Fix PR4188. TailMerging can't tolerate inexact

sucessor info.

llvm-svn: 71478

1 files changed, 23 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/X86/2009-05-11-tailmerge-crash.ll b/llvm/test/CodeGen/X86/2009-05-11-tailmerge-crash.ll
new file mode 100644
index 00000000000..817872598ea
--- /dev/null
+++ b/llvm/test/CodeGen/X86/2009-05-11-tailmerge-crash.ll
@@ -0,0 +1,23 @@
+; RUN: llvm-as < %s | llc -march=x86
+; PR4188
+; ModuleID = '<stdin>'
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i386-apple-darwin9.6"
+@g_9 = external global i32		; <i32*> [#uses=1]
+
+define i32 @int86(i32 %p_87) nounwind {
+entry:
+	%0 = trunc i32 %p_87 to i8		; <i8> [#uses=1]
+	%1 = icmp ne i8 %0, 0		; <i1> [#uses=1]
+	br label %bb
+
+bb:		; preds = %bb.i, %bb, %entry
+	%2 = volatile load i32* @g_9, align 4		; <i32> [#uses=2]
+	%3 = icmp sgt i32 %2, 1		; <i1> [#uses=1]
+	%4 = and i1 %3, %1		; <i1> [#uses=1]
+	br i1 %4, label %bb.i, label %bb
+
+bb.i:		; preds = %bb
+	%5 = icmp sgt i32 0, %2		; <i1> [#uses=0]
+	br label %bb
+}