations must be 0. */ + addend = bfd_get_32 (abfd, contents + roff); + if (addend != 0) + continue; + modrm = bfd_get_8 (abfd, contents + roff - 1); baseless = (modrm & 0xc7) == 0x5; @@ -2913,11 +2918,6 @@ elf_i386_convert_load (bfd *abfd, asection *sec, { /* The function is locally defined. */ convert_branch: - addend = bfd_get_32 (abfd, contents + roff); - /* Addend for R_386_GOT32X relocation must be 0. */ - if (addend != 0) - continue; - /* Convert R_386_GOT32X to R_386_PC32. */ if (modrm == 0x15 || (modrm & 0xf8) == 0x90) { @@ -3007,11 +3007,6 @@ convert_load: } else { - /* Addend for R_386_GOT32X relocation must be 0. */ - addend = bfd_get_32 (abfd, contents + roff); - if (addend != 0) - continue; - if (opcode == 0x85) { /* Convert "test %reg1, foo@GOT(%reg2)" to @@ -3998,8 +3993,11 @@ elf_i386_relocate_section (bfd *output_bfd, branch to direct branch. It is OK to convert adc, add, and, cmp, or, sbb, sub, test, xor only when PIC is false. */ - unsigned int opcode; - opcode = bfd_get_8 (abfd, contents + rel->r_offset - 2); + unsigned int opcode, addend; + addend = bfd_get_32 (input_bfd, contents + rel->r_offset); + if (addend != 0) + goto r_386_got32; + opcode = bfd_get_8 (input_bfd, contents + rel->r_offset - 2); if (opcode != 0x8b && opcode != 0xff) goto r_386_got32; } @@ -4031,7 +4029,7 @@ elf_i386_relocate_section (bfd *output_bfd, /* If not PIC, add the .got.plt section address for baseless addressing. */ unsigned int modrm; - modrm = bfd_get_8 (abfd, contents + rel->r_offset - 1); + modrm = bfd_get_8 (input_bfd, contents + rel->r_offset - 1); if ((modrm & 0xc7) == 0x5) relocation += offplt; } |