This patch makes the dead_on_return parameter attribute optionally require a number
of bytes to be passed in to specify the number of bytes known to be dead
upon function return/unwind. This is aimed at enabling annotating the
this pointer in C++ destructors with dead_on_return in clang. We need
this to handle cases like the following:
```
struct X {
int n;
~X() {
this[n].n = 0;
}
};
void f() {
X xs[] = {42, -1};
}
```
Where we only certain that sizeof(X) bytes are dead upon return of ~X.
Otherwise DSE would be able to eliminate the store in ~X which would not
be correct.
This patch only does the wiring within IR. Future patches will make
clang emit correct sizing information and update DSE to only delete
stores to objects marked dead_on_return that are provably in bounds of
the number of bytes specified to be dead_on_return.
Reviewers: nikic, alinas, antoniofrighetto
Pull Request: https://github.com/llvm/llvm-project/pull/171712
Let Clang emit `dead_on_return` attribute on pointer arguments
that are passed indirectly, namely, large aggregates that the
ABI mandates be passed by value; thus, the parameter is destroyed
within the callee. Writes to such arguments are not observable by
the caller after the callee returns.
This should desirably enable further MemCpyOpt/DSE optimizations.
Previous discussion: https://discourse.llvm.org/t/rfc-add-dead-on-return-attribute/86871.
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
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
This reverts commit aacfbb953eb705af2ecfeb95a6262818fa85dd92.
Revert "Fix lit test failures in CodeGenCoroutines"
This reverts commit 63fff0f5bffe20fa2c84a45a41161afa0043cb34.
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
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
Now that the legacy PM is deprecated for the optimization pipeline, we
can start deleting legacy PM tests.
For tests that test both PMs, merge the RUN lines.
Delete tests specific to the legacy PM.
This reverts the following commits:
37ca7a795b277c20c02a218bf44052278c03344b
9aa6c72b92b6c89cc6d23b693257df9af7de2d15
705387c5074bcca36d626882462ebbc2bcc3bed4
8ca4b3ef19fe82d7ad6a6e1515317dcc01b41515
80dba72a669b5416e97a42fd2c2a7bc5a6d3f44a
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
Looking at this test I did not see why MinGW was using a different command
line until I looked at the git history. Add a comment explaining what this
RUN line is actually testing. Also add two more RUN lines to show that
indirectly passed member pointers don't inhibit the optimization.
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.
This aims to fix a missed inlining case.
If there's a virtual call in the callee on an alloca (stack allocated object) in
the caller, and the callee is inlined into the caller, the post-inline cleanup
would devirtualize the virtual call, but if the next iteration of
DevirtSCCRepeatedPass doesn't happen (under the new pass manager), which is
based on a heuristic to determine whether to reiterate, we may miss inlining the
devirtualized call.
This enables inlining in clang/test/CodeGenCXX/member-function-pointer-calls.cpp.
This is a second commit after a revert
https://reviews.llvm.org/rG4569b3a86f8a4b1b8ad28fe2321f936f9d7ffd43 and a fix
https://reviews.llvm.org/rG41e06ae7ba91.
Differential Revision: https://reviews.llvm.org/D69591
DevirtSCCRepeatedPass iteration. Needs ReviewPublic
This aims to fix a missed inlining case.
If there's a virtual call in the callee on an alloca (stack allocated object) in
the caller, and the callee is inlined into the caller, the post-inline cleanup
would devirtualize the virtual call, but if the next iteration of
DevirtSCCRepeatedPass doesn't happen (under the new pass manager), which is
based on a heuristic to determine whether to reiterate, we may miss inlining the
devirtualized call.
This enables inlining in clang/test/CodeGenCXX/member-function-pointer-calls.cpp.
As per the discussion on D58375, we disable test that have optimizations under
the new PM. This patch adds -fno-experimental-new-pass-manager to RUNS that:
- Already run with optimizations (-O1 or higher) that were missed in D58375.
- Explicitly test new PM behavior along side some new PM RUNS, but are missing
this flag if new PM is enabled by default.
- Specify -O without the number. Based on getOptimizationLevel(), it seems the
default is 2, and the IR appears to be the same when changed to -O2, so
update the test to explicitly say -O2 and provide -fno-experimental-new-pass-manager`.
Differential Revision: https://reviews.llvm.org/D63156
llvm-svn: 364066
The tests that failed on a windows host have been fixed.
Original message:
Start setting dso_local for COFF.
With this there are still some GVs where we don't set dso_local
because setGVProperties is never called. I intend to fix that in
followup commits. This is just the bare minimum to teach
shouldAssumeDSOLocal what it should do for COFF.
llvm-svn: 325940
With this there are still some GVs where we don't set dso_local
because setGVProperties is never called. I intend to fix that in
followup commits. This is just the bare minimum to teach
shouldAssumeDSOLocal what it should do for COFF.
llvm-svn: 325915
The Win64 ABI docs on MSDN say that arguments bigger than 8 bytes are
passed by reference. Prior to this change, we were only applying this
logic to RecordType arguments. This affects both the Itanium and
Microsoft C++ ABIs.
Reviewers: majnemer
Differential Revision: http://reviews.llvm.org/D3587
llvm-svn: 207817
relied on an artifact of how the inliner and subsequent passes in
clang's -O3 mode happen to treat basic blocks and the labels for the
basic blocks. In my work on the inliner, and changed this fundamental
assumption, and the label that was being checked on the entry basic
block will no longer appear in opt builds. There was no reason to expect
the label to always be present anyways, much to my regret.
I've changed the test to just ensure that we return an immediate
constant. If there are intervening instructions, that's bad, but not
really that relevant to the test.
I'd love it if others have a better way of checking that a function body
contains only a 'ret' instruction that isn't dependent on whether or not
the entry block receives a label...
llvm-svn: 153243
