This patch resumes the work of D16586.
According to the AAPCS, volatile bit-fields should
be accessed using containers of the widht of their
declarative type. In such case:
```
struct S1 {
short a : 1;
}
```
should be accessed using load and stores of the width
(sizeof(short)), where now the compiler does only load
the minimum required width (char in this case).
However, as discussed in D16586,
that could overwrite non-volatile bit-fields, which
conflicted with C and C++ object models by creating
data race conditions that are not part of the bit-field,
e.g.
```
struct S2 {
short a;
int b : 16;
}
```
Accessing `S2.b` would also access `S2.a`.
The AAPCS Release 2020Q2
(https://documentation-service.arm.com/static/5efb7fbedbdee951c1ccf186?token=)
section 8.1 Data Types, page 36, "Volatile bit-fields -
preserving number and width of container accesses" has been
updated to avoid conflict with the C++ Memory Model.
Now it reads in the note:
```
This ABI does not place any restrictions on the access widths of bit-fields where the container
overlaps with a non-bit-field member or where the container overlaps with any zero length bit-field
placed between two other bit-fields. This is because the C/C++ memory model defines these as being
separate memory locations, which can be accessed by two threads simultaneously. For this reason,
compilers must be permitted to use a narrower memory access width (including splitting the access into
multiple instructions) to avoid writing to a different memory location. For example, in
struct S { int a:24; char b; }; a write to a must not also write to the location occupied by b, this requires at least two
memory accesses in all current Arm architectures. In the same way, in struct S { int a:24; int:0; int b:8; };,
writes to a or b must not overwrite each other.
```
Patch D16586 was updated to follow such behavior by verifying that we
only change volatile bit-field access when:
- it won't overlap with any other non-bit-field member
- we only access memory inside the bounds of the record
- avoid overlapping zero-length bit-fields.
Regarding the number of memory accesses, that should be preserved, that will
be implemented by D67399.
Differential Revision: https://reviews.llvm.org/D72932
The following people contributed to this patch:
- Diogo Sampaio
- Ties Stuij
Discussed with @craig.topper and @spatel - this is to try and tidyup the codegen folder and move the x86 specific tests (as opposed to general tests that just happen to use x86 triples) into subfolders. Its up to other targets if they follow suit.
It also helps speed up test iterations as using wildcards on lit commands often misses some filenames.
We're now getting close to having the necessary analysis/combines etc. for the new generic llvm.abs.* intrinsics.
This patch updates the SSE/AVX ABS vector intrinsics to emit the generic equivalents instead of the icmp+sub+select code pattern.
Differential Revision: https://reviews.llvm.org/D87101
This patch implements the vec_expandm function prototypes in altivec.h in order
to utilize the vector expand with mask instructions introduced in Power10.
Differential Revision: https://reviews.llvm.org/D82727
These overloads are listed in appendix A of the ELFv2 ABI specification
without a requirement for ISA 3.0. So these need to be available on
all Altivec-capable architectures. The implementation in altivec.h
erroneously had them guarded for Power9 due to the availability of
the VCMPNE[BHW] instructions. However these need to be implemented
in terms of the VCMPEQ[BHW] instructions on older architectures.
Fixes: https://bugs.llvm.org/show_bug.cgi?id=47423
The load builtins in altivec.h do not have const in the signature
for the pointer parameter. This prevents using them for loading
from constant pointers. A notable case for such a use is Eigen.
This patch simply adds the missing const.
Fixes: https://bugs.llvm.org/show_bug.cgi?id=47408
The __ARM_FEATURE_SVE_BITS feature macro is specified in the Arm C
Language Extensions (ACLE) for SVE [1] (version 00bet5). From the spec,
where __ARM_FEATURE_SVE_BITS==N:
When N is nonzero, indicates that the implementation is generating
code for an N-bit SVE target and that the arm_sve_vector_bits(N)
attribute is available.
This was defined in D83550 as __ARM_FEATURE_SVE_BITS_EXPERIMENTAL and
enabled under the -msve-vector-bits flag to simplify initial tests.
This patch drops _EXPERIMENTAL now there is support for the feature.
[1] https://developer.arm.com/documentation/100987/latest
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D86720
This patch implements the builtins for Vector Multiply Builtins (vmulxxd family of instructions), and adds the appropriate test cases for these builtins. The builtins utilize the vector multiply instructions itnroduced with ISA 3.1.
Differential Revision: https://reviews.llvm.org/D83955
As a prerequisite to doing experimental buids of pieces of FreeBSD PowerPC64 as little-endian, allow actually targeting it.
