llvm-project/llvm/test/Transforms/SimplifyCFG/switch_switch_fold.ll

66 lines
1.6 KiB
LLVM

; RUN: opt < %s -simplifycfg -S | FileCheck %s
; Test that a switch going to a switch on the same value can be merged.
; All three switches in this example can be merged into one big one.
declare void @foo1()
declare void @foo2()
declare void @foo3()
declare void @foo4()
define void @test1(i32 %V) {
switch i32 %V, label %F [
i32 4, label %T
i32 17, label %T
i32 5, label %T
i32 1234, label %F
]
T: ; preds = %0, %0, %0
switch i32 %V, label %F [
i32 4, label %A
i32 17, label %B
i32 42, label %C
]
A: ; preds = %T
call void @foo1( )
ret void
B: ; preds = %F, %F, %T
call void @foo2( )
ret void
C: ; preds = %T
call void @foo3( )
ret void
F: ; preds = %F, %T, %0, %0
switch i32 %V, label %F [
i32 4, label %B
i32 18, label %B
i32 42, label %D
]
D: ; preds = %F
call void @foo4( )
ret void
; CHECK-LABEL: @test1(
; CHECK-NEXT: switch i32 %V, label %infloop [
; CHECK-NEXT: i32 4, label %A
; CHECK-NEXT: i32 17, label %B
; CHECK-NEXT: i32 18, label %B
; CHECK-NEXT: i32 42, label %D
; CHECK-NEXT: ]
; CHECK: A:
; CHECK-NEXT: call void @foo1()
; CHECK-NEXT: ret void
; CHECK: B:
; CHECK-NEXT: call void @foo2()
; CHECK-NEXT: ret void
; CHECK: D:
; CHECK-NEXT: call void @foo4()
; CHECK-NEXT: ret void
; CHECK: infloop:
; CHECK-NEXT: br label %infloop
}