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[mips][ias] Work around incorrect another microMIPS relocation evaluation exposed by r268900 

As explained in r269196, microMIPS has a special case that is not correctly
implemented in LLVM. If we have a symbol 'foo' which is equivalent to
'.text+0x10'. The value of an R_MICROMIPS_LO16 relocation using 'foo' is
'foo+0x11' and not 'foo+0x10'. The in-place addend should therefore be 0x11.

This commit reverts a little more of the effect of r268900 by keeping the
symbol when the STO_MIPS_MICROMIPS flag is set for R_MIPS_GPREL32 relocations.
This fixes SingleSource/UnitTests/2003-08-11-VaListArg, and
SingleSource/UnitTests/2003-05-07-VarArgs for microMIPS.

I believe there are additional relocations that have the same issue (e.g.
R_MIPS_64, and R_MIPS_GPREL16) but for now I'm focusing on restoring our
internal buildbots back to the green state we had in r268899.

llvm-svn: 269294
This commit is contained in:
Daniel Sanders 2016-05-12 13:39:13 +00:00
parent 3a0736e279
commit 5fb391c893
2 changed files with 10 additions and 1 deletions
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2
llvm/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
View File

@ -518,13 +518,13 @@ bool MipsELFObjectWriter::needsRelocateWithSymbol(const MCSymbol &Sym,
case ELF::R_MIPS_16:
case ELF::R_MIPS_32:
case ELF::R_MIPS_GPREL32:
if (cast<MCSymbolELF>(Sym).getOther() & ELF::STO_MIPS_MICROMIPS)
return true;
// fallthrough
case ELF::R_MIPS_26:
case ELF::R_MIPS_64:
case ELF::R_MIPS_GPREL16:
case ELF::R_MIPS_GPREL32:
case ELF::R_MIPS_PC16:
case ELF::R_MIPS_SUB:
return false;

9
llvm/test/MC/Mips/relocation-xfail.s
View File

@ -9,12 +9,21 @@
// baz is equivalent to .text+0x8 and is recorded in the symbol table as such
// but it refers to microMIPS code so the addend must indicate this in the LSB.
// The addend must therefore be 0x9.
// DATA-LABEL: Name: .text
// DATA: SectionData (
// DATA: 0000: 30430000 30420009
addiu $2, $3, %got(baz)
addiu $2, $2, %lo(baz)
baz:
// DATA-LABEL: Name: .data
// DATA: SectionData (
.data
.word 0
bar:
.word 1
// baz is equivalent to .text+0x8 and is recorded in the symbol table as such
// but it refers to microMIPS code so the addend must indicate this in the LSB.
// The addend must therefore be 0x9.
// DATA: 0000: 00000000 00000001 00000009
.gpword baz