This patch makes determining alignment and width of BitInt to be target
ABI specific and makes it consistent with [Procedure Call Standard for
the LoongArch™ Architecture] for LoongArch target
(https://github.com/loongson/la-abi-specs/blob/release/lapcs.adoc).
The LoongArch psABI recently added __bf16 type support. Now we can
enable this new type in clang.
Currently, bf16 operations are automatically supported by promoting to
float. This patch adds bf16 support by ensuring that load extension /
truncate store operations are properly expanded.
And this commit implements support for bf16 truncate/extend on hard FP
targets. The extend operation is implemented by a shift just as in the
standard legalization. This requires custom lowering of the truncate
libcall on hard float ABIs (the normal libcall code path is used on soft
ABIs).
Enable _Float16 for LoongArch target. Additionally, this change fixes
incorrect ABI lowering of _Float16 in the case of structs containing
fp16 that are eligible for passing via GPR+FPR or FPR+FPR. Finally, it
also fixes int16 -> __fp16 conversion code gen, which uses generic LLVM
IR rather than llvm.convert.to.fp16 intrinsics.
This adds support under LoongArch for the target("..") attributes.
The supported formats are:
- "arch=<arch>" strings, that specify the architecture features for a
function as per the -march=arch option.
- "tune=<cpu>" strings, that specify the tune-cpu cpu for a function as
per -mtune.
- "<feature>", "no-<feature>" enabled/disables the specific feature.
This both reapplies #118734, the initial attempt at this, and updates it
significantly.
First, it uses the newly added `StringTable` abstraction for string
tables, and simplifies the construction to build the string table and
info arrays separately. This should reduce any `constexpr` compile time
memory or CPU cost of the original PR while significantly improving the
APIs throughout.
It also restructures the builtins to support sharding across several
independent tables. This accomplishes two improvements from the
original PR:
1) It improves the APIs used significantly.
2) When builtins are defined from different sources (like SVE vs MVE in
AArch64), this allows each of them to build their own string table
independently rather than having to merge the string tables and info
structures.
3) It allows each shard to factor out a common prefix, often cutting the
size of the strings needed for the builtins by a factor two.
The second point is important both to allow different mechanisms of
construction (for example a `.def` file and a tablegen'ed `.inc` file,
or different tablegen'ed `.inc files), it also simply reduces the sizes
of these tables which is valuable given how large they are in some
cases. The third builds on that size reduction.
Initially, we use this new sharding rather than merging tables in
AArch64, LoongArch, RISCV, and X86. Mostly this helps ensure the system
works, as without further changes these still push scaling limits.
Subsequent commits will more deeply leverage the new structure,
including using the prefix capabilities which cannot be easily factored
out here and requires deep changes to the targets.
Reverts llvm/llvm-project#118734
There are currently some specific versions of MSVC that are miscompiling
this code (we think). We don't know why as all the other build bots and
at least some folks' local Windows builds work fine.
This is a candidate revert to help the relevant folks catch their
builders up and have time to debug the issue. However, the expectation
is to roll forward at some point with a workaround if at all possible.
The Clang binary (and any binary linking Clang as a library), when built
using PIE, ends up with a pretty shocking number of dynamic relocations
to apply to the executable image: roughly 400k.
Each of these takes up binary space in the executable, and perhaps most
interestingly takes start-up time to apply the relocations.
The largest pattern I identified were the strings used to describe
target builtins. The addresses of these string literals were stored into
huge arrays, each one requiring a dynamic relocation. The way to avoid
this is to design the target builtins to use a single large table of
strings and offsets within the table for the individual strings. This
switches the builtin management to such a scheme.