This is needed so basic platform definitions are pulled in. Without it, the compiler will only run freestanding.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D73425
This patch implements the builtins for Vector Load with Zero and Signed Extend Builtins (lxvr_x for b, h, w, d), and adds the appropriate test cases for these builtins. The builtins utilize the vector load instructions itnroduced with ISA 3.1.
Differential Revision: https://reviews.llvm.org/D82502#inline-797941
This relands D85743 with a fix for test
CodeGen/attr-arm-sve-vector-bits-call.c that disables the new pass
manager with '-fno-experimental-new-pass-manager'. Test was failing due
to IR differences with the new pass manager which broke the Fuchsia
builder [1]. Reverted in 2e7041f.
[1] http://lab.llvm.org:8011/builders/fuchsia-x86_64-linux/builds/10375
Original summary:
This patch implements codegen for the 'arm_sve_vector_bits' type
attribute, defined by the Arm C Language Extensions (ACLE) for SVE [1].
The purpose of this attribute is to define vector-length-specific (VLS)
versions of existing vector-length-agnostic (VLA) types.
VLSTs are represented as VectorType in the AST and fixed-length vectors
in the IR everywhere except in function args/return. Implemented in this
patch is codegen support for the following:
* Implicit casting between VLA <-> VLS types.
* Coercion of VLS types in function args/return.
* Mangling of VLS types.
Casting is handled by the CK_BitCast operation, which has been extended
to support the two new vector kinds for fixed-length SVE predicate and
data vectors, where the cast is implemented through memory rather than a
bitcast which is unsupported. Implementing this as a normal bitcast
would require relaxing checks in LLVM to allow bitcasting between
scalable and fixed types. Another option was adding target-specific
intrinsics, although codegen support would need to be added for these
intrinsics. Given this, casting through memory seemed like the best
approach as it's supported today and existing optimisations may remove
unnecessary loads/stores, although there is room for improvement here.
Coercion of VLSTs in function args/return from fixed to scalable is
implemented through the AArch64 ABI in TargetInfo.
The VLA and VLS types are defined by the ACLE to map to the same
machine-level SVE vectors. VLS types are mangled in the same way as:
__SVE_VLS<typename, unsigned>
where the first argument is the underlying variable-length type and the
second argument is the SVE vector length in bits. For example:
#if __ARM_FEATURE_SVE_BITS==512
// Mangled as 9__SVE_VLSIu11__SVInt32_tLj512EE
typedef svint32_t vec __attribute__((arm_sve_vector_bits(512)));
// Mangled as 9__SVE_VLSIu10__SVBool_tLj512EE
typedef svbool_t pred __attribute__((arm_sve_vector_bits(512)));
#endif
The latest ACLE specification (00bet5) does not contain details of this
mangling scheme, it will be specified in the next revision. The
mangling scheme is otherwise defined in the appendices to the Procedure
Call Standard for the Arm Architecture, see [2] for more information.
[1] https://developer.arm.com/documentation/100987/latest
[2] https://github.com/ARM-software/abi-aa/blob/master/aapcs64/aapcs64.rst#appendix-c-mangling
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D85743
It's not undefined behavior for an unsigned left shift to overflow (i.e. to
shift bits out), but it has been the source of bugs and exploits in certain
codebases in the past. As we do in other parts of UBSan, this patch adds a
dynamic checker which acts beyond UBSan and checks other sources of errors. The
option is enabled as part of -fsanitize=integer.
The flag is named: -fsanitize=unsigned-shift-base
This matches shift-base and shift-exponent flags.
<rdar://problem/46129047>
Differential Revision: https://reviews.llvm.org/D86000
This patch adjusts the following ARM/AArch64 LLVM IR intrinsics:
- neon_bfmmla
- neon_bfmlalb
- neon_bfmlalt
so that they take and return bf16 and float types. Previously these
intrinsics used <8 x i8> and <4 x i8> vectors (a rudiment from
implementation lacking bf16 IR type).
The neon_vbfdot[q] intrinsics are adjusted similarly. This change
required some additional selection patterns for vbfdot itself and
also for vector shuffles (in a previous patch) because of SelectionDAG
transformations kicking in and mangling the original code.
This patch makes the generated IR cleaner (less useless bitcasts are
produced), but it does not affect the final assembly.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D86146
This patch implements codegen for the 'arm_sve_vector_bits' type
attribute, defined by the Arm C Language Extensions (ACLE) for SVE [1].
The purpose of this attribute is to define vector-length-specific (VLS)
versions of existing vector-length-agnostic (VLA) types.
VLSTs are represented as VectorType in the AST and fixed-length vectors
in the IR everywhere except in function args/return. Implemented in this
patch is codegen support for the following:
* Implicit casting between VLA <-> VLS types.
* Coercion of VLS types in function args/return.
