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Better fix for ARM MOVT relocation encoding of thumb bit.

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Replaces r145318 with a more targetted fix for the relocation handling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145346 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2011-11-29 01:15:25 +00:00
parent 45d7963950
commit 6200611dff
2 changed files with 16 additions and 9 deletions
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16
lib/MC/MCAssembler.cpp
View File

@ -273,17 +273,13 @@ bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout,
Value = Target.getConstant();
bool SetThumbBit = false;
bool IsThumb = false;
if (const MCSymbolRefExpr *A = Target.getSymA()) {
const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
if (Sym.isDefined())
Value += Layout.getSymbolOffset(&getSymbolData(Sym));
// ARM data fixups based from a thumb function address need to have the low
// bit set. The actual value is always at least 16-bit aligned, so the
// low bit is normally clear and available for use as an ISA flag for
// interworking.
if (Fixup.getKind() == FK_Data_4 && isThumbFunc(&Sym))
SetThumbBit = true;
if (isThumbFunc(&Sym))
IsThumb = true;
}
if (const MCSymbolRefExpr *B = Target.getSymB()) {
const MCSymbol &Sym = B->getSymbol().AliasedSymbol();
@ -306,7 +302,11 @@ bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout,
Value -= Offset;
}
if (SetThumbBit)
// ARM fixups based from a thumb function address need to have the low
// bit set. The actual value is always at least 16-bit aligned, so the
// low bit is normally clear and available for use as an ISA flag for
// interworking.
if (IsThumb)
Value |= 1;
return IsResolved;

9
lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp
View File

@ -16,6 +16,7 @@
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCMachOSymbolFlags.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Object/MachOFormat.h"
#include "llvm/Support/ErrorHandling.h"
@ -178,9 +179,16 @@ RecordARMMovwMovtRelocation(MachObjectWriter *Writer,
case ARM::fixup_arm_movt_hi16:
case ARM::fixup_arm_movt_hi16_pcrel:
MovtBit = 1;
// The thumb bit shouldn't be set in the 'other-half' bit of the
// relocation, but it will be set in FixedValue if the base symbol
// is a thumb function. Clear it out here.
if (A_SD->getFlags() & SF_ThumbFunc)
FixedValue &= 0xfffffffe;
break;
case ARM::fixup_t2_movt_hi16:
case ARM::fixup_t2_movt_hi16_pcrel:
if (A_SD->getFlags() & SF_ThumbFunc)
FixedValue &= 0xfffffffe;
MovtBit = 1;
// Fallthrough
case ARM::fixup_t2_movw_lo16:
@ -189,7 +197,6 @@ RecordARMMovwMovtRelocation(MachObjectWriter *Writer,
break;
}
if (Type == macho::RIT_ARM_HalfDifference) {
uint32_t OtherHalf = MovtBit
? (FixedValue & 0xffff) : ((FixedValue & 0xffff0000) >> 16);