[X86] Add basic xor+cmp test coverage for #6146

Author: RKSimon

llvm/test/CodeGen/X86/cmp-xor.ll

@@ -0,0 +1,64 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=i686--| FileCheck %s --check-prefixes=X86
+; RUN: llc < %s -mtriple=x86_64--| FileCheck %s --check-prefixes=X64
+
+;
+; PR6146
+;
+
+define i32 @cmp_xor_i32(i32 %a, i32 %b, i32 %c)
+; X86-LABEL: cmp_xor_i32:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    cmpl %ecx, %eax
+; X86-NEXT:    je .LBB0_1
+; X86-NEXT:  # %bb.2:
+; X86-NEXT:    xorl %ecx, %eax
+; X86-NEXT:    retl
+; X86-NEXT:  .LBB0_1:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: cmp_xor_i32:
+; X64:       # %bb.0:
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    xorl %esi, %eax
+; X64-NEXT:    cmpl %esi, %edi
+; X64-NEXT:    cmovel %edx, %eax
+; X64-NEXT:    retq
+{
+  %xor = xor i32 %a, %b
+  %cmp = icmp eq i32 %a, %b
+  %sel = select i1 %cmp, i32 %c, i32 %xor
+  ret i32 %sel
+}
+
+define i32 @cmp_xor_i32_commute(i32 %a, i32 %b, i32 %c)
+; X86-LABEL: cmp_xor_i32_commute:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    cmpl %eax, %ecx
+; X86-NEXT:    je .LBB1_1
+; X86-NEXT:  # %bb.2:
+; X86-NEXT:    xorl %ecx, %eax
+; X86-NEXT:    retl
+; X86-NEXT:  .LBB1_1:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: cmp_xor_i32_commute:
+; X64:       # %bb.0:
+; X64-NEXT:    movl %esi, %eax
+; X64-NEXT:    xorl %edi, %eax
+; X64-NEXT:    cmpl %esi, %edi
+; X64-NEXT:    cmovel %edx, %eax
+; X64-NEXT:    retq
+{
+  %xor = xor i32 %b, %a
+  %cmp = icmp eq i32 %a, %b
+  %sel = select i1 %cmp, i32 %c, i32 %xor
+  ret i32 %sel
+}
+