[llvm] r269294 - [mips][ias] Work around incorrect another microMIPS relocation evaluation exposed by r268900

[Daniel Sanders via llvm-commits]

Author: dsanders
Date: Thu May 12 08:39:13 2016
New Revision: 269294

URL: http://llvm.org/viewvc/llvm-project?rev=269294&view=rev
Log:
[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.


Modified:
    llvm/trunk/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
    llvm/trunk/test/MC/Mips/relocation-xfail.s

Modified: llvm/trunk/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp?rev=269294&r1=269293&r2=269294&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/Mips/MCTargetDesc/MipsELFObjectWriter.cpp Thu May 12 08:39:13 2016
@@ -518,13 +518,13 @@ bool MipsELFObjectWriter::needsRelocateW
 
   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;

Modified: llvm/trunk/test/MC/Mips/relocation-xfail.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/Mips/relocation-xfail.s?rev=269294&r1=269293&r2=269294&view=diff
==============================================================================
--- llvm/trunk/test/MC/Mips/relocation-xfail.s (original)
+++ llvm/trunk/test/MC/Mips/relocation-xfail.s Thu May 12 08:39:13 2016
@@ -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