[IR] Add a dedicated FNeg IR Instruction
The IEEE-754 Standard makes it clear that fneg(x) and
fsub(-0.0, x) are two different operations. The former is a bitwise
operation, while the latter is an arithmetic operation. This patch
creates a dedicated FNeg IR Instruction to model that behavior.
Differential Revision: https://reviews.llvm.org/D53877
llvm-svn: 346774
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index af4f439..4f8ce3d 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -823,6 +823,8 @@
} \
} while (false)
+ INSTKEYWORD(fneg, FNeg);
+
INSTKEYWORD(add, Add); INSTKEYWORD(fadd, FAdd);
INSTKEYWORD(sub, Sub); INSTKEYWORD(fsub, FSub);
INSTKEYWORD(mul, Mul); INSTKEYWORD(fmul, FMul);
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 5fe1e12..856be2f 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -3295,7 +3295,31 @@
ID.Kind = ValID::t_Constant;
return false;
}
-
+
+ // Unary Operators.
+ case lltok::kw_fneg: {
+ unsigned Opc = Lex.getUIntVal();
+ Constant *Val;
+ Lex.Lex();
+ if (ParseToken(lltok::lparen, "expected '(' in unary constantexpr") ||
+ ParseGlobalTypeAndValue(Val) ||
+ ParseToken(lltok::rparen, "expected ')' in unary constantexpr"))
+ return true;
+
+ // Check that the type is valid for the operator.
+ switch (Opc) {
+ case Instruction::FNeg:
+ if (!Val->getType()->isFPOrFPVectorTy())
+ return Error(ID.Loc, "constexpr requires fp operands");
+ break;
+ default: llvm_unreachable("Unknown unary operator!");
+ }
+ unsigned Flags = 0;
+ Constant *C = ConstantExpr::get(Opc, Val, Flags);
+ ID.ConstantVal = C;
+ ID.Kind = ValID::t_Constant;
+ return false;
+ }
// Binary Operators.
case lltok::kw_add:
case lltok::kw_fadd:
@@ -5492,6 +5516,16 @@
case lltok::kw_catchswitch: return ParseCatchSwitch(Inst, PFS);
case lltok::kw_catchpad: return ParseCatchPad(Inst, PFS);
case lltok::kw_cleanuppad: return ParseCleanupPad(Inst, PFS);
+ // Unary Operators.
+ case lltok::kw_fneg: {
+ FastMathFlags FMF = EatFastMathFlagsIfPresent();
+ int Res = ParseUnaryOp(Inst, PFS, KeywordVal, 2);
+ if (Res != 0)
+ return Res;
+ if (FMF.any())
+ Inst->setFastMathFlags(FMF);
+ return false;
+ }
// Binary Operators.
case lltok::kw_add:
case lltok::kw_sub:
@@ -6064,6 +6098,43 @@
}
//===----------------------------------------------------------------------===//
+// Unary Operators.
+//===----------------------------------------------------------------------===//
+
+/// ParseUnaryOp
+/// ::= UnaryOp TypeAndValue ',' Value
+///
+/// If OperandType is 0, then any FP or integer operand is allowed. If it is 1,
+/// then any integer operand is allowed, if it is 2, any fp operand is allowed.
+bool LLParser::ParseUnaryOp(Instruction *&Inst, PerFunctionState &PFS,
+ unsigned Opc, unsigned OperandType) {
+ LocTy Loc; Value *LHS;
+ if (ParseTypeAndValue(LHS, Loc, PFS))
+ return true;
+
+ bool Valid;
+ switch (OperandType) {
+ default: llvm_unreachable("Unknown operand type!");
+ case 0: // int or FP.
+ Valid = LHS->getType()->isIntOrIntVectorTy() ||
+ LHS->getType()->isFPOrFPVectorTy();
+ break;
+ case 1:
+ Valid = LHS->getType()->isIntOrIntVectorTy();
+ break;
+ case 2:
+ Valid = LHS->getType()->isFPOrFPVectorTy();
+ break;
+ }
+
+ if (!Valid)
+ return Error(Loc, "invalid operand type for instruction");
+
+ Inst = UnaryOperator::Create((Instruction::UnaryOps)Opc, LHS);
+ return false;
+}
+
+//===----------------------------------------------------------------------===//
// Binary Operators.
//===----------------------------------------------------------------------===//
diff --git a/llvm/lib/AsmParser/LLParser.h b/llvm/lib/AsmParser/LLParser.h
index cec1a8e..6f8962b 100644
--- a/llvm/lib/AsmParser/LLParser.h
+++ b/llvm/lib/AsmParser/LLParser.h
@@ -571,6 +571,8 @@
bool ParseCatchPad(Instruction *&Inst, PerFunctionState &PFS);
bool ParseCleanupPad(Instruction *&Inst, PerFunctionState &PFS);
+ bool ParseUnaryOp(Instruction *&Inst, PerFunctionState &PFS, unsigned Opc,
+ unsigned OperandType);
bool ParseArithmetic(Instruction *&Inst, PerFunctionState &PFS, unsigned Opc,
unsigned OperandType);
bool ParseLogical(Instruction *&Inst, PerFunctionState &PFS, unsigned Opc);
diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
index f8f5955..dae1d41 100644
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -270,6 +270,7 @@
kw_umin,
// Instruction Opcodes (Opcode in UIntVal).
+ kw_fneg,
kw_add,
kw_fadd,
kw_sub,