From e08c32249fca32cd7b122024a4ca252fcb235694 Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Fri, 13 Jul 2012 23:33:10 +0000
Subject: LSR Fix: check SCEV expression safety before expansion.

All SCEV expressions used by LSR formulae must be safe to
expand. i.e. they may not contain UDiv unless we can prove nonzero
denominator.

Fixes PR11356: LSR hoists UDiv.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160205 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../LoopStrengthReduce/2012-07-13-ExpandUDiv.ll    | 90 ++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 test/Transforms/LoopStrengthReduce/2012-07-13-ExpandUDiv.ll

(limited to 'test/Transforms/LoopStrengthReduce')

diff --git a/test/Transforms/LoopStrengthReduce/2012-07-13-ExpandUDiv.ll b/test/Transforms/LoopStrengthReduce/2012-07-13-ExpandUDiv.ll
new file mode 100644
index 0000000000..a1222083ab
--- /dev/null
+++ b/test/Transforms/LoopStrengthReduce/2012-07-13-ExpandUDiv.ll
@@ -0,0 +1,90 @@
+; RUN: opt -loop-reduce -S < %s | FileCheck %s
+;
+; PR11356: likely wrong code bug
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-darwin"
+
+@g_66 = global [1 x i32] zeroinitializer, align 4
+@g_775 = global i32 0, align 4
+@g_752 = global i32 0, align 4
+@g_3 = global i32 0, align 4
+
+; Ensure that %div.i.i.us is not hoisted.
+; CHECK: @main
+; CHECK: for.body.i.i.us:
+; CHECK: %div.i.i.i.us
+; CHECK: %cmp5.i.i.us
+define i32 @main() nounwind uwtable ssp {
+entry:
+  %l_2 = alloca [1 x i32], align 4
+  %arrayidx = getelementptr inbounds [1 x i32]* %l_2, i64 0, i64 0
+  store i32 0, i32* %arrayidx, align 4, !tbaa !0
+  %tmp = load i32* @g_3, align 4, !tbaa !0
+  %idxprom = sext i32 %tmp to i64
+  %arrayidx1 = getelementptr inbounds [1 x i32]* %l_2, i64 0, i64 %idxprom
+  %tmp1 = load i32* %arrayidx1, align 4, !tbaa !0
+  %conv.i.i = and i32 %tmp1, 65535
+  %tobool.i.i.i = icmp ne i32 %tmp, 0
+  br label %codeRepl
+
+codeRepl.loopexit.us-lcssa:                       ; preds = %for.body.i.i, %codeRepl5
+  br label %codeRepl.loopexit
+
+codeRepl.loopexit:                                ; preds = %codeRepl.loopexit.us-lcssa.us, %codeRepl.loopexit.us-lcssa
+  br label %codeRepl
+
+codeRepl:                                         ; preds = %codeRepl.loopexit, %entry
+  br i1 %tobool.i.i.i, label %codeRepl.split.us, label %codeRepl.codeRepl.split_crit_edge
+
+codeRepl.codeRepl.split_crit_edge:                ; preds = %codeRepl
+  br label %codeRepl.split
+
+codeRepl.split.us:                                ; preds = %codeRepl
+  br label %for.cond.i.i.us
+
+for.cond.i.i.us:                                  ; preds = %for.inc.i.i.us, %codeRepl.split.us
+  %tmp2 = phi i32 [ 0, %codeRepl.split.us ], [ %add.i.i.us, %for.inc.i.i.us ]
+  br label %codeRepl5.us
+
+for.inc.i.i.us:                                   ; preds = %for.body.i.i.us
+  %add.i.i.us = add nsw i32 %tmp2, 1
+  store i32 %add.i.i.us, i32* @g_752, align 4, !tbaa !0
+  br label %for.cond.i.i.us
+
+for.body.i.i.us:                                  ; preds = %codeRepl5.us
+  %div.i.i.i.us = udiv i32 1, %conv.i.i
+  %cmp5.i.i.us = icmp eq i32 %div.i.i.i.us, %tmp2
+  br i1 %cmp5.i.i.us, label %codeRepl.loopexit.us-lcssa.us, label %for.inc.i.i.us
+
+codeRepl5.us:                                     ; preds = %for.cond.i.i.us
+  br i1 true, label %codeRepl.loopexit.us-lcssa.us, label %for.body.i.i.us
+
+codeRepl.loopexit.us-lcssa.us:                    ; preds = %codeRepl5.us, %for.body.i.i.us
+  br label %codeRepl.loopexit
+
+codeRepl.split:                                   ; preds = %codeRepl.codeRepl.split_crit_edge
+  br label %for.cond.i.i
+
+for.cond.i.i:                                     ; preds = %for.inc.i.i, %codeRepl.split
+  %tmp3 = phi i32 [ 0, %codeRepl.split ], [ %add.i.i, %for.inc.i.i ]
+  br label %codeRepl5
+
+codeRepl5:                                        ; preds = %for.cond.i.i
+  br i1 true, label %codeRepl.loopexit.us-lcssa, label %for.body.i.i
+
+for.body.i.i:                                     ; preds = %codeRepl5
+  %cmp5.i.i = icmp eq i32 0, %tmp3
+  br i1 %cmp5.i.i, label %codeRepl.loopexit.us-lcssa, label %for.inc.i.i
+
+for.inc.i.i:                                      ; preds = %for.body.i.i
+  %add.i.i = add nsw i32 %tmp3, 1
+  store i32 %add.i.i, i32* @g_752, align 4, !tbaa !0
+  br label %for.cond.i.i
+
+func_4.exit:                                      ; No predecessors!
+  ret i32 0
+}
+
+!0 = metadata !{metadata !"int", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA", null}
-- 
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