[Clang][OpenMP] Fix the issue that `llvm.lifetime.end` is emitted too early for variables captured in linear clause

Currently if an OpenMP program uses `linear` clause, and is compiled with
optimiza

[Clang][OpenMP] Fix the issue that `llvm.lifetime.end` is emitted too early for variables captured in linear clause

Currently if an OpenMP program uses `linear` clause, and is compiled with
optimization, `llvm.lifetime.end` for variables listed in `linear` clause are
emitted too early such that there could still be uses after that. Let's take the
following code as example:
```
// loop.c
int j;
int *u;

void loop(int n) {
int i;
for (i = 0; i < n; ++i) {
++j;
u = &j;
}
}
```
We compile using the command:
```
clang -cc1 -fopenmp-simd -O3 -x c -triple x86_64-apple-darwin10 -emit-llvm loop.c -o loop.ll
```
The following IR (simplified) will be generated:
```
@j = local_unnamed_addr global i32 0, align 4
@u = local_unnamed_addr global ptr null, align 8

define void @loop(i32 noundef %n) local_unnamed_addr {
entry:
%j = alloca i32, align 4
%cmp = icmp sgt i32 %n, 0
br i1 %cmp, label %simd.if.then, label %simd.if.end

simd.if.then: ; preds = %entry
call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %j)
store ptr %j, ptr @u, align 8
call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %j)
%0 = load i32, ptr %j, align 4
store i32 %0, ptr @j, align 4
br label %simd.if.end

simd.if.end: ; preds = %simd.if.then, %entry
ret void
}
```
The most important part is:
```
call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %j)
%0 = load i32, ptr %j, align 4
store i32 %0, ptr @j, align 4
```
`%j` is still loaded after `@llvm.lifetime.end.p0(i64 4, ptr nonnull %j)`. This
could cause the backend incorrectly optimizes the code and further generates
incorrect code. The root cause is, when we emit a construct that could have
`linear` clause, it usually has the following pattern:
```
EmitOMPLinearClauseInit(S)
{
OMPPrivateScope LoopScope(*this);
...
EmitOMPLinearClause(S, LoopScope);
...
(void)LoopScope.Privatize();
...
}
EmitOMPLinearClauseFinal(S, [](CodeGenFunction &) { return nullptr; });
```
Variables that need to be privatized are added into `LoopScope`, which also
serves as a RAII object. When `LoopScope` is destructed and if optimization is
enabled, a `@llvm.lifetime.end` is also emitted for each privatized variable.
However, the writing back to original variables in `linear` clause happens after
the scope in `EmitOMPLinearClauseFinal`, causing the issue we see above.

A quick "fix" seems to be, moving `EmitOMPLinearClauseFinal` inside the scope.
However, it doesn't work. That's because the local variable map has been updated
by `LoopScope` such that a variable declaration is mapped to the privatized
variable, instead of the actual one. In that way, the following code will be
generated:
```
%0 = load i32, ptr %j, align 4
store i32 %0, ptr %j, align 4
call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %j)
```
Well, now the life time is correct, but apparently the writing back is broken.

In this patch, a new function `OMPPrivateScope::restoreMap` is added and called
before calling `EmitOMPLinearClauseFinal`. This can make sure that
`EmitOMPLinearClauseFinal` can find the orignal varaibls to write back.

Fixes #56913.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D131272

(cherry picked from commit e21202dac18ed7f718d26a0e131f96b399b4891c)

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Inliner: don't mark call sites as 'nounwind' if that would be redundant

When F calls G calls H, G is nounwind, and G is inlined into F, then the
inlined call-site to H should be effectively nounwind

Inliner: don't mark call sites as 'nounwind' if that would be redundant

When F calls G calls H, G is nounwind, and G is inlined into F, then the
inlined call-site to H should be effectively nounwind so as not to lose
information during inlining.

