SimplifyCFG: Use ComputeMaskedBits to prune dead cases from switch instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131345 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Transforms/SimplifyCFG/switch-masked-bits.ll b/test/Transforms/SimplifyCFG/switch-masked-bits.ll
new file mode 100644
index 0000000..fc83ec2
--- /dev/null
+++ b/test/Transforms/SimplifyCFG/switch-masked-bits.ll
@@ -0,0 +1,38 @@
+; RUN: opt -S -simplifycfg < %s | FileCheck %s
+
+define i32 @test1(i32 %x) nounwind {
+ %i = shl i32 %x, 1
+ switch i32 %i, label %a [
+ i32 21, label %b
+ i32 24, label %c
+ ]
+
+a:
+ ret i32 0
+b:
+ ret i32 3
+c:
+ ret i32 5
+; CHECK: @test1
+; CHECK: %cond = icmp eq i32 %i, 24
+; CHECK: %merge = select i1 %cond, i32 5, i32 0
+; CHECK: ret i32 %merge
+}
+
+
+define i32 @test2(i32 %x) nounwind {
+ %i = shl i32 %x, 1
+ switch i32 %i, label %a [
+ i32 21, label %b
+ i32 23, label %c
+ ]
+
+a:
+ ret i32 0
+b:
+ ret i32 3
+c:
+ ret i32 5
+; CHECK: @test2
+; CHECK: ret i32 0
+}