Commit Graph

125 Commits

Author SHA1 Message Date
Zequan Wu a7fa5febaa [Test] Fix CHECK typo.
Differential Revision: https://reviews.llvm.org/D137287
2022-11-04 10:18:04 -07:00
Chuanqi Xu 327141fb1d [C++] [Coroutines] Prefer aligned (de)allocation for coroutines -
implement the option2 of P2014R0

This implements the option2 of
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2014r0.pdf.

This also fixes https://github.com/llvm/llvm-project/issues/56671.

Although wg21 didn't get consensus for the direction of the problem,
we're happy to have some implementation and user experience first. And
from issue56671, the option2 should be the pursued one.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D133341
2022-09-22 11:28:29 +08:00
Chuanqi Xu 1c0a90fd47 [C++20] [Coroutines] Prefer sized deallocation in promise_type
Now when the compiler can't find the sized deallocation function
correctly in promise_type if there are multiple deallocation function
overloads there.

According to [dcl.fct.def.coroutine]p12:
> If both a usual deallocation function with only a pointer parameter
> and a usual deallocation function with both a pointer parameter and a
> size parameter are found, then the selected deallocation function
> shall be the one with two parameters.

So when there are multiple deallocation functions, the compiler should
choose the sized one instead of the unsized one. The patch fixes this.
2022-09-14 15:07:31 +08:00
Chuanqi Xu 495419628b [NFC] Add test of sized deallocation for coroutines
[dcl.fct.def.coroutine]p12 says:

> If both a usual deallocation function with only a pointer parameter
> and a usual deallocation function with both a pointer parameter and a
> size parameter are found, then the selected deallocation function
> shall be the one with two parameters.

However, the sized deallocation function is disabled by default for ABI
reasons. This leads the sentence never get tested and covered. This
commit tries to add a test for it
2022-09-06 14:44:16 +08:00
Chuanqi Xu 17631ac676 [Coroutines] Store the index for final suspend point if there is unwind coro end
Closing https://github.com/llvm/llvm-project/issues/57339

The root cause for this issue is an pre-mature optimization to eliminate
the index for the final suspend point since we feel like we can judge
if a coroutine is suspended at the final suspend by if resume_fn_addr is
null. However this is not true if the coroutine exists via an exception
in promise.unhandled_exception(). According to
[dcl.fct.def.coroutine]p14:

> If the evaluation of the expression promise.unhandled_exception()
> exits via an exception, the coroutine is considered suspended at the
> final suspend point.

But from the perspective of the implementation, we can't set the coro
index to the final suspend point directly since it breaks the states.

To fix the issue, we block the optimization if we find there is any
unwind coro end, which indicates that it is possible that the coroutine
exists via an exception from promise.unhandled_exception().

Test Plan: folly
2022-08-26 14:05:46 +08:00
Ting Wang d2d77e050b [PowerPC][Coroutines] Add tail-call check with call information for coroutines
Fixes #56679.

Reviewed By: ChuanqiXu, shchenz

Differential Revision: https://reviews.llvm.org/D131953
2022-08-21 22:20:40 -04:00
Chuanqi Xu e190b7cc90 [Coroutines] Maintain the position of final suspend
Closing https://github.com/llvm/llvm-project/issues/56329

The problem happens when we try to simplify the suspend points. We might
break the assumption that the final suspend lives in the last slot of
Shape.CoroSuspends. This patch tries to main the assumption and fixes
the problem.
2022-08-12 13:05:08 +08:00
Chuanqi Xu 809b416641 [NFC] Requires x86-registered-target for test/pr56919.cpp 2022-08-05 16:46:38 +08:00
Chuanqi Xu 230d6f93aa [Coroutines] Remove lifetime intrinsics for spliied allocas in coroutine frames
Closing https://github.com/llvm/llvm-project/issues/56919

It is meaningless to preserve the lifetime markers for the spilled
allocas in the coroutine frames and it would block some optimizations
too.
2022-08-05 14:50:43 +08:00
Yuanfang Chen fcb7d76d65 [coroutine] add nomerge function attribute to `llvm.coro.save`
It is illegal to merge two `llvm.coro.save` calls unless their
`llvm.coro.suspend` users are also merged. Marks it "nomerge" for
the moment.

This reverts D129025.

Alternative to D129025, which affects other token type users like WinEH.

