NewGVN: Fix PR 33185 by checking whether we need to recursively

generate a phi of ops, which we don't currently support.

llvm-svn: 304272

1 files changed, 59 insertions, 0 deletions

diff --git a/llvm/test/Transforms/NewGVN/pr33185.ll b/llvm/test/Transforms/NewGVN/pr33185.ll
new file mode 100644
index 00000000000..c687d8fe51e
--- /dev/null
+++ b/llvm/test/Transforms/NewGVN/pr33185.ll
@@ -0,0 +1,59 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -newgvn -S %s | FileCheck %s
+
+@a = local_unnamed_addr global i32 9, align 4
+@.str4 = private unnamed_addr constant [6 x i8] c"D:%d\0A\00", align 1
+
+define i32 @main() local_unnamed_addr {
+; CHECK-LABEL: @main(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP:%.*]] = load i32, i32* @a, align 4
+; CHECK-NEXT:    [[CMP1_I:%.*]] = icmp ne i32 [[TMP]], 0
+; CHECK-NEXT:    br label [[FOR_BODY_I:%.*]]
+; CHECK:       for.body.i:
+; CHECK-NEXT:    [[TMP1:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ false, [[COND_END_I:%.*]] ]
+; CHECK-NEXT:    [[F_08_I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[COND_END_I]] ]
+; CHECK-NEXT:    [[MUL_I:%.*]] = select i1 [[CMP1_I]], i32 [[F_08_I]], i32 0
+; CHECK-NEXT:    br i1 [[TMP1]], label [[COND_END_I]], label [[COND_TRUE_I:%.*]]
+; CHECK:       cond.true.i:
+; CHECK-NEXT:    [[DIV_I:%.*]] = udiv i32 [[MUL_I]], [[F_08_I]]
+; CHECK-NEXT:    br label [[COND_END_I]]
+; CHECK:       cond.end.i:
+; CHECK-NEXT:    [[COND_I:%.*]] = phi i32 [ [[DIV_I]], [[COND_TRUE_I]] ], [ 0, [[FOR_BODY_I]] ]
+; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[F_08_I]], 1
+; CHECK-NEXT:    [[EXITCOND_I:%.*]] = icmp eq i32 [[INC_I]], 4
+; CHECK-NEXT:    br i1 [[EXITCOND_I]], label [[FN1_EXIT:%.*]], label [[FOR_BODY_I]]
+; CHECK:       fn1.exit:
+; CHECK-NEXT:    [[CALL4:%.*]] = tail call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str4, i64 0, i64 0), i32 [[COND_I]])
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  %tmp = load i32, i32* @a, align 4
+  %cmp1.i = icmp ne i32 %tmp, 0
+  br label %for.body.i
+
+for.body.i:
+  %tmp1 = phi i1 [ true, %entry ], [ false, %cond.end.i ]
+  %f.08.i = phi i32 [ 0, %entry ], [ %inc.i, %cond.end.i ]
+  %mul.i = select i1 %cmp1.i, i32 %f.08.i, i32 0
+  br i1 %tmp1, label %cond.end.i, label %cond.true.i
+
+cond.true.i:
+  ;; Ensure we don't replace this divide with a phi of ops that merges the wrong loop iteration value
+  %div.i = udiv i32 %mul.i, %f.08.i
+  br label %cond.end.i
+
+cond.end.i:
+  %cond.i = phi i32 [ %div.i, %cond.true.i ], [ 0, %for.body.i ]
+  %inc.i = add nuw nsw i32 %f.08.i, 1
+  %exitcond.i = icmp eq i32 %inc.i, 4
+  br i1 %exitcond.i, label %fn1.exit, label %for.body.i
+
+fn1.exit:
+  %cond.i.lcssa = phi i32 [ %cond.i, %cond.end.i ]
+  %call4= tail call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str4, i64 0, i64 0), i32 %cond.i.lcssa)
+  ret i32 0
+}
+
+declare i32 @printf(i8* nocapture readonly, ...)
+