The current values for PrivateGlobalPrefix and PrivateLabelPrefix (@@
and @ respectively) are, in hindsight, poor choices for multiple
reasons:
First, there exist externally visible routines from the language
environment that begin with @@. These functions are certainly not
local/private by any means and they should not share a prefix with
private globals.
Secondly, both private globals and private labels should be handled the
same way by GOFF, so it doesn't make much sense for them to have
separate prefixes. GOFF remains the only file format where these are
different and there is no reason for that to be the case
The casting of FP atomic loads and stores were always done by the
front-end, even though the AtomicExpandPass will do it if the target
requests it (which is the default).
This patch removes this casting in the front-end entirely.
In the beginning, Clang only emitted atomic IR for operations it knew
the
underlying microarch had instructions for, meaning it required
significant
knowledge of the target. Later, the backend acquired the ability to
lower
IR to libcalls. To avoid duplicating logic and improve logic locality,
we'd like to move as much as possible to the backend.
There are many ways to describe this change. For example, this change
reduces the variables Clang uses to decide whether to emit libcalls or
IR, down to only the atomic's size.
The test added in #73511 currently fails in
CLANG_DEFAULT_PIE_ON_LINUX=OFF configuration, because it uses the clang
driver in a codegen test.
Split the test into two, a driver test that checks that the appropriate
target feature is passed, and a codegen test that uses cc1.
When this option is passed to clang, external (and/or weak) symbols
are not assumed to have the minimum ABI alignment normally required.
Symbols defined locally that are not weak are however still given the
minimum alignment.
This is implemented by passing a new parameter to getMinGlobalAlign()
named HasNonWeakDef that is used to return the right alignment value.
This is needed when external symbols created from a linker script may
not get the ABI minimum alignment and must therefore be treated as
unaligned by the compiler.
Set the writable and dead_on_unwind attributes for sret arguments. These
indicate that the argument points to writable memory (and it's legal to
introduce spurious writes to it on entry to the function) and that the
argument memory will not be used if the call unwinds.
This enables additional MemCpyOpt/DSE/LICM optimizations.
On processors supporting vector registers and SIMD instructions, enable
i128 as legal type in VRs. This allows many operations to be implemented
via native instructions directly in VRs (including add, subtract,
logical operations and shifts). For a few other operations (e.g.
multiply and divide, as well as atomic operations), we need to move the
i128 value back to a GPR pair to use the corresponding instruction
there. Overall, this is still beneficial.
The patch includes the following LLVM changes:
- Enable i128 as legal type
- Set up legal operations (in SystemZInstrVector.td)
- Custom expansion for i128 add/subtract with carry
- Custom expansion for i128 comparisons and selects
- Support for moving i128 to/from GPR pairs when required
- Handle 128-bit integer constant values everywhere
- Use i128 as intrinsic operand type where appropriate
- Updated and new test cases
In addition, clang builtins are updated to reflect the intrinsic operand
type changes (which also improves compatibility with GCC).
- Clang FE now has MaxAtomicPromoteWidth / MaxAtomicInlineWidth set to 128, and now produces IR
instead of calls to __atomic instrinsics for 16 bytes as well.
- Atomic __int128 (and long double) variables are now aligned to 16 bytes by default (like gcc 14).
- AtomicExpand pass now expands 16 byte operations as well.
- tests for __atomic builtins for all integer widths, and __atomic_is_lock_free with friends.
- TODO: AtomicExpand pass handles with this patch expansion of i128 atomicrmw:s. As a next step
smaller integer types should also be possible to handle this way instead of by the backend.
The __builtin_s390_vceq* family of builtins currently take
signed arguments with clang, but unsigned with GCC. Update
clang to match existing GCC precendent.
The builtins that expand to the vlrl/vlrlr and vstrl/vstrlr
instructions are currently named inconsistently between GCC
and clang. Rename the clang versions to match GCC.
Clang currently implements a set of vector rotate builtins
(__builtin_s390_verll*) in terms of platform-specific LLVM
intrinsics. To simplify the IR (and allow for common code
optimizations if applicable), this patch removes those LLVM
intrinsics and implements the builtins in terms of the
platform-independent funnel shift intrinsics instead.
Also, fix the prototype of the __builtin_s390_verll*
builtins for full compatibility with GCC.
GCC supports building individual functions with backchain using the
__attribute__((target("backchain"))) syntax, and Clang should too.
Clang translates this into the "target-features"="+backchain" attribute,
and the -mbackchain command-line option into the "backchain" attribute.
The backend currently checks only the latter; furthermore, the backchain
target feature is not defined.
Handle backchain like soft-float. Define a target feature, convert
function attribute into it in getSubtargetImpl(), and check for target
feature instead of function attribute everywhere. Add an end-to-end test
to the Clang testsuite.
Make CheckAtomicAlignment() return the computed pointer for reuse to avoid
emitting it twice.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D148422
This patch is to isolate the lax vector conversions warning only for PPC,
the reason is that SystemZ wants different logic in terms of
vector bool compatibility.
Reviewed By: lei
Differential Revision: https://reviews.llvm.org/D145506
On SystemZ, int128 values are generally aligned to only 8 bytes per the ABI
while 128 bit atomic ISA instructions exist with a full 16 byte alignment
requirement.
