[llvm] r276777 - [InstSimplify] Cast folding can be made more generic
David Majnemer via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 26 10:58:06 PDT 2016
Author: majnemer
Date: Tue Jul 26 12:58:05 2016
New Revision: 276777
URL: http://llvm.org/viewvc/llvm-project?rev=276777&view=rev
Log:
[InstSimplify] Cast folding can be made more generic
Use isEliminableCastPair to determine if a pair of casts are foldable.
Modified:
llvm/trunk/include/llvm/Analysis/InstructionSimplify.h
llvm/trunk/lib/Analysis/InstructionSimplify.cpp
llvm/trunk/test/Transforms/GVN/pr14166.ll
Modified: llvm/trunk/include/llvm/Analysis/InstructionSimplify.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/InstructionSimplify.h?rev=276777&r1=276776&r2=276777&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/InstructionSimplify.h (original)
+++ llvm/trunk/include/llvm/Analysis/InstructionSimplify.h Tue Jul 26 12:58:05 2016
@@ -238,19 +238,13 @@ namespace llvm {
AssumptionCache *AC = nullptr,
const Instruction *CxtI = nullptr);
- /// Given operands for an TruncInst, fold the result or return null.
- Value *SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout &DL,
- const TargetLibraryInfo *TLI = nullptr,
- const DominatorTree *DT = nullptr,
- AssumptionCache *AC = nullptr,
- const Instruction *CxtI = nullptr);
-
- /// Given operands for an BitCastInst, fold the result or return null.
- Value *SimplifyBitCastInst(Value *Op, Type *Ty, const DataLayout &DL,
- const TargetLibraryInfo *TLI = nullptr,
- const DominatorTree *DT = nullptr,
- AssumptionCache *AC = nullptr,
- const Instruction *CxtI = nullptr);
+ /// Given operands for a CastInst, fold the result or return null.
+ Value *SimplifyCastInst(unsigned CastOpc, Value *Op, Type *Ty,
+ const DataLayout &DL,
+ const TargetLibraryInfo *TLI = nullptr,
+ const DominatorTree *DT = nullptr,
+ AssumptionCache *AC = nullptr,
+ const Instruction *CxtI = nullptr);
//=== Helper functions for higher up the class hierarchy.
Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=276777&r1=276776&r2=276777&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Tue Jul 26 12:58:05 2016
@@ -69,8 +69,8 @@ static Value *SimplifyCmpInst(unsigned,
unsigned);
static Value *SimplifyOrInst(Value *, Value *, const Query &, unsigned);
static Value *SimplifyXorInst(Value *, Value *, const Query &, unsigned);
-static Value *SimplifyTruncInst(Value *, Type *, const Query &, unsigned);
-static Value *SimplifyBitCastInst(Value *, Type *, const Query &, unsigned);
+static Value *SimplifyCastInst(unsigned, Value *, Type *,
+ const Query &, unsigned);
/// For a boolean type, or a vector of boolean type, return false, or
/// a vector with every element false, as appropriate for the type.
@@ -748,7 +748,8 @@ static Value *SimplifySubInst(Value *Op0
// See if "V === X - Y" simplifies.
if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1))
// It does! Now see if "trunc V" simplifies.
- if (Value *W = SimplifyTruncInst(V, Op0->getType(), Q, MaxRecurse-1))
+ if (Value *W = SimplifyCastInst(Instruction::Trunc, V, Op0->getType(),
+ Q, MaxRecurse - 1))
// It does, return the simplified "trunc V".
return W;
@@ -3790,49 +3791,47 @@ static Value *SimplifyPHINode(PHINode *P
return CommonValue;
}
-static Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) {
+static Value *SimplifyCastInst(unsigned CastOpc, Value *Op,
+ Type *Ty, const Query &Q, unsigned MaxRecurse) {
if (auto *C = dyn_cast<Constant>(Op))
- return ConstantFoldCastOperand(Instruction::Trunc, C, Ty, Q.DL);
+ return ConstantFoldCastOperand(CastOpc, C, Ty, Q.DL);
- // trunc([zs]ext(x)) -> x if the trunc undoes the work of the [zs]ext.
