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[Thumb2] Improve disassembly of memory hints 

Currently, the ARM disassembler will disassemble the Thumb2 memory hint
instructions (PLD, PLDW and PLI), even for targets which do not have
these instructions. This patch adds the required checks to the
disassmebler.

llvm-svn: 220472
This commit is contained in:
Oliver Stannard 2014-10-23 08:52:58 +00:00
parent 83fb578e4e
commit 39a85abddf
2 changed files with 128 additions and 9 deletions
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68
llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
View File

@ -3269,6 +3269,11 @@ static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
unsigned Rt = fieldFromInstruction(Insn, 12, 4);
unsigned Rn = fieldFromInstruction(Insn, 16, 4);
uint64_t featureBits = ((const MCDisassembler*)Decoder)->getSubtargetInfo()
.getFeatureBits();
bool hasMP = featureBits & ARM::FeatureMP;
bool hasV7Ops = featureBits & ARM::HasV7Ops;
if (Rn == 15) {
switch (Inst.getOpcode()) {
case ARM::t2LDRBs:
@ -3304,11 +3309,10 @@ static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
case ARM::t2LDRSHs:
return MCDisassembler::Fail;
case ARM::t2LDRHs:
// FIXME: this instruction is only available with MP extensions,
// this should be checked first but we don't have access to the
// feature bits here.
Inst.setOpcode(ARM::t2PLDWs);
break;
case ARM::t2LDRSBs:
Inst.setOpcode(ARM::t2PLIs);
default:
break;
}
@ -3316,8 +3320,14 @@ static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
switch (Inst.getOpcode()) {
case ARM::t2PLDs:
case ARM::t2PLDWs:
break;
case ARM::t2PLIs:
if (!hasV7Ops)
return MCDisassembler::Fail;
break;
case ARM::t2PLDWs:
if (!hasV7Ops || !hasMP)
return MCDisassembler::Fail;
break;
default:
if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
@ -3343,6 +3353,12 @@ static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
unsigned imm = fieldFromInstruction(Insn, 0, 8);
imm |= (U << 8);
imm |= (Rn << 9);
unsigned add = fieldFromInstruction(Insn, 9, 1);
uint64_t featureBits = ((const MCDisassembler*)Decoder)->getSubtargetInfo()
.getFeatureBits();
bool hasMP = featureBits & ARM::FeatureMP;
bool hasV7Ops = featureBits & ARM::HasV7Ops;
if (Rn == 15) {
switch (Inst.getOpcode()) {
@ -3377,6 +3393,13 @@ static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
switch (Inst.getOpcode()) {
case ARM::t2LDRSHi8:
return MCDisassembler::Fail;
case ARM::t2LDRHi8:
if (!add)
Inst.setOpcode(ARM::t2PLDWi8);
break;
case ARM::t2LDRSBi8:
Inst.setOpcode(ARM::t2PLIi8);
break;
default:
break;
}
@ -3384,9 +3407,15 @@ static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
switch (Inst.getOpcode()) {
case ARM::t2PLDi8:
case ARM::t2PLIi8:
case ARM::t2PLDWi8:
break;
case ARM::t2PLIi8:
if (!hasV7Ops)
return MCDisassembler::Fail;
break;
case ARM::t2PLDWi8:
if (!hasV7Ops || !hasMP)
return MCDisassembler::Fail;
break;
default:
if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
return MCDisassembler::Fail;
@ -3406,6 +3435,11 @@ static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
unsigned imm = fieldFromInstruction(Insn, 0, 12);
imm |= (Rn << 13);
uint64_t featureBits = ((const MCDisassembler*)Decoder)->getSubtargetInfo()
.getFeatureBits();
bool hasMP = (featureBits & ARM::FeatureMP);
bool hasV7Ops = (featureBits & ARM::HasV7Ops);
if (Rn == 15) {
switch (Inst.getOpcode()) {
case ARM::t2LDRi12:
@ -3440,7 +3474,10 @@ static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
case ARM::t2LDRSHi12:
return MCDisassembler::Fail;
case ARM::t2LDRHi12:
Inst.setOpcode(ARM::t2PLDi12);
Inst.setOpcode(ARM::t2PLDWi12);
break;
case ARM::t2LDRSBi12:
Inst.setOpcode(ARM::t2PLIi12);
break;
default:
break;
@ -3449,9 +3486,15 @@ static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
switch (Inst.getOpcode()) {
case ARM::t2PLDi12:
case ARM::t2PLDWi12:
case ARM::t2PLIi12:
break;
case ARM::t2PLIi12:
if (!hasV7Ops)
return MCDisassembler::Fail;
break;
case ARM::t2PLDWi12:
if (!hasV7Ops || !hasMP)
return MCDisassembler::Fail;
break;
default:
if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
return MCDisassembler::Fail;
@ -3509,6 +3552,10 @@ static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
unsigned U = fieldFromInstruction(Insn, 23, 1);
int imm = fieldFromInstruction(Insn, 0, 12);
uint64_t featureBits = ((const MCDisassembler*)Decoder)->getSubtargetInfo()
.getFeatureBits();
bool hasV7Ops = (featureBits & ARM::HasV7Ops);
if (Rt == 15) {
switch (Inst.getOpcode()) {
case ARM::t2LDRBpci:
@ -3527,7 +3574,10 @@ static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
switch(Inst.getOpcode()) {
case ARM::t2PLDpci:
break;
case ARM::t2PLIpci:
if (!hasV7Ops)
return MCDisassembler::Fail;
break;
default:
if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))

