This option is confusingly named. What it actually controls is whether,
under the default of `-ffloat16-excess-precision=standard`, it is
beneficial for performance to perform calculations on float (without
intermediate rounding) or not. For `-ffloat16-excess-precision=none` the
LLVM `half` type will always be used, and all backends are expected to
legalize it correctly.
This is handled by the instcombine added in #147930; there is no need
for any clang-specific folding. NFC as all clang tests for
`__arm_in_streaming_mode()` used -O1, which applies the LLVM
instcombines.
FMV priority is the returned value of a polymorphic function. On RISC-V
and X86 targets a 32-bit value is enough. On AArch64 we currently need
64 bits and we will soon exceed that. APInt seems to be a suitable
replacement for uint64_t, presumably with minimal compile time overhead.
It allows bit manipulation, comparison and variable bit width.
Adds support for __sys Clang builtin for AArch64
__sys is a long existing MSVC intrinsic used to manage caches, tlbs, etc
by writing to system registers:
* It takes a macro-generated constant and uses it to form the AArch64 SYS instruction which is MSR with op0=1. The macro drops op0 and expects the implementation to hardcode it to 1 in the encoding.
* Volume use is in systems code (kernels, hypervisors, boot environments, firmware)
* Has an unused return value due to MSVC cut/paste error
Implementation:
* Clang builtin, sharing code with Read/WriteStatusReg
* Hardcodes the op0=1
* Explicitly returns 0
* Code-format change from clang-format
* Unittests included
* Not limited to MSVC-environment as its generally useful and neutral
This marks ffloor as legal providing that armv8 and neon is present (or
fullfp16 for the fp16 instructions). The existing arm_neon_vrintm
intrinsics are auto-upgraded to llvm.floor.
If this is OK I will update the other vrint intrinsics.
CreateVScale took a scaling parameter that had a single use outside of
IRBuilder with all other callers having to create a redundant
ConstantInt. To work round this some code perferred to use
CreateIntrinsic directly.
This patch simplifies CreateVScale to return a call to the llvm.vscale()
intrinsic and nothing more. As well as simplifying the existing call
sites I've also migrated the uses of CreateIntrinsic.
Whilst IRBuilder used CreateVScale's scaling parameter as part of the
implementations of CreateElementCount and CreateTypeSize, I have
follow-on work to switch them to the NUW varaiety and thus they would
stop using CreateVScale's scaling as well. To prepare for this I have
moved the multiplication and constant folding into the implementations
of CreateElementCount and CreateTypeSize.
As a final step I have replaced some callers of CreateVScale with
CreateElementCount where it's clear from the code they wanted the
latter.
This patch adds fp8 variants to existing intrinsics, whose operation
doesn't depend on arguments being a specific type.
It also changes mfloat8 type representation in memory from `i8` to
`<1xi8>`
Most callers want a constant index. Instead of making every caller
create a ConstantInt, we can do it in IRBuilder. This is similar to
createInsertElement/createExtractElement.
This is an expensive header, only include it where needed. Move some
functions out of line to achieve that.
This reduces time to build clang by ~0.5% in terms of instructions
retired.
Currently arm_neon.h emits C-style casts to do vector type casts. This
relies on implicit conversion between vector types to be enabled, which
is currently deprecated behaviour and soon will disappear. To ensure
NEON code will keep working afterwards, this patch changes all this
vector type casts into bitcasts.
Co-authored-by: Momchil Velikov <momchil.velikov@arm.com>
clang/lib/CodeGen/CGBuiltin.cpp is over 1MB long (>23k LoC), and can
take minutes to recompile (depending on compiler and host system) when
modified, and 5 seconds for clangd to update for every edit. Splitting
this file was discussed in this thread:
https://discourse.llvm.org/t/splitting-clang-s-cgbuiltin-cpp-over-23k-lines-long-takes-1min-to-compile/
and the idea has received a number of +1 votes, hence this change.