- if (auto *CI = dyn_cast<CastInst>(Op))
- if (isa<ZExtInst>(CI) || isa<SExtInst>(CI))
- if (CI->getOperand(0)->getType() == Ty)
- return CI->getOperand(0);
-
- return nullptr;
-}
-
-Value *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout &DL,
- const TargetLibraryInfo *TLI,
- const DominatorTree *DT, AssumptionCache *AC,
- const Instruction *CxtI) {
- return ::SimplifyTruncInst(Op, Ty, Query(DL, TLI, DT, AC, CxtI),
- RecursionLimit);
-}
-
-static Value *SimplifyBitCastInst(Value *Op, Type *Ty, const Query &Q, unsigned) {
- if (auto *C = dyn_cast<Constant>(Op))
- return ConstantFoldCastOperand(Instruction::BitCast, C, Ty, Q.DL);
+ if (auto *CI = dyn_cast<CastInst>(Op)) {
+ auto *Src = CI->getOperand(0);
+ Type *SrcTy = Src->getType();
+ Type *MidTy = CI->getType();
+ Type *DstTy = Ty;
+ if (Src->getType() == Ty) {
+ auto FirstOp = static_cast<Instruction::CastOps>(CI->getOpcode());
+ auto SecondOp = static_cast<Instruction::CastOps>(CastOpc);
+ Type *SrcIntPtrTy =
+ SrcTy->isPtrOrPtrVectorTy() ? Q.DL.getIntPtrType(SrcTy) : nullptr;
+ Type *MidIntPtrTy =
+ MidTy->isPtrOrPtrVectorTy() ? Q.DL.getIntPtrType(MidTy) : nullptr;
+ Type *DstIntPtrTy =
+ DstTy->isPtrOrPtrVectorTy() ? Q.DL.getIntPtrType(DstTy) : nullptr;
+ if (CastInst::isEliminableCastPair(FirstOp, SecondOp, SrcTy, MidTy, DstTy,
+ SrcIntPtrTy, MidIntPtrTy,
+ DstIntPtrTy) == Instruction::BitCast)
+ return Src;
+ }
+ }
// bitcast x -> x
- if (Op->getType() == Ty)
- return Op;
-
- // bitcast(bitcast x) -> x
- if (auto *BC = dyn_cast<BitCastInst>(Op))
- if (BC->getOperand(0)->getType() == Ty)
- return BC->getOperand(0);
+ if (CastOpc == Instruction::BitCast)
+ if (Op->getType() == Ty)
+ return Op;
return nullptr;
}
-Value *llvm::SimplifyBitCastInst(Value *Op, Type *Ty, const DataLayout &DL,
- const TargetLibraryInfo *TLI,
- const DominatorTree *DT, AssumptionCache *AC,
- const Instruction *CxtI) {
- return ::SimplifyBitCastInst(Op, Ty, Query(DL, TLI, DT, AC, CxtI),
- RecursionLimit);
+Value *llvm::SimplifyCastInst(unsigned CastOpc, Value *Op, Type *Ty,
+ const DataLayout &DL,
+ const TargetLibraryInfo *TLI,
+ const DominatorTree *DT, AssumptionCache *AC,
+ const Instruction *CxtI) {
+ return ::SimplifyCastInst(CastOpc, Op, Ty, Query(DL, TLI, DT, AC, CxtI),
+ RecursionLimit);
}
//=== Helper functions for higher up the class hierarchy.
@@ -4301,13 +4300,11 @@ Value *llvm::SimplifyInstruction(Instruc
TLI, DT, AC, I);
break;
}
- case Instruction::Trunc:
- Result =
- SimplifyTruncInst(I->getOperand(0), I->getType(), DL, TLI, DT, AC, I);
- break;
- case Instruction::BitCast:
- Result =
- SimplifyBitCastInst(I->getOperand(0), I->getType(), DL, TLI, DT, AC, I);
+#define HANDLE_CAST_INST(num, opc, clas) case Instruction::opc:
+#include "llvm/IR/Instruction.def"
+#undef HANDLE_CAST_INST
+ Result = SimplifyCastInst(I->getOpcode(), I->getOperand(0), I->getType(),
+ DL, TLI, DT, AC, I);
break;
}
Modified: llvm/trunk/test/Transforms/GVN/pr14166.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/pr14166.ll?rev=276777&r1=276776&r2=276777&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/pr14166.ll (original)
+++ llvm/trunk/test/Transforms/GVN/pr14166.ll Tue Jul 26 12:58:05 2016
@@ -17,8 +17,7 @@ define <2 x i32> @test1() {
; CHECK: %v3 = inttoptr <2 x i32> %v2 to <2 x i8*>
; CHECK: %v4 = bitcast <2 x i32>* %v1 to <2 x i8*>*
; CHECK: store <2 x i8*> %v3, <2 x i8*>* %v4
-; CHECK: %1 = ptrtoint <2 x i8*> %v3 to <2 x i32>
-; CHECK: ret <2 x i32> %1
+; CHECK: ret <2 x i32> %v2
}
declare void @anything(<2 x i32>*)
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