Index: llvm/trunk/include/llvm/MC/MCExpr.h =================================================================== --- llvm/trunk/include/llvm/MC/MCExpr.h +++ llvm/trunk/include/llvm/MC/MCExpr.h @@ -589,6 +589,8 @@ virtual bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout, const MCFixup *Fixup) const = 0; + // allow Target Expressions to be checked for equality + virtual bool isEqualTo(const MCExpr *x) const { return false; } // This should be set when assigned expressions are not valid ".set" // expressions, e.g. registers, and must be inlined. virtual bool inlineAssignedExpr() const { return false; } Index: llvm/trunk/include/llvm/MC/MCParser/MCAsmParserUtils.h =================================================================== --- llvm/trunk/include/llvm/MC/MCParser/MCAsmParserUtils.h +++ llvm/trunk/include/llvm/MC/MCParser/MCAsmParserUtils.h @@ -25,7 +25,7 @@ /// On success, returns false and sets the Symbol and Value output parameters. bool parseAssignmentExpression(StringRef Name, bool allow_redef, MCAsmParser &Parser, MCSymbol *&Symbol, - const MCExpr *&Value, bool AllowExtendedExpr = false); + const MCExpr *&Value); } // namespace MCParserUtils Index: llvm/trunk/include/llvm/MC/MCParser/MCTargetAsmParser.h =================================================================== --- llvm/trunk/include/llvm/MC/MCParser/MCTargetAsmParser.h +++ llvm/trunk/include/llvm/MC/MCParser/MCTargetAsmParser.h @@ -372,9 +372,9 @@ SemaCallback = Callback; } - // Target-specific parsing of assembler-level variable assignment. - virtual bool parseAssignmentExpression(const MCExpr *&Res, SMLoc &EndLoc) { - return getParser().parseExpression(Res, EndLoc); + // Target-specific parsing of expression. + virtual bool parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) { + return getParser().parsePrimaryExpr(Res, EndLoc); } virtual bool ParseRegister(unsigned &RegNo, SMLoc &StartLoc, Index: llvm/trunk/lib/MC/MCExpr.cpp =================================================================== --- llvm/trunk/lib/MC/MCExpr.cpp +++ llvm/trunk/lib/MC/MCExpr.cpp @@ -751,8 +751,22 @@ if (!ABE->getLHS()->evaluateAsRelocatableImpl(LHSValue, Asm, Layout, Fixup, Addrs, InSet) || !ABE->getRHS()->evaluateAsRelocatableImpl(RHSValue, Asm, Layout, Fixup, - Addrs, InSet)) + Addrs, InSet)) { + // Check if both are Target Expressions, see if we can compare them. + if (const MCTargetExpr *L = dyn_cast(ABE->getLHS())) + if (const MCTargetExpr *R = cast(ABE->getRHS())) { + switch (ABE->getOpcode()) { + case MCBinaryExpr::EQ: + Res = MCValue::get((L->isEqualTo(R)) ? -1 : 0); + return true; + case MCBinaryExpr::NE: + Res = MCValue::get((R->isEqualTo(R)) ? 0 : -1); + return true; + default: {} + } + } return false; + } // We only support a few operations on non-constant expressions, handle // those first. Index: llvm/trunk/lib/MC/MCParser/AsmParser.cpp =================================================================== --- llvm/trunk/lib/MC/MCParser/AsmParser.cpp +++ llvm/trunk/lib/MC/MCParser/AsmParser.cpp @@ -337,7 +337,7 @@ StringRef parseStringToComma(); bool parseAssignment(StringRef Name, bool allow_redef, - bool NoDeadStrip = false, bool AllowExtendedExpr = false); + bool NoDeadStrip = false); unsigned getBinOpPrecedence(AsmToken::TokenKind K, MCBinaryExpr::Opcode &Kind); @@ -1363,7 +1363,8 @@ bool AsmParser::parseExpression(const MCExpr *&Res, SMLoc &EndLoc) { // Parse the expression. Res = nullptr; - if (parsePrimaryExpr(Res, EndLoc) || parseBinOpRHS(1, Res, EndLoc)) + if (getTargetParser().parsePrimaryExpr(Res, EndLoc) || + parseBinOpRHS(1, Res, EndLoc)) return true; // As a special case, we support 'a op b @ modifier' by rewriting the @@ -1617,7 +1618,7 @@ // Eat the next primary expression. const MCExpr *RHS; - if (parsePrimaryExpr(RHS, EndLoc)) + if (getTargetParser().parsePrimaryExpr(RHS, EndLoc)) return true; // If BinOp binds less tightly with RHS than the operator after RHS, let @@ -1826,7 +1827,7 @@ // identifier '=' ... -> assignment statement Lex(); - return parseAssignment(IDVal, true, /*NoDeadStrip*/ false, /*AllowExtendedExpr*/true); + return parseAssignment(IDVal, true); default: // Normal instruction or directive. break; @@ -2766,11 +2767,11 @@ } bool AsmParser::parseAssignment(StringRef Name, bool allow_redef, - bool NoDeadStrip, bool AllowExtendedExpr) { + bool