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r339895 | niravd | 2018-08-16 18:31:14 +0200 (Thu, 16 Aug 2018) | 13 lines
[MC][X86] Enhance X86 Register expression handling to more closely match GCC.
Allow the comparison of x86 registers in the evaluation of assembler
directives. This generalizes and simplifies the extension from r334022
to catch another case found in the Linux kernel.
Reviewers: rnk, void
Reviewed By: rnk
Subscribers: hiraditya, nickdesaulniers, llvm-commits
Differential Revision: https://reviews.llvm.org/D50795
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r339896 | d0k | 2018-08-16 18:50:23 +0200 (Thu, 16 Aug 2018) | 1 line
[MC] Remove unused variable
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_70@340329
91177308-0d34-0410-b5e6-
96231b3b80d8
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; }
/// 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
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,
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<MCTargetExpr>(ABE->getLHS()))
+ if (const MCTargetExpr *R = cast<MCTargetExpr>(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.
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);
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
// 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
// identifier '=' ... -> assignment statement
Lex();
- return parseAssignment(IDVal, true, /*NoDeadStrip*/ false, /*AllowExtendedExpr*/true);
+ return parseAssignment(IDVal, true);
default: // Normal instruction or directive.
break;
}
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) {
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
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;
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();
/// @}
void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override {
- if (MAI->getAssemblerDialect() == 0)
+ if (!MAI || MAI->getAssemblerDialect() == 0)
OS << '%';
OS << X86ATTInstPrinter::getRegisterName(RegNo);
}
}
// 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<X86MCExpr>(X))
+ return getRegNo() == E->getRegNo();
+ return false;
+ }
void visitUsedExpr(MCStreamer &Streamer) const override{};
MCFragment *findAssociatedFragment() const override { return nullptr; }
-// 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
// 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