Subzero: Don't use key SSE instructions on potentially unaligned loads.

tests_lit/llvm2ice_tests/vector-align.ll

+; This test checks that when SSE instructions access memory and require full
+; alignment, memory operands are limited to properly aligned stack operands.
+; This would only happen when we fuse a load instruction with another
+; instruction, which currently only happens with non-scalarized Arithmetic
+; instructions.
+
+; RUN: %p2i -i %s --filetype=obj --disassemble --args -O2  | FileCheck %s
+; RUN: %p2i -i %s --filetype=obj --disassemble --args -Om1 | FileCheck %s
+
+define <4 x i32> @test_add(i32 %addr_i, <4 x i32> %addend) {
+entry:
+  %addr = inttoptr i32 %addr_i to <4 x i32>*
+  %loaded = load <4 x i32>* %addr, align 4
+  %result = add <4 x i32> %addend, %loaded
+  ret <4 x i32> %result
+}
+; CHECK-LABEL: test_add
+; CHECK-NOT: paddd xmm{{.}},XMMWORD PTR [e{{ax|cx|dx|di|si|bx|bp}}
+; CHECK: paddd xmm{{.}},
+
+define <4 x i32> @test_and(i32 %addr_i, <4 x i32> %addend) {
+entry:
+  %addr = inttoptr i32 %addr_i to <4 x i32>*
+  %loaded = load <4 x i32>* %addr, align 4
+  %result = and <4 x i32> %addend, %loaded
+  ret <4 x i32> %result
+}
+; CHECK-LABEL: test_and
+; CHECK-NOT: pand xmm{{.}},XMMWORD PTR [e{{ax|cx|dx|di|si|bx|bp}}
+; CHECK: pand xmm{{.}},
+
+define <4 x i32> @test_or(i32 %addr_i, <4 x i32> %addend) {
+entry:
+  %addr = inttoptr i32 %addr_i to <4 x i32>*
+  %loaded = load <4 x i32>* %addr, align 4
+  %result = or <4 x i32> %addend, %loaded
+  ret <4 x i32> %result
+}
+; CHECK-LABEL: test_or
+; CHECK-NOT: por xmm{{.}},XMMWORD PTR [e{{ax|cx|dx|di|si|bx|bp}}
+; CHECK: por xmm{{.}},
+
+define <4 x i32> @test_xor(i32 %addr_i, <4 x i32> %addend) {
+entry:
+  %addr = inttoptr i32 %addr_i to <4 x i32>*
+  %loaded = load <4 x i32>* %addr, align 4
+  %result = xor <4 x i32> %addend, %loaded
+  ret <4 x i32> %result
+}
+; CHECK-LABEL: test_xor
+; CHECK-NOT: pxor xmm{{.}},XMMWORD PTR [e{{ax|cx|dx|di|si|bx|bp}}
+; CHECK: pxor xmm{{.}},
+
+define <4 x i32> @test_sub(i32 %addr_i, <4 x i32> %addend) {
+entry:
+  %addr = inttoptr i32 %addr_i to <4 x i32>*
+  %loaded = load <4 x i32>* %addr, align 4
+  %result = sub <4 x i32> %addend, %loaded
+  ret <4 x i32> %result
+}
+; CHECK-LABEL: test_sub
+; CHECK-NOT: psubd xmm{{.}},XMMWORD PTR [e{{ax|cx|dx|di|si|bx|bp}}
+; CHECK: psubd xmm{{.}},
+
+define <4 x float> @test_fadd(i32 %addr_i, <4 x float> %addend) {
+entry:
+  %addr = inttoptr i32 %addr_i to <4 x float>*
+  %loaded = load <4 x float>* %addr, align 4
+  %result = fadd <4 x float> %addend, %loaded
+  ret <4 x float> %result
+}
+; CHECK-LABEL: test_fadd
+; CHECK-NOT: addps xmm{{.}},XMMWORD PTR [e{{ax|cx|dx|di|si|bx|bp}}
+; CHECK: addps xmm{{.}},
+
+define <4 x float> @test_fsub(i32 %addr_i, <4 x float> %addend) {
+entry:
+  %addr = inttoptr i32 %addr_i to <4 x float>*
+  %loaded = load <4 x float>* %addr, align 4
+  %result = fsub <4 x float> %addend, %loaded
+  ret <4 x float> %result
+}
+; CHECK-LABEL: test_fsub
+; CHECK-NOT: subps xmm{{.}},XMMWORD PTR [e{{ax|cx|dx|di|si|bx|bp}}
+; CHECK: subps xmm{{.}},