From 61ec2280308bd5e2161efe2959d7d26798c85cb4 Mon Sep 17 00:00:00 2001
From: Roman Lebedev <lebedev.ri@gmail.com>
Date: Fri, 15 Jan 2021 19:44:18 +0300
Subject: [PATCH] [NFC][SimplifyCFG] Add testcase showing that we fail to
 preserve DomTree in switchToSelect()

---
 ...switchToSelect-domtree-preservation-edgecase.ll | 57 ++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 llvm/test/Transforms/SimplifyCFG/switchToSelect-domtree-preservation-edgecase.ll

diff --git a/llvm/test/Transforms/SimplifyCFG/switchToSelect-domtree-preservation-edgecase.ll b/llvm/test/Transforms/SimplifyCFG/switchToSelect-domtree-preservation-edgecase.ll
new file mode 100644
index 0000000..7f3428b
--- /dev/null
+++ b/llvm/test/Transforms/SimplifyCFG/switchToSelect-domtree-preservation-edgecase.ll
@@ -0,0 +1,57 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -simplifycfg -simplifycfg-require-and-preserve-domtree=0 -sink-common-insts=1 < %s | FileCheck %s
+
+declare void @widget(i8)
+
+define void @baz(i8 %arg, i8 %arg10, i1 %arg11) {
+; CHECK-LABEL: @baz(
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    br label [[BB12:%.*]]
+; CHECK:       bb12:
+; CHECK-NEXT:    [[TMP:%.*]] = icmp eq i8 [[ARG:%.*]], 0
+; CHECK-NEXT:    br i1 [[TMP]], label [[BB17:%.*]], label [[BB13:%.*]]
+; CHECK:       bb13:
+; CHECK-NEXT:    tail call void @widget(i8 11)
+; CHECK-NEXT:    [[SWITCH_SELECTCMP:%.*]] = icmp eq i8 [[ARG10:%.*]], 73
+; CHECK-NEXT:    [[SWITCH_SELECT:%.*]] = select i1 [[SWITCH_SELECTCMP]], i8 44, i8 22
+; CHECK-NEXT:    [[SWITCH_SELECTCMP1:%.*]] = icmp eq i8 [[ARG10]], 68
+; CHECK-NEXT:    [[SWITCH_SELECT2:%.*]] = select i1 [[SWITCH_SELECTCMP1]], i8 33, i8 [[SWITCH_SELECT]]
+; CHECK-NEXT:    tail call void @widget(i8 [[SWITCH_SELECT2]])
+; CHECK-NEXT:    br label [[BB17]]
+; CHECK:       bb17:
+; CHECK-NEXT:    br i1 [[ARG11:%.*]], label [[BB12]], label [[BB18:%.*]]
+; CHECK:       bb18:
+; CHECK-NEXT:    ret void
+;
+bb:
+  br label %bb12
+
+bb12:                                             ; preds = %bb17, %bb
+  %tmp = icmp eq i8 %arg, 0
+  br i1 %tmp, label %bb17, label %bb13
+
+bb13:                                             ; preds = %bb12
+  tail call void @widget(i8 11)
+  switch i8 %arg10, label %bb14 [
+  i8 68, label %bb15
+  i8 73, label %bb16
+  ]
+
+bb14:                                             ; preds = %bb13
+  tail call void @widget(i8 22)
+  br label %bb17
+
+bb15:                                             ; preds = %bb13
+  tail call void @widget(i8 33)
+  br label %bb17
+
+bb16:                                             ; preds = %bb13
+  tail call void @widget(i8 44)
+  br label %bb17
+
+bb17:                                             ; preds = %bb16, %bb15, %bb14, %bb12
+  br i1 %arg11, label %bb12, label %bb18
+
+bb18:                                             ; preds = %bb17
+  ret void
+}
-- 
2.7.4