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| author | Tim Northover <tnorthover@apple.com> | 2014-05-30 10:09:59 +0000 |
|---|---|---|
| committer | Tim Northover <tnorthover@apple.com> | 2014-05-30 10:09:59 +0000 |
| commit | d0dbe02fd26d47ed32c9e04a2a0385b26a49f4ed (patch) | |
| tree | 9ca25621a85c9af7e635fcebf3774ce33b6da7ae /test/CodeGen/ARM/2013-07-29-vector-or-combine.ll | |
| parent | 7be505ae8877d99d761da08952afbe74bacdae9e (diff) | |
ARM & AArch64: make use of common cmpxchg idioms after expansion
The C and C++ semantics for compare_exchange require it to return a bool
indicating success. This gets mapped to LLVM IR which follows each cmpxchg with
an icmp of the value loaded against the desired value.
When lowered to ldxr/stxr loops, this extra comparison is redundant: its
results are implicit in the control-flow of the function.
This commit makes two changes: it replaces that icmp with appropriate PHI
nodes, and then makes sure earlyCSE is called after expansion to actually make
use of the opportunities revealed.
I've also added -{arm,aarch64}-enable-atomic-tidy options, so that
existing fragile tests aren't perturbed too much by the change. Many
of them either rely on undef/unreachable too pervasively to be
restored to something well-defined (particularly while making sure
they test the same obscure assert from many years ago), or depend on a
particular CFG shape, which is disrupted by SimplifyCFG.
rdar://problem/16227836
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209883 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/ARM/2013-07-29-vector-or-combine.ll')
| -rw-r--r-- | test/CodeGen/ARM/2013-07-29-vector-or-combine.ll | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/test/CodeGen/ARM/2013-07-29-vector-or-combine.ll b/test/CodeGen/ARM/2013-07-29-vector-or-combine.ll index a438c1f4556..05a4ef05e95 100644 --- a/test/CodeGen/ARM/2013-07-29-vector-or-combine.ll +++ b/test/CodeGen/ARM/2013-07-29-vector-or-combine.ll @@ -1,4 +1,4 @@ -; RUN: llc < %s -mcpu=cortex-a8 | FileCheck %s +; RUN: llc < %s -mcpu=cortex-a8 -arm-atomic-cfg-tidy=0 | FileCheck %s ; ModuleID = 'bugpoint-reduced-simplified.bc' target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:64:128-a0:0:64-n32-S64" target triple = "armv7--linux-gnueabi" |