[llvm-commits] CVS: llvm/test/Regression/Transforms/SimplifyCFG/switch_thread.ll

[Chris Lattner]

Changes in directory llvm/test/Regression/Transforms/SimplifyCFG:

switch_thread.ll added (r1.1)
---
Log message:

new testcase for a simple optimization that simplifycfg is about to do.
All CFG edges to DEAD should be eliminated.


---
Diffs of the changes:  (+78 -0)

 switch_thread.ll |   78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 78 insertions(+)


Index: llvm/test/Regression/Transforms/SimplifyCFG/switch_thread.ll
diff -c /dev/null llvm/test/Regression/Transforms/SimplifyCFG/switch_thread.ll:1.1
*** /dev/null	Thu Feb 24 00:15:37 2005
--- llvm/test/Regression/Transforms/SimplifyCFG/switch_thread.ll	Thu Feb 24 00:15:27 2005
***************
*** 0 ****
--- 1,78 ----
+ ; RUN: llvm-as < %s | opt -simplifycfg | llvm-dis | not grep 'call void %DEAD'
+ 
+ ; Test that we can thread a simple known condition through switch statements.
+ 
+ declare void %foo1()
+ declare void %foo2()
+ declare void %DEAD()
+ 
+ void %test1(uint %V) {
+         switch uint %V, label %A [
+                  uint 4, label %T
+                  uint 17, label %Done
+                  uint 1234, label %A
+         ]
+ 
+ T:  ;; V == 4 if we get here.
+ 	call void %foo1()
+         ;; This switch is always statically determined.
+         switch uint %V, label %A2 [
+                  uint 4, label %B
+                  uint 17, label %C
+ 		 uint 42, label %C
+         ]
+ A2:
+ 	call void %DEAD()
+ 	call void %DEAD()
+ 	%cond2 = seteq uint %V, 4    ;; always false
+ 	br bool %cond2, label %Done, label %C
+ 
+ A:
+ 	call void %foo1()
+ 	%cond = setne uint %V, 4    ;; always true
+ 	br bool %cond, label %Done, label %C
+ 
+ 
+ Done:
+         ret void
+ 
+ B:
+         call void %foo2()
+ 	%cond3 = seteq uint %V, 4    ;; always true
+ 	br bool %cond3, label %Done, label %C
+ C:
+ 	call void %DEAD()
+ 	ret void
+ }
+ 
+ void %test2(uint %V) {
+         switch uint %V, label %A [
+                  uint 4, label %T
+                  uint 17, label %D
+                  uint 1234, label %E
+         ]
+ 
+ A:  ;; V != 4, 17, 1234 here.
+ 	call void %foo1()
+         ;; This switch is always statically determined.
+         switch uint %V, label %E [
+                  uint 4, label %C
+                  uint 17, label %C
+ 		 uint 42, label %D
+         ]
+ C:
+ 	call void %DEAD()  ;; unreacahble.
+ 	ret void
+ T:
+ 	call void %foo1()
+ 	call void %foo1()
+ 	ret void
+ 
+ D:
+ 	call void %foo1()
+ 	ret void
+ 
+ E:
+         ret void
+ }
+