[X86] Add PR35202 test case for commuted cmp merging

Test coverage for Issue #34550

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

+; 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
+
+;
+; PR35202
+;
+
+declare void @on_less()
+declare void @on_equal()
+declare void @on_greater()
+
+define void @eq_first(i32 %0, i32 %1) {
+; X86-LABEL: eq_first:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    cmpl %eax, {{[0-9]+}}(%esp)
+; X86-NEXT:    jge .LBB0_1
+; X86-NEXT:  # %bb.3:
+; X86-NEXT:    jmp on_less@PLT # TAILCALL
+; X86-NEXT:  .LBB0_1:
+; X86-NEXT:    jne .LBB0_2
+; X86-NEXT:  # %bb.4:
+; X86-NEXT:    jmp on_equal@PLT # TAILCALL
+; X86-NEXT:  .LBB0_2:
+; X86-NEXT:    jmp on_greater@PLT # TAILCALL
+;
+; X64-LABEL: eq_first:
+; X64:       # %bb.0:
+; X64-NEXT:    cmpl %esi, %edi
+; X64-NEXT:    jge .LBB0_1
+; X64-NEXT:  # %bb.3:
+; X64-NEXT:    jmp on_less@PLT # TAILCALL
+; X64-NEXT:  .LBB0_1:
+; X64-NEXT:    jne .LBB0_2
+; X64-NEXT:  # %bb.4:
+; X64-NEXT:    jmp on_equal@PLT # TAILCALL
+; X64-NEXT:  .LBB0_2:
+; X64-NEXT:    jmp on_greater@PLT # TAILCALL
+  %3 = icmp slt i32 %0, %1
+  br i1 %3, label %4, label %5
+4:
+  tail call void @on_less()
+  br label %9
+5:
+  %6 = icmp eq i32 %0, %1
+  br i1 %6, label %7, label %8
+7:
+  tail call void @on_equal()
+  br label %9
+8:
+  tail call void @on_greater()
+  br label %9
+9:
+  ret void
+}
+
+define void @gt_first(i32 %0, i32 %1) {
+; X86-LABEL: gt_first:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    cmpl %eax, %ecx
+; X86-NEXT:    jge .LBB1_1
+; X86-NEXT:  # %bb.3:
+; X86-NEXT:    jmp on_less@PLT # TAILCALL
+; X86-NEXT:  .LBB1_1:
+; X86-NEXT:    jle .LBB1_2
+; X86-NEXT:  # %bb.4:
+; X86-NEXT:    jmp on_greater@PLT # TAILCALL
+; X86-NEXT:  .LBB1_2:
+; X86-NEXT:    jmp on_equal@PLT # TAILCALL
+;
+; X64-LABEL: gt_first:
+; X64:       # %bb.0:
+; X64-NEXT:    cmpl %esi, %edi
+; X64-NEXT:    jge .LBB1_1
+; X64-NEXT:  # %bb.3:
+; X64-NEXT:    jmp on_less@PLT # TAILCALL
+; X64-NEXT:  .LBB1_1:
+; X64-NEXT:    jle .LBB1_2
+; X64-NEXT:  # %bb.4:
+; X64-NEXT:    jmp on_greater@PLT # TAILCALL
+; X64-NEXT:  .LBB1_2:
+; X64-NEXT:    jmp on_equal@PLT # TAILCALL
+  %3 = icmp slt i32 %0, %1
+  br i1 %3, label %4, label %5
+4:
+  tail call void @on_less()
+  br label %9
+5:
+  %6 = icmp slt i32 %1, %0
+  br i1 %6, label %7, label %8
+7:
+  tail call void @on_greater()
+  br label %9
+8:
+  tail call void @on_equal()
+  br label %9
+9:
+  ret void
+}