[llvm-commits] [llvm] r85085 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/or.ll test/Transforms/InstCombine/xor-demorgans.ll
Chris Lattner
sabre at nondot.org
Sun Oct 25 18:06:32 PDT 2009
Author: lattner
Date: Sun Oct 25 20:06:31 2009
New Revision: 85085
URL: http://llvm.org/viewvc/llvm-project?rev=85085&view=rev
Log:
Implement PR3266 & PR5276, folding:
not (or (icmp, icmp)) -> and(icmp, icmp)
Removed:
llvm/trunk/test/Transforms/InstCombine/xor-demorgans.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
llvm/trunk/test/Transforms/InstCombine/or.ll
Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=85085&r1=85084&r2=85085&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Sun Oct 25 20:06:31 2009
@@ -631,9 +631,32 @@
return 0;
}
-static inline Value *dyn_castNotVal(Value *V) {
+/// isFreeToInvert - Return true if the specified value is free to invert (apply
+/// ~ to). This happens in cases where the ~ can be eliminated.
+static inline bool isFreeToInvert(Value *V) {
+ // ~(~(X)) -> X.
if (BinaryOperator::isNot(V))
- return BinaryOperator::getNotArgument(V);
+ return true;
+
+ // Constants can be considered to be not'ed values.
+ if (isa<ConstantInt>(V))
+ return true;
+
+ // Compares can be inverted if they have a single use.
+ if (CmpInst *CI = dyn_cast<CmpInst>(V))
+ return CI->hasOneUse();
+
+ return false;
+}
+
+static inline Value *dyn_castNotVal(Value *V) {
+ // If this is not(not(x)) don't return that this is a not: we want the two
+ // not's to be folded first.
+ if (BinaryOperator::isNot(V)) {
+ Value *Operand = BinaryOperator::getNotArgument(V);
+ if (!isFreeToInvert(Operand))
+ return Operand;
+ }
// Constants can be considered to be not'ed values...
if (ConstantInt *C = dyn_cast<ConstantInt>(V))
@@ -641,6 +664,8 @@
return 0;
}
+
+
// dyn_castFoldableMul - If this value is a multiply that can be folded into
// other computations (because it has a constant operand), return the
// non-constant operand of the multiply, and set CST to point to the multiplier.
@@ -4166,7 +4191,7 @@
if (Instruction *CastOp = dyn_cast<Instruction>(CI->getOperand(0))) {
if ((isa<TruncInst>(CI) || isa<BitCastInst>(CI)) &&
CastOp->getNumOperands() == 2)
- if (ConstantInt *AndCI = dyn_cast<ConstantInt>(CastOp->getOperand(1))) {
+ if (ConstantInt *AndCI =dyn_cast<ConstantInt>(CastOp->getOperand(1))){
if (CastOp->getOpcode() == Instruction::And) {
// Change: and (cast (and X, C1) to T), C2
// into : and (cast X to T), trunc_or_bitcast(C1)&C2
@@ -5064,12 +5089,13 @@
// Is this a ~ operation?
if (Value *NotOp = dyn_castNotVal(&I)) {
- // ~(~X & Y) --> (X | ~Y) - De Morgan's Law
- // ~(~X | Y) === (X & ~Y) - De Morgan's Law
if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(NotOp)) {
if (Op0I->getOpcode() == Instruction::And ||
Op0I->getOpcode() == Instruction::Or) {
- if (dyn_castNotVal(Op0I->getOperand(1))) Op0I->swapOperands();
+ // ~(~X & Y) --> (X | ~Y) - De Morgan's Law
+ // ~(~X | Y) === (X & ~Y) - De Morgan's Law
+ if (dyn_castNotVal(Op0I->getOperand(1)))
+ Op0I->swapOperands();
if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0))) {
Value *NotY =
Builder->CreateNot(Op0I->getOperand(1),
@@ -5078,6 +5104,19 @@
return BinaryOperator::CreateOr(Op0NotVal, NotY);
return BinaryOperator::CreateAnd(Op0NotVal, NotY);
}
+
+ // ~(X & Y) --> (~X | ~Y) - De Morgan's Law
+ // ~(X | Y) === (~X & ~Y) - De Morgan's Law
+ if (isFreeToInvert(Op0I->getOperand(0)) &&
+ isFreeToInvert(Op0I->getOperand(1))) {
+ Value *NotX =
+ Builder->CreateNot(Op0I->getOperand(0), "notlhs");
+ Value *NotY =
+ Builder->CreateNot(Op0I->getOperand(1), "notrhs");
+ if (Op0I->getOpcode() == Instruction::And)
+ return BinaryOperator::CreateOr(NotX, NotY);
+ return BinaryOperator::CreateAnd(NotX, NotY);
+ }
}
}
}
Modified: llvm/trunk/test/Transforms/InstCombine/or.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/or.ll?rev=85085&r1=85084&r2=85085&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/or.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/or.ll Sun Oct 25 20:06:31 2009
@@ -237,4 +237,19 @@
; CHECK: @test24
; CHECK: %bothcond = fcmp uno double %Y, %X ; <i1> [#uses=1]
; CHECK: ret i1 %bothcond
-}
\ No newline at end of file
+}
+
+; PR3266 & PR5276
+define i1 @test25(i32 %A, i32 %B) {
+ %C = icmp eq i32 %A, 0
+ %D = icmp eq i32 %B, 57
+ %E = or i1 %C, %D
+ %F = xor i1 %E, -1
+ ret i1 %F
+
+; CHECK: @test25
+; CHECK: icmp ne i32 %A, 0
+; CHECK-NEXT: icmp ne i32 %B, 57
+; CHECK-NEXT: %F = and i1
+; CHECK-NEXT: ret i1 %F
+}
Removed: llvm/trunk/test/Transforms/InstCombine/xor-demorgans.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/xor-demorgans.ll?rev=85084&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/xor-demorgans.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/xor-demorgans.ll (removed)
@@ -1,12 +0,0 @@
-; RUN: opt < %s -instcombine -S | not grep {= or}
-; PR3266
-; XFAIL: *
-
-define i1 @foo(i32 %x, i32 %y) nounwind {
-.summary:
- %0 = icmp sgt i32 %x, 4 ; <i1> [#uses=1]
- %1 = icmp sgt i32 %y, 0 ; <i1> [#uses=1]
- %.demorgan = or i1 %1, %0 ; <i1> [#uses=1]
- %2 = xor i1 %.demorgan, true ; <i1> [#uses=1]
- ret i1 %2
-}
More information about the llvm-commits
mailing list