[DAG] x & x --> x

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285521 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sanjay Patel 2016-10-30 18:13:30 +00:00
parent 6c05e2a692
commit 73a78bf8d3
2 changed files with 4 additions and 2 deletions

View File

@ -3134,6 +3134,10 @@ SDValue DAGCombiner::visitAND(SDNode *N) {
SDValue N1 = N->getOperand(1);
EVT VT = N1.getValueType();
// x & x --> x
if (N0 == N1)
return N0;
// fold vector ops
if (VT.isVector()) {
if (SDValue FoldedVOp = SimplifyVBinOp(N))

View File

@ -4,7 +4,6 @@
define i32 @and_self(i32 %x) {
; CHECK-LABEL: and_self:
; CHECK: # BB#0:
; CHECK-NEXT: andl %edi, %edi
; CHECK-NEXT: movl %edi, %eax
; CHECK-NEXT: retq
%and = and i32 %x, %x
@ -14,7 +13,6 @@ define i32 @and_self(i32 %x) {
define <4 x i32> @and_self_vec(<4 x i32> %x) {
; CHECK-LABEL: and_self_vec:
; CHECK: # BB#0:
; CHECK-NEXT: andps %xmm0, %xmm0
; CHECK-NEXT: retq
%and = and <4 x i32> %x, %x
ret <4 x i32> %and