From 39a85abddf414a38577a4a2a89076ef96883fa13 Mon Sep 17 00:00:00 2001 From: Oliver Stannard Date: Thu, 23 Oct 2014 08:52:58 +0000 Subject: [PATCH] [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 --- .../ARM/Disassembler/ARMDisassembler.cpp | 68 +++++++++++++++--- .../MC/Disassembler/ARM/thumb2-preloads.txt | 69 +++++++++++++++++++ 2 files changed, 128 insertions(+), 9 deletions(-) create mode 100644 llvm/test/MC/Disassembler/ARM/thumb2-preloads.txt diff --git a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp index 04b856866e11..b85b7eba7947 100644 --- a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp +++ b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp @@ -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))) diff --git a/llvm/test/MC/Disassembler/ARM/thumb2-preloads.txt b/llvm/test/MC/Disassembler/ARM/thumb2-preloads.txt new file mode 100644 index 000000000000..dec4d648e92c --- /dev/null +++ b/llvm/test/MC/Disassembler/ARM/thumb2-preloads.txt @@ -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