This saves over 100k dynamic relocations by my measurement, an over 25%
reduction. Just looking at byte size improvements, using the `bloaty`
tool to compare a newly built `clang` binary to an old one:
```
FILE SIZE VM SIZE
-------------- --------------
+1.4% +653Ki +1.4% +653Ki .rodata
+0.0% +960 +0.0% +960 .text
+0.0% +197 +0.0% +197 .dynstr
+0.0% +184 +0.0% +184 .eh_frame
+0.0% +96 +0.0% +96 .dynsym
+0.0% +40 +0.0% +40 .eh_frame_hdr
+114% +32 [ = ] 0 [Unmapped]
+0.0% +20 +0.0% +20 .gnu.hash
+0.0% +8 +0.0% +8 .gnu.version
+0.9% +7 +0.9% +7 [LOAD #2 [R]]
[ = ] 0 -75.4% -3.00Ki .relro_padding
-16.1% -802Ki -16.1% -802Ki .data.rel.ro
-27.3% -2.52Mi -27.3% -2.52Mi .rela.dyn
-1.6% -2.66Mi -1.6% -2.66Mi TOTAL
```
We get a 16% reduction in the `.data.rel.ro` section, and nearly 30%
reduction in `.rela.dyn` where those reloctaions are stored.
This is also visible in my benchmarking of binary start-up overhead at
least:
```
Benchmark 1: ./old_clang --version
Time (mean ± σ): 17.6 ms ± 1.5 ms [User: 4.1 ms, System: 13.3 ms]
Range (min … max): 14.2 ms … 22.8 ms 162 runs
Benchmark 2: ./new_clang --version
Time (mean ± σ): 15.5 ms ± 1.4 ms [User: 3.6 ms, System: 11.8 ms]
Range (min … max): 12.4 ms … 20.3 ms 216 runs
Summary
'./new_clang --version' ran
1.13 ± 0.14 times faster than './old_clang --version'
```
We get about 2ms faster `--version` runs. While there is a lot of noise
in binary execution time, this delta is pretty consistent, and
represents over 10% improvement. This is particularly interesting to me
because for very short source files, repeatedly starting the `clang`
binary is actually the dominant cost. For example, `configure` scripts
running against the `clang` compiler are slow in large part because of
binary start up time, not the time to process the actual inputs to the
compiler.
----
This PR implements the string tables using `constexpr` code and the
existing macro system. I understand that the builtins are moving towards
a TableGen model, and if complete that would provide more options for
modeling this. Unfortunately, that migration isn't complete, and even
the parts that are migrated still rely on the ability to break out of
the TableGen model and directly expand an X-macro style `BUILTIN(...)`
textually. I looked at trying to complete the move to TableGen, but it
would both require the difficult migration of the remaining targets, and
solving some tricky problems with how to move away from any macro-based
expansion.
I was also able to find a reasonably clean and effective way of doing
this with the existing macros and some `constexpr` code that I think is
clean enough to be a pretty good intermediate state, and maybe give a
good target for the eventual TableGen solution. I was also able to
factor the macros into set of consistent patterns that avoids a
significant regression in overall boilerplate.
Two options for clang
-mdiv32: Use div.w[u] and mod.w[u] instructions with input not
sign-extended.
-mno-div32: Do not use div.w[u] and mod.w[u] instructions with input not
sign-extended.
The default is -mno-div32.
Two options for clang
-mld-seq-sa: Do not generate load-load barrier instructions (dbar 0x700)
-mno-ld-seq-sa: Generate load-load barrier instructions (dbar 0x700)
The default is -mno-ld-seq-sa
Two options for clang: -mlam-bh & -mno-lam-bh.
Enable or disable amswap[__db].{b/h} and amadd[__db].{b/h} instructions.
The default is -mno-lam-bh.
Only works on LoongArch64.
The newly added strings `la64v1.0` and `la64v1.1` in `-march` are as
described in LoongArch toolchains conventions (see [1]).
The target-cpu/feature attributes are forwarded to compiler when
specifying particular `-march` parameter. The default cpu `loongarch64`
is returned when archname is `la64v1.0` or `la64v1.1`.
In addition, this commit adds `la64v1.0`/`la64v1.1` to
"__loongarch_arch" and adds definition for macro "__loongarch_frecipe".
[1]: https://github.com/loongson/la-toolchain-conventions
Although i32 type is illegal in the backend, LA64 has pretty good
support for i32 types by using W instructions.
By adding n32 to the DataLayout string, middle end optimizations will
consider i32 to be a native type. One known effect of this is enabling
LoopStrengthReduce on loops with i32 induction variables. This can be
beneficial because C/C++ code often has loops with i32 induction
variables due to the use of `int` or `unsigned int`.
