--- a/test/CodeGen/X86/sse1.ll	Fri Nov 25 19:14:25 2016 +0900
+++ b/test/CodeGen/X86/sse1.ll	Fri Oct 27 17:07:41 2017 +0900
@@ -60,7 +60,16 @@
 ; X32-NEXT:    xorps %xmm1, %xmm1
 ; X32-NEXT:    cmpl $0, {{[0-9]+}}(%esp)
 ; X32-NEXT:    jne .LBB1_5
-; X32-NEXT:    jmp .LBB1_4
+; X32-NEXT:  .LBB1_4:
+; X32-NEXT:    movss {{.*#+}} xmm2 = mem[0],zero,zero,zero
+; X32-NEXT:    cmpl $0, {{[0-9]+}}(%esp)
+; X32-NEXT:    jne .LBB1_8
+; X32-NEXT:  .LBB1_7:
+; X32-NEXT:    movss {{.*#+}} xmm3 = mem[0],zero,zero,zero
+; X32-NEXT:    cmpl $0, {{[0-9]+}}(%esp)
+; X32-NEXT:    unpcklps {{.*#+}} xmm2 = xmm2[0],xmm3[0],xmm2[1],xmm3[1]
+; X32-NEXT:    je .LBB1_10
+; X32-NEXT:    jmp .LBB1_11
 ; X32-NEXT:  .LBB1_1:
 ; X32-NEXT:    movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
 ; X32-NEXT:    cmpl $0, {{[0-9]+}}(%esp)
@@ -68,65 +77,56 @@
 ; X32-NEXT:  .LBB1_5: # %entry
 ; X32-NEXT:    xorps %xmm2, %xmm2
 ; X32-NEXT:    cmpl $0, {{[0-9]+}}(%esp)
-; X32-NEXT:    jne .LBB1_8
-; X32-NEXT:    jmp .LBB1_7
-; X32-NEXT:  .LBB1_4:
-; X32-NEXT:    movss {{.*#+}} xmm2 = mem[0],zero,zero,zero
-; X32-NEXT:    cmpl $0, {{[0-9]+}}(%esp)
 ; X32-NEXT:    je .LBB1_7
 ; X32-NEXT:  .LBB1_8: # %entry
 ; X32-NEXT:    xorps %xmm3, %xmm3
-; X32-NEXT:    jmp .LBB1_9
-; X32-NEXT:  .LBB1_7:
-; X32-NEXT:    movss {{.*#+}} xmm3 = mem[0],zero,zero,zero
-; X32-NEXT:  .LBB1_9: # %entry
 ; X32-NEXT:    cmpl $0, {{[0-9]+}}(%esp)
 ; X32-NEXT:    unpcklps {{.*#+}} xmm2 = xmm2[0],xmm3[0],xmm2[1],xmm3[1]
 ; X32-NEXT:    jne .LBB1_11
-; X32-NEXT:  # BB#10:
+; X32-NEXT:  .LBB1_10:
 ; X32-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
 ; X32-NEXT:  .LBB1_11: # %entry
 ; X32-NEXT:    unpcklps {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
-; X32-NEXT:    unpcklps {{.*#+}} xmm0 = xmm0[0],xmm2[0],xmm0[1],xmm2[1]
+; X32-NEXT:    movlhps {{.*#+}} xmm0 = xmm0[0],xmm2[0]
 ; X32-NEXT:    retl
 ;
 ; X64-LABEL: vselect:
 ; X64:       # BB#0: # %entry
-; X64-NEXT:    testl %ecx, %ecx
+; X64-NEXT:    testl %edx, %edx
 ; X64-NEXT:    xorps %xmm0, %xmm0
 ; X64-NEXT:    je .LBB1_1
 ; X64-NEXT:  # BB#2: # %entry
 ; X64-NEXT:    xorps %xmm1, %xmm1
-; X64-NEXT:    testl %edx, %edx
+; X64-NEXT:    testl %ecx, %ecx
 ; X64-NEXT:    jne .LBB1_5
-; X64-NEXT:    jmp .LBB1_4
+; X64-NEXT:  .LBB1_4:
+; X64-NEXT:    movss {{.*#+}} xmm2 = mem[0],zero,zero,zero
+; X64-NEXT:    testl %r8d, %r8d
+; X64-NEXT:    jne .LBB1_8
+; X64-NEXT:  .LBB1_7:
+; X64-NEXT:    movss {{.*#+}} xmm3 = mem[0],zero,zero,zero
+; X64-NEXT:    testl %esi, %esi
+; X64-NEXT:    unpcklps {{.*#+}} xmm2 = xmm2[0],xmm3[0],xmm2[1],xmm3[1]
+; X64-NEXT:    je .LBB1_10
+; X64-NEXT:    jmp .LBB1_11
 ; X64-NEXT:  .LBB1_1:
 ; X64-NEXT:    movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
-; X64-NEXT:    testl %edx, %edx
+; X64-NEXT:    testl %ecx, %ecx
 ; X64-NEXT:    je .LBB1_4
 ; X64-NEXT:  .LBB1_5: # %entry
 ; X64-NEXT:    xorps %xmm2, %xmm2
 ; X64-NEXT:    testl %r8d, %r8d
-; X64-NEXT:    jne .LBB1_8
-; X64-NEXT:    jmp .LBB1_7
-; X64-NEXT:  .LBB1_4:
-; X64-NEXT:    movss {{.*#+}} xmm2 = mem[0],zero,zero,zero