69
llvm/test/MC/Disassembler/ARM/thumb2-preloads.txt Normal file
View File

@ -0,0 +1,69 @@
# RUN: not llvm-mc -triple=thumbv6t2-none-eabi -disassemble < %s 2>/dev/null | FileCheck %s --check-prefix=V6T2
# RUN: not llvm-mc -triple=thumbv7a-none-eabi -disassemble -mattr=-mp < %s 2>/dev/null | FileCheck %s --check-prefix=V6T2 --check-prefix=V7
# RUN: llvm-mc -triple=thumbv7a-none-eabi -disassemble -mattr=+mp < %s 2>/dev/null | FileCheck %s --check-prefix=V6T2 --check-prefix=V7 --check-prefix=MP
# RUN: not llvm-mc -triple=thumbv7m-none-eabi -disassemble < %s 2>/dev/null | FileCheck %s --check-prefix=V6T2 --check-prefix=V7
# RUN: not llvm-mc -triple=thumbv6t2-none-eabi -disassemble < %s 2>&1 >/dev/null | FileCheck %s --check-prefix=MP-ERR --check-prefix=V7-ERR
# RUN: not llvm-mc -triple=thumbv7a-none-eabi -disassemble -mattr=-mp < %s 2>&1 >/dev/null | FileCheck %s --check-prefix=MP-ERR
# RUN: llvm-mc -triple=thumbv7a-none-eabi -disassemble -mattr=+mp < %s 2>&1 >/dev/null
# RUN: not llvm-mc -triple=thumbv7m-none-eabi -disassemble < %s 2>&1 >/dev/null | FileCheck %s --check-prefix=MP-ERR
# V6T2: pld [r1, #3]
[0x91,0xf8,0x03,0xf0]
# V6T2: pld [r2, #-5]
[0x12,0xf8,0x05,0xfc]
# MP: pldw [r3, #4]
# MP-ERR: invalid instruction encoding
# MP-ERR-NEXT: [0xb3,0xf8,0x04,0xf0]
[0xb3,0xf8,0x04,0xf0]
# MP: pldw [r4, #-6]
# MP-ERR: invalid instruction encoding
# MP-ERR-NEXT: [0x34,0xf8,0x06,0xfc]
[0x34,0xf8,0x06,0xfc]
# V6T2: pld [pc, #8]
[0x9f,0xf8,0x08,0xf0]
# V6T2: pld [pc, #-5]
[0x1f,0xf8,0x05,0xf0]
# V6T2: pld [r5, r6]
[0x15,0xf8,0x06,0xf0]
# V6T2: pld [r7, r8, lsl #1]
[0x17,0xf8,0x18,0xf0]
# MP: pldw [r9, r10]
# MP-ERR: invalid instruction encoding
# MP-ERR-NEXT: [0x39,0xf8,0x0a,0xf0]
[0x39,0xf8,0x0a,0xf0]
# MP: pldw [r11, r12, lsl #2]
# MP-ERR: invalid instruction encoding
# MP-ERR-NEXT: [0x3b,0xf8,0x2c,0xf0]
[0x3b,0xf8,0x2c,0xf0]
# V7: pli [r1, #10]
# V7-ERR: invalid instruction encoding
# V7-ERR-NEXT: [0x91,0xf9,0x0a,0xf0]
[0x91,0xf9,0x0a,0xf0]
# V7: pli [r2, #-3]
# V7-ERR: invalid instruction encoding
# V7-ERR-NEXT: [0x12,0xf9,0x03,0xfc]
[0x12,0xf9,0x03,0xfc]
# V7: pli [pc, #6]
# V7-ERR: invalid instruction encoding
# V7-ERR-NEXT: [0x9f,0xf9,0x06,0xf0]
[0x9f,0xf9,0x06,0xf0]
# V7: pli [pc, #-8]
# V7-ERR: invalid instruction encoding
# V7-ERR-NEXT: [0x1f,0xf9,0x08,0xf0]
[0x1f,0xf9,0x08,0xf0]
# NO-ERR-NOT: invalid instruction encoding