llvm/test/Transforms/SimplifyCFG/switch-to-icmp.ll
Benjamin Kramer 33828bcb24 SimplifyCFG: Track the number of used icmps when turning a icmp chain into a switch. If we used only one icmp, don't turn it into a switch.
Also prevent the switch-to-icmp transform from creating identity adds, noticed by Marius Wachtler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125056 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-07 22:37:28 +00:00

40 lines
801 B
LLVM

; RUN: opt -S -simplifycfg < %s | FileCheck %s
define zeroext i1 @test1(i32 %x) nounwind readnone ssp noredzone {
entry:
switch i32 %x, label %lor.rhs [
i32 2, label %lor.end
i32 1, label %lor.end
i32 3, label %lor.end
]
lor.rhs:
br label %lor.end
lor.end:
%0 = phi i1 [ true, %entry ], [ false, %lor.rhs ], [ true, %entry ], [ true, %entry ]
ret i1 %0
; CHECK: @test1
; CHECK: %x.off = add i32 %x, -1
; CHECK: %switch = icmp ult i32 %x.off, 3
}
define zeroext i1 @test2(i32 %x) nounwind readnone ssp noredzone {
entry:
switch i32 %x, label %lor.rhs [
i32 0, label %lor.end
i32 1, label %lor.end
]
lor.rhs:
br label %lor.end
lor.end:
%0 = phi i1 [ true, %entry ], [ false, %lor.rhs ], [ true, %entry ]
ret i1 %0
; CHECK: @test2
; CHECK: %switch = icmp ult i32 %x, 2
}