__sync builtins are emitted as atomicrmw instructions which always require
the natural alignment (16 bytes in this case), and they always get it
regardless of the alignment of the value being addressed.
This patch improves this situation by giving a warning if the alignment is
not known to be sufficient. This check is done in CodeGen instead of in Sema
as this is currently the only place where the alignment can be computed. This
could/should be moved into Sema in case the alignment computation could be
made there eventually.
Reviewed By: efriedma, jyknight, uweigand
Differential Revision: https://reviews.llvm.org/D143813
This patch is to fix some missing lax-vector-conversion warnings including
cases that involve vector bool and vector pixel, also to fix the vector
compatibility check for the warnings.
Differential Revision: https://reviews.llvm.org/D143210
- Global vector variables expose the vector ABI through their alignments only
if they are >=16 bytes in size.
- Vectors passed between functions expose the vector ABI only if they are
<=16 bytes in size.
LLVM test suite builds with gcc/clang now give the same gnu attributes emitted.
Reviewed By: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D141409
Instcombine prefers this canonical form (see getPreferredVectorIndex),
as does IRBuilder when passing the index as an integer so we may as
well use the prefered form from creation.
NOTE: All test changes are mechanical with nothing else expected
beyond a change of index type from i32 to i64.
Differential Revision: https://reviews.llvm.org/D140983
On SystemZ, the vector ABI changes depending on the presence of hardware
vector support. Therefore, each binary compiled with a visible vector ABI
(e.g. one that calls an external function with a vector argument) should be
marked with a .gnu_attribute describing this.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D105067
Updated the RUN line in several test cases to use the new PM syntax
opt -passes=<pipeline>
instead of the deprecated syntax
opt -pass1 -pass2
This was not a complete cleanup in clang/test. But just a swipe using
some simple search-and-replace. Mainly for RUN lines involving
-mem2reg, -instnamer and -early-cse.
Make the DataLayout string always hold a vector alignment of 8 bytes,
regardless of the vector ABI. This makes the datalayout depend only on the
target triple which is the general expectation (in assertions).
On older architectures where vectors use the natural alignment (16 bytes),
the front end will maintain the same behavior and produce an overalignment
compared to the datalayout.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D131158
The SystemZ ABI says that 128 bit integers should be aligned to only 8 bytes.
Reviewed By: Ulrich Weigand, Nikita Popov
Differential Revision: https://reviews.llvm.org/D130900
A struct like { float a; int :0; } should per the SystemZ ABI be passed in a
GPR, but to match a bug in GCC it has been passed in an FPR (see 759449c).
GCC has now corrected the C++ ABI for this case, and this patch for clang
follows suit.
Reviewed By: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D122388
The recently announced IBM z16 processor implements the architecture
already supported as "arch14" in LLVM. This patch adds support for
"z16" as an alternate architecture name for arch14.
This patch adds support for inline assembly address operands using the "p"
constraint on X86 and SystemZ.
This was in fact broken on X86 (see example at
https://reviews.llvm.org/D110267, Nov 23).
These operands should probably be treated the same as memory operands by
CodeGenPrepare, which have been commented with "TODO" there.
Review: Xiang Zhang and Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D122220
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
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
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).
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 implements the clang side of D116531. The elementtype
attribute is added for all indirect constraints (*) and tests are
updated accordingly.
Differential Revision: https://reviews.llvm.org/D116666
~(iN X s>> (N-1)) & Y --> (X s< 0) ? 0 : Y
https://alive2.llvm.org/ce/z/JKlQ9x
This is similar to D111410 / 727e642e97 ,
but it includes a 'not' of the signbit and so it
saves an instruction in the basic pattern.
DAGCombiner or target-specific folds can expand
this back into bit-hacks.
The diffs in the logical-select tests are not true
regressions - running early-cse and another round
of instcombine is expected in a normal opt pipeline,
and that reduces back to a minimal form as shown
in the duplicated PhaseOrdering test.
I have no understanding of the SystemZ diffs, so
I made the minimal edits suggested by FileCheck to
make that test pass again. That whole test file is
wrong though. It is running the entire optimizer (-O2)
to check IR, and then topping that by even running
codegen and checking asm. It needs to be split up.
Fixes#52631
The basic idea to this is that a) having a single canonical type makes CSE easier, and b) many of our transforms are inconsistent about which types we end up with based on visit order.
I'm restricting this to constants as for non-constants, we'd have to decide whether the simplicity was worth extra instructions. For constants, there are no extra instructions.
We chose the canonical type as i64 arbitrarily. We might consider changing this to something else in the future if we have cause.
Differential Revision: https://reviews.llvm.org/D115387
This change extends the current logic for inferring readonly and readnone argument attributes to also infer writeonly.
This change is deliberately minimal; there's a couple of areas for follow up.
* I left out all call handling and thus any benefit from the SCC walk. When examining the test changes, I realized the existing code is imprecise, and am going to fix that in it's own revision before adding in the writeonly handling. (Mostly because updating the tests is hard when I, the human, can't figure out whether the result is correct.)
* I left out handling for storing a value (as opposed to storing to a pointer). This should benefit readonly/readnone as well, and applies to a bunch of other instructions. Seemed worth having as a separate review.
Differential Revision: https://reviews.llvm.org/D114963
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