If H itself is nounwind (which often happens when H is an intrinsic), we
no longer mark the callsite explicitly as nounwind. Previously, there
were cases where the inlined call-site of H differs from a pre-existing
call-site of H in F *only* in the explicitly added nounwind attribute,
thus preventing common subexpression elimination.

v2:
- just check CI->doesNotThrow

v3 (resubmit after revert at 344378808778c61d5599f4e0ac783ef7e6f8ed05):
- update Clang tests

Differential Revision: https://reviews.llvm.org/D129860

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Rerun ./utils/update_cc_test.py on a bunch of tests

Due to update script changes; this reduces the size of a later "real"
diff.

[OpenMP][NFC] Reuse check lines for Clang/OpenMP tests

I used a script to reuse existing check lines rather than creating new
ones. There are more opportunities to reduce the line count but the
"che

[OpenMP][NFC] Reuse check lines for Clang/OpenMP tests

I used a script to reuse existing check lines rather than creating new
ones. There are more opportunities to reduce the line count but the
"check generated functions" logic makes that somewhat tricky.

FWIW, we really should redo the update script with all these use cases
in mind...

Differential Revision: https://reviews.llvm.org/D128686

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[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 p

[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

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[IRGen] Do not overwrite existing attributes in CGCall.

When adding new attributes, existing attributes are dropped. While
this appears to be a longstanding issue, this was highlighted by D105169
wh

[IRGen] Do not overwrite existing attributes in CGCall.

When adding new attributes, existing attributes are dropped. While
this appears to be a longstanding issue, this was highlighted by D105169
which dropped a lot of attributes due to adding the new noundef
attribute.

Ahmed Bougacha (@ab) tracked down the issue and provided the fix in
CGCall.cpp. I bundled it up and updated the tests.

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[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

[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

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[OPENMP]Fix PR50733: unexpected final value of list-item in linear clause in loop construct.

Currently the last value of linear is calculated as var = init + num_iters * step.
Replaced it with var =

[OPENMP]Fix PR50733: unexpected final value of list-item in linear clause in loop construct.

Currently the last value of linear is calculated as var = init + num_iters * step.
Replaced it with var = var_priv, i.e. original variable gets the value
of the last private copy.

Differential Revision: https://reviews.llvm.org/D105151

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Revert "[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default"

This reverts commit aacfbb953eb705af2ecfeb95a6262818fa85dd92.

Revert "Fix lit test failu

Revert "[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default"

This reverts commit aacfbb953eb705af2ecfeb95a6262818fa85dd92.

Revert "Fix lit test failures in CodeGenCoroutines"

This reverts commit 63fff0f5bffe20fa2c84a45a41161afa0043cb34.

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[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

[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

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Revert "[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default"

This reverts commit 7584ef766a7219b6ee5a400637206d26e0fa98ac.

[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

[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

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Revert D105169 due to the two-stage failure in ASAN

This reverts the following commits:
37ca7a795b277c20c02a218bf44052278c03344b
9aa6c72b92b6c89cc6d23b693257df9af7de2d15
705387c5074bcca36d626882462e

Revert D105169 due to the two-stage failure in ASAN

This reverts the following commits:
37ca7a795b277c20c02a218bf44052278c03344b
9aa6c72b92b6c89cc6d23b693257df9af7de2d15
705387c5074bcca36d626882462ebbc2bcc3bed4
8ca4b3ef19fe82d7ad6a6e1515317dcc01b41515
80dba72a669b5416e97a42fd2c2a7bc5a6d3f44a

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[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/up

[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

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Revert "[OpenMP] Codegen aggregate for outlined function captures"

This reverts commit 1d66649adf28d48ae1731516d87fb899426e3349.

Revert to fix AMG GPU issue.

[OpenMP] Codegen aggregate for outlined function captures

Parallel regions are outlined as functions with capture variables explicitly generated as distinct parameters in the function's argument lis

[OpenMP] Codegen aggregate for outlined function captures

Parallel regions are outlined as functions with capture variables explicitly generated as distinct parameters in the function's argument list. That complicates the fork_call interface in the OpenMP runtime: (1) the fork_call is variadic since there is a variable number of arguments to forward to the outlined function, (2) wrapping/unwrapping arguments happens in the OpenMP runtime, which is sub-optimal, has been a source of ABI bugs, and has a hardcoded limit (16) in the number of arguments, (3) forwarded arguments must cast to pointer types, which complicates debugging. This patch avoids those issues by aggregating captured arguments in a struct to pass to the fork_call.

