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|
; RUN: opt < %s -simplifycfg -S | FileCheck %s
; Test that we can thread a simple known condition through switch statements.
declare void @foo1()
declare void @foo2()
declare void @DEAD()
define void @test1(i32 %V) {
switch i32 %V, label %A [
i32 4, label %T
i32 17, label %Done
i32 1234, label %A
]
;; V == 4 if we get here.
T: ; preds = %0
call void @foo1( )
;; This switch is always statically determined.
switch i32 %V, label %A2 [
i32 4, label %B
i32 17, label %C
i32 42, label %C
]
A2: ; preds = %T
call void @DEAD( )
call void @DEAD( )
;; always true
%cond2 = icmp eq i32 %V, 4 ; <i1> [#uses=1]
br i1 %cond2, label %Done, label %C
A: ; preds = %0, %0
call void @foo1( )
;; always true
%cond = icmp ne i32 %V, 4 ; <i1> [#uses=1]
br i1 %cond, label %Done, label %C
Done: ; preds = %B, %A, %A2, %0
ret void
B: ; preds = %T
call void @foo2( )
;; always true
%cond3 = icmp eq i32 %V, 4 ; <i1> [#uses=1]
br i1 %cond3, label %Done, label %C
C: ; preds = %B, %A, %A2, %T, %T
call void @DEAD( )
ret void
; CHECK-LABEL: @test1(
; CHECK-NEXT: switch i32 %V, label %A [
; CHECK-NEXT: i32 4, label %T
; CHECK-NEXT: i32 17, label %Done
; CHECK-NEXT: ]
; CHECK: T:
; CHECK-NEXT: call void @foo1()
; CHECK-NEXT: call void @foo2()
; CHECK-NEXT: br label %Done
; CHECK: A:
; CHECK-NEXT: call void @foo1()
; CHECK-NEXT: br label %Done
; CHECK: Done:
; CHECK-NEXT: ret void
}
define void @test2(i32 %V) {
switch i32 %V, label %A [
i32 4, label %T
i32 17, label %D
i32 1234, label %E
]
;; V != 4, 17, 1234 here.
A: ; preds = %0
call void @foo1( )
;; This switch is always statically determined.
switch i32 %V, label %E [
i32 4, label %C
i32 17, label %C
i32 42, label %D
]
;; unreacahble.
C: ; preds = %A, %A
call void @DEAD( )
ret void
T: ; preds = %0
call void @foo1( )
call void @foo1( )
ret void
D: ; preds = %A, %0
call void @foo1( )
ret void
E: ; preds = %A, %0
ret void
; CHECK-LABEL: @test2(
; CHECK-NEXT: switch i32 %V, label %A [
; CHECK-NEXT: i32 4, label %T
; CHECK-NEXT: i32 17, label %D
; CHECK-NEXT: i32 1234, label %E
; CHECK-NEXT: ]
; CHECK: A:
; CHECK-NEXT: call void @foo1()
; CHECK-NEXT: [[COND:%.*]] = icmp eq i32 %V, 42
; CHECK-NEXT: br i1 [[COND]], label %D, label %E
; CHECK: T:
; CHECK-NEXT: call void @foo1()
; CHECK-NEXT: call void @foo1()
; CHECK-NEXT: ret void
; CHECK: D:
; CHECK-NEXT: call void @foo1()
; CHECK-NEXT: ret void
; CHECK: E:
; CHECK-NEXT: ret void
}
|