Reviewed By: ChuanqiXu

Differential Revision: https://reviews.llvm.org/D129530
2022-07-12 10:39:38 -07:00
Dawid Jurczak f54ca1f632 [NFC][Coroutines] Add regression test for heap allocation elision optimization
Recently C++ snippet included in this patch popped up at least twice in different regression contexts:
https://github.com/llvm/llvm-project/issues/56262 and https://reviews.llvm.org/D123300
It appears that Clang users rely on HALO so adding C++ example coming originally from Gor Nishanov to tests
should help in avoiding similar regressions in future.

Differential Revision: https://reviews.llvm.org/D129279
2022-07-11 16:41:05 +02:00
Chuanqi Xu 735e6c40b5 [Coroutines] Convert coroutine.presplit to enum attr
This is required by @nikic in https://reviews.llvm.org/D127383 to
decrease the cost to check whether a function is a coroutine and this
fixes a FIXME too.

Reviewed By: rjmccall, ezhulenev

Differential Revision: https://reviews.llvm.org/D127471
2022-06-14 14:23:46 +08:00
Chuanqi Xu a1ffba8d52 [C++20] [Coroutines] Conform the updates for CWG issue 2585
According to the updates in CWG issue 2585
https://cplusplus.github.io/CWG/issues/2585.html, we shouldn't find an
allocation function with (size, p0, …, pn) in global scope.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D126187
2022-05-25 10:31:26 +08:00
Nathan Sidwell 80bebbc7cb [clang][NFC] Cleanup some coroutine tests
I noticed these two tests emit a warning about a missing
unhandled_exception.  That's irrelevant to what is being tested, but
is unnecessary noise.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D125535
2022-05-16 05:15:12 -07:00
Arthur Eubanks 61d418f971 [test] Remove references to -fexperimental-new-pass-manager in tests
This has been the default for a while and we're in the process of removing the legacy PM optimization pipeline.
2022-04-11 13:29:08 -07:00
Nikita Popov 532dc62b90 [OpaquePtrs][Clang] Add -no-opaque-pointers to tests (NFC)
This adds -no-opaque-pointers to clang tests whose output will
change when opaque pointers are enabled by default. This is
intended to be part of the migration approach described in
https://discourse.llvm.org/t/enabling-opaque-pointers-by-default/61322/9.

The patch has been produced by replacing %clang_cc1 with
%clang_cc1 -no-opaque-pointers for tests that fail with opaque
pointers enabled. Worth noting that this doesn't cover all tests,
there's a remaining ~40 tests not using %clang_cc1 that will need
a followup change.

Differential Revision: https://reviews.llvm.org/D123115
2022-04-07 12:09:47 +02:00
hyeongyukim b529744c29 [Clang] Rename `disable-noundef-analysis` flag to `-[no-]enable-noundef-analysis`
This flag was previously renamed `enable_noundef_analysis` to
`disable-noundef-analysis,` which is not a conventional name. (Driver and
CC1's boolean options are using [no-] prefix)
As discussed at https://reviews.llvm.org/D105169, this patch reverts its
name to `[no-]enable_noundef_analysis` and enables noundef-analysis as
default.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D119998
2022-02-18 17:02:41 +09:00
Chuanqi Xu d30ca5e2e2 [C++20] [Coroutines] Implement return value optimization for get_return_object
This patch tries to implement RVO for coroutine's return object got from
get_return_object.
From [dcl.fct.def.coroutine]/p7 we could know that the return value of
get_return_object is either a reference or a prvalue. So it makes sense
to do copy elision for the return value. The return object should be
constructed directly into the storage where they would otherwise be
copied/moved to.

Test Plan: folly, check-all

Reviewed By: junparser

Differential revision: https://reviews.llvm.org/D117087
2022-02-16 13:38:00 +08:00
Aaron Ballman 1ea584377e A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,

  void func();

becomes

  void func(void);

This is the ninth batch of tests being updated (there are a
significant number of other tests left to be updated).
2022-02-13 08:03:40 -05:00
hyeongyu kim 1b1c8d83d3 [Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.

Test updates are made as a separate patch: D108453

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D105169
2022-01-16 18:54:17 +09:00
Chuanqi Xu bf5f2354fa [NFC] [Coroutines] Add regression tests for symmetric transfer and coroutine elision 2022-01-12 19:39:56 +08:00
Chuanqi Xu c75cedc237 [Coroutines] Set presplit attribute in Clang and mlir
This fixes bug49264.

