Index: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp =================================================================== --- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -3750,6 +3750,12 @@ // Trivial extraction. if (VT.getSimpleVT() == N1.getSimpleValueType()) return N1; + + // EXTRACT_SUBVECTOR of INSERT_SUBVECTOR is often created + // during shuffle legalization. + if (N1.getOpcode() == ISD::INSERT_SUBVECTOR && N2 == N1.getOperand(2) && + VT == N1.getOperand(1).getValueType()) + return N1.getOperand(1); } break; } Index: llvm/trunk/test/CodeGen/X86/vector-shuffle-256-v16.ll =================================================================== --- llvm/trunk/test/CodeGen/X86/vector-shuffle-256-v16.ll +++ llvm/trunk/test/CodeGen/X86/vector-shuffle-256-v16.ll @@ -3500,8 +3500,7 @@ ; AVX1-LABEL: insert_dup_mem_v16i16_i32: ; AVX1: # BB#0: ; AVX1-NEXT: vmovd {{.*#+}} xmm0 = mem[0],zero,zero,zero -; AVX1-NEXT: vpshuflw {{.*#+}} xmm0 = xmm0[0,0,0,0,4,5,6,7] -; AVX1-NEXT: vpshufd {{.*#+}} xmm0 = xmm0[0,0,1,1] +; AVX1-NEXT: vpshufb {{.*#+}} xmm0 = xmm0[0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1] ; AVX1-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0 ; AVX1-NEXT: retq ; @@ -3521,8 +3520,7 @@ ; AVX1: # BB#0: ; AVX1-NEXT: movswl (%rdi), %eax ; AVX1-NEXT: vmovd %eax, %xmm0 -; AVX1-NEXT: vpshuflw {{.*#+}} xmm0 = xmm0[0,0,0,0,4,5,6,7] -; AVX1-NEXT: vpshufd {{.*#+}} xmm0 = xmm0[0,0,1,1] +; AVX1-NEXT: vpshufb {{.*#+}} xmm0 = xmm0[0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1] ; AVX1-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0 ; AVX1-NEXT: retq ; @@ -3544,8 +3542,7 @@ ; AVX1-LABEL: insert_dup_elt1_mem_v16i16_i32: ; AVX1: # BB#0: ; AVX1-NEXT: vmovd {{.*#+}} xmm0 = mem[0],zero,zero,zero -; AVX1-NEXT: vpshuflw {{.*#+}} xmm0 = xmm0[1,1,1,1,4,5,6,7] -; AVX1-NEXT: vpshufd {{.*#+}} xmm0 = xmm0[0,0,1,1] +; AVX1-NEXT: vpshufb {{.*#+}} xmm0 = xmm0[2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,3] ; AVX1-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0 ; AVX1-NEXT: retq ; @@ -3564,9 +3561,7 @@ ; AVX1-LABEL: insert_dup_elt3_mem_v16i16_i32: ; AVX1: # BB#0: ; AVX1-NEXT: vmovd {{.*#+}} xmm0 = mem[0],zero,zero,zero -; AVX1-NEXT: vpshufd {{.*#+}} xmm0 = xmm0[1,0,1,1] -; AVX1-NEXT: vpshuflw {{.*#+}} xmm0 = xmm0[3,3,3,3,4,5,6,7] -; AVX1-NEXT: vpshufd {{.*#+}} xmm0 = xmm0[0,0,1,1] +; AVX1-NEXT: vpshufb {{.*#+}} xmm0 = xmm0[2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,3] ; AVX1-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0 ; AVX1-NEXT: retq ;