SimplifyCFG: don't remove unreachable default switch destinations

[oota-llvm.git] / test / Transforms / SimplifyCFG / X86 / switch_to_lookup_table.ll

diff --git a/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll b/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll
index 29f1a35fb144febe842a32e890c0ab4923208d64..9cf57b38dfeb48bedc6b5944e8cf3fbc27821198 100644 (file)
--- a/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll
+++ b/test/Transforms/SimplifyCFG/X86/switch_to_lookup_table.ll
@@ -781,35 +781,6 @@ return:
 ; CHECK: getelementptr inbounds [9 x i32]* @switch.table6, i32 0, i32 %switch.tableidx
 }
 
-define i32 @unreachable_default(i32 %x)  {
-entry:
-  switch i32 %x, label %default [
-    i32 0, label %bb0
-    i32 1, label %bb1
-    i32 2, label %bb2
-    i32 3, label %bb3
-  ]
-
-bb0: br label %return
-bb1: br label %return
-bb2: br label %return
-bb3: br label %return
-default: unreachable
-
-return:
-  %retval = phi i32 [ 42, %bb0 ], [ 52, %bb1 ], [ 1, %bb2 ], [ 2, %bb3 ]
-  ret i32 %retval
-
-; CHECK-LABEL: @unreachable_default(
-; CHECK: entry:
-; CHECK-NEXT: %switch.tableidx = sub i32 %x, 0
-; CHECK-NOT: icmp
-; CHECK-NOT: br 1i
-; CHECK-NEXT: %switch.gep = getelementptr inbounds [4 x i32]* @switch.table7, i32 0, i32 %switch.tableidx
-; CHECK-NEXT: %switch.load = load i32* %switch.gep
-; CHECK-NEXT: ret i32 %switch.load
-}
-
 ; Don't create a table with illegal type
 define i96 @illegaltype(i32 %c) {
 entry:
@@ -1233,3 +1204,43 @@ return:
 ; CHECK-NEXT:  [[R:%.+]] = select i1 %cmp
 ; CHECK-NEXT:  ret i32 [[R]]
 }
+
+define void @pr20210(i8 %x, i1 %y) {
+; %z has uses outside of its BB or the phi it feeds into,
+; so doing a table lookup and jumping directly to while.cond would
+; cause %z to cease dominating all its uses.
+
+entry:
+  br i1 %y, label %sw, label %intermediate
+
+sw:
+  switch i8 %x, label %end [
+    i8 7, label %intermediate
+    i8 3, label %intermediate
+    i8 2, label %intermediate
+    i8 1, label %intermediate
+    i8 0, label %intermediate
+  ]
+
+intermediate:
+  %z = zext i8 %x to i32
+  br label %while.cond
+
+while.cond:
+  %i = phi i32 [ %z, %intermediate ], [ %j, %while.body ]
+  %b = icmp ne i32 %i, 7
+  br i1 %b, label %while.body, label %while.end
+
+while.body:
+  %j = add i32 %i, 1
+  br label %while.cond
+
+while.end:
+  call void @exit(i32 %z)
+  unreachable
+
+end:
+  ret void
+; CHECK-LABEL: @pr20210
+; CHECK: switch i8 %x
+}