Simply, coroutine shouldn't be inlined before CoroSplit. And the marker
for pre-splited coroutine is created in CoroEarly pass, which ran after
AlwaysInliner Pass in O0 pipeline. So that the AlwaysInliner couldn't
detect it shouldn't inline a coroutine. So here is the error.

This patch set the presplit attribute in clang and mlir. So the inliner
would always detect the attribute before splitting.

Reviewed By: rjmccall, ezhulenev

Differential Revision: https://reviews.llvm.org/D115790
2022-01-05 10:25:02 +08:00
Chuanqi Xu 352e36e10d [Coroutines] Remove unused coroutine builtin/intrinsics llvm.coro.param (NFC-ish)
I found that the coroutine intrinsic llvm.coro.param in documentation
(https://llvm.org/docs/Coroutines.html#id101) didn't get used actually
since there isn't lowering codes in LLVM. I also checked the
implementation of libstdc++ and libc++. Both of them didn't use
llvm.coro.param. So I am pretty sure that the llvm.coro.param intrinsic
is unused. I think it would be better t to remove it to avoid possible
misleading understandings.

Note: according to [class.copy.elision]/p1.3, this optimization is
allowed by the C++ language specification. Let's make it someday.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D115222
2021-12-09 14:40:25 +08:00
Chuanqi Xu 3666cd0216 [Coroutines] Make suspend_always in test noexcept (NFC) 2021-12-01 16:16:36 +08:00
hyeongyu kim 8d3b28e754 [NFC] Fix lit test failures for clang/CodegenCoroutines 2021-11-09 02:47:16 +09:00
hyeongyu kim fd9b099906 Revert "[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default"
This reverts commit aacfbb953e.

Revert "Fix lit test failures in CodeGenCoroutines"

This reverts commit 63fff0f5bf.
2021-11-09 02:15:55 +09:00
hyeongyu kim 63fff0f5bf Fix lit test failures in CodeGenCoroutines 2021-11-06 19:58:34 +09:00
hyeongyukim aacfbb953e [Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.

Test updates are made as a separate patch: D108453

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D105169

[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default (2)

This patch updates test files after D105169.
Autogenerated test codes are changed by `utils/update_cc_test_checks.py,` and non-autogenerated test codes are changed as follows:

(1) I wrote a python script that (partially) updates the tests using regex: {F18594904} The script is not perfect, but I believe it gives hints about which patterns are updated to have `noundef` attached.

(2) The remaining tests are updated manually.

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D108453

Resolve lit failures in clang after 8ca4b3e's land

Fix lit test failures in clang-ppc* and clang-x64-windows-msvc

Fix missing failures in clang-ppc64be* and retry fixing clang-x64-windows-msvc

Fix internal_clone(aarch64) inline assembly
2021-11-06 19:19:22 +09:00
Juneyoung Lee 89ad2822af Revert "[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default"
This reverts commit 7584ef766a.
2021-11-06 15:39:19 +09:00
Juneyoung Lee 7584ef766a [Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.

Test updates are made as a separate patch: D108453

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D105169
2021-11-06 15:36:42 +09:00
Chuanqi Xu ec117158a3 [Coroutines] [Frontend] Lookup in std namespace first
Now in libcxx and clang, all the coroutine components are defined in
std::experimental namespace.
And now the coroutine TS is merged into C++20. So in the working draft
like N4892, we could find the coroutine components is defined in std
namespace instead of std::experimental namespace.
And the coroutine support in clang seems to be relatively stable. So I
think it may be suitable to move the coroutine component into the
experiment namespace now.

This patch would make clang lookup coroutine_traits in std namespace
first. For the compatibility consideration, clang would lookup in
std::experimental namespace if it can't find definitions in std
namespace. So the existing codes wouldn't be break after update
compiler.

And in case the compiler found std::coroutine_traits and
std::experimental::coroutine_traits at the same time, it would emit an
error for it.

The support for looking up std::experimental::coroutine_traits would be
removed in Clang16.