NoDeadStrip) { MCSymbol *Sym; const MCExpr *Value; if (MCParserUtils::parseAssignmentExpression(Name, allow_redef, *this, Sym, - Value, AllowExtendedExpr)) + Value)) return true; if (!Sym) { @@ -5839,17 +5840,13 @@ bool parseAssignmentExpression(StringRef Name, bool allow_redef, MCAsmParser &Parser, MCSymbol *&Sym, - const MCExpr *&Value, bool AllowExtendedExpr) { + const MCExpr *&Value) { // FIXME: Use better location, we should use proper tokens. SMLoc EqualLoc = Parser.getTok().getLoc(); SMLoc EndLoc; - if (AllowExtendedExpr) { - if (Parser.getTargetParser().parseAssignmentExpression(Value, EndLoc)) { - return Parser.TokError("missing expression"); - } - } else if (Parser.parseExpression(Value, EndLoc)) - return Parser.TokError("missing expression"); + if (Parser.parseExpression(Value)) + return Parser.TokError("missing expression"); // Note: we don't count b as used in "a = b". This is to allow // a = b Index: llvm/trunk/lib/Target/X86/AsmParser/X86AsmParser.cpp =================================================================== --- llvm/trunk/lib/Target/X86/AsmParser/X86AsmParser.cpp +++ llvm/trunk/lib/Target/X86/AsmParser/X86AsmParser.cpp @@ -955,7 +955,7 @@ void SetFrameRegister(unsigned RegNo) override; - bool parseAssignmentExpression(const MCExpr *&Res, SMLoc &EndLoc) override; + bool parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) override; bool ParseInstruction(ParseInstructionInfo &Info, StringRef Name, SMLoc NameLoc, OperandVector &Operands) override; @@ -2260,15 +2260,17 @@ return X86Operand::CreateMem(getPointerWidth(), Disp, MemStart, MemEnd); } -// Parse either a standard expression or a register. -bool X86AsmParser::parseAssignmentExpression(const MCExpr *&Res, - SMLoc &EndLoc) { +// Parse either a standard primary expression or a register. +bool X86AsmParser::parsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) { MCAsmParser &Parser = getParser(); - if (Parser.parseExpression(Res, EndLoc)) { + if (Parser.parsePrimaryExpr(Res, EndLoc)) { SMLoc StartLoc = Parser.getTok().getLoc(); // Normal Expression parse fails, check if it could be a register. unsigned RegNo; - if (Parser.getTargetParser().ParseRegister(RegNo, StartLoc, EndLoc)) + bool TryRegParse = + getTok().is(AsmToken::Percent) || + (isParsingIntelSyntax() && getTok().is(AsmToken::Identifier)); + if (!TryRegParse || ParseRegister(RegNo, StartLoc, EndLoc)) return true; // Clear previous parse error and return correct expression. Parser.clearPendingErrors(); Index: llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCExpr.h =================================================================== --- llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCExpr.h +++ llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCExpr.h @@ -48,7 +48,7 @@ /// @} void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override { - if (MAI->getAssemblerDialect() == 0) + if (!MAI || MAI->getAssemblerDialect() == 0) OS << '%'; OS << X86ATTInstPrinter::getRegisterName(RegNo); } @@ -59,6 +59,11 @@ } // Register values should be inlined as they are not valid .set expressions. bool inlineAssignedExpr() const override { return true; } + bool isEqualTo(const MCExpr *X) const override { + if (auto *E = dyn_cast(X)) + return getRegNo() == E->getRegNo(); + return false; + } void visitUsedExpr(MCStreamer &Streamer) const override{}; MCFragment *findAssociatedFragment() const override { return nullptr; } Index: llvm/trunk/test/MC/X86/pr37425.s =================================================================== --- llvm/trunk/test/MC/X86/pr37425.s +++ llvm/trunk/test/MC/X86/pr37425.s @@ -1,5 +1,4 @@ -// RUN: llvm-mc -triple x86_64-unknown-unknown -defsym=ERR=0 %s -o - | FileCheck %s -// RUN: not llvm-mc -triple x86_64-unknown-unknown -defsym=ERR=1 %s -o - 2>&1 | FileCheck --check-prefix=ERR %s +// RUN: llvm-mc -triple x86_64-unknown-unknown %s -o - | FileCheck %s // CHECK-NOT: .set var_xdata var_xdata = %rcx @@ -7,10 +6,15 @@ // CHECK: xorq %rcx, %rcx xorq var_xdata, var_xdata -.if (ERR==1) -// ERR: [[@LINE+2]]:15: error: unknown token in expression in '.set' directive -// ERR: [[@LINE+1]]:15: error: missing expression in '.set' directive -.set err_var, %rcx -.endif +// CHECK: .data +// CHECK-NEXT: .byte 1 +.data +.if var_xdata == %rax + .byte 0 +.elseif var_xdata == %rcx + .byte 1 +.else + .byte 2 +.endif