* Mangling of VLS types.
Casting is handled by the CK_BitCast operation, which has been extended
to support the two new vector kinds for fixed-length SVE predicate and
data vectors, where the cast is implemented through memory rather than a
bitcast which is unsupported. Implementing this as a normal bitcast
would require relaxing checks in LLVM to allow bitcasting between
scalable and fixed types. Another option was adding target-specific
intrinsics, although codegen support would need to be added for these
intrinsics. Given this, casting through memory seemed like the best
approach as it's supported today and existing optimisations may remove
unnecessary loads/stores, although there is room for improvement here.
Coercion of VLSTs in function args/return from fixed to scalable is
implemented through the AArch64 ABI in TargetInfo.
The VLA and VLS types are defined by the ACLE to map to the same
machine-level SVE vectors. VLS types are mangled in the same way as:
__SVE_VLS<typename, unsigned>
where the first argument is the underlying variable-length type and the
second argument is the SVE vector length in bits. For example:
#if __ARM_FEATURE_SVE_BITS==512
// Mangled as 9__SVE_VLSIu11__SVInt32_tLj512EE
typedef svint32_t vec __attribute__((arm_sve_vector_bits(512)));
// Mangled as 9__SVE_VLSIu10__SVBool_tLj512EE
typedef svbool_t pred __attribute__((arm_sve_vector_bits(512)));
#endif
The latest ACLE specification (00bet5) does not contain details of this
mangling scheme, it will be specified in the next revision. The
mangling scheme is otherwise defined in the appendices to the Procedure
Call Standard for the Arm Architecture, see [2] for more information.
[1] https://developer.arm.com/documentation/100987/latest
[2] https://github.com/ARM-software/abi-aa/blob/master/aapcs64/aapcs64.rst#appendix-c-mangling
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D85743
This patch adds type information for SVE ACLE vector types,
by describing them as vectors, with a lower bound of 0, and
an upper bound described by a DWARF expression using the
AArch64 Vector Granule register (VG), which contains the
runtime multiple of 64bit granules in an SVE vector.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D86101
This patch implements the function prototypes vec_mulh and vec_dive in order to
utilize the vector multiply high (vmulh[s|u][w|d]) and vector divide extended
(vdive[s|u][w|d]) instructions introduced in Power10.
Differential Revision: https://reviews.llvm.org/D82609
Support -march=sapphirerapids for x86.
Compare with Icelake Server, it includes 14 more new features. They are
amxtile, amxint8, amxbf16, avx512bf16, avx512vp2intersect, cldemote,
enqcmd, movdir64b, movdiri, ptwrite, serialize, shstk, tsxldtrk, waitpkg.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D86503
As suggested by @rsmith on PR47267, by replacing the builtin_memcpy bitcast pattern with builtin_bit_cast we can use _castf32_u32, _castu32_f32, _castf64_u64 and _castu64_f64 inside constant expresssions (constexpr). Although __builtin_bit_cast was added for c++20 it works on all clang c/c++ modes.
Differential Revision: https://reviews.llvm.org/D86398
Currently ConstantExpr::getWithOperands does not handle FNeg and
subsequently treats FNeg as binary operator, leading to an assertion
failure or segmentation fault if built without assertions.
Originally I reproduced this with llvm-dis on a bitcode file, which I
unfortunately cannot share and also cannot really reduce.
But PR45426 describes the same issue and has a reproducer with Clang, so
I'll go with that.
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D86274
Commit dbcfbffc adds ppc.readflm and ppc.setflm intrinsics to read or
write FPSCR register. This patch adds them to Clang.
Reviewed By: steven.zhang
Differential Revision: https://reviews.llvm.org/D85874
This is a first step patch to enable constexpr support and testing to a large number of x86 intrinsics.
All I've done here is provide a DEFAULT_FN_ATTRS_CONSTEXPR variant to our existing DEFAULT_FN_ATTRS tag approach that adds constexpr on c++ builds. The clang cuda headers do something similar.
I've started with POPCNT mainly as its tiny and are wrappers to generic __builtin_* intrinsics which already act as constexpr.
Differential Revision: https://reviews.llvm.org/D86229
This adds parsing and codegen support for tune in target attribute.
I've implemented this so that arch in the target attribute implicitly disables tune from the command line. I'm not sure what gcc does here. But since -march implies -mtune. I assume 'arch' in the target attribute implies tune in the target attribute.
Differential Revision: https://reviews.llvm.org/D86187
This patch implements the vec_extractm function prototypes in altivec.h in
order to utilize the vector extract with mask instructions introduced in Power10.
Differential Revision: https://reviews.llvm.org/D82675
Pin the test to use -enable-npm-optnone.