Reviewed By: lxfind, Quuxplusone

Differential Revision: https://reviews.llvm.org/D108696
2021-11-04 11:53:47 +08:00
Juneyoung Lee f193bcc701 Revert D105169 due to the two-stage failure in ASAN
This reverts the following commits:
37ca7a795b
9aa6c72b92
705387c507
8ca4b3ef19
80dba72a66
2021-10-18 23:52:46 +09:00
Juneyoung Lee 8ca4b3ef19 [Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default (2)
This patch updates test files after D105169.
Autogenerated test codes are changed by `utils/update_cc_test_checks.py,` and non-autogenerated test codes are changed as follows:

(1) I wrote a python script that (partially) updates the tests using regex: {F18594904} The script is not perfect, but I believe it gives hints about which patterns are updated to have `noundef` attached.

(2) The remaining tests are updated manually.

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D108453
2021-10-16 12:01:41 +09:00
Louis Dionne 79f8b5f0d0 Revert "[Coroutines] [Clang] Look up coroutine component in std namespace first"
This reverts commit 2fbd254aa4, which broke the libc++ CI. I'm reverting
to get things stable again until we've figured out a way forward.

Differential Revision: https://reviews.llvm.org/D108696
2021-09-03 16:01:09 -04:00
Chuanqi Xu 2fbd254aa4 [Coroutines] [Clang] Look up coroutine component in std namespace first
Summary: Now in libcxx and clang, all the coroutine components are
defined in std::experimental namespace.
And now the coroutine TS is merged into C++20. So in the working draft
like N4892, we could find the coroutine components is defined in std
namespace instead of std::experimental namespace.
And the coroutine support in clang seems to be relatively stable. So I
think it may be suitable to move the coroutine component into the
experiment namespace now.

But move the coroutine component into the std namespace may be an break
change. So I planned to split this change into two patch. One in clang
and other in libcxx.

This patch would make clang lookup coroutine_traits in std namespace
first. For the compatibility consideration, clang would lookup in
std::experimental namespace if it can't find definitions in std
namespace and emit a warning in this case. So the existing codes
wouldn't be break after update compiler.

Test Plan: check-clang, check-libcxx

Reviewed By: lxfind

Differential Revision: https://reviews.llvm.org/D108696
2021-09-03 10:22:55 +08:00
Ellis Hoag 47b239eb5a [DIBuilder] Do not replace empty enum types
It looks like this array was missed in 4276d4a8d0

Fixed tests that expected `elements` to be empty or depeneded on the order of the empty DINode.

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D107024
2021-08-30 12:33:03 -07:00
Chuanqi Xu 8a1727ba51 [Coroutines] Run coroutine passes by default
This patch make coroutine passes run by default in LLVM pipeline. Now
the clang and opt could handle IR inputs containing coroutine intrinsics
without special options.
It should be fine. On the one hand, the coroutine passes seems to be stable
since there are already many projects using coroutine feature.
On the other hand, the coroutine passes should do nothing for IR who doesn't
contain coroutine intrinsic.

Test Plan: check-llvm

Reviewed by: lxfind, aeubanks

Differential Revision: https://reviews.llvm.org/D105877
2021-07-15 14:33:40 +08:00
Xun Li 822b92aae4 [Coroutines] Add the newly generated SCCs back to the CGSCC work queue after CoroSplit actually happened
Relevant discussion can be found at: https://lists.llvm.org/pipermail/llvm-dev/2021-January/148197.html
In the existing design, An SCC that contains a coroutine will go through the folloing passes:
Inliner -> CoroSplitPass (fake) -> FunctionSimplificationPipeline -> Inliner -> CoroSplitPass (real) -> FunctionSimplificationPipeline

The first CoroSplitPass doesn't do anything other than putting the SCC back to the queue so that the entire pipeline can repeat.
As you can see, we run Inliner twice on the SCC consecutively without doing any real split, which is unnecessary and likely unintended.
What we really wanted is this:
Inliner -> FunctionSimplificationPipeline -> CoroSplitPass -> FunctionSimplificationPipeline
(note that we don't really need to run Inliner again on the ramp function after split).

Hence the way we do it here is to move CoroSplitPass to the end of the CGSCC pipeline, make it once for real, insert the newly generated SCCs (the clones) back to the pipeline so that they can be optimized, and also add a function simplification pipeline after CoroSplit to optimize the post-split ramp function.

This approach also conforms to how the new pass manager works instead of relying on an adhoc post split cleanup, making it ready for full switch to new pass manager eventually.

