mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-13 20:32:21 +00:00
8ef7b17dfc
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
14 lines
223 B
LLVM
14 lines
223 B
LLVM
; RUN: opt -instsimplify -S < %s | FileCheck %s
|
|
|
|
define void @test1() {
|
|
call void @llvm.assume(i1 1)
|
|
ret void
|
|
|
|
; CHECK-LABEL: @test1
|
|
; CHECK-NOT: llvm.assume
|
|
; CHECK: ret void
|
|
}
|
|
|
|
declare void @llvm.assume(i1) nounwind
|
|
|