From 99bcab7b850fd57143e4103939a27ad78655b721 Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Wed, 31 Dec 2014 07:07:31 +0000 Subject: [PATCH] [X86] Fix disassembly of absolute moves to work correctly in 16 and 32-bit modes with all 4 combinations of OpSize and AdSize prefixes being present or not. llvm-svn: 225036 --- .../X86/Disassembler/X86DisassemblerDecoder.cpp | 26 ++++++++++++++++++++ .../Disassembler/X86DisassemblerDecoderCommon.h | 15 +++++++----- llvm/utils/TableGen/X86DisassemblerTables.cpp | 28 +++++++++++----------- llvm/utils/TableGen/X86RecognizableInstr.cpp | 4 ++++ 4 files changed, 53 insertions(+), 20 deletions(-) diff --git a/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp b/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp index a5fcf15..cc19ec2 100644 --- a/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp +++ b/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp @@ -1019,6 +1019,32 @@ static int getID(struct InternalInstruction* insn, const void *miiArg) { } } + /* + * Absolute moves need special handling. + * -For 16-bit mode because the meaning of the AdSize and OpSize prefixes are + * inverted w.r.t. + * -For 32-bit mode we need to ensure the ADSIZE prefix is observed in + * any position. + */ + if (insn->opcodeType == ONEBYTE && ((insn->opcode & 0xFC) == 0xA0)) { + /* Make sure we observed the prefixes in any position. */ + if (insn->prefixPresent[0x67]) + attrMask |= ATTR_ADSIZE; + if (insn->prefixPresent[0x66]) + attrMask |= ATTR_OPSIZE; + + /* In 16-bit, invert the attributes. */ + if (insn->mode == MODE_16BIT) + attrMask ^= ATTR_ADSIZE | ATTR_OPSIZE; + + if (getIDWithAttrMask(&instructionID, insn, attrMask)) + return -1; + + insn->instructionID = instructionID; + insn->spec = specifierForUID(instructionID); + return 0; + } + if ((insn->mode == MODE_16BIT || insn->prefixPresent[0x66]) && !(attrMask & ATTR_OPSIZE)) { /* diff --git a/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h b/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h index bec4f0e..d04d8c0 100644 --- a/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h +++ b/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoderCommon.h @@ -82,6 +82,7 @@ enum attributeBits { "operands change width") \ ENUM_ENTRY(IC_ADSIZE, 3, "requires an ADSIZE prefix, so " \ "operands change width") \ + ENUM_ENTRY(IC_OPSIZE_ADSIZE, 4, "requires ADSIZE and OPSIZE prefixes") \ ENUM_ENTRY(IC_XD, 2, "may say something about the opcode " \ "but not the operands") \ ENUM_ENTRY(IC_XS, 2, "may say something about the opcode " \ @@ -90,20 +91,22 @@ enum attributeBits { "operands change width") \ ENUM_ENTRY(IC_XS_OPSIZE, 3, "requires an OPSIZE prefix, so " \ "operands change width") \ - ENUM_ENTRY(IC_64BIT_REXW, 4, "requires a REX.W prefix, so operands "\ + ENUM_ENTRY(IC_64BIT_REXW, 5, "requires a REX.W prefix, so operands "\ "change width; overrides IC_OPSIZE") \ ENUM_ENTRY(IC_64BIT_OPSIZE, 3, "Just as meaningful as IC_OPSIZE") \ ENUM_ENTRY(IC_64BIT_ADSIZE, 3, "Just as meaningful as IC_ADSIZE") \ - ENUM_ENTRY(IC_64BIT_XD, 5, "XD instructions are SSE; REX.W is " \ + ENUM_ENTRY(IC_64BIT_OPSIZE_ADSIZE, 4, "Just as meaningful as IC_OPSIZE/" \ + "IC_ADSIZE") \ + ENUM_ENTRY(IC_64BIT_XD, 6, "XD instructions are SSE; REX.W is " \ "secondary") \ - ENUM_ENTRY(IC_64BIT_XS, 5, "Just as meaningful as IC_64BIT_XD") \ + ENUM_ENTRY(IC_64BIT_XS, 6, "Just as meaningful as IC_64BIT_XD") \ ENUM_ENTRY(IC_64BIT_XD_OPSIZE, 3, "Just as meaningful as IC_XD_OPSIZE") \ ENUM_ENTRY(IC_64BIT_XS_OPSIZE, 3, "Just as meaningful as IC_XS_OPSIZE") \ - ENUM_ENTRY(IC_64BIT_REXW_XS, 6, "OPSIZE could mean a different " \ + ENUM_ENTRY(IC_64BIT_REXW_XS, 7, "OPSIZE could mean a different " \ "opcode") \ - ENUM_ENTRY(IC_64BIT_REXW_XD, 6, "Just as meaningful as " \ + ENUM_ENTRY(IC_64BIT_REXW_XD, 7, "Just as meaningful as " \ "IC_64BIT_REXW_XS") \ - ENUM_ENTRY(IC_64BIT_REXW_OPSIZE, 7, "The Dynamic Duo! Prefer over all " \ + ENUM_ENTRY(IC_64BIT_REXW_OPSIZE, 8, "The Dynamic Duo! Prefer over all " \ "else because this changes most " \ "operands' meaning") \ ENUM_ENTRY(IC_VEX, 1, "requires