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-rw-r--r--lib/CodeGen/CGExprComplex.cpp271
1 files changed, 232 insertions, 39 deletions
diff --git a/lib/CodeGen/CGExprComplex.cpp b/lib/CodeGen/CGExprComplex.cpp
index 7244b9e..1580bbe 100644
--- a/lib/CodeGen/CGExprComplex.cpp
+++ b/lib/CodeGen/CGExprComplex.cpp
@@ -15,9 +15,13 @@
#include "CodeGenModule.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/StmtVisitor.h"
+#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/MDBuilder.h"
+#include "llvm/IR/Metadata.h"
#include <algorithm>
using namespace clang;
using namespace CodeGen;
@@ -142,7 +146,7 @@ public:
// FIXME: CompoundLiteralExpr
- ComplexPairTy EmitCast(CastExpr::CastKind CK, Expr *Op, QualType DestTy);
+ ComplexPairTy EmitCast(CastKind CK, Expr *Op, QualType DestTy);
ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
// Unlike for scalars, we don't have to worry about function->ptr demotion
// here.
@@ -230,6 +234,9 @@ public:
ComplexPairTy EmitBinMul(const BinOpInfo &Op);
ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
+ ComplexPairTy EmitComplexBinOpLibCall(StringRef LibCallName,
+ const BinOpInfo &Op);
+
ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
return EmitBinAdd(EmitBinOps(E));
}
@@ -326,8 +333,7 @@ ComplexPairTy ComplexExprEmitter::EmitLoadOfLValue(LValue lvalue,
/// EmitStoreOfComplex - Store the specified real/imag parts into the
/// specified value pointer.
-void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val,
- LValue lvalue,
+void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, LValue lvalue,
bool isInit) {
if (lvalue.getType()->isAtomicType())
return CGF.EmitAtomicStore(RValue::getComplex(Val), lvalue, isInit);
@@ -410,7 +416,7 @@ ComplexPairTy ComplexExprEmitter::EmitScalarToComplexCast(llvm::Value *Val,
return ComplexPairTy(Val, llvm::Constant::getNullValue(Val->getType()));
}
-ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
+ComplexPairTy ComplexExprEmitter::EmitCast(CastKind CK, Expr *Op,
QualType DestTy) {
switch (CK) {
case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
@@ -528,9 +534,15 @@ ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
if (Op.LHS.first->getType()->isFloatingPointTy()) {
ResR = Builder.CreateFAdd(Op.LHS.first, Op.RHS.first, "add.r");
- ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
+ if (Op.LHS.second && Op.RHS.second)
+ ResI = Builder.CreateFAdd(Op.LHS.second, Op.RHS.second, "add.i");
+ else
+ ResI = Op.LHS.second ? Op.LHS.second : Op.RHS.second;
+ assert(ResI && "Only one operand may be real!");
} else {
ResR = Builder.CreateAdd(Op.LHS.first, Op.RHS.first, "add.r");
+ assert(Op.LHS.second && Op.RHS.second &&
+ "Both operands of integer complex operators must be complex!");
ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
}
return ComplexPairTy(ResR, ResI);
@@ -539,63 +551,222 @@ ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
llvm::Value *ResR, *ResI;
if (Op.LHS.first->getType()->isFloatingPointTy()) {
- ResR = Builder.CreateFSub(Op.LHS.first, Op.RHS.first, "sub.r");
- ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
+ ResR = Builder.CreateFSub(Op.LHS.first, Op.RHS.first, "sub.r");
+ if (Op.LHS.second && Op.RHS.second)
+ ResI = Builder.CreateFSub(Op.LHS.second, Op.RHS.second, "sub.i");
+ else
+ ResI = Op.LHS.second ? Op.LHS.second
+ : Builder.CreateFNeg(Op.RHS.second, "sub.i");
+ assert(ResI && "Only one operand may be real!");
} else {
- ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
+ ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
+ assert(Op.LHS.second && Op.RHS.second &&
+ "Both operands of integer complex operators must be complex!");
ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
}
return ComplexPairTy(ResR, ResI);
}
+/// \brief Emit a libcall for a binary operation on complex types.
+ComplexPairTy ComplexExprEmitter::EmitComplexBinOpLibCall(StringRef LibCallName,
+ const BinOpInfo &Op) {
+ CallArgList Args;
+ Args.add(RValue::get(Op.LHS.first),
+ Op.Ty->castAs<ComplexType>()->getElementType());
+ Args.add(RValue::get(Op.LHS.second),
+ Op.Ty->castAs<ComplexType>()->getElementType());
+ Args.add(RValue::get(Op.RHS.first),
+ Op.Ty->castAs<ComplexType>()->getElementType());
+ Args.add(RValue::get(Op.RHS.second),
+ Op.Ty->castAs<ComplexType>()->getElementType());
+
+ // We *must* use the full CG function call building logic here because the
+ // complex type has special ABI handling. We also should not forget about
+ // special calling convention which may be used for compiler builtins.
