From: Sanjay Patel Date: Tue, 10 Jan 2017 23:49:07 +0000 (+0000) Subject: [InstCombine] add a wrapper for a common pair of transforms; NFCI X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e9fdb8bc46769e1894595def1883f9b4d99023f7;p=llvm [InstCombine] add a wrapper for a common pair of transforms; NFCI Some of the callers are artificially limiting this transform to integer types; this should make it easier to incrementally remove that restriction. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291620 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 55151c13b43..2d34c1cc74b 100644 --- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1371,15 +1371,9 @@ Instruction *InstCombiner::visitFAdd(BinaryOperator &I) { SimplifyFAddInst(LHS, RHS, I.getFastMathFlags(), DL, &TLI, &DT, &AC)) return replaceInstUsesWith(I, V); - if (isa(RHS)) { - if (isa(LHS)) - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; - - if (SelectInst *SI = dyn_cast(LHS)) - if (Instruction *NV = FoldOpIntoSelect(I, SI)) - return NV; - } + if (isa(RHS)) + if (Instruction *FoldedFAdd = foldOpWithConstantIntoOperand(I)) + return FoldedFAdd; // -A + B --> B - A // -A + -B --> -(A + B) diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index a59b43d6af5..da5384a86aa 100644 --- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1382,13 +1382,8 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { } } - // Try to fold constant and into select arguments. - if (SelectInst *SI = dyn_cast(Op0)) - if (Instruction *R = FoldOpIntoSelect(I, SI)) - return R; - if (isa(Op0)) - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; + if (Instruction *FoldedLogic = foldOpWithConstantIntoOperand(I)) + return FoldedLogic; } if (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder)) @@ -2125,14 +2120,8 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { Builder->getInt(C1->getValue() & ~RHS->getValue())); } - // Try to fold constant and into select arguments. - if (SelectInst *SI = dyn_cast(Op0)) - if (Instruction *R = FoldOpIntoSelect(I, SI)) - return R; - - if (isa(Op0)) - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; + if (Instruction *FoldedLogic = foldOpWithConstantIntoOperand(I)) + return FoldedLogic; } // Given an OR instruction, check to see if this is a bswap. @@ -2594,13 +2583,8 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { } } - // Try to fold constant and into select arguments. - if (SelectInst *SI = dyn_cast(Op0)) - if (Instruction *R = FoldOpIntoSelect(I, SI)) - return R; - if (isa(Op0)) - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; + if (Instruction *FoldedLogic = foldOpWithConstantIntoOperand(I)) + return FoldedLogic; } BinaryOperator *Op1I = dyn_cast(Op1); diff --git a/lib/Transforms/InstCombine/InstCombineInternal.h b/lib/Transforms/InstCombine/InstCombineInternal.h index 3cefe715e56..2847ce858e7 100644 --- a/lib/Transforms/InstCombine/InstCombineInternal.h +++ b/lib/Transforms/InstCombine/InstCombineInternal.h @@ -320,7 +320,6 @@ private: Value *dyn_castFNegVal(Value *V, bool NoSignedZero = false) const; Type *FindElementAtOffset(PointerType *PtrTy, int64_t Offset, SmallVectorImpl &NewIndices); - Instruction *FoldOpIntoSelect(Instruction &Op, SelectInst *SI); /// Classify whether a cast is worth optimizing. /// @@ -537,13 +536,21 @@ private: Value *SimplifyVectorOp(BinaryOperator &Inst); Value *SimplifyBSwap(BinaryOperator &Inst); - // FoldOpIntoPhi - Given a binary operator, cast instruction, or select - // which has a PHI node as operand #0, see if we can fold the instruction - // into the PHI (which is only possible if all operands to the PHI are - // constants). - // + + /// Given a binary operator, cast instruction, or select which has a PHI node + /// as operand #0, see if we can fold the instruction into the PHI (which is + /// only possible if all operands to the PHI are constants). Instruction *FoldOpIntoPhi(Instruction &I); + /// Given an instruction with a select as one operand and a constant as the + /// other operand, try to fold the binary operator into the select arguments. + /// This also works for Cast instructions, which obviously do not have a + /// second operand. + Instruction *FoldOpIntoSelect(Instruction &Op, SelectInst *SI); + + /// This is a convenience wrapper function for the above two functions. + Instruction *foldOpWithConstantIntoOperand(Instruction &I); + /// \brief Try to rotate an operation