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ARM: For thumb fixups store halfwords high first and low second

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208076 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Christian Pirker 2014-05-06 10:05:11 +00:00
parent 03145ebd88
commit 80fd09110d
2 changed files with 58 additions and 37 deletions
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83
lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
View File

@ -306,8 +306,36 @@ bool ARMAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const {
return true;
}
static uint32_t swapHalfWords(uint32_t Value, bool IsLittleEndian) {
if (IsLittleEndian) {
// Note that the halfwords are stored high first and low second in thumb;
// so we need to swap the fixup value here to map properly.
uint32_t Swapped = (Value & 0xFFFF0000) >> 16;
Swapped |= (Value & 0x0000FFFF) << 16;
return Swapped;
}
else
return Value;
}
static uint32_t joinHalfWords(uint32_t FirstHalf, uint32_t SecondHalf,
bool IsLittleEndian) {
uint32_t Value;
if (IsLittleEndian) {
Value = (SecondHalf & 0xFFFF) << 16;
Value |= (FirstHalf & 0xFFFF);
} else {
Value = (SecondHalf & 0xFFFF);
Value |= (FirstHalf & 0xFFFF) << 16;
}
return Value;
}
static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
bool IsPCRel, MCContext *Ctx) {
bool IsPCRel, MCContext *Ctx,
bool IsLittleEndian) {
unsigned Kind = Fixup.getKind();
switch (Kind) {
default:
@ -344,9 +372,7 @@ static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
// inst{14-12} = Mid3;
// inst{7-0} = Lo8;
Value = (Hi4 << 16) | (i << 26) | (Mid3 << 12) | (Lo8);
uint64_t swapped = (Value & 0xFFFF0000) >> 16;
swapped |= (Value & 0x0000FFFF) << 16;
return swapped;
return swapHalfWords(Value, IsLittleEndian);
}
case ARM::fixup_arm_ldst_pcrel_12:
// ARM PC-relative values are offset by 8.
@ -366,11 +392,8 @@ static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
// Same addressing mode as fixup_arm_pcrel_10,
// but with 16-bit halfwords swapped.
if (Kind == ARM::fixup_t2_ldst_pcrel_12) {
uint64_t swapped = (Value & 0xFFFF0000) >> 16;
swapped |= (Value & 0x0000FFFF) << 16;
return swapped;
}
if (Kind == ARM::fixup_t2_ldst_pcrel_12)
return swapHalfWords(Value, IsLittleEndian);
return Value;
}
@ -403,9 +426,7 @@ static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
out |= (Value & 0x700) << 4;
out |= (Value & 0x0FF);
uint64_t swapped = (out & 0xFFFF0000) >> 16;
swapped |= (out & 0x0000FFFF) << 16;
return swapped;
return swapHalfWords(out, IsLittleEndian);
}
case ARM::fixup_arm_condbranch:
@ -436,9 +457,7 @@ static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
out |= (Value & 0x1FF800) << 5; // imm6 field
out |= (Value & 0x0007FF); // imm11 field
uint64_t swapped = (out & 0xFFFF0000) >> 16;
swapped |= (out & 0x0000FFFF) << 16;
return swapped;
return swapHalfWords(out, IsLittleEndian);
}
case ARM::fixup_t2_condbranch: {
Value = Value - 4;
@ -451,9 +470,7 @@ static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
out |= (Value & 0x1F800) << 5; // imm6 field
out |= (Value & 0x007FF); // imm11 field
uint32_t swapped = (out & 0xFFFF0000) >> 16;
swapped |= (out & 0x0000FFFF) << 16;
return swapped;
return swapHalfWords(out, IsLittleEndian);
}
case ARM::fixup_arm_thumb_bl: {
// The value doesn't encode the low bit (always zero) and is offset by
@ -477,13 +494,10 @@ static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
uint32_t imm10Bits = (offset & 0x1FF800) >> 11;
uint32_t imm11Bits = (offset & 0x000007FF);
uint32_t Binary = 0;
uint32_t firstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10Bits);
uint32_t secondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
uint32_t FirstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10Bits);
uint32_t SecondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
(uint16_t)imm11Bits);
Binary |= secondHalf << 16;
Binary |= firstHalf;
return Binary;
return joinHalfWords(FirstHalf, SecondHalf, IsLittleEndian);
}
case ARM::fixup_arm_thumb_blx: {
// The value doesn't encode the low two bits (always zero) and is offset by
@ -510,13 +524,10 @@ static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
uint32_t imm10HBits = (offset & 0xFFC00) >> 10;
uint32_t imm10LBits = (offset & 0x3FF);
uint32_t Binary = 0;
uint32_t firstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10HBits);
uint32_t secondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
uint32_t FirstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10HBits);
uint32_t SecondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
((uint16_t)imm10LBits) << 1);
Binary |= secondHalf << 16;
Binary |= firstHalf;
return Binary;
return joinHalfWords(FirstHalf, SecondHalf, IsLittleEndian);
}
case ARM::fixup_arm_thumb_cp:
// Offset by 4, and don't encode the low two bits. Two bytes of that
@ -568,11 +579,8 @@ static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
// Same addressing mode as fixup_arm_pcrel_10, but with 16-bit halfwords
// swapped.
if (Kind == ARM::fixup_t2_pcrel_10) {
uint32_t swapped = (Value & 0xFFFF0000) >> 16;
swapped |= (Value & 0x0000FFFF) << 16;
return swapped;
}
if (Kind == ARM::fixup_t2_pcrel_10)
return swapHalfWords(Value, IsLittleEndian);
return Value;
}
@ -620,7 +628,8 @@ void ARMAsmBackend::processFixupValue(const MCAssembler &Asm,
// Try to get the encoded value for the fixup as-if we're mapping it into
// the instruction. This allows adjustFixupValue() to issue a diagnostic
// if the value aren't invalid.
(void)adjustFixupValue(Fixup, Value, false, &Asm.getContext());
(void)adjustFixupValue(Fixup, Value, false, &Asm.getContext(),
IsLittleEndian);
}
/// getFixupKindNumBytes - The number of bytes the fixup may change.
@ -721,7 +730,7 @@ void ARMAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
unsigned DataSize, uint64_t Value,
bool IsPCRel) const {
unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind());
Value = adjustFixupValue(Fixup, Value, IsPCRel, nullptr);
Value = adjustFixupValue(Fixup, Value, IsPCRel, nullptr, IsLittleEndian);
if (!Value) return; // Doesn't change encoding.
unsigned Offset = Fixup.getOffset();

12
test/MC/ARM/thumb2be-b.w-encoding.s Normal file
View File

@ -0,0 +1,12 @@
// RUN: llvm-mc -triple=thumbv7-none-linux-gnueabi -mcpu=cortex-a8 -filetype=obj < %s | llvm-objdump -arch=thumb -s - | FileCheck %s --check-prefix=CHECK-LE
// RUN: llvm-mc -triple=thumbebv7-none-linux-gnueabi -mcpu=cortex-a8 -filetype=obj < %s | llvm-objdump -arch=thumbeb -s - | FileCheck %s --check-prefix=CHECK-BE
.syntax unified
.code 16
.thumb_func
foo:
b.w bar
// CHECK-LE: Contents of section .text:
// CHECK-LE-NEXT: 0000 fff7febf
// CHECK-BE: Contents of section .text:
// CHECK-BE-NEXT: 0000 f7ffbffe