Fix a DAGCombiner abort on an invalid shift count constant. This fixes PR3250.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61613 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/pr3250.ll b/test/CodeGen/X86/pr3250.ll
new file mode 100644
index 0000000..dce154f
--- /dev/null
+++ b/test/CodeGen/X86/pr3250.ll
@@ -0,0 +1,17 @@
+; RUN: llvm-as < %s | llc -march=x86
+; PR3250
+
+declare i32 @safe_sub_func_short_u_u(i16 signext, i16 signext) nounwind
+
+define i32 @func_106(i32 %p_107) nounwind {
+entry:
+        %0 = tail call i32 (...)* @safe_div_(i32 %p_107, i32 1) nounwind       
+        ; <i32> [#uses=1]
+        %1 = lshr i32 %0, -9            ; <i32> [#uses=1]
+        %2 = trunc i32 %1 to i16                ; <i16> [#uses=1]
+        %3 = tail call i32 @safe_sub_func_short_u_u(i16 signext 1, i16 signext
+%2) nounwind             ; <i32> [#uses=0]
+        ret i32 undef
+}
+
+declare i32 @safe_div_(...)