[X86][AVX] Ensure EltsFromConsecutiveLoads tests the entire vector for consecutive loads/zeros

Fix for issue introduced D17297, where we were breaking early from the loop detecting consecutive loads which could leave us thinking a consecutive load with zeros was possible.

llvm-svn: 264922

2 files changed, 39 insertions, 1 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index f58b4dcff55..d7c3c654bca 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -5772,7 +5772,6 @@ static SDValue EltsFromConsecutiveLoads(EVT VT, ArrayRef<SDValue> Elts,
       }
     } else if (ZeroMask[i]) {
       IsConsecutiveLoad = false;
-      break;
     }
   }
 
diff --git a/llvm/test/CodeGen/X86/merge-consecutive-loads-128.ll b/llvm/test/CodeGen/X86/merge-consecutive-loads-128.ll
index 56bcfed6c91..401e6ccc5d8 100644
--- a/llvm/test/CodeGen/X86/merge-consecutive-loads-128.ll
+++ b/llvm/test/CodeGen/X86/merge-consecutive-loads-128.ll
@@ -742,3 +742,42 @@ define <4 x float> @merge_4f32_f32_2345_volatile(float* %ptr) nounwind uwtable n
   %res3 = insertelement <4 x float> %res2, float %val3, i32 3
   ret <4 x float> %res3
 }
+
+;
+; Non-consecutive test.
+;
+
+define <4 x float> @merge_4f32_f32_X0YY(float* %ptr0, float* %ptr1) nounwind uwtable noinline ssp {
+; SSE-LABEL: merge_4f32_f32_X0YY:
+; SSE:       # BB#0:
+; SSE-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; SSE-NEXT:    movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
+; SSE-NEXT:    unpcklps {{.*#+}} xmm1 = xmm1[0,0,1,1]
+; SSE-NEXT:    unpcklpd {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; SSE-NEXT:    retq
+;
+; AVX-LABEL: merge_4f32_f32_X0YY:
+; AVX:       # BB#0:
+; AVX-NEXT:    vmovss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; AVX-NEXT:    vmovss {{.*#+}} xmm1 = mem[0],zero,zero,zero
+; AVX-NEXT:    vunpcklps {{.*#+}} xmm1 = xmm1[0,0,1,1]
+; AVX-NEXT:    vunpcklpd {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; AVX-NEXT:    retq
+;
+; X32-SSE-LABEL: merge_4f32_f32_X0YY:
+; X32-SSE:       # BB#0:
+; X32-SSE-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-SSE-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X32-SSE-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; X32-SSE-NEXT:    movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
+; X32-SSE-NEXT:    unpcklps {{.*#+}} xmm1 = xmm1[0,0,1,1]
+; X32-SSE-NEXT:    unpcklpd {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; X32-SSE-NEXT:    retl
+  %val0 = load float, float* %ptr0, align 4
+  %val1 = load float, float* %ptr1, align 4
+  %res0 = insertelement <4 x float> undef, float %val0, i32 0
+  %res1 = insertelement <4 x float> %res0, float 0.000000e+00, i32 1
+  %res2 = insertelement <4 x float> %res1, float %val1, i32 2
+  %res3 = insertelement <4 x float> %res2, float %val1, i32 3
+  ret <4 x float> %res3
+}