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| author | Hal Finkel <hfinkel@anl.gov> | 2014-07-25 21:13:35 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2014-07-25 21:13:35 +0000 |
| commit | 8ef7b17dfc790ffcd28829312b6ad727298e11bb (patch) | |
| tree | 30d1ef8cbe042232665a0d23ffbfc409d59fa51d /test/Analysis/BasicAA | |
| parent | 9c5f6b8c654d0ee6648474f353b4c2ba36b835e1 (diff) | |
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
Diffstat (limited to 'test/Analysis/BasicAA')
| -rw-r--r-- | test/Analysis/BasicAA/assume.ll | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/test/Analysis/BasicAA/assume.ll b/test/Analysis/BasicAA/assume.ll new file mode 100644 index 00000000000..e163b5a4161 --- /dev/null +++ b/test/Analysis/BasicAA/assume.ll @@ -0,0 +1,23 @@ +; RUN: opt < %s -basicaa -aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s +target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:32-f32:32:32-f64:32:32-v64:32:64-v128:32:128-a0:0:32-n32" + +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) #0 +declare void @llvm.assume(i1) #0 + +define void @test1(i8* %P, i8* %Q) nounwind ssp { + tail call void @llvm.assume(i1 true) + tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) + ret void + +; CHECK-LABEL: Function: test1: + +; CHECK: MayAlias: i8* %P, i8* %Q +; CHECK: NoModRef: Ptr: i8* %P <-> tail call void @llvm.assume(i1 true) +; CHECK: NoModRef: Ptr: i8* %Q <-> tail call void @llvm.assume(i1 true) +; CHECK: Both ModRef: Ptr: i8* %P <-> tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) +; CHECK: Both ModRef: Ptr: i8* %Q <-> tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) +; CHECK: NoModRef: tail call void @llvm.assume(i1 true) <-> tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) +; CHECK: NoModRef: tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) <-> tail call void @llvm.assume(i1 true) +} + +attributes #0 = { nounwind } |