Subzero: Legalize FP constants directly into memory operands.

tests_lit/llvm2ice_tests/undef.ll

 ; This test checks that undef values are represented as zero.
 
 ; RUN: %p2i -i %s --filetype=obj --disassemble --args -O2 \
 ; RUN:   | FileCheck %s
 ; RUN: %p2i -i %s --filetype=obj --disassemble --args -Om1 \
 ; RUN:   | FileCheck %s
 ; RUN: %p2i -i %s --filetype=obj --disassemble --args -O2 -mattr=sse4.1 \
 ; RUN:   | FileCheck %s
 ; RUN: %p2i -i %s --filetype=obj --disassemble --args -Om1 -mattr=sse4.1 \
 ; RUN:   | FileCheck %s
@@ skipping 164 matching lines @@
   ret <4 x float> %val
 ; CHECK-LABEL: vector_insertelement_arg1
 ; CHECK: pxor
 }
 
 define <4 x float> @vector_insertelement_arg2(<4 x float> %arg) {
 entry:
   %val = insertelement <4 x float> %arg, float undef, i32 0
   ret <4 x float> %val
 ; CHECK-LABEL: vector_insertelement_arg2
-; CHECK: movss {{.*}},DWORD PTR {{.*}} .L$float$0
+; CHECK: {{movss|insertps}} {{.*}},DWORD PTR {{.*}} .L$float$0
 }
 
 define float @vector_extractelement_v4f32_index_0() {
 entry:
   %val = extractelement <4 x float> undef, i32 0
   ret float %val
 ; CHECK-LABEL: vector_extractelement_v4f32_index_0
 ; CHECK: pxor
 }
 
@@ skipping 78 matching lines @@
 ; CHECK: pxor
 }
 
 define <4 x float> @vector_select_v4f32_arg2(<4 x i1> %cond, <4 x float> %a) {
 entry:
   %val = select <4 x i1> %cond, <4 x float> %a, <4 x float> undef
   ret <4 x float> %val
 ; CHECK-LABEL: vector_select_v4f32_arg2
 ; CHECK: pxor
 }