[ConstraintElimination] Add test from PR54228.

Test for https://github.com/llvm/llvm-project/issues/54228

diff --git a/llvm/test/Transforms/ConstraintElimination/pr54228-variable-name-order.ll b/llvm/test/Transforms/ConstraintElimination/pr54228-variable-name-order.ll
new file mode 100644 (file)
index 0000000..60225dd
--- /dev/null
+++ b/llvm/test/Transforms/ConstraintElimination/pr54228-variable-name-order.ll
@@ -0,0 +1,55 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=constraint-elimination -S %s | FileCheck %s
+
+
+declare void @fn()
+
+define i1 @test_pr54228(i32 %a, i32 %b, i1 %i.0, i1 %i.1) {
+; CHECK-LABEL: @test_pr54228(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br i1 [[I_0:%.*]], label [[PH_1:%.*]], label [[LOOP_HEADER:%.*]]
+; CHECK:       ph.1:
+; CHECK-NEXT:    [[C_1:%.*]] = icmp eq i32 [[A:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[C_1]])
+; CHECK-NEXT:    br label [[LOOP_HEADER]]
+; CHECK:       loop.header:
+; CHECK-NEXT:    br i1 [[I_1:%.*]], label [[LOOP_THEN:%.*]], label [[LOOP_LATCH:%.*]]
+; CHECK:       loop.then:
+; CHECK-NEXT:    call void @fn()
+; CHECK-NEXT:    [[C_2:%.*]] = icmp eq i32 [[B:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[C_2]])
+; CHECK-NEXT:    br label [[LOOP_LATCH]]
+; CHECK:       loop.latch:
+; CHECK-NEXT:    [[C_3:%.*]] = icmp eq i32 [[B]], 1
+; CHECK-NEXT:    br i1 [[C_3]], label [[EXIT:%.*]], label [[LOOP_HEADER]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[C_4:%.*]] = icmp eq i32 [[A]], 0
+; CHECK-NEXT:    ret i1 true
+;
+entry:
+  br i1 %i.0, label %ph.1, label %loop.header
+
+ph.1:                                             ; preds = %entry
+  %c.1 = icmp eq i32 %a, 0
+  call void @llvm.assume(i1 %c.1)
+  br label %loop.header
+
+loop.header:                                      ; preds = %loop.latch, %ph.1, %entry
+  br i1 %i.1, label %loop.then, label %loop.latch
+
+loop.then:                                        ; preds = %loop.header
+  call void @fn()
+  %c.2 = icmp eq i32 %b, 0
+  call void @llvm.assume(i1 %c.2)
+  br label %loop.latch
+
+loop.latch:                                       ; preds = %loop.then, %loop.header
+  %c.3 = icmp eq i32 %b, 1
+  br i1 %c.3, label %exit, label %loop.header
+
+exit:                                             ; preds = %loop.latch
+  %c.4 = icmp eq i32 %a, 0
+  ret i1 %c.4
+}
+
+declare void @llvm.assume(i1 noundef)