Test case for PR1271 involving construction of a bad mask to replace a

shift instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35349 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/InstCombine/2007-03-25-BadShiftMask.ll b/test/Transforms/InstCombine/2007-03-25-BadShiftMask.ll
new file mode 100644 (file)
index 0000000..3a706a5
--- /dev/null
+++ b/test/Transforms/InstCombine/2007-03-25-BadShiftMask.ll
@@ -0,0 +1,28 @@
+; PR1271
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep 'br i1 %1'
+%struct..0anon = type { i32, i32 }
+%struct..1anon = type { double }
+
+define i32 @main() {
+entry:
+       %u = alloca %struct..1anon, align 8             ; <%struct..1anon*> [#uses=4]
+       %tmp1 = getelementptr %struct..1anon* %u, i32 0, i32 0          ; <double*> [#uses=1]
+       store double 0x7FF0000000000000, double* %tmp1
+       %tmp3 = getelementptr %struct..1anon* %u, i32 0, i32 0          ; <double*> [#uses=1]
+       %tmp34 = bitcast double* %tmp3 to %struct..0anon*               ; <%struct..0anon*> [#uses=1]
+       %tmp5 = getelementptr %struct..0anon* %tmp34, i32 0, i32 1              ; <i32*> [#uses=1]
+       %tmp6 = load i32* %tmp5         ; <i32> [#uses=1]
+       %tmp7 = shl i32 %tmp6, 1                ; <i32> [#uses=1]
+       %tmp8 = lshr i32 %tmp7, 21              ; <i32> [#uses=1]
+       %tmp89 = trunc i32 %tmp8 to i16         ; <i16> [#uses=1]
+       icmp ne i16 %tmp89, 2047                ; <i1>:0 [#uses=1]
+       zext i1 %0 to i8                ; <i8>:1 [#uses=1]
+       icmp ne i8 %1, 0                ; <i1>:2 [#uses=1]
+       br i1 %2, label %cond_true, label %cond_false
+
+cond_true:             ; preds = %entry
+       ret i32 0
+
+cond_false:            ; preds = %entry
+        ret i32 1
+}