PR9446: RecursivelyDeleteTriviallyDeadInstructions can delete the instruction
after the given instruction; make sure to handle that case correctly.
(It's difficult to trigger; the included testcase involves a dead
block, but I don't think that's a requirement.)
While I'm here, get rid of the unnecessary warning about
SimplifyInstructionsInBlock, since it should work correctly as far as I know.
llvm-svn: 128782
diff --git a/llvm/test/Transforms/JumpThreading/2011-04-02-SimplifyDeadBlock.ll b/llvm/test/Transforms/JumpThreading/2011-04-02-SimplifyDeadBlock.ll
new file mode 100644
index 0000000..76dd2d1
--- /dev/null
+++ b/llvm/test/Transforms/JumpThreading/2011-04-02-SimplifyDeadBlock.ll
@@ -0,0 +1,32 @@
+; RUN: opt < %s -jump-threading
+; PR9446
+; Just check that it doesn't crash
+
+define void @int327() nounwind {
+entry:
+ unreachable
+
+for.cond: ; preds = %for.cond4
+ %tobool3 = icmp eq i8 undef, 0
+ br i1 %tobool3, label %for.cond23, label %for.cond4
+
+for.cond4: ; preds = %for.cond
+ br label %for.cond
+
+for.cond23: ; preds = %for.body28, %for.cond23, %for.cond
+ %conv321 = phi i32 [ %conv32, %for.body28 ], [ 0, %for.cond ], [ %conv321, %for.cond23 ]
+ %l_266.0 = phi i32 [ %phitmp, %for.body28 ], [ 0, %for.cond ], [ 0, %for.cond23 ]
+ %cmp26 = icmp eq i32 %l_266.0, 0
+ br i1 %cmp26, label %for.body28, label %for.cond23
+
+for.body28: ; preds = %for.cond23
+ %and = and i32 %conv321, 1
+ %conv32 = zext i8 undef to i32
+ %add = add nsw i32 %l_266.0, 1
+ %phitmp = and i32 %add, 255
+ br label %for.cond23
+
+if.end43: ; No predecessors!
+ ret void
+}
+