diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/include/llvm/Analysis/ConstantFolding.h | 6 | ||||
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 3 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstSimplify/select.ll | 8 |
3 files changed, 17 insertions, 0 deletions
diff --git a/llvm/include/llvm/Analysis/ConstantFolding.h b/llvm/include/llvm/Analysis/ConstantFolding.h index 42034741b8e..cb314e3766c 100644 --- a/llvm/include/llvm/Analysis/ConstantFolding.h +++ b/llvm/include/llvm/Analysis/ConstantFolding.h @@ -79,6 +79,12 @@ ConstantFoldCompareInstOperands(unsigned Predicate, Constant *LHS, Constant *ConstantFoldBinaryOpOperands(unsigned Opcode, Constant *LHS, Constant *RHS, const DataLayout &DL); +/// \brief Attempt to constant fold a select instruction with the specified +/// operands. The constant result is returned if successful; if not, null is +/// returned. +Constant *ConstantFoldSelectInstruction(Constant *Cond, Constant *V1, + Constant *V2); + /// \brief Attempt to constant fold a cast with the specified operand. If it /// fails, it returns a constant expression of the specified operand. Constant *ConstantFoldCastOperand(unsigned Opcode, Constant *C, Type *DestTy, diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index 05afc4f5501..6eac4b3b4af 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -3580,6 +3580,9 @@ static Value *SimplifySelectInst(Value *CondVal, Value *TrueVal, // select true, X, Y -> X // select false, X, Y -> Y if (Constant *CB = dyn_cast<Constant>(CondVal)) { + if (Constant *CT = dyn_cast<Constant>(TrueVal)) + if (Constant *CF = dyn_cast<Constant>(FalseVal)) + return ConstantFoldSelectInstruction(CB, CT, CF); if (CB->isAllOnesValue()) return TrueVal; if (CB->isNullValue()) diff --git a/llvm/test/Transforms/InstSimplify/select.ll b/llvm/test/Transforms/InstSimplify/select.ll index 7ede76d4dfa..e1b7877c17a 100644 --- a/llvm/test/Transforms/InstSimplify/select.ll +++ b/llvm/test/Transforms/InstSimplify/select.ll @@ -17,6 +17,14 @@ define <2 x i8> @vsel_fvec(<2 x i8> %x, <2 x i8> %y) { ret <2 x i8> %s } +define <2 x i8> @vsel_mixedvec() { +; CHECK-LABEL: @vsel_mixedvec( +; CHECK-NEXT: ret <2 x i8> <i8 0, i8 3> +; + %s = select <2 x i1><i1 true, i1 false>, <2 x i8> <i8 0, i8 1>, <2 x i8> <i8 2, i8 3> + ret <2 x i8> %s +} + define i32 @test1(i32 %x) { ; CHECK-LABEL: @test1( ; CHECK-NEXT: ret i32 %x |
