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Fix handling of ARM negative pc-relative fixups for loads and stores. 

llvm-svn: 120480
This commit is contained in:
Jim Grosbach 2010-11-30 22:40:36 +00:00
parent 1922a8dbea
commit 2d3e5c1aec
2 changed files with 36 additions and 9 deletions
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32
llvm/lib/Target/ARM/ARMAsmBackend.cpp
View File

@ -131,8 +131,8 @@ static unsigned getFixupKindNumBytes(unsigned Kind) {
switch (Kind) {
default: llvm_unreachable("Unknown fixup kind!");
case FK_Data_4: return 4;
case ARM::fixup_arm_pcrel_12: return 2;
case ARM::fixup_arm_vfp_pcrel_12: return 1;
case ARM::fixup_arm_pcrel_12: return 3;
case ARM::fixup_arm_vfp_pcrel_12: return 3;
case ARM::fixup_arm_branch: return 3;
}
}
@ -143,14 +143,36 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
llvm_unreachable("Unknown fixup kind!");
case FK_Data_4:
return Value;
case ARM::fixup_arm_pcrel_12:
case ARM::fixup_arm_pcrel_12: {
bool isAdd = true;
// ARM PC-relative values are offset by 8.
return Value - 8;
Value -= 8;
if ((int64_t)Value < 0) {
Value = -Value;
isAdd = false;
}
assert ((Value < 4096) && "Out of range pc-relative fixup value!");
Value |= isAdd << 23;
return Value;
}
case ARM::fixup_arm_branch:
case ARM::fixup_arm_vfp_pcrel_12:
// These values don't encode the low two bits since they're always zero.
// Offset by 8 just as above.
return (Value - 8) >> 2;
case ARM::fixup_arm_vfp_pcrel_12: {
// Offset by 8 just as above.
Value = Value - 8;
bool isAdd = true;
if ((int64_t)Value < 0) {
Value = -Value;
isAdd = false;
}
// These values don't encode the low two bits since they're always zero.
Value >>= 2;
assert ((Value < 256) && "Out of range pc-relative fixup value!");
Value |= isAdd << 23;
return Value;
}
}
}

13
llvm/lib/Target/ARM/ARMMCCodeEmitter.cpp
View File

@ -46,8 +46,8 @@ public:
const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
const static MCFixupKindInfo Infos[] = {
// name offset bits flags
{ "fixup_arm_pcrel_12", 2, 12, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_arm_vfp_pcrel_12", 3, 8, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_arm_pcrel_12", 1, 24, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_arm_vfp_pcrel_12", 1, 24, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_arm_branch", 1, 24, MCFixupKindInfo::FKF_IsPCRel },
};
@ -395,6 +395,7 @@ getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
if (!MO.isReg()) {
Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
Imm12 = 0;
isAdd = false ; // 'U' bit is set as part of the fixup.
assert(MO.isExpr() && "Unexpected machine operand type!");
const MCExpr *Expr = MO.getExpr();
@ -574,11 +575,13 @@ getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
// {8} = (U)nsigned (add == '1', sub == '0')
// {7-0} = imm8
unsigned Reg, Imm8;
bool isAdd;
// If The first operand isn't a register, we have a label reference.
const MCOperand &MO = MI.getOperand(OpIdx);
if (!MO.isReg()) {
Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
Imm8 = 0;
isAdd = false; // 'U' bit is handled as part of the fixup.
assert(MO.isExpr() && "Unexpected machine operand type!");
const MCExpr *Expr = MO.getExpr();
@ -586,12 +589,14 @@ getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
Fixups.push_back(MCFixup::Create(0, Expr, Kind));
++MCNumCPRelocations;
} else
} else {
EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups);
isAdd = ARM_AM::getAM5Op(Imm8) == ARM_AM::add;
}
uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
// Immediate is always encoded as positive. The 'U' bit controls add vs sub.
if (ARM_AM::getAM5Op(Imm8) == ARM_AM::add)
if (isAdd)
Binary |= (1 << 8);
Binary |= (Reg << 9);
return Binary;