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author | Tim Northover <tnorthover@apple.com> | 2014-05-30 10:09:59 +0000 |
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committer | Tim Northover <tnorthover@apple.com> | 2014-05-30 10:09:59 +0000 |
commit | b4ddc0845ab5260023e9afa3f7bc71a0bc731ae6 (patch) | |
tree | 37a8539f9db4739dd57e7bdf39433594e822e2ec /llvm/test/CodeGen/ARM/struct-byval-frame-index.ll | |
parent | 5070c18928e4b4855202ee327f537c7a1969051e (diff) | |
download | bcm5719-llvm-b4ddc0845ab5260023e9afa3f7bc71a0bc731ae6.tar.gz bcm5719-llvm-b4ddc0845ab5260023e9afa3f7bc71a0bc731ae6.zip |
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
llvm-svn: 209883
Diffstat (limited to 'llvm/test/CodeGen/ARM/struct-byval-frame-index.ll')
-rw-r--r-- | llvm/test/CodeGen/ARM/struct-byval-frame-index.ll | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/llvm/test/CodeGen/ARM/struct-byval-frame-index.ll b/llvm/test/CodeGen/ARM/struct-byval-frame-index.ll index 465ee1218fd..0fd55ec6c94 100644 --- a/llvm/test/CodeGen/ARM/struct-byval-frame-index.ll +++ b/llvm/test/CodeGen/ARM/struct-byval-frame-index.ll @@ -1,4 +1,4 @@ -; RUN: llc < %s -mcpu=cortex-a15 -verify-machineinstrs | FileCheck %s +; RUN: llc < %s -mcpu=cortex-a15 -verify-machineinstrs -arm-atomic-cfg-tidy=0 | FileCheck %s ; Check a spill right after a function call with large struct byval is correctly ; generated. |