Before, optnone wasn't implemented under NPM, so the LPM and NPM runs produced different IR. Now with -enable-npm-optnone, that is no longer necessary.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D86008
This fails due to the clang invocation running at -O0, producing an optnone function.
Then even with -O2 in the later invocations, LoopVectorizePass doesn't run on the optnone function.
So split this into an -O0 run and an -O2 run.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D86011
When casting an enumerate with a fixed bool type the casting should use
an IntegralToBoolean instead of an IntegralCast as is required per Core
Issue 2338.
Fixes PR47055: Incorrect codegen for enum with bool underlying type
Differential Revision: https://reviews.llvm.org/D85612
This was done by turning on -enable-npm-optnone and fixing failures.
That will be enabled in a follow-up change for ease of reverting.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D85457
These functions won't ever unwind. This is useful for MemorySanitizer
as it simplifies handling __atomic_load in particular.
Differential Revision: https://reviews.llvm.org/D85573
This patch implements the builtins for the vector shifts (shl, srl, sra), and
adds the appropriate test cases for these builtins. The builtins utilize the
vector shift instructions introduced within ISA 3.1.
Differential Revision: https://reviews.llvm.org/D83338
This recommits the following patches now that D85684 has landed
1cf6f210a2 [IR] Disable select ? C : undef -> C fold in ConstantFoldSelectInstruction unless we know C isn't poison.
469da663f2 [InstSimplify] Re-enable select ?, undef, X -> X transform when X is provably not poison
122b0640fc [InstSimplify] Don't fold vectors of partial undef in SimplifySelectInst if the non-undef element value might produce poison
ac0af12ed2 [InstSimplify] Add test cases for opportunities to fold select ?, X, undef -> X when we can prove X isn't poison
9b1e95329a [InstSimplify] Remove select ?, undef, X -> X and select ?, X, undef -> X transforms
COFF targets have a max object alignment of 8192, so trying to create
one with a larger size results in an unreachable in WinCOFFObjectWriter.
For the reproducer I have uses thread local storage, however other
alignments are likely affected as well.
This patch sets the MaxVectorAlign for COFF to 8192. Additionally,
though there is no longer a way to reproduce that I could find, it
correctly sets the MaxTLSAlign for COFF to that value as well, so that
if anyone comes up with a situation where this is true, it will cause an
error.
Differential Revision: https://reviews.llvm.org/D85543
When we use mask compare intrinsics under strict FP option, the masked
elements shouldn't raise any exception. So, we cann't replace the
intrinsic with a full compare + "and" operation.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D85385
Fixes pr/11710.
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Resubmit after breaking Windows and OSX builds.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D80242
This patch adds the missing information to the LF_BUILDINFO record, which allows for rebuilding a .CPP without any external dependency but the .OBJ itself (other than the compiler).
Some external tools that we are using (Recode, Live++) are extracting the information to reproduce a build without any knowledge of the build system. The LF_BUILDINFO stores a full path to the compiler, the PWD (CWD at program startup), a relative or absolute path to the TU, and the full CC1 command line. The command line needs to be freestanding (not depend on any environment variables). In the same way, MSVC doesn't store the provided command-line, but an expanded version (somehow their equivalent of CC1) which is also freestanding.
For more information see PR36198 and D43002.
Differential Revision: https://reviews.llvm.org/D80833
If the CPU string is empty, the target feature map may end up having
an empty string inserted to it. The symptom of the problem is a warning
message:
'+' is not a recognized feature for this target (ignoring feature)
Also, the target-features attribute in the module will have an empty
string in it.
This patch adds noundef to return value and arguments of standard I/O functions.
With this patch, passing undef or poison to the functions becomes undefined
behavior in LLVM IR. Since undef/poison is lowered from operations having UB in C/C++,
passing undef to them was already UB in source.
With this patch, the functions cannot return undef or poison anymore as well.
According to C17 standard, ungetc/ungetwc/fgetpos/ftell can generate unspecified
value; 3.19.3 says unspecified value is a valid value of the relevant type,
and using unspecified value is unspecified behavior, which is not UB, so it
cannot be undef (using undef is UB when e.g. it is used at branch condition).
— The value of the file position indicator after a successful call to the ungetc function for a text stream, or the ungetwc function for any stream, until all pushed-back characters are read or discarded (7.21.7.10, 7.29.3.10).
— The details of the value stored by the fgetpos function (7.21.9.1).
— The details of the value returned by the ftell function for a text stream (7.21.9.4).
In the long run, most of the functions listed in BuildLibCalls should have noundefs; to remove redundant diffs which will anyway disappear in the future, I added noundef to a few more non-I/O functions as well.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D85345
Ties Stuij