-; X64-NEXT:    testl %r8d, %r8d
 ; X64-NEXT:    je .LBB1_7
 ; X64-NEXT:  .LBB1_8: # %entry
 ; X64-NEXT:    xorps %xmm3, %xmm3
-; X64-NEXT:    jmp .LBB1_9
-; X64-NEXT:  .LBB1_7:
-; X64-NEXT:    movss {{.*#+}} xmm3 = mem[0],zero,zero,zero
-; X64-NEXT:  .LBB1_9: # %entry
 ; X64-NEXT:    testl %esi, %esi
 ; X64-NEXT:    unpcklps {{.*#+}} xmm2 = xmm2[0],xmm3[0],xmm2[1],xmm3[1]
 ; X64-NEXT:    jne .LBB1_11
-; X64-NEXT:  # BB#10:
+; X64-NEXT:  .LBB1_10:
 ; X64-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
 ; X64-NEXT:  .LBB1_11: # %entry
 ; X64-NEXT:    unpcklps {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
-; X64-NEXT:    unpcklps {{.*#+}} xmm0 = xmm0[0],xmm2[0],xmm0[1],xmm2[1]
+; X64-NEXT:    movlhps {{.*#+}} xmm0 = xmm0[0],xmm2[0]
 ; X64-NEXT:    retq
 entry:
   %a1 = icmp eq <4 x i32> %q, zeroinitializer
@@ -215,3 +215,136 @@
   ret <4 x i32> %zext
 }
 
+; Fragile test warning - we need to induce the generation of a vselect
+; post-legalization to cause the crash seen in:
+; https://llvm.org/bugs/show_bug.cgi?id=31672
+; Is there a way to do that without an unsafe/fast sqrt intrinsic call?
+; Also, although the goal for adding this test is to prove that we
+; don't crash, I have no idea what this code is doing, so I'm keeping
+; the full codegen checks in case there's motivation to improve this.
+
+define <2 x float> @PR31672() #0 {
+; X32-LABEL: PR31672:
+; X32:       # BB#0:
+; X32-NEXT:    pushl %ebp
+; X32-NEXT:    movl %esp, %ebp
+; X32-NEXT:    andl $-16, %esp
+; X32-NEXT:    subl $80, %esp
+; X32-NEXT:    xorps %xmm0, %xmm0
+; X32-NEXT:    movaps {{.*#+}} xmm1 = <42,3,u,u>
+; X32-NEXT:    movaps %xmm1, %xmm2
+; X32-NEXT:    cmpeqps %xmm0, %xmm2
+; X32-NEXT:    movaps %xmm2, {{[0-9]+}}(%esp)
+; X32-NEXT:    movaps %xmm0, {{[0-9]+}}(%esp)
+; X32-NEXT:    rsqrtps %xmm1, %xmm0
+; X32-NEXT:    mulps %xmm0, %xmm1
+; X32-NEXT:    mulps %xmm0, %xmm1
+; X32-NEXT:    addps {{\.LCPI.*}}, %xmm1
+; X32-NEXT:    mulps {{\.LCPI.*}}, %xmm0
+; X32-NEXT:    mulps %xmm1, %xmm0
+; X32-NEXT:    movaps %xmm0, {{[0-9]+}}(%esp)
+; X32-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X32-NEXT:    andl %eax, %ecx
+; X32-NEXT:    notl %eax
+; X32-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; X32-NEXT:    orl %ecx, %eax
+; X32-NEXT:    movl %eax, (%esp)
+; X32-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X32-NEXT:    andl %eax, %ecx
+; X32-NEXT:    notl %eax
+; X32-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; X32-NEXT:    orl %ecx, %eax
+; X32-NEXT:    movl %eax, {{[0-9]+}}(%esp)
+; X32-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X32-NEXT:    movl {{[0-9]+}}(%esp), %edx
+; X32-NEXT:    andl %ecx, %edx
+; X32-NEXT:    notl %ecx
+; X32-NEXT:    andl {{[0-9]+}}(%esp), %ecx
+; X32-NEXT:    orl %edx, %ecx
+; X32-NEXT:    movl %ecx, {{[0-9]+}}(%esp)
+; X32-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X32-NEXT:    andl %eax, %ecx
+; X32-NEXT:    notl %eax
+; X32-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; X32-NEXT:    orl %ecx, %eax
+; X32-NEXT:    movl %eax, {{[0-9]+}}(%esp)