By looking at some of the changes to the tests, we can already observe that this changes allows for more optimizations applied to coroutines.

Reviewed By: aeubanks, ChuanqiXu

Differential Revision: https://reviews.llvm.org/D95807
2021-06-30 11:38:14 -07:00
Xun Li 31eb696fc4 [Coroutines] Remove CoroElide from O0 pipeline
CoroElide pass works only when a post-split coroutine is inlined into another post-split coroutine.
In O0, there is no inlining after CoroSplit, and hence no CoroElide can happen.
It's useless to put CoroElide pass in the O0 pipeline and it will never be triggered (unless I miss anything).

Differential Revision: https://reviews.llvm.org/D105066
2021-06-28 19:28:27 -07:00
Roman Lebedev 16d0381841
Return "[CGCall] Annotate `this` argument with alignment"
The original change was reverted because it was discovered
that clang mishandles thunks, and they receive wrong
attributes for their this/return types - the ones for the function
they will call, not the ones they have.

While i have tried to fix this in https://reviews.llvm.org/D100388
that patch has been up and stuck for a month now,
with little signs of progress.

So while it will be good to solve this for real,
for now we can simply avoid introducing the bug,
by not annotating this/return for thunks.

This reverts commit 6270b3a1ea,
relanding 0aa0458f14.
2021-05-13 20:33:14 +03:00
Yuanfang Chen 9ffd4924e8 [NFC][Coroutines] Fix two tests by removing hardcoded SSA value. 2021-05-09 19:06:16 -07:00
Arthur Eubanks 34a8a437bf [NewPM] Hide pass manager debug logging behind -debug-pass-manager-verbose
Printing pass manager invocations is fairly verbose and not super
useful.

This allows us to remove DebugLogging from pass managers and PassBuilder
since all logging (aside from analysis managers) goes through
instrumentation now.

This has the downside of never being able to print the top level pass
manager via instrumentation, but that seems like a minor downside.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D101797
2021-05-07 21:51:47 -07:00
Jeremy Morse 3c9bcf0e35 [Clang][Coroutine][DebugInfo] Relax test ordering requirement
The test added in D97533 (and modified by this patch) has some overly
strict printed metadata ordering requirements, specifically the
interleaving of DILocalVariable nodes and DILocation nodes. Slight changes
in metadata emission can easily break this unfortunately.

This patch stops after clang codegen rather than allowing the coro splitter
to run,  and reduces the need for ordering: it picks out the
DILocalVariable nodes being sought, in any order (CHECK-DAG), and doesn't
examine any DILocations. The implicit CHECK-NOT is what's important: the
test seeks to ensure a duplicate set of DILocalVariables aren't emitted in
the same scope.

Differential Revision: https://reviews.llvm.org/D100298
2021-04-26 10:07:22 +01:00
Xun Li 5faba87938 Revert "[Coroutines] Set presplit attribute in Clang instead of CoroEarly pass"
This reverts commit fa6b54c44a.
The commited patch broke mlir tests. It seems that mlir tests depend on coroutine function properties set in CoroEarly pass.
2021-04-18 17:22:28 -07:00
Xun Li fa6b54c44a [Coroutines] Set presplit attribute in Clang instead of CoroEarly pass
Presplit coroutines cannot be inlined. During AlwaysInliner we check if a function is a presplit coroutine, if so we skip inlining.
The presplit coroutine attributes are set in CoroEarly pass.
However in O0 pipeline, AlwaysInliner runs before CoroEarly, so the attribute isn't set yet and will still inline the coroutine.
This causes Clang to crash: https://bugs.llvm.org/show_bug.cgi?id=49920

To fix this, we set the attributes in the Clang front-end instead of in CoroEarly pass.

