We have the `clang -cc1` command-line option `-funwind-tables=1|2` and
the codegen option `VALUE_CODEGENOPT(UnwindTables, 2, 0) ///< Unwind
tables (1) or asynchronous unwind tables (2)`. However, this is
encoded in LLVM IR by the presence or the absence of the `uwtable`
attribute, i.e. we lose the information whether to generate want just
some unwind tables or asynchronous unwind tables.
Asynchronous unwind tables take more space in the runtime image, I'd
estimate something like 80-90% more, as the difference is adding
roughly the same number of CFI directives as for prologues, only a bit
simpler (e.g. `.cfi_offset reg, off` vs. `.cfi_restore reg`). Or even
more, if you consider tail duplication of epilogue blocks.
Asynchronous unwind tables could also restrict code generation to
having only a finite number of frame pointer adjustments (an example
of *not* having a finite number of `SP` adjustments is on AArch64 when
untagging the stack (MTE) in some cases the compiler can modify `SP`
in a loop).
Having the CFI precise up to an instruction generally also means one
cannot bundle together CFI instructions once the prologue is done,
they need to be interspersed with ordinary instructions, which means
extra `DW_CFA_advance_loc` commands, further increasing the unwind
tables size.
That is to say, async unwind tables impose a non-negligible overhead,
yet for the most common use cases (like C++ exceptions), they are not
even needed.
This patch extends the `uwtable` attribute with an optional
value:
- `uwtable` (default to `async`)
- `uwtable(sync)`, synchronous unwind tables
- `uwtable(async)`, asynchronous (instruction precise) unwind tables
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D114543
The UpdateTestChecks tool itself does not care about which pass
manager that is used in the opt invocation. So the lit tests that
are verifying the behavior of the UpdateTestChecks tool is updated
to use the new-PM syntax (-passes=) when specifying the pass pipeline
in the test cases that are used for verifying the UpdateTestChecks
tool.
Differential Revision: https://reviews.llvm.org/D114517
Since d6de1e1a71406c75a4ea4d5a2fe84289f07ea3a1, no attributes is quivalent to
setting attribute to false.
This is a preliminary commit for https://reviews.llvm.org/D99080
This has been rather useful in our downstream CHERI target where we want
to run tests both with addrspace(0) and addrspace(200) pointers.
With this patch we can prefix the opt command with
`sed -e 's/addrspace(200)/addrspace(0)/g' -e 's/-A200-P200-G200//g'` to
test both cases using the same IR input.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D95137
This allows to check for various globals (metadata/attributes/...) and
also resolves problems with globals (metadata/attributes/...) being
reused across different prefixes.
Reviewed By: sstefan1
Differential Revision: https://reviews.llvm.org/D94741
Two RUN lines produce outputs that, each, have some common parts and
some different parts. The common parts are checked under label A. The
differing parts are associated to a function and checked under labels B
and C, respectivelly.
When build_function_body_dictionary is called for the first RUN line, it
will attribute the function body to labels A and C. When the second RUN
is passed to build_function_body_dictionary, it sees that the function
body under A is different from what it has. If in this second RUN line,
A were at the end of the prefixes list, A's body is still kept
associated with the first run's function.
When we output the function body (i.e. add_checks), we stop after
emitting for the first prefix matching that function. So we end up with
the wrong function body (first RUN's A-association).
There is no reason to special-case the last label in the prefixes list,
and the fix is to always clear a label association if we find a RUN line
where the body is different.
Differential Revision: https://reviews.llvm.org/D93078
This broke Chromium's PGO build, it seems because hot-cold-splitting got turned
on unintentionally. See comment on the code review for repro etc.
> This patch adds -f[no-]split-cold-code CC1 options to clang. This allows
> the splitting pass to be toggled on/off. The current method of passing
> `-mllvm -hot-cold-split=true` to clang isn't ideal as it may not compose
> correctly (say, with `-O0` or `-Oz`).
>
> To implement the -fsplit-cold-code option, an attribute is applied to
> functions to indicate that they may be considered for splitting. This
> removes some complexity from the old/new PM pipeline builders, and
> behaves as expected when LTO is enabled.
>
> Co-authored by: Saleem Abdulrasool <compnerd@compnerd.org>
> Differential Revision: https://reviews.llvm.org/D57265
> Reviewed By: Aditya Kumar, Vedant Kumar
> Reviewers: Teresa Johnson, Aditya Kumar, Fedor Sergeev, Philip Pfaffe, Vedant Kumar
This reverts commit 273c299d5d649a0222fbde03c9a41e41913751b4.
This patch adds -f[no-]split-cold-code CC1 options to clang. This allows
the splitting pass to be toggled on/off. The current method of passing
`-mllvm -hot-cold-split=true` to clang isn't ideal as it may not compose
correctly (say, with `-O0` or `-Oz`).
To implement the -fsplit-cold-code option, an attribute is applied to
functions to indicate that they may be considered for splitting. This
removes some complexity from the old/new PM pipeline builders, and
behaves as expected when LTO is enabled.