+; X32-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; X32-NEXT:    movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
+; X32-NEXT:    unpcklps {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
+; X32-NEXT:    movss {{.*#+}} xmm2 = mem[0],zero,zero,zero
+; X32-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; X32-NEXT:    unpcklps {{.*#+}} xmm0 = xmm0[0],xmm2[0],xmm0[1],xmm2[1]
+; X32-NEXT:    movlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; X32-NEXT:    movl %ebp, %esp
+; X32-NEXT:    popl %ebp
+; X32-NEXT:    retl
+;
+; X64-LABEL: PR31672:
+; X64:       # BB#0:
+; X64-NEXT:    xorps %xmm0, %xmm0
+; X64-NEXT:    movaps %xmm0, -{{[0-9]+}}(%rsp)
+; X64-NEXT:    movaps {{.*#+}} xmm1 = <42,3,u,u>
+; X64-NEXT:    cmpeqps %xmm1, %xmm0
+; X64-NEXT:    movaps %xmm0, -{{[0-9]+}}(%rsp)
+; X64-NEXT:    rsqrtps %xmm1, %xmm0
+; X64-NEXT:    mulps %xmm0, %xmm1
+; X64-NEXT:    mulps %xmm0, %xmm1
+; X64-NEXT:    addps {{.*}}(%rip), %xmm1
+; X64-NEXT:    mulps {{.*}}(%rip), %xmm0
+; X64-NEXT:    mulps %xmm1, %xmm0
+; X64-NEXT:    movaps %xmm0, -{{[0-9]+}}(%rsp)
+; X64-NEXT:    movq -{{[0-9]+}}(%rsp), %r8
+; X64-NEXT:    movq -{{[0-9]+}}(%rsp), %rsi
+; X64-NEXT:    movq -{{[0-9]+}}(%rsp), %r9
+; X64-NEXT:    movq -{{[0-9]+}}(%rsp), %rdi
+; X64-NEXT:    movl %esi, %eax
+; X64-NEXT:    andl %edi, %eax
+; X64-NEXT:    movl %edi, %ecx
+; X64-NEXT:    notl %ecx
+; X64-NEXT:    movq -{{[0-9]+}}(%rsp), %r10
+; X64-NEXT:    movq -{{[0-9]+}}(%rsp), %rdx
+; X64-NEXT:    andl %edx, %ecx
+; X64-NEXT:    orl %eax, %ecx
+; X64-NEXT:    movl %ecx, -{{[0-9]+}}(%rsp)
+; X64-NEXT:    shrq $32, %rsi
+; X64-NEXT:    shrq $32, %rdi
+; X64-NEXT:    andl %edi, %esi
+; X64-NEXT:    notl %edi
+; X64-NEXT:    shrq $32, %rdx
+; X64-NEXT:    andl %edi, %edx
+; X64-NEXT:    orl %esi, %edx
+; X64-NEXT:    movl %edx, -{{[0-9]+}}(%rsp)
+; X64-NEXT:    movl %r8d, %eax
+; X64-NEXT:    andl %r9d, %eax
+; X64-NEXT:    movl %r9d, %ecx
+; X64-NEXT:    notl %ecx
+; X64-NEXT:    andl %r10d, %ecx
+; X64-NEXT:    orl %eax, %ecx
+; X64-NEXT:    movl %ecx, -{{[0-9]+}}(%rsp)
+; X64-NEXT:    shrq $32, %r8
+; X64-NEXT:    shrq $32, %r9
+; X64-NEXT:    andl %r9d, %r8d
+; X64-NEXT:    notl %r9d
+; X64-NEXT:    shrq $32, %r10
+; X64-NEXT:    andl %r9d, %r10d
+; X64-NEXT:    orl %r8d, %r10d
+; X64-NEXT:    movl %r10d, -{{[0-9]+}}(%rsp)
+; X64-NEXT:    movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
+; X64-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; X64-NEXT:    unpcklps {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
+; X64-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; X64-NEXT:    movss {{.*#+}} xmm2 = mem[0],zero,zero,zero
+; X64-NEXT:    unpcklps {{.*#+}} xmm0 = xmm0[0],xmm2[0],xmm0[1],xmm2[1]
+; X64-NEXT:    movlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; X64-NEXT:    retq
+  %t0 = call fast <2 x float> @llvm.sqrt.v2f32(<2 x float> <float 42.0, float 3.0>)
+  ret <2 x float> %t0
+}
+
+declare <2 x float> @llvm.sqrt.v2f32(<2 x float>) #1
+
+attributes #0 = { nounwind "unsafe-fp-math"="true" }
+