a VEX prefix") \ diff --git a/llvm/utils/TableGen/X86DisassemblerTables.cpp b/llvm/utils/TableGen/X86DisassemblerTables.cpp index 86cd0c7..5c3931f 100644 --- a/llvm/utils/TableGen/X86DisassemblerTables.cpp +++ b/llvm/utils/TableGen/X86DisassemblerTables.cpp @@ -93,9 +93,15 @@ static inline bool inheritsFrom(InstructionContext child, inheritsFrom(child, IC_64BIT_XD) || inheritsFrom(child, IC_64BIT_XS)); case IC_OPSIZE: - return inheritsFrom(child, IC_64BIT_OPSIZE); + return inheritsFrom(child, IC_64BIT_OPSIZE) || + inheritsFrom(child, IC_OPSIZE_ADSIZE); case IC_ADSIZE: + return inheritsFrom(child, IC_OPSIZE_ADSIZE); + case IC_OPSIZE_ADSIZE: + return false; case IC_64BIT_ADSIZE: + return inheritsFrom(child, IC_64BIT_OPSIZE_ADSIZE); + case IC_64BIT_OPSIZE_ADSIZE: return false; case IC_XD: return inheritsFrom(child, IC_64BIT_XD); @@ -110,7 +116,8 @@ static inline bool inheritsFrom(InstructionContext child, inheritsFrom(child, IC_64BIT_REXW_XD) || inheritsFrom(child, IC_64BIT_REXW_OPSIZE)); case IC_64BIT_OPSIZE: - return(inheritsFrom(child, IC_64BIT_REXW_OPSIZE)); + return inheritsFrom(child, IC_64BIT_REXW_OPSIZE) || + inheritsFrom(child, IC_64BIT_OPSIZE_ADSIZE); case IC_64BIT_XD: return(inheritsFrom(child, IC_64BIT_REXW_XD)); case IC_64BIT_XS: @@ -721,6 +728,9 @@ void DisassemblerTables::emitContextTable(raw_ostream &o, unsigned &i) const { o << "IC_64BIT_XS"; else if ((index & ATTR_64BIT) && (index & ATTR_XD)) o << "IC_64BIT_XD"; + else if ((index & ATTR_64BIT) && (index & ATTR_OPSIZE) && + (index & ATTR_ADSIZE)) + o << "IC_64BIT_OPSIZE_ADSIZE"; else if ((index & ATTR_64BIT) && (index & ATTR_OPSIZE)) o << "IC_64BIT_OPSIZE"; else if ((index & ATTR_64BIT) && (index & ATTR_ADSIZE)) @@ -737,6 +747,8 @@ void DisassemblerTables::emitContextTable(raw_ostream &o, unsigned &i) const { o << "IC_XS"; else if (index & ATTR_XD) o << "IC_XD"; + else if ((index & ATTR_OPSIZE) && (index & ATTR_ADSIZE)) + o << "IC_OPSIZE_ADSIZE"; else if (index & ATTR_OPSIZE) o << "IC_OPSIZE"; else if (index & ATTR_ADSIZE) @@ -822,18 +834,6 @@ void DisassemblerTables::setTableFields(ModRMDecision &decision, InstructionSpecifier &previousInfo = InstructionSpecifiers[decision.instructionIDs[index]]; - // FIXME this doesn't actually work. The MCInsts the disassembler - // create don't encode re-encode correctly. They just manage to mostly - // print correctly. - // Instructions such as MOV8ao8 and MOV8ao8_16 differ only in the - // presence of the AdSize prefix. However, the disassembler doesn't - // care about that difference in the instruction definition; it - // handles 16-bit vs. 32-bit addressing for itself based purely - // on the 0x67 prefix and the CPU mode. So there's no need to - // disambiguate between them; just let them conflict/coexist. - if (previousInfo.name + "_16" == newInfo.name) - continue; - if(previousInfo.name == "NOOP" && (newInfo.name == "XCHG16ar" || newInfo.name == "XCHG32ar" || newInfo.name == "XCHG32ar64" || diff --git a/llvm/utils/TableGen/X86RecognizableInstr.cpp b/llvm/utils/TableGen/X86RecognizableInstr.cpp index 6b2b060..288d3d6 100644 --- a/llvm/utils/TableGen/X86RecognizableInstr.cpp +++ b/llvm/utils/TableGen/X86RecognizableInstr.cpp @@ -412,6 +412,8 @@ InstructionContext RecognizableInstr::insnContext() const { insnContext = IC_64BIT_XD_OPSIZE; else if (OpSize == X86Local::OpSize16 && OpPrefix == X86Local::XS) insnContext = IC_64BIT_XS_OPSIZE; + else if (OpSize == X86Local::OpSize16 && AdSize == X86Local::AdSize32) + insnContext = IC_64BIT_OPSIZE_ADSIZE; else if (OpSize == X86Local::OpSize16 || OpPrefix == X86Local::PD) insnContext = IC_64BIT_OPSIZE; else if (AdSize == X86Local::AdSize32) @@ -433,6 +435,8 @@ InstructionContext RecognizableInstr::insnContext() const { insnContext = IC_XD_OPSIZE; else if (OpSize == X86Local::OpSize16 && OpPrefix == X86Local::XS) insnContext = IC_XS_OPSIZE; + else if (OpSize == X86Local::OpSize16 && AdSize == X86Local::AdSize16) + insnContext = IC_OPSIZE_ADSIZE; else if (OpSize == X86Local::OpSize16 || OpPrefix == X86Local::PD) insnContext = IC_OPSIZE; else if (AdSize == X86Local::AdSize16) -- 2.7.4