[llvm] r199604 - InstCombine: Replace a hand-rolled version of isKnownToBeAPowerOfTwo with the real thing.
Benjamin Kramer
benny.kra at googlemail.com
Sun Jan 19 08:48:41 PST 2014
Author: d0k
Date: Sun Jan 19 10:48:41 2014
New Revision: 199604
URL: http://llvm.org/viewvc/llvm-project?rev=199604&view=rev
Log:
InstCombine: Replace a hand-rolled version of isKnownToBeAPowerOfTwo with the real thing.
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
llvm/trunk/test/Transforms/InstCombine/onehot_merge.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp?rev=199604&r1=199603&r2=199604&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp Sun Jan 19 10:48:41 2014
@@ -1543,23 +1543,6 @@ static Instruction *MatchSelectFromAndOr
return 0;
}
-/// IsOneHotValue - Returns true for "one-hot" values (values where at most
-/// one bit can be set).
-static bool IsOneHotValue(Value *V) {
- // Match 1<<K.
- if (BinaryOperator *BO = dyn_cast<BinaryOperator>(V))
- if (BO->getOpcode() == Instruction::Shl) {
- ConstantInt *One = dyn_cast<ConstantInt>(BO->getOperand(0));
- return One && One->isOne();
- }
-
- // Check for power of two integer constants.
- if (ConstantInt *K = dyn_cast<ConstantInt>(V))
- return K->getValue().isPowerOf2();
-
- return false;
-}
-
/// FoldOrOfICmps - Fold (icmp)|(icmp) if possible.
Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
@@ -1581,13 +1564,13 @@ Value *InstCombiner::FoldOrOfICmps(ICmpI
Value *Mask = 0;
Value *Masked = 0;
if (LAnd->getOperand(0) == RAnd->getOperand(0) &&
- IsOneHotValue(LAnd->getOperand(1)) &&
- IsOneHotValue(RAnd->getOperand(1))) {
+ isKnownToBeAPowerOfTwo(LAnd->getOperand(1)) &&
+ isKnownToBeAPowerOfTwo(RAnd->getOperand(1))) {
Mask = Builder->CreateOr(LAnd->getOperand(1), RAnd->getOperand(1));
Masked = Builder->CreateAnd(LAnd->getOperand(0), Mask);
} else if (LAnd->getOperand(1) == RAnd->getOperand(1) &&
- IsOneHotValue(LAnd->getOperand(0)) &&
- IsOneHotValue(RAnd->getOperand(0))) {
+ isKnownToBeAPowerOfTwo(LAnd->getOperand(0)) &&
+ isKnownToBeAPowerOfTwo(RAnd->getOperand(0))) {
Mask = Builder->CreateOr(LAnd->getOperand(0), RAnd->getOperand(0));
Masked = Builder->CreateAnd(LAnd->getOperand(1), Mask);
}
Modified: llvm/trunk/test/Transforms/InstCombine/onehot_merge.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/onehot_merge.ll?rev=199604&r1=199603&r2=199604&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/onehot_merge.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/onehot_merge.ll Sun Jan 19 10:48:41 2014
@@ -16,7 +16,7 @@ bb:
;CHECK: @foo1_and
;CHECK: shl i32 1, %c1
-;CHECK-NEXT: shl i32 1, %c2
+;CHECK-NEXT: lshr i32 -2147483648, %c2
;CHECK-NEXT: or i32
;CHECK-NEXT: and i32
;CHECK-NEXT: icmp ne i32 %1, %0
@@ -24,7 +24,7 @@ bb:
define i1 @foo1_and(i32 %k, i32 %c1, i32 %c2) {
bb:
%tmp = shl i32 1, %c1
- %tmp4 = shl i32 1, %c2
+ %tmp4 = lshr i32 -2147483648, %c2
%tmp1 = and i32 %tmp, %k
%tmp2 = icmp eq i32 %tmp1, 0
%tmp5 = and i32 %tmp4, %k
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