[llvm-commits] [llvm] r101873 - in /llvm/trunk: include/llvm/Analysis/InstructionSimplify.h lib/Analysis/InstructionSimplify.cpp lib/Transforms/InstCombine/InstCombineSelect.cpp
Chris Lattner
sabre at nondot.org
Mon Apr 19 22:32:14 PDT 2010
Author: lattner
Date: Tue Apr 20 00:32:14 2010
New Revision: 101873
URL: http://llvm.org/viewvc/llvm-project?rev=101873&view=rev
Log:
move some select simplifications out out instcombine into
inst simplify. No functionality change.
Modified:
llvm/trunk/include/llvm/Analysis/InstructionSimplify.h
llvm/trunk/lib/Analysis/InstructionSimplify.cpp
llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
Modified: llvm/trunk/include/llvm/Analysis/InstructionSimplify.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/InstructionSimplify.h?rev=101873&r1=101872&r2=101873&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/InstructionSimplify.h (original)
+++ llvm/trunk/include/llvm/Analysis/InstructionSimplify.h Tue Apr 20 00:32:14 2010
@@ -46,6 +46,10 @@
Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
const TargetData *TD = 0);
+ /// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
+ /// the result. If not, this returns null.
+ Value *SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
+ const TargetData *TD = 0);
/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
/// fold the result. If not, this returns null.
Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=101873&r1=101872&r2=101873&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Tue Apr 20 00:32:14 2010
@@ -314,6 +314,35 @@
return 0;
}
+/// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
+/// the result. If not, this returns null.
+Value *llvm::SimplifySelectInst(Value *CondVal, Value *TrueVal, Value *FalseVal,
+ const TargetData *TD) {
+ // select true, X, Y -> X
+ // select false, X, Y -> Y
+ if (ConstantInt *CB = dyn_cast<ConstantInt>(CondVal))
+ return CB->getZExtValue() ? TrueVal : FalseVal;
+
+ // select C, X, X -> X
+ if (TrueVal == FalseVal)
+ return TrueVal;
+
+ if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
+ return FalseVal;
+ if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
+ return TrueVal;
+ if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y
+ if (isa<Constant>(TrueVal))
+ return TrueVal;
+ return FalseVal;
+ }
+
+
+
+ return 0;
+}
+
+
/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
/// fold the result. If not, this returns null.
Value *llvm::SimplifyGEPInst(Value *const *Ops, unsigned NumOps,
@@ -391,6 +420,9 @@
case Instruction::FCmp:
return SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(),
I->getOperand(0), I->getOperand(1), TD);
+ case Instruction::Select:
+ return SimplifySelectInst(I->getOperand(0), I->getOperand(1),
+ I->getOperand(2), TD);
case Instruction::GetElementPtr: {
SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end());
return SimplifyGEPInst(&Ops[0], Ops.size(), TD);
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp?rev=101873&r1=101872&r2=101873&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp Tue Apr 20 00:32:14 2010
@@ -13,6 +13,7 @@
#include "InstCombine.h"
#include "llvm/Support/PatternMatch.h"
+#include "llvm/Analysis/InstructionSimplify.h"
using namespace llvm;
using namespace PatternMatch;
@@ -421,49 +422,30 @@
Value *TrueVal = SI.getTrueValue();
Value *FalseVal = SI.getFalseValue();
- // select true, X, Y -> X
- // select false, X, Y -> Y
- if (ConstantInt *C = dyn_cast<ConstantInt>(CondVal))
- return ReplaceInstUsesWith(SI, C->getZExtValue() ? TrueVal : FalseVal);
-
- // select C, X, X -> X
- if (TrueVal == FalseVal)
- return ReplaceInstUsesWith(SI, TrueVal);
-
- if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X
- return ReplaceInstUsesWith(SI, FalseVal);
- if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X
- return ReplaceInstUsesWith(SI, TrueVal);
- if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y
- if (isa<Constant>(TrueVal))
- return ReplaceInstUsesWith(SI, TrueVal);
- else
- return ReplaceInstUsesWith(SI, FalseVal);
- }
+ if (Value *V = SimplifySelectInst(CondVal, TrueVal, FalseVal, TD))
+ return ReplaceInstUsesWith(SI, V);
if (SI.getType()->isIntegerTy(1)) {
if (ConstantInt *C = dyn_cast<ConstantInt>(TrueVal)) {
if (C->getZExtValue()) {
// Change: A = select B, true, C --> A = or B, C
return BinaryOperator::CreateOr(CondVal, FalseVal);
- } else {
- // Change: A = select B, false, C --> A = and !B, C
- Value *NotCond =
- InsertNewInstBefore(BinaryOperator::CreateNot(CondVal,
- "not."+CondVal->getName()), SI);
- return BinaryOperator::CreateAnd(NotCond, FalseVal);
}
+ // Change: A = select B, false, C --> A = and !B, C
+ Value *NotCond =
+ InsertNewInstBefore(BinaryOperator::CreateNot(CondVal,
+ "not."+CondVal->getName()), SI);
+ return BinaryOperator::CreateAnd(NotCond, FalseVal);
} else if (ConstantInt *C = dyn_cast<ConstantInt>(FalseVal)) {
if (C->getZExtValue() == false) {
// Change: A = select B, C, false --> A = and B, C
return BinaryOperator::CreateAnd(CondVal, TrueVal);
- } else {
- // Change: A = select B, C, true --> A = or !B, C
- Value *NotCond =
- InsertNewInstBefore(BinaryOperator::CreateNot(CondVal,
- "not."+CondVal->getName()), SI);
- return BinaryOperator::CreateOr(NotCond, TrueVal);
}
+ // Change: A = select B, C, true --> A = or !B, C
+ Value *NotCond =
+ InsertNewInstBefore(BinaryOperator::CreateNot(CondVal,
+ "not."+CondVal->getName()), SI);
+ return BinaryOperator::CreateOr(NotCond, TrueVal);
}
// select a, b, a -> a&b
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