+ const CGFunctionInfo &FuncInfo =
+ CGF.CGM.getTypes().arrangeFreeFunctionCall(
+ Op.Ty, Args, FunctionType::ExtInfo(/* No CC here - will be added later */),
+ RequiredArgs::All);
+ llvm::FunctionType *FTy = CGF.CGM.getTypes().GetFunctionType(FuncInfo);
+ llvm::Constant *Func = CGF.CGM.CreateBuiltinFunction(FTy, LibCallName);
+ llvm::Instruction *Call;
+
+ RValue Res = CGF.EmitCall(FuncInfo, Func, ReturnValueSlot(), Args,
+ nullptr, &Call);
+ cast<llvm::CallInst>(Call)->setCallingConv(CGF.CGM.getBuiltinCC());
+ cast<llvm::CallInst>(Call)->setDoesNotThrow();
+
+ return Res.getComplexVal();
+}
+
+/// \brief Lookup the libcall name for a given floating point type complex
+/// multiply.
+static StringRef getComplexMultiplyLibCallName(llvm::Type *Ty) {
+ switch (Ty->getTypeID()) {
+ default:
+ llvm_unreachable("Unsupported floating point type!");
+ case llvm::Type::HalfTyID:
+ return "__mulhc3";
+ case llvm::Type::FloatTyID:
+ return "__mulsc3";
+ case llvm::Type::DoubleTyID:
+ return "__muldc3";
+ case llvm::Type::PPC_FP128TyID:
+ return "__multc3";
+ case llvm::Type::X86_FP80TyID:
+ return "__mulxc3";
+ case llvm::Type::FP128TyID:
+ return "__multc3";
+ }
+}
+// See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
+// typed values.
ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
using llvm::Value;
Value *ResR, *ResI;
+ llvm::MDBuilder MDHelper(CGF.getLLVMContext());
if (Op.LHS.first->getType()->isFloatingPointTy()) {
- Value *ResRl = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
- Value *ResRr = Builder.CreateFMul(Op.LHS.second, Op.RHS.second,"mul.rr");
- ResR = Builder.CreateFSub(ResRl, ResRr, "mul.r");
+ // The general formulation is:
+ // (a + ib) * (c + id) = (a * c - b * d) + i(a * d + b * c)
+ //
+ // But we can fold away components which would be zero due to a real
+ // operand according to C11 Annex G.5.1p2.
+ // FIXME: C11 also provides for imaginary types which would allow folding
+ // still more of this within the type system.
+
+ if (Op.LHS.second && Op.RHS.second) {
+ // If both operands are complex, emit the core math directly, and then
+ // test for NaNs. If we find NaNs in the result, we delegate to a libcall
+ // to carefully re-compute the correct infinity representation if
+ // possible. The expectation is that the presence of NaNs here is
+ // *extremely* rare, and so the cost of the libcall is almost irrelevant.
+ // This is good, because the libcall re-computes the core multiplication
+ // exactly the same as we do here and re-tests for NaNs in order to be
+ // a generic complex*complex libcall.
+
+ // First compute the four products.
+ Value *AC = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul_ac");
+ Value *BD = Builder.CreateFMul(Op.LHS.second, Op.RHS.second, "mul_bd");
+ Value *AD = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul_ad");
+ Value *BC = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul_bc");
+
+ // The real part is the difference of the first two, the imaginary part is
+ // the sum of the second.
+ ResR = Builder.CreateFSub(AC, BD, "mul_r");
+ ResI = Builder.CreateFAdd(AD, BC, "mul_i");
+
+ // Emit the test for the real part becoming NaN and create a branch to
+ // handle it. We test for NaN by comparing the number to itself.
+ Value *IsRNaN = Builder.CreateFCmpUNO(ResR, ResR, "isnan_cmp");
+ llvm::BasicBlock *ContBB = CGF.createBasicBlock("complex_mul_cont");
+ llvm::BasicBlock *INaNBB = CGF.createBasicBlock("complex_mul_imag_nan");
+ llvm::Instruction *Branch = Builder.CreateCondBr(IsRNaN, INaNBB, ContBB);
+ llvm::BasicBlock *OrigBB = Branch->getParent();
+
+ // Give hint that we very much don't expect to see NaNs.
+ // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
+ llvm::MDNode *BrWeight = MDHelper.createBranchWeights(1, (1U << 20) - 1);
+ Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
+
+ // Now test the imaginary part and create its branch.
+ CGF.EmitBlock(INaNBB);
+ Value *IsINaN = Builder.CreateFCmpUNO(ResI, ResI, "isnan_cmp");
+ llvm::BasicBlock *LibCallBB = CGF.createBasicBlock("complex_mul_libcall");
+ Branch = Builder.CreateCondBr(IsINaN, LibCallBB, ContBB);
+ Branch->setMetadata(llvm::LLVMContext::MD_prof, BrWeight);
+
+ // Now emit the libcall on this slowest of the slow paths.
+ CGF.EmitBlock(LibCallBB);
+ Value *LibCallR, *LibCallI;
+ std::tie(LibCallR, LibCallI) = EmitComplexBinOpLibCall(
+ getComplexMultiplyLibCallName(Op.LHS.first->getType()), Op);
+ Builder.CreateBr(ContBB);
+
+ // Finally continue execution by phi-ing together the different
+ // computation paths.
+ CGF.EmitBlock(ContBB);
+ llvm::PHINode *RealPHI = Builder.CreatePHI(ResR->getType(), 3, "real_mul_phi");
+ RealPHI->addIncoming(ResR, OrigBB);
+ RealPHI->addIncoming(ResR, INaNBB);
+ RealPHI->addIncoming(LibCallR, LibCallBB);
+ llvm::PHINode *ImagPHI = Builder.CreatePHI(ResI->getType(), 3, "imag_mul_phi");
+ ImagPHI->addIncoming(ResI, OrigBB);
+ ImagPHI->addIncoming(ResI, INaNBB);
+ ImagPHI->addIncoming(LibCallI, LibCallBB);
+ return ComplexPairTy(RealPHI, ImagPHI);
+ }
+ assert((Op.LHS.second || Op.RHS.second) &&
+ "At least one operand must be complex!");
+
+ // If either of the operands is a real rather than a complex, the
+ // imaginary component is ignored when computing the real component of the
+ // result.
+ ResR = Builder.CreateFMul(Op.LHS.first, Op.RHS.first, "mul.rl");
- Value *ResIl = Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il");
- Value *ResIr = Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
- ResI = Builder.CreateFAdd(ResIl, ResIr, "mul.i");
+ ResI = Op.LHS.second
+ ? Builder.CreateFMul(Op.LHS.second, Op.RHS.first, "mul.il")
+ : Builder.CreateFMul(Op.LHS.first, Op.RHS.second, "mul.ir");
} else {
+ assert(Op.LHS.second && Op.RHS.second &&
+ "Both operands of integer complex operators must be complex!");
Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
- Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
- ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
+ Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second, "mul.rr");
+ ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
- ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
+ ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
}
return ComplexPairTy(ResR, ResI);
}
+// See C11 Annex G.5.1 for the semantics of multiplicative operators on complex
+// typed values.
ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
llvm::Value *DSTr, *DSTi;
- if (Op.LHS.first->getType()->isFloatingPointTy()) {
- // (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
- llvm::Value *Tmp1 = Builder.CreateFMul(LHSr, RHSr); // a*c
- llvm::Value *Tmp2 = Builder.CreateFMul(LHSi, RHSi); // b*d
- llvm::Value *Tmp3 = Builder.CreateFAdd(Tmp1, Tmp2); // ac+bd
-
- llvm::Value *Tmp4 = Builder.CreateFMul(RHSr, RHSr); // c*c
- llvm::Value *Tmp5 = Builder.CreateFMul(RHSi, RHSi); // d*d
- llvm::Value *Tmp6 = Builder.CreateFAdd(Tmp4, Tmp5); // cc+dd
-
- llvm::Value *Tmp7 = Builder.CreateFMul(LHSi, RHSr); // b*c
- llvm::Value *Tmp8 = Builder.CreateFMul(LHSr, RHSi); // a*d
- llvm::Value *Tmp9 = Builder.CreateFSub(Tmp7, Tmp8); // bc-ad
+ if (LHSr->getType()->isFloatingPointTy()) {
+ // If we have a complex operand on the RHS, we delegate to a libcall to
+ // handle all of the complexities and minimize underflow/overflow cases.
+ //
+ // FIXME: We would be able to avoid the libcall in many places if we
+ // supported imaginary types in addition to complex types.
+ if (RHSi) {
+ BinOpInfo LibCallOp = Op;
+ // If LHS was a real, supply a null imaginary part.
