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|
; RUN: opt %s -S -simplifycfg | FileCheck %s
declare void @foo(i32)
define void @test(i1 %a) {
; CHECK-LABEL: @test
; CHECK: br i1 [[IGNORE:%.*]], label %true, label %false
switch i1 %a, label %default [i1 1, label %true
i1 0, label %false]
true:
call void @foo(i32 1)
ret void
false:
call void @foo(i32 3)
ret void
default:
call void @foo(i32 2)
ret void
}
define void @test2(i2 %a) {
; CHECK-LABEL: @test2
switch i2 %a, label %default [i2 0, label %case0
i2 1, label %case1
i2 2, label %case2
i2 3, label %case3]
case0:
call void @foo(i32 0)
ret void
case1:
call void @foo(i32 1)
ret void
case2:
call void @foo(i32 2)
ret void
case3:
call void @foo(i32 3)
ret void
default:
; CHECK-LABEL: default1:
; CHECK-NEXT: unreachable
call void @foo(i32 4)
ret void
}
; This one is a negative test - we know the value of the default,
; but that's about it
define void @test3(i2 %a) {
; CHECK-LABEL: @test3
switch i2 %a, label %default [i2 0, label %case0
i2 1, label %case1
i2 2, label %case2]
case0:
call void @foo(i32 0)
ret void
case1:
call void @foo(i32 1)
ret void
case2:
call void @foo(i32 2)
ret void
default:
; CHECK-LABEL: default:
; CHECK-NEXT: call void @foo
call void @foo(i32 0)
ret void
}
; Negative test - check for possible overflow when computing
; number of possible cases.
define void @test4(i128 %a) {
; CHECK-LABEL: @test4
switch i128 %a, label %default [i128 0, label %case0
i128 1, label %case1]
case0:
call void @foo(i32 0)
ret void
case1:
call void @foo(i32 1)
ret void
default:
; CHECK-LABEL: default:
; CHECK-NEXT: call void @foo
call void @foo(i32 0)
ret void
}
; All but one bit known zero
define void @test5(i8 %a) {
; CHECK-LABEL: @test5
; CHECK: br i1 [[IGNORE:%.*]], label %true, label %false
%cmp = icmp ult i8 %a, 2
call void @llvm.assume(i1 %cmp)
switch i8 %a, label %default [i8 1, label %true
i8 0, label %false]
true:
call void @foo(i32 1)
ret void
false:
call void @foo(i32 3)
ret void
default:
call void @foo(i32 2)
ret void
}
;; All but one bit known one
define void @test6(i8 %a) {
; CHECK-LABEL: @test6
; CHECK: @llvm.assume
; CHECK: br i1 [[IGNORE:%.*]], label %true, label %false
%and = and i8 %a, 254
%cmp = icmp eq i8 %and, 254
call void @llvm.assume(i1 %cmp)
switch i8 %a, label %default [i8 255, label %true
i8 254, label %false]
true:
call void @foo(i32 1)
ret void
false:
call void @foo(i32 3)
ret void
default:
call void @foo(i32 2)
ret void
}
; Check that we can eliminate both dead cases and dead defaults
; within a single run of simplify-cfg
define void @test7(i8 %a) {
; CHECK-LABEL: @test7
; CHECK: @llvm.assume
; CHECK: br i1 [[IGNORE:%.*]], label %true, label %false
%and = and i8 %a, 254
%cmp = icmp eq i8 %and, 254
call void @llvm.assume(i1 %cmp)
switch i8 %a, label %default [i8 255, label %true
i8 254, label %false
i8 0, label %also_dead]
true:
call void @foo(i32 1)
ret void
false:
call void @foo(i32 3)
ret void
also_dead:
call void @foo(i32 5)
ret void
default:
call void @foo(i32 2)
ret void
}
;; All but one bit known undef
;; Note: This is currently testing an optimization which doesn't trigger. The
;; case this is protecting against is that a bit could be assumed both zero
;; *or* one given we know it's undef. ValueTracking doesn't do this today,
;; but it doesn't hurt to confirm.
define void @test8(i8 %a) {
; CHECK-LABEL: @test8(
; CHECK: switch i8
%and = and i8 %a, 254
%cmp = icmp eq i8 %and, undef
call void @llvm.assume(i1 %cmp)
switch i8 %a, label %default [i8 255, label %true
i8 254, label %false]
true:
call void @foo(i32 1)
ret void
false:
call void @foo(i32 3)
ret void
default:
call void @foo(i32 2)
ret void
}
declare void @llvm.assume(i1)
|
