This cc1 option -fallow-half-arguments-and-returns allows __fp16 to be
passed by argument and returned, without giving an error. It is
currently always enabled for Arm and AArch64, by forcing the option in
the driver. This means any cc1 tests (especially those needing
arm_neon.h) need to specify the option too, to prevent the error from
being emitted.
This changes it to a target option instead, set to true for Arm and
AArch64. This allows the option to be removed. Previously it was implied
by -fnative_half_arguments_and_returns, which is set for certain
languages like open_cl, renderscript and hlsl, so that option now too
controls the errors. There were are few other non-arm uses of
-fallow-half-arguments-and-returns but I believe they were unnecessary.
The strictfp_builtins.c tests were converted from __fp16 to _Float16 to
avoid the issues.
Differential Revision: https://reviews.llvm.org/D133885
c17d9b4b125e5561925aa added REQUIRES lines to a lot of Arm and AArch64
test, but added them to the very beginning, before the existing
update_cc_test_checks lines. This just moves them later so as to not
mess up the existing ordering when the checks are regenerated.
This splits out the generated headers and conditonalises them upon the
target being enabled.
The motivation here is that the RISCV header alone added 10MB to the
resource directory, which was previously at 10MB, increasing the build
size and time. This header is contributing ~50% of the size of the
resource headers (~10MB).
The ARM generated headers are contributing about ~10% or 1MB.
This could be extended further adding only the static resource headers
for the targets that the LLVM build supports.
The changes to the tests for ARM mirror what the RISCV target already
did and rnk identified as a possible issue.
Testing:
cmake -G Ninja -D LLVM_TARGETS_TO_BUILD=X86 -D LLVM_ENABLE_PROJECTS="clang;lld" ../clang
ninja check-clang
Differential Revision: https://reviews.llvm.org/D112890
Reviewed By: craig.topper
Use of bitcast resulted in lanes being swapped for vcreateq with big
endian. Fix this by using vreinterpret. No code change for little
endian. Adds IR lit test.
Differential Revision: https://reviews.llvm.org/D101606
Summary:
In big-endian MVE, the simple vector load/store instructions (i.e.
both contiguous and non-widening) don't all store the bytes of a
register to memory in the same order: it matters whether you did a
VSTRB.8, VSTRH.16 or VSTRW.32. Put another way, the in-register
formats of different vector types relate to each other in a different
way from the in-memory formats.
So, if you want to 'bitcast' or 'reinterpret' one vector type as
another, you have to carefully specify which you mean: did you want to
reinterpret the //register// format of one type as that of the other,
or the //memory// format?
The ACLE `vreinterpretq` intrinsics are specified to reinterpret the
register format. But I had implemented them as LLVM IR bitcast, which
is specified for all types as a reinterpretation of the memory format.
So a `vreinterpretq` intrinsic, applied to values already in registers,
would code-generate incorrectly if compiled big-endian: instead of
emitting no code, it would emit a `vrev`.
To fix this, I've introduced a new IR intrinsic to perform a
register-format reinterpretation: `@llvm.arm.mve.vreinterpretq`. It's
implemented by a trivial isel pattern that expects the input in an
MQPR register, and just returns it unchanged.
In the clang codegen, I only emit this new intrinsic where it's
actually needed: I prefer a bitcast wherever it will have the right
effect, because LLVM understands bitcasts better. So we still generate
bitcasts in little-endian mode, and even in big-endian when you're
casting between two vector types with the same lane size.
For testing, I've moved all the codegen tests of vreinterpretq out
into their own file, so that they can have a different set of RUN
lines to check both big- and little-endian.
Reviewers: dmgreen, MarkMurrayARM, miyuki, ostannard
Reviewed By: dmgreen
Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73786
This batch of intrinsics includes lots of things that move vector data
around or change its type without really affecting its value very
much. It includes the `vreinterpretq` family (cast one vector type to
another); `vuninitializedq` (create a vector of a given type with
don't-care contents); and `vcreateq` (make a 128-bit vector out of two
`uint64_t` halves).
These are all implemented using completely standard IR that's already
tested in existing LLVM unit tests, so I've just written a clang test
to check the IR is correct, and left it at that.
I've also added some richer infrastructure to the MveEmitter Tablegen
backend, to make it specify the exact integer type of integer
arguments passed to IR construction functions, and wrap those
arguments in a `static_cast` in the autogenerated C++. That was
necessary to prevent an overloading ambiguity when passing the integer
literal `0` to `IRBuilder::CreateInsertElement`, because otherwise, it
could mean either a null pointer `llvm::Value *` or a zero `uint64_t`.
Reviewers: ostannard, MarkMurrayARM, dmgreen
Subscribers: kristof.beyls, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D70133