+ if (!LHSi)
+ LibCallOp.LHS.second = llvm::Constant::getNullValue(LHSr->getType());
+
+ StringRef LibCallName;
+ switch (LHSr->getType()->getTypeID()) {
+ default:
+ llvm_unreachable("Unsupported floating point type!");
+ case llvm::Type::HalfTyID:
+ return EmitComplexBinOpLibCall("__divhc3", LibCallOp);
+ case llvm::Type::FloatTyID:
+ return EmitComplexBinOpLibCall("__divsc3", LibCallOp);
+ case llvm::Type::DoubleTyID:
+ return EmitComplexBinOpLibCall("__divdc3", LibCallOp);
+ case llvm::Type::PPC_FP128TyID:
+ return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
+ case llvm::Type::X86_FP80TyID:
+ return EmitComplexBinOpLibCall("__divxc3", LibCallOp);
+ case llvm::Type::FP128TyID:
+ return EmitComplexBinOpLibCall("__divtc3", LibCallOp);
+ }
+ }
+ assert(LHSi && "Can have at most one non-complex operand!");
- DSTr = Builder.CreateFDiv(Tmp3, Tmp6);
- DSTi = Builder.CreateFDiv(Tmp9, Tmp6);
+ DSTr = Builder.CreateFDiv(LHSr, RHSr);
+ DSTi = Builder.CreateFDiv(LHSi, RHSr);
} else {
+ assert(Op.LHS.second && Op.RHS.second &&
+ "Both operands of integer complex operators must be complex!");
// (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr); // a*c
llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi); // b*d
@@ -626,8 +797,15 @@ ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
TestAndClearIgnoreReal();
TestAndClearIgnoreImag();
BinOpInfo Ops;
- Ops.LHS = Visit(E->getLHS());
- Ops.RHS = Visit(E->getRHS());
+ if (E->getLHS()->getType()->isRealFloatingType())
+ Ops.LHS = ComplexPairTy(CGF.EmitScalarExpr(E->getLHS()), nullptr);
+ else
+ Ops.LHS = Visit(E->getLHS());
+ if (E->getRHS()->getType()->isRealFloatingType())
+ Ops.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
+ else
+ Ops.RHS = Visit(E->getRHS());
+
Ops.Ty = E->getType();
return Ops;
}
@@ -647,12 +825,19 @@ EmitCompoundAssignLValue(const CompoundAssignOperator *E,
// __block variables need to have the rhs evaluated first, plus this should
// improve codegen a little.
OpInfo.Ty = E->getComputationResultType();
+ QualType ComplexElementTy = cast<ComplexType>(OpInfo.Ty)->getElementType();
// The RHS should have been converted to the computation type.
- assert(OpInfo.Ty->isAnyComplexType());
- assert(CGF.getContext().hasSameUnqualifiedType(OpInfo.Ty,
- E->getRHS()->getType()));
- OpInfo.RHS = Visit(E->getRHS());
+ if (E->getRHS()->getType()->isRealFloatingType()) {
+ assert(
+ CGF.getContext()
+ .hasSameUnqualifiedType(ComplexElementTy, E->getRHS()->getType()));
+ OpInfo.RHS = ComplexPairTy(CGF.EmitScalarExpr(E->getRHS()), nullptr);
+ } else {
+ assert(CGF.getContext()
+ .hasSameUnqualifiedType(OpInfo.Ty, E->getRHS()->getType()));
+ OpInfo.RHS = Visit(E->getRHS());
+ }
LValue LHS = CGF.EmitLValue(E->getLHS());
@@ -662,7 +847,15 @@ EmitCompoundAssignLValue(const CompoundAssignOperator *E,
OpInfo.LHS = EmitComplexToComplexCast(LHSVal, LHSTy, OpInfo.Ty);
} else {
llvm::Value *LHSVal = CGF.EmitLoadOfScalar(LHS, E->getExprLoc());
- OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty);
+ // For floating point real operands we can directly pass the scalar form
+ // to the binary operator emission and potentially get more efficient code.
+ if (LHSTy->isRealFloatingType()) {
+ if (!CGF.getContext().hasSameUnqualifiedType(ComplexElementTy, LHSTy))
+ LHSVal = CGF.EmitScalarConversion(LHSVal, LHSTy, ComplexElementTy);
+ OpInfo.LHS = ComplexPairTy(LHSVal, nullptr);
+ } else {
+ OpInfo.LHS = EmitScalarToComplexCast(LHSVal, LHSTy, OpInfo.Ty);
+ }
}
// Expand the binary operator.
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