llvm-6502/test/Transforms/SimplifyCFG/assume.ll

; RUN: opt -simplifycfg -S < %s | FileCheck %s

define void @test1() {
        call void @llvm.assume(i1 0)
        ret void

; CHECK-LABEL: @test1
; CHECK-NOT: llvm.assume
; CHECK: unreachable
}

define void @test2() {
        call void @llvm.assume(i1 undef)
        ret void

; CHECK-LABEL: @test2
; CHECK-NOT: llvm.assume
; CHECK: unreachable
}

declare void @llvm.assume(i1) nounwind
Add @llvm.assume, lowering, and some basic properties This is the first commit in a series that add an @llvm.assume intrinsic which can be used to provide the optimizer with a condition it may assume to be true (when the control flow would hit the intrinsic call). Some basic properties are added here: - llvm.invariant(true) is dead. - llvm.invariant(false) is unreachable (this directly corresponds to the documented behavior of MSVC's __assume(0)), so is llvm.invariant(undef). The intrinsic is tagged as writing arbitrarily, in order to maintain control dependencies. BasicAA has been updated, however, to return NoModRef for any particular location-based query so that we don't unnecessarily block code motion. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213973 91177308-0d34-0410-b5e6-96231b3b80d8 2014-07-25 21:13:35 +00:00			`; RUN: opt -simplifycfg -S < %s \| FileCheck %s`

			`define void @test1() {`
			`call void @llvm.assume(i1 0)`
			`ret void`

			`; CHECK-LABEL: @test1`
			`; CHECK-NOT: llvm.assume`
			`; CHECK: unreachable`
			`}`

			`define void @test2() {`
			`call void @llvm.assume(i1 undef)`
			`ret void`

			`; CHECK-LABEL: @test2`
			`; CHECK-NOT: llvm.assume`
			`; CHECK: unreachable`
			`}`

			`declare void @llvm.assume(i1) nounwind`