llvm/test/Transforms/SimplifyCFG/basictest.ll
Dan Gohman e2c6d131d1 Teach SimplifyCFG how to simplify indirectbr instructions.
- Eliminate redundant successors.
 - Convert an indirectbr with one successor into a direct branch.

Also, generalize SimplifyCFG to be able to be run on a function entry block.
It knows quite a few simplifications which are applicable to the entry
block, and it only needs a few checks to avoid trouble with the entry block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111060 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-14 00:29:42 +00:00

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1.1 KiB
LLVM

; Test CFG simplify removal of branch instructions.
;
; RUN: opt < %s -simplifycfg -S | FileCheck %s
define void @test1() {
br label %BB1
BB1: ; preds = %0
ret void
; CHECK: @test1
; CHECK-NEXT: ret void
}
define void @test2() {
ret void
BB1: ; No predecessors!
ret void
; CHECK: @test2
; CHECK-NEXT: ret void
; CHECK-NEXT: }
}
define void @test3(i1 %T) {
br i1 %T, label %BB1, label %BB1
BB1: ; preds = %0, %0
ret void
; CHECK: @test3
; CHECK-NEXT: ret void
}
define void @test4() {
br label %return
return:
ret void
; CHECK: @test4
; CHECK-NEXT: ret void
}
@test4g = global i8* blockaddress(@test4, %return)
; PR5795
define void @test5(i32 %A) {
switch i32 %A, label %return [
i32 2, label %bb
i32 10, label %bb1
]
bb: ; preds = %entry
ret void
bb1: ; preds = %entry
ret void
return: ; preds = %entry
ret void
; CHECK: @test5
; CHECK-NEXT: ret void
}