Reviewed By: rjmccall, ChuanqiXu

Differential Revision: https://reviews.llvm.org/D100282
2021-04-18 15:41:09 -07:00
Xun Li c0211e8d7d Revert "[Coroutines] Move CoroEarly pass to before AlwaysInliner"
This reverts commit 2b50f5a434.
Forgot to update the description of the commit to sync with phabricator. Going to redo the commit.
2021-04-18 15:38:19 -07:00
Xun Li 2b50f5a434 [Coroutines] Move CoroEarly pass to before AlwaysInliner
Presplit coroutines cannot be inlined. During AlwaysInliner we check if a function is a presplit coroutine, if so we skip inlining.
The presplit coroutine attributes are set in CoroEarly pass.
However in O0 pipeline, AlwaysInliner runs before CoroEarly, so the attribute isn't set yet and will still inline the coroutine.
This causes Clang to crash: https://bugs.llvm.org/show_bug.cgi?id=49920

Differential Revision: https://reviews.llvm.org/D100282
2021-04-18 14:54:04 -07:00
yifeng.dongyifeng 3a6a80b641 [Clang][Coroutine][DebugInfo] In c++ coroutine, clang will emit different debug info variables for parameters and move-parameters.
The first one is the real parameters of the coroutine function, the
other one just for copying parameters to the coroutine frame.

Considering the following c++ code:
```
struct coro {
  ...
};

coro foo(struct test & t) {
  ...
  co_await suspend_always();
    ...
    co_await suspend_always();
    ...
    co_await suspend_always();
}

int main(int argc, char *argv[]) {
  auto c = foo(...);
    c.handle.resume();
      ...
  }
```

Function foo is the standard coroutine function, and it has only
one parameter named t (ignoring this at first),
when we use the llvm code to compile this function, we can get the
following ir:

```
!2921 = distinct !DISubprogram(name: "foo", linkageName:
"_ZN6Object3fooE4test", scope: !2211, file: !45, li\
ne: 48, type: !2329, scopeLine: 48, flags: DIFlagPrototyped |
DIFlagAllCallsDescribed, spFlags: DISPFlagDefi\
nition | DISPFlagOptimized, unit: !44, declaration: !2328,
retainedNodes: !2922)
!2924 = !DILocalVariable(name: "t", arg: 2, scope: !2921, file: !45,
line: 48, type: !838)
...
!2926 = !DILocalVariable(name: "t", scope: !2921, type: !838, flags:
DIFlagArtificial)
```
We can find there are two `the same` DIVariable named t in the same
dwarf scope for foo.resume.
And when we try to use llvm-dwarfdump to dump the dwarf info of this
elf, we get the following output:

```
0x00006684:   DW_TAG_subprogram
                DW_AT_low_pc    (0x00000000004013a0)
                DW_AT_high_pc   (0x00000000004013a8)
                DW_AT_frame_base        (DW_OP_reg7 RSP)
                DW_AT_object_pointer    (0x0000669c)
                DW_AT_GNU_all_call_sites        (true)
                DW_AT_specification     (0x00005b5c "_ZN6Object3fooE4test")

0x000066a5:     DW_TAG_formal_parameter
                DW_AT_name    ("t")
                DW_AT_decl_file       ("/disk1/yifeng.dongyifeng/my_code/llvm/build/bin/coro-debug-1.cpp")
                DW_AT_decl_line       (48)
                DW_AT_type    (0x00004146 "test")

0x000066ba:     DW_TAG_variable
                  DW_AT_name    ("t")
                  DW_AT_type    (0x00004146 "test")
                  DW_AT_artificial      (true)
```
The elf also has two 't' in the same scope.
But unluckily, it might let the debugger
confused. And failed to print parameters for O0 or above.
This patch will make coroutine parameters and move
parameters use the same DIVar and try to fix the problems
that I mentioned before.

Test Plan: check-clang

Reviewed By: aprantl, jmorse

Differential Revision: https://reviews.llvm.org/D97533
2021-04-12 11:10:47 +08:00
Roman Lebedev 6270b3a1ea
Temporairly revert "[CGCall] Annotate `this` argument with alignment"
As per @jyknight, "It seems like there's a bug with vtable thunks getting the wrong information."
See https://reviews.llvm.org/D99790#2680857, https://godbolt.org/z/MxhYMe1q7

This reverts commit 0aa0458f14.
2021-04-10 10:43:16 +03:00
Roman Lebedev 0aa0458f14
[CGCall] Annotate `this` argument with alignment
As it is being noted in D99249, lack of alignment information on `this`
has been preventing LICM from happening.

For some time now, lack of alignment attribute does *not* imply
natural alignment, but an alignment of `1`.
Also, we used to treat dereferenceable as implying alignment,
but we no longer do, so it's a bugfix.

Differential Revision: https://reviews.llvm.org/D99790
2021-04-07 11:02:01 +03:00