Commit Graph

14 Commits

Author SHA1 Message Date
James Y Knight 8043d5a964 NFC: update clang tests to check ordering and alignment for atomicrmw/cmpxchg.
The ability to specify alignment was recently added, and it's an
important property which we should ensure is set as expected by
Clang. (Especially before making further changes to Clang's code in
this area.) But, because it's on the end of the lines, the existing
tests all ignore it.

Therefore, update all the tests to also verify the expected alignment
for atomicrmw and cmpxchg. While I was in there, I also updated uses
of 'load atomic' and 'store atomic', and added the memory ordering,
where that was missing.
2021-02-11 17:35:09 -05:00
Fangrui Song 6b3351792c [test] Add {{.*}} to make tests immune to dso_local/dso_preemptable/(none) differences
For a definition (of most linkage types), dso_local is set for ELF -fno-pic/-fpie
and COFF, but not for Mach-O.  This nuance causes unneeded binary format differences.

This patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `
if there is an explicit linkage.

* Clang will set dso_local for Mach-O, which is currently implied by TargetMachine.cpp. This will make COFF/Mach-O and executable ELF similar.
* Eventually I hope we can make dso_local the textual LLVM IR default (write explicit "dso_preemptable" when applicable) and -fpic ELF will be similar to everything else. This patch helps move toward that goal.
2020-12-30 20:52:01 -08:00
Jennifer Yu 6cf0dac1ca orrectly generate invert xor value for Binary Atomics of int size > 64
When using __sync_nand_and_fetch with __int128, a problem is found that
the wrong value for the 'invert' value gets emitted to the xor in case
where the int size is greater than 64 bits.

This is because uses of llvm::ConstantInt::get which zero extends the
greater than 64 bits, so instead -1 that we require, it end up
getting 18446744073709551615

This patch replaces the call to llvm::ConstantInt::get with the call
to llvm::Constant::getAllOnesValue which works for all integer types.

Reviewers: jfp, erichkeane, rjmccall, hfinkel

Differential Revision: https://reviews.llvm.org/D82832
2020-07-07 10:20:14 -07:00
Elena Demikhovsky d31327d505 Added atomic_fetch_min, max, umin, umax intrinsics to clang.
These intrinsics work exactly as all other atomic_fetch_* intrinsics and allow to create *atomicrmw* with ordering.
Updated the clang-extensions document.

Differential Revision: https://reviews.llvm.org/D46386

llvm-svn: 332193
2018-05-13 07:45:58 +00:00
Hal Finkel d2208b59cf Add __sync_fetch_and_nand (again)
Prior to GCC 4.4, __sync_fetch_and_nand was implemented as:

  { tmp = *ptr; *ptr = ~tmp & value; return tmp; }

but this was changed in GCC 4.4 to be:

  { tmp = *ptr; *ptr = ~(tmp & value); return tmp; }

in response to this change, support for sync_fetch_and_nand (and
sync_nand_and_fetch) was removed in r99522 in order to avoid miscompiling code
depending on the old semantics. However, at this point:

  1. Many years have passed, and the amount of code relying on the old
     semantics is likely smaller.

  2. Through the work of many contributors, all LLVM backends have been updated
     such that "atomicrmw nand" provides the newer GCC 4.4+ semantics (this process
     was complete July of 2014 (added to the release notes in r212635).

  3. The lack of this intrinsic is now a needless impediment to porting codes
     from GCC to Clang (I've now seen several examples of this).

It is true, however, that we still set GNUC_MINOR to 2 (corresponding to GCC
4.2). To compensate for this, and to address the original concern regarding
code relying on the old semantics, I've added a warning that specifically
details the fact that the semantics have changed and that we provide the newer
semantics.

Fixes PR8842.

llvm-svn: 218905
2014-10-02 20:53:50 +00:00
Tim Northover b49b04bbe0 IR-change: cmpxchg operations now return { iN, i1 }.
This is a minimal fix for clang. I'll soon add support for generating
weak variants when requested, but that's not really necessary for the
LLVM change in isolation.

llvm-svn: 210907
2014-06-13 14:24:59 +00:00
Stephen Lin 4362261b00 CHECK-LABEL-ify some code gen tests to improve diagnostic experience when tests fail.
llvm-svn: 188447
2013-08-15 06:47:53 +00:00
Nuno Lopes 729e6a056c hopefully fix a bunch of ARM buildbot failures
llvm-svn: 156513
2012-05-09 21:21:49 +00:00
Eli Friedman 84d2812111 Re-commit r139643.
Make clang use Acquire loads and Release stores where necessary.

llvm-svn: 139650
2011-09-13 22:21:56 +00:00
Eli Friedman acca089617 Revert r139643 while I look into it; it's breaking selfhost.
llvm-svn: 139648
2011-09-13 22:08:16 +00:00
Eli Friedman f92b2e0714 Make clang use Acquire loads and Release stores where necessary.
llvm-svn: 139643
2011-09-13 21:31:32 +00:00
Eli Friedman e9f8113ec4 Switch clang over to using fence/atomicrmw/cmpxchg instead of the intrinsics (which will go away). LLVM CodeGen does almost exactly the same thing with these and the old intrinsics, so I'm reasonably confident this will not break anything.
There are still a few issues which need to be resolved with code generation for atomic load and store, so I'm not converting the places which need those for now.

I'm not entirely sure what to do about __builtin_llvm_memory_barrier: the fence instruction doesn't expose all the possibilities which can be expressed by __builtin_llvm_memory_barrier.  I would appreciate hearing from anyone who is using this intrinsic.

llvm-svn: 139216
2011-09-07 01:41:24 +00:00
Eric Christopher 6455d84653 This works on arm.
llvm-svn: 136303
2011-07-28 00:10:10 +00:00
Eric Christopher 85e5156598 Migrate most of the rest of test/FrontendC from llvm and migrate
most of them to FileCheck.

llvm-svn: 136159
2011-07-26 22:17:02 +00:00