below a PHI node, using PHI nodes for /// its operands. Instruction *FoldPHIArgOpIntoPHI(PHINode &PN); diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index 04f03844ea6..45a19fb0f1f 100644 --- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -267,14 +267,8 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) { // Simplify mul instructions with a constant RHS. if (isa(Op1)) { - // Try to fold constant mul into select arguments. - if (SelectInst *SI = dyn_cast(Op0)) - if (Instruction *R = FoldOpIntoSelect(I, SI)) - return R; - - if (isa(Op0)) - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; + if (Instruction *FoldedMul = foldOpWithConstantIntoOperand(I)) + return FoldedMul; // Canonicalize (X+C1)*CI -> X*CI+C1*CI. { @@ -626,14 +620,8 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) { // Simplify mul instructions with a constant RHS. if (isa(Op1)) { - // Try to fold constant mul into select arguments. - if (SelectInst *SI = dyn_cast(Op0)) - if (Instruction *R = FoldOpIntoSelect(I, SI)) - return R; - - if (isa(Op0)) - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; + if (Instruction *FoldedMul = foldOpWithConstantIntoOperand(I)) + return FoldedMul; // (fmul X, -1.0) --> (fsub -0.0, X) if (match(Op1, m_SpecificFP(-1.0))) { @@ -956,14 +944,9 @@ Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) { } } - if (*C2 != 0) { // avoid X udiv 0 - if (SelectInst *SI = dyn_cast(Op0)) - if (Instruction *R = FoldOpIntoSelect(I, SI)) - return R; - if (isa(Op0)) - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; - } + if (*C2 != 0) // avoid X udiv 0 + if (Instruction *FoldedDiv = foldOpWithConstantIntoOperand(I)) + return FoldedDiv; } } diff --git a/lib/Transforms/InstCombine/InstCombineShifts.cpp b/lib/Transforms/InstCombine/InstCombineShifts.cpp index 5ad2a1c0e3e..4ff9b64ac57 100644 --- a/lib/Transforms/InstCombine/InstCombineShifts.cpp +++ b/lib/Transforms/InstCombine/InstCombineShifts.cpp @@ -530,13 +530,8 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, Constant *Op1, return BinaryOperator::CreateMul(BO->getOperand(0), ConstantExpr::getShl(BOOp, Op1)); - // Try to fold constant and into select arguments. - if (SelectInst *SI = dyn_cast(Op0)) - if (Instruction *R = FoldOpIntoSelect(I, SI)) - return R; - if (isa(Op0)) - if (Instruction *NV = FoldOpIntoPhi(I)) - return NV; + if (Instruction *FoldedShift = foldOpWithConstantIntoOperand(I)) + return FoldedShift; // Fold shift2(trunc(shift1(x,c1)), c2) -> trunc(shift2(shift1(x,c1),c2)) if (TruncInst *TI = dyn_cast(Op0)) { diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp index 9a52874c4c2..27fc34d2317 100644 --- a/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -770,10 +770,6 @@ static Value *foldOperationIntoSelectOperand(Instruction &I, Value *SO, return RI; } -/// Given an instruction with a select as one operand and a constant as the -/// other operand, try to fold the binary operator into the select arguments. -/// This also works for Cast instructions, which obviously do not have a second -/// operand. Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { // Don't modify shared select instructions. if (!SI->hasOneUse()) @@ -824,9 +820,6 @@ Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { return SelectInst::Create(SI->getCondition(), NewTV, NewFV, "", nullptr, SI); } -/// Given a binary operator, cast instruction, or select which has a PHI node as -/// operand #0, see if we can fold the instruction into the PHI (which is only -/// possible if all operands to the PHI are constants). Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { PHINode *PN = cast(I.getOperand(0)); unsigned NumPHIValues = PN->getNumIncomingValues(); @@ -964,6 +957,19 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { return replaceInstUsesWith(I, NewPN); } +Instruction *InstCombiner::foldOpWithConstantIntoOperand(Instruction &I) { + assert(isa(I.getOperand(1)) && "Unexpected operand type"); + + if (auto *Sel = dyn_cast(I.getOperand(0))) { + if (Instruction *NewSel = FoldOpIntoSelect(I, Sel)) + return NewSel; + } else if (isa(I.getOperand(0))) { + if (Instruction *NewPhi = FoldOpIntoPhi(I)) + return NewPhi; + } + return nullptr; +} + /// Given a pointer type and a constant offset, determine whether or not there /// is a sequence of GEP indices into the pointed type that will land us at the /// specified offset. If so, fill them into NewIndices and return the resultant