Fix SCEVExpander::visitAddRecExpr so that it remembers the induction variable

it inserted rather than using LoopInfo::getCanonicalInductionVariable to
rediscover it, since that doesn't work on non-canonical loops. This fixes
infinite recurrsion on such loops; PR7562.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109419 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 36 insertions, 0 deletions

diff --git a/test/Transforms/IndVarSimplify/crash.ll b/test/Transforms/IndVarSimplify/crash.ll
index ab438334c6..516fd8084d 100644
--- a/test/Transforms/IndVarSimplify/crash.ll
+++ b/test/Transforms/IndVarSimplify/crash.ll
@@ -1,4 +1,5 @@
 ; RUN: opt -indvars %s -disable-output
+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"
 
 declare i32 @putchar(i8) nounwind
 
@@ -17,3 +18,38 @@ define void @t2(i1* %P) nounwind {
 ; <label>:6                                       ; preds = %1
   ret void
 }
+
+; PR7562
+define void @fannkuch() nounwind {
+entry:                                              ; preds = %entry
+  br label %bb12
+
+bb12:                                             ; preds = %bb29, %entry
+  %i.1 = phi i32 [ undef, %entry ], [ %i.0, %bb29 ] ; <i32> [#uses=2]
+  %r.1 = phi i32 [ undef, %entry ], [ %r.0, %bb29 ] ; <i32> [#uses=2]
+  br i1 undef, label %bb13, label %bb24
+
+bb13:                                             ; preds = %bb12
+  br label %bb24
+
+bb24:                                             ; preds = %bb30, %bb13, %bb12
+  %i.2 = phi i32 [ %i.1, %bb13 ], [ %i.0, %bb30 ], [ %i.1, %bb12 ] ; <i32> [#uses=1]
+  %r.0 = phi i32 [ %r.1, %bb13 ], [ %2, %bb30 ], [ %r.1, %bb12 ] ; <i32> [#uses=3]
+  br label %bb28
+
+bb27:                                             ; preds = %bb28
+  %0 = add nsw i32 %i.0, 1                        ; <i32> [#uses=1]
+  br label %bb28
+
+bb28:                                             ; preds = %bb27, %bb26
+  %i.0 = phi i32 [ %i.2, %bb24 ], [ %0, %bb27 ]   ; <i32> [#uses=4]
+  %1 = icmp slt i32 %i.0, %r.0                    ; <i1> [#uses=1]
+  br i1 %1, label %bb27, label %bb29
+
+bb29:                                             ; preds = %bb28
+  br i1 undef, label %bb12, label %bb30
+
+bb30:                                             ; preds = %bb29
+  %2 = add nsw i32 %r.0, 1                        ; <i32> [#uses=1]
+  br label %bb24
+}