enhance the "change or icmp's into switch" xform to handle one value in an

'or sequence' that it doesn't understand.  This allows us to optimize
something insane like this:

int crud (unsigned char c, unsigned x)
 {
   if(((((((((( (int) c <= 32 ||
                    (int) c == 46) || (int) c == 44)
                  || (int) c == 58) || (int) c == 59) || (int) c == 60)
               || (int) c == 62) || (int) c == 34) || (int) c == 92)
            || (int) c == 39) != 0)
     foo();
 }

into:

define i32 @crud(i8 zeroext %c, i32 %x) nounwind ssp noredzone {
entry:
  %cmp = icmp ult i8 %c, 33
  br i1 %cmp, label %if.then, label %switch.early.test

switch.early.test:                                ; preds = %entry
  switch i8 %c, label %if.end [
    i8 39, label %if.then
    i8 44, label %if.then
    i8 58, label %if.then
    i8 59, label %if.then
    i8 60, label %if.then
    i8 62, label %if.then
    i8 46, label %if.then
    i8 92, label %if.then
    i8 34, label %if.then
  ]

by pulling the < comparison out ahead of the newly formed switch.

llvm-svn: 121680

1 files changed, 25 insertions, 2 deletions

diff --git a/llvm/test/Transforms/SimplifyCFG/switch_create.ll b/llvm/test/Transforms/SimplifyCFG/switch_create.ll
index 9edbf0f7500..bac457cd9f0 100644
--- a/llvm/test/Transforms/SimplifyCFG/switch_create.ll
+++ b/llvm/test/Transforms/SimplifyCFG/switch_create.ll
@@ -149,7 +149,30 @@ UnifiedReturnBlock:             ; preds = %shortcirc_done.4, %shortcirc_next.4
 ; CHECK:       i32 18, label %UnifiedReturnBlock
 ; CHECK:       i32 19, label %switch.edge
 ; CHECK:     ]
-
 }
 
-
+define void @test7(i8 zeroext %c, i32 %x) nounwind ssp noredzone {
+entry:
+  %cmp = icmp ult i32 %x, 32
+  %cmp4 = icmp eq i8 %c, 97
+  %or.cond = or i1 %cmp, %cmp4
+  %cmp9 = icmp eq i8 %c, 99
+  %or.cond11 = or i1 %or.cond, %cmp9
+  br i1 %or.cond11, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  tail call void @foo1() nounwind noredzone
+  ret void
+
+if.end:                                           ; preds = %entry
+  ret void
+  
+; CHECK: @test7
+; CHECK:   %cmp = icmp ult i32 %x, 32
+; CHECK:   br i1 %cmp, label %if.then, label %switch.early.test
+; CHECK: switch.early.test:
+; CHECK:   switch i8 %c, label %if.end [
+; CHECK:     i8 99, label %if.then
+; CHECK:     i8 97, label %if.then
+; CHECK:   ]
+}