[DAGCombiner] Remove extra bitcasts surrounding vector shuffles

Patch to remove extra bitcasts from shuffles, this is often a legacy of XformToShuffleWithZero being used to combine bitmaskings (of float vectors bitcast to integer vectors) into shuffles: bitcast(shuffle(bitcast(s0),bitcast(s1))) -> shuffle(s0,s1)

Differential Revision: http://reviews.llvm.org/D9097

llvm-svn: 235578

1 files changed, 64 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/combine-or.ll b/llvm/test/CodeGen/X86/combine-or.ll
index 8a0ffc128e5..970f1762c1b 100644
--- a/llvm/test/CodeGen/X86/combine-or.ll
+++ b/llvm/test/CodeGen/X86/combine-or.ll
@@ -277,6 +277,70 @@ define <2 x i64> @test21(<2 x i64> %a, <2 x i64> %b) {
   ret <2 x i64> %or
 }
 
+
+; Verify that the dag-combiner keeps the correct domain for float/double vectors
+; bitcast to use the mask-or blend combine.
+
+define <2 x double> @test22(<2 x double> %a0, <2 x double> %a1) {
+; CHECK-LABEL: test22:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    blendpd {{.*#+}} xmm0 = xmm1[0],xmm0[1]
+; CHECK-NEXT:    retq
+  %bc1 = bitcast <2 x double> %a0 to <2 x i64>
+  %bc2 = bitcast <2 x double> %a1 to <2 x i64>
+  %and1 = and <2 x i64> %bc1, <i64 0, i64 -1>
+  %and2 = and <2 x i64> %bc2, <i64 -1, i64 0>
+  %or = or <2 x i64> %and1, %and2
+  %bc3 = bitcast <2 x i64> %or to <2 x double>
+  ret <2 x double> %bc3
+}
+
+
+define <4 x float> @test23(<4 x float> %a0, <4 x float> %a1) {
+; CHECK-LABEL: test23:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    blendps {{.*#+}} xmm0 = xmm1[0],xmm0[1,2],xmm1[3]
+; CHECK-NEXT:    retq
+  %bc1 = bitcast <4 x float> %a0 to <4 x i32>
+  %bc2 = bitcast <4 x float> %a1 to <4 x i32>
+  %and1 = and <4 x i32> %bc1, <i32 0, i32 -1, i32 -1, i32 0>
+  %and2 = and <4 x i32> %bc2, <i32 -1, i32 0, i32 0, i32 -1>
+  %or = or <4 x i32> %and1, %and2
+  %bc3 = bitcast <4 x i32> %or to <4 x float>
+  ret <4 x float> %bc3
+}
+
+
+define <4 x float> @test24(<4 x float> %a0, <4 x float> %a1) {
+; CHECK-LABEL: test24:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    blendpd {{.*#+}} xmm0 = xmm1[0],xmm0[1]
+; CHECK-NEXT:    retq
+  %bc1 = bitcast <4 x float> %a0 to <2 x i64>
+  %bc2 = bitcast <4 x float> %a1 to <2 x i64>
+  %and1 = and <2 x i64> %bc1, <i64 0, i64 -1>
+  %and2 = and <2 x i64> %bc2, <i64 -1, i64 0>
+  %or = or <2 x i64> %and1, %and2
+  %bc3 = bitcast <2 x i64> %or to <4 x float>
+  ret <4 x float> %bc3
+}
+
+
+define <4 x float> @test25(<4 x float> %a0) {
+; CHECK-LABEL: test25:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    blendps {{.*#+}} xmm0 = mem[0],xmm0[1,2],mem[3]
+; CHECK-NEXT:    retq
+  %bc1 = bitcast <4 x float> %a0 to <4 x i32>
+  %bc2 = bitcast <4 x float> <float 1.0, float 1.0, float 1.0, float 1.0> to <4 x i32>
+  %and1 = and <4 x i32> %bc1, <i32 0, i32 -1, i32 -1, i32 0>
+  %and2 = and <4 x i32> %bc2, <i32 -1, i32 0, i32 0, i32 -1>
+  %or = or <4 x i32> %and1, %and2
+  %bc3 = bitcast <4 x i32> %or to <4 x float>
+  ret <4 x float> %bc3
+}
+
+
 ; Verify that the DAGCombiner doesn't crash in the attempt to check if a shuffle
 ; with illegal type has a legal mask. Method 'isShuffleMaskLegal' only knows how to
 ; handle legal vector value types.