Switch to select optimization for two-case switches

[oota-llvm.git] / test / Transforms / SimplifyCFG / switch-to-select-two-case.ll

diff --git a/test/Transforms/SimplifyCFG/switch-to-select-two-case.ll b/test/Transforms/SimplifyCFG/switch-to-select-two-case.ll
new file mode 100644 (file)
index 0000000..69f97e5
--- /dev/null
+++ b/test/Transforms/SimplifyCFG/switch-to-select-two-case.ll
@@ -0,0 +1,72 @@
+; RUN: opt < %s -simplifycfg -S | FileCheck %s
+
+; int foo1_with_default(int a) {
+;   switch(a) {
+;     case 10:
+;       return 10;
+;     case 20:
+;       return 2;
+;   }
+;   return 4;
+; }
+
+define i32 @foo1_with_default(i32 %a) {
+; CHECK-LABEL: @foo1_with_default
+; CHECK: %switch.selectcmp = icmp eq i32 %a, 20
+; CHECK-NEXT: %switch.select = select i1 %switch.selectcmp, i32 2, i32 4
+; CHECK-NEXT: %switch.selectcmp1 = icmp eq i32 %a, 10
+; CHECK-NEXT: %switch.select2 = select i1 %switch.selectcmp1, i32 10, i32 %switch.select
+entry:
+  switch i32 %a, label %sw.epilog [
+    i32 10, label %sw.bb
+    i32 20, label %sw.bb1
+  ]
+
+sw.bb:
+  br label %return
+
+sw.bb1:
+  br label %return
+
+sw.epilog:
+  br label %return
+
+return:
+  %retval.0 = phi i32 [ 4, %sw.epilog ], [ 2, %sw.bb1 ], [ 10, %sw.bb ]
+  ret i32 %retval.0
+}
+
+; int foo1_without_default(int a) {
+;   switch(a) {
+;     case 10:
+;       return 10;
+;     case 20:
+;       return 2;
+;   }
+;   __builtin_unreachable();
+; }
+
+define i32 @foo1_without_default(i32 %a) {
+; CHECK-LABEL: @foo1_without_default
+; CHECK: %switch.selectcmp = icmp eq i32 %a, 10
+; CHECK-NEXT: %switch.select = select i1 %switch.selectcmp, i32 10, i32 2
+; CHECK-NOT: %switch.selectcmp1
+entry:
+  switch i32 %a, label %sw.epilog [
+    i32 10, label %sw.bb
+    i32 20, label %sw.bb1
+  ]
+
+sw.bb:
+  br label %return
+
+sw.bb1:
+  br label %return
+
+sw.epilog:
+  unreachable
+
+return:
+  %retval.0 = phi i32 [ 2, %sw.bb1 ], [ 10, %sw.bb ]
+  ret i32 %retval.0
+}