[X86] Prevent using X * rsqrt(X) to approximate sqrt when only sse1 is enabled.

This optimization can occur after type legalization and emit a vselect with v4i32 type. But that type is not legal with sse1. This ultimately gets scalarized by the second type legalization that runs after vector op legalization, but that's really intended to handle the scalar types that might be introduced by legalizing vector ops.

For now just stop this from happening by disabling the optimization with sse1.

llvm-svn: 318965

1 files changed, 6 insertions, 112 deletions

diff --git a/llvm/test/CodeGen/X86/sse1.ll b/llvm/test/CodeGen/X86/sse1.ll
index c74dec3e21b..d5a902fe11b 100644
--- a/llvm/test/CodeGen/X86/sse1.ll
+++ b/llvm/test/CodeGen/X86/sse1.ll
@@ -219,126 +219,20 @@ define <4 x i32> @PR30512(<4 x i32> %x, <4 x i32> %y) nounwind {
 ; 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.
+;
+; We now no longer try to lower sqrt using rsqrt with SSE1 only as the
+; v4i32 vselect mentioned above should never have been created. We ended up
+; scalarizing it anyway.
 
 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:    sqrtps {{\.LCPI.*}}, %xmm0
 ; 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:    sqrtps {{.*}}(%rip), %xmm0
 ; 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