Reviewed By: jdoerfert, jhuber6

Differential Revision: https://reviews.llvm.org/D102107

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Revert "[OpenMP] Codegen aggregate for outlined function captures"

This reverts commit e9c7291cb25f071f1a1dfa4049ed9f5a8a217b3e.

Fix failing tests

[OpenMP] Codegen aggregate for outlined function captures

Parallel regions are outlined as functions with capture variables explicitly generated as distinct parameters in the function's argument lis

[OpenMP] Codegen aggregate for outlined function captures

Parallel regions are outlined as functions with capture variables explicitly generated as distinct parameters in the function's argument list. That complicates the fork_call interface in the OpenMP runtime: (1) the fork_call is variadic since there is a variable number of arguments to forward to the outlined function, (2) wrapping/unwrapping arguments happens in the OpenMP runtime, which is sub-optimal, has been a source of ABI bugs, and has a hardcoded limit (16) in the number of arguments, (3) forwarded arguments must cast to pointer types, which complicates debugging. This patch avoids those issues by aggregating captured arguments in a struct to pass to the fork_call.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D102107

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[OpenMP] Add Module metadata for OpenMP compilation

This patch adds a module level metadata flag indicating that the module
was compiled with the `-fopenmp` flag. This will make it easier for
passes

[OpenMP] Add Module metadata for OpenMP compilation

This patch adds a module level metadata flag indicating that the module
was compiled with the `-fopenmp` flag. This will make it easier for
passes like OpenMPOpt to determine if it should be run.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D102361

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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/re

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 6270b3a1eafaba4279e021418c5a2c5a35abc002,
relanding 0aa0458f1429372038ca6a4edc7e94c96cd9a753.

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[OpenMP][NFC] Refactor Clang OpenMP tests using update_cc_test_checks

This patch refactors a subset of Clang OpenMP tests, generating checklines using the update_cc_test_checks script. This refactor

[OpenMP][NFC] Refactor Clang OpenMP tests using update_cc_test_checks

This patch refactors a subset of Clang OpenMP tests, generating checklines using the update_cc_test_checks script. This refactoring facilitates updating the Clang OpenMP code generation codebase by automating test generation.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D101849

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Revert "[OpenMP][NFC] Refactor Clang OpenMP tests using update_cc_test_checks"

This reverts commit 956cae2f09b21429dbcb02066c99e35a239aa4bf.

[OpenMP][NFC] Refactor Clang OpenMP tests using update_cc_test_checks

This patch refactors a subset of Clang OpenMP tests, generating checklines using the update_cc_test_checks script. This refactor

[OpenMP][NFC] Refactor Clang OpenMP tests using update_cc_test_checks

This patch refactors a subset of Clang OpenMP tests, generating checklines using the update_cc_test_checks script. This refactoring facilitates updating the Clang OpenMP code generation codebase by automating test generation.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D101849

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[OpenMP, test] Fix uses of undef S*VAR FileCheck var

Fix the many cases of use of undefined SIVAR/SVAR/SFVAR in OpenMP
*private_codegen tests, due to a missing BLOCK directive to capture the
IR vari

[OpenMP, test] Fix uses of undef S*VAR FileCheck var

Fix the many cases of use of undefined SIVAR/SVAR/SFVAR in OpenMP
*private_codegen tests, due to a missing BLOCK directive to capture the
IR variable when it is declared. It also fixes a few typo in its use.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D99770

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[OPENMP]Fix PR48885: Crash in passing firstprivate args to tasks on Apple M1.

Need to bitcast the function pointer passed as a parameter to the real
type to avoid possible problem with calling conve

[OPENMP]Fix PR48885: Crash in passing firstprivate args to tasks on Apple M1.

Need to bitcast the function pointer passed as a parameter to the real
type to avoid possible problem with calling conventions.

Differential Revision: https://reviews.llvm.org/D99521

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