Co-authored by: Saleem Abdulrasool <compnerd@compnerd.org>
Differential Revision: https://reviews.llvm.org/D57265
Reviewed By: Aditya Kumar, Vedant Kumar
Reviewers: Teresa Johnson, Aditya Kumar, Fedor Sergeev, Philip Pfaffe, Vedant Kumar
Add the --include-generated-funcs option to update_cc_test_checks.py so that any
functions created by the compiler that don't exist in the source will also be
checked.
We need to maintain the output order of generated function checks so that
CHECK-LABEL works properly. To do so, maintain a list of functions output for
each prefix in the order they are output. Use this list to output checks for
generated functions in the proper order.
Differential Revision: https://reviews.llvm.org/D83004
Some compilers generation functions with '$' in their names, so recognize those
functions.
This also requires recognizing function names inside quotes in some contexts in
order to escape certain characters.
Differential Revision: https://reviews.llvm.org/D82995
After D85099, if we have attribute group in the function signature that hasn't
been seen before, and later a callsite with the same attribute group, filecheck will evaluate
the first attribute group to for example '#0 {'. We now include { in the args_and_sig group to avoid this.
Differential Revision: https://reviews.llvm.org/D86769
With this patch we will match most *uses* of "temporary" named things in
the IR via regular expressions, not their name at creation time. The new
"values" we match are:
- "unnamed" globals: `@[0-9]+`
- debug metadata: `!dbg ![0-9]+`
- loop metadata: `!loop ![0-9]+`
- tbaa metadata: `!tbaa ![0-9]+`
- range metadata: `!range ![0-9]+`
- generic metadata: `metadata ![0-9]+`
- attributes groups: `#[0-9]`
We still don't match the declarations but that can be done later. This
patch can introduce churn when existing check lines contain the old
hardcoded versions of the above "values". We can add a flag to opt-out,
or opt-in, if necessary.
Reviewed By: arichardson, MaskRay
Differential Revision: https://reviews.llvm.org/D85099
Summary:
This introduces new flag to the update_test_checks and
update_cc_test_checks that allows for function attributes
to be checked in a check-line. If the flag is not set,
the behavior should remain the same.
Reviewers: jdoerfert
Subscribers: arichardson, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D83629
This is effectively reverting rGbfdc2552664d to avoid test churn
while we figure out a better way forward.
We at least salvage the warning on name conflict from that patch
though.
If we change the default string again, we may want to mass update
tests at the same time. Alternatively, we could live with the poor
naming if we change -instnamer.
This also adds a test to LLVM as suggested in the post-commit
review. There's a clang test that is also affected. That seems
like a layering violation, but I have not looked at fixing that yet.
Differential Revision: https://reviews.llvm.org/D80584
We now use the argparse Action objects to determine the name of the flags.
This fixes cases where the key for the stored result ('dest') is not the
same as the command line flag (e.g. --enable/--disable).
Also add a test that --disabled can be part of the initial UTC_ARGS.
This is split out from D78478
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D78617
While D68850 allowed functions to be deleted I accidentally saved some
version of the function to be used once a suitable prefix was found.
This turned out to be problematic when the occasionally deleted function
is also occasionally modified. The test case is adjusted to resemble the
case in which the problem was found.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D76586
Update test scripts were limited because they performed a single action
on the entire file and if that action was controlled by arguments, like
the one introduced in D68819, there was no record of it.
This patch introduces the capability of changing the arguments passed to
the script "on-the-fly" while processing a test file. In addition, an
"on/off" switch was added so that processing can be disabled for parts
of the file where the content is simply copied. The last extension is a
record of the invocation arguments in the auto generated NOTE. These
arguments are also picked up in a subsequent invocation, allowing
updates with special options enabled without user interaction.
To change the arguments the string `UTC_ARGS:` has to be present in a
line, followed by "additional command line arguments". That is
everything that follows `UTC_ARGS:` will be added to a growing list
of "command line arguments" which is reparsed after every update.
Reviewed By: arichardson
Differential Revision: https://reviews.llvm.org/D69701
When functions exist for some but not all run lines we need to be
careful when selecting the prefix. So far, a common prefix was
potentially chosen as there was never a "conflict" that would have
caused otherwise. With this patch we avoid common prefixes if they
are used by run lines that do not emit the function.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D68850
If we have `int foo(int a) { return a; }` and we run with --function-signature
enabled, we want a single variable declaration for `a` which is reused
later.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D69722
Attribute annotations on calls, e.g., #0, are not useful on their own.
This patch adds a flag to update_test_checks.py to scrub them.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D68851
Summary:
This commit adds basic tests for these update script to validate that
they still work as expected. In the future we could extend these tests
whenever new features are added to avoid introducing regressions.
Reviewers: xbolva00, MaskRay, jdoerfert
Reviewed By: jdoerfert
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70660