If this patch exposes performance issues, those are better addressed by
tuning LSR or other passes.
This patch adds compiler options -mlsx/-mlasx which enables the
instruction sets of LSX and LASX, and sets related predefined macros
according to the options.
When building the LoongArch Linux kernel without
`CONFIG_DYNAMIC_FTRACE`, the build fails to link because the mcount
symbol is `mcount`, not `_mcount` like GCC generates and the kernel
expects:
```
ld.lld: error: undefined symbol: mcount
>>> referenced by version.c
>>> init/version.o:(early_hostname) in archive vmlinux.a
>>> referenced by do_mounts.c
>>> init/do_mounts.o:(rootfs_init_fs_context) in archive vmlinux.a
>>> referenced by main.c
>>> init/main.o:(__traceiter_initcall_level) in archive vmlinux.a
>>> referenced 97011 more times
>>> did you mean: _mcount
>>> defined in: vmlinux.a(arch/loongarch/kernel/mcount.o)
```
Set `MCountName` in `LoongArchTargetInfo` to `_mcount`, which resolves
the build failure.
As described in [1][2], `-mtune=` is used to select the type of target
microarchitecture, defaults to the value of `-march`. The set of
possible values should be a superset of `-march` values. Currently
possible values of `-march=` and `-mtune=` are `native`, `loongarch64`
and `la464`.
D136146 has supported `-march={loongarch64,la464}` and this patch adds
support for `-march=native` and `-mtune=`.
A new ProcessorModel called `loongarch64` is defined in LoongArch.td
to support `-mtune=loongarch64`.
`llvm::sys::getHostCPUName()` returns `generic` on unknown or future
LoongArch CPUs, e.g. the not yet added `la664`, leading to
`llvm::LoongArch::isValidArchName()` failing to parse the arch name.
In this case, use `loongarch64` as the default arch name for 64-bit
CPUs.
Two preprocessor macros are defined based on user-provided `-march=`
and `-mtune=` options and the defaults.
- __loongarch_arch
- __loongarch_tune
Note that, to work with `-fno-integrated-cc1` we leverage cc1 options
`-target-cpu` and `-tune-cpu` to pass driver options `-march=` and
`-mtune=` respectively because cc1 needs these information to define
macros in `LoongArchTargetInfo::getTargetDefines`.
[1]: https://github.com/loongson/LoongArch-Documentation/blob/2023.04.20/docs/LoongArch-toolchain-conventions-EN.adoc
[2]: https://github.com/loongson/la-softdev-convention/blob/v0.1/la-softdev-convention.adoc
Reviewed By: xen0n, wangleiat, steven_wu, MaskRay
Differential Revision: https://reviews.llvm.org/D155824
This reverts commit c56514f21b2cf08eaa7ac3a57ba4ce403a9c8956. This
commit adds global state that is shared between clang driver and clang
cc1, which is not correct when clang is used with `-fno-integrated-cc1`
option (no integrated cc1). The -march and -mtune option needs to be
properly passed through cc1 command-line and stored in TargetInfo.
As described in [1][2], `-mtune=` is used to select the type of target
microarchitecture, defaults to the value of `-march`. The set of
possible values should be a superset of `-march` values. Currently
possible values of `-march=` and `-mtune=` are `native`, `loongarch64`
and `la464`.
D136146 has supported `-march={loongarch64,la464}` and this patch adds
support for `-march=native` and `-mtune=`.
A new ProcessorModel called `loongarch64` is defined in LoongArch.td
to support `-mtune=loongarch64`.
`llvm::sys::getHostCPUName()` returns `generic` on unknown or future
LoongArch CPUs, e.g. the not yet added `la664`, leading to
`llvm::LoongArch::isValidArchName()` failing to parse the arch name.
In this case, use `loongarch64` as the default arch name for 64-bit
CPUs.
And these two preprocessor macros are defined:
- __loongarch_arch
- __loongarch_tune
[1]: https://github.com/loongson/LoongArch-Documentation/blob/2023.04.20/docs/LoongArch-toolchain-conventions-