Revert 72493 and replace it with a more conservative fix, for now: don't

rewrite the comparison if there is any implicit extension or truncation
on the induction variable. I'm planning for IVUsers to eventually take
over some of the work of this code, and for it to be generalized.

llvm-svn: 72496

1 files changed, 25 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopStrengthReduce/change-compare-stride-trickiness-2.ll b/llvm/test/Transforms/LoopStrengthReduce/change-compare-stride-trickiness-2.ll
index e3cb3a50953..f77aea39370 100644
--- a/llvm/test/Transforms/LoopStrengthReduce/change-compare-stride-trickiness-2.ll
+++ b/llvm/test/Transforms/LoopStrengthReduce/change-compare-stride-trickiness-2.ll
@@ -31,3 +31,28 @@ if.end52:		; preds = %for.cond.i.preheader
 	%indvar.next689 = add i64 %indvar688, 1		; <i64> [#uses=1]
 	br i1 %phitmp654, label %for.cond.i.preheader, label %if.end
 }
+
+define void @promote(%struct.dumperinfo* %di) nounwind {
+entry:
+	br label %if.end
+
+if.end:		; preds = %if.end52, %entry
+	br label %for.cond.i.preheader
+
+for.cond.i.preheader:		; preds = %if.end52, %if.end
+	%indvar688 = phi i32 [ 0, %if.end ], [ %indvar.next689, %if.end52 ]		; <i64> [#uses=3]
+	%tmp690 = shl i32 %indvar688, 12		; <i64> [#uses=1]
+	%pa.0642 = add i32 %tmp690, 0		; <i64> [#uses=1]
+	%tmp692693 = add i32 %indvar688, 1		; <i32> [#uses=1]
+	%phitmp = sext i32 %tmp692693 to i64		; <i64> [#uses=1]
+	br i1 false, label %if.end52, label %land.lhs.true.i
+
+land.lhs.true.i:		; preds = %for.cond.i.preheader
+	%shr2.i = lshr i32 %pa.0642, 18		; <i64> [#uses=0]
+	unreachable
+
+if.end52:		; preds = %for.cond.i.preheader
+	%phitmp654 = icmp ult i64 %phitmp, 512		; <i1> [#uses=1]
+	%indvar.next689 = add i32 %indvar688, 1		; <i64> [#uses=1]
+	br i1 %phitmp654, label %for.cond.i.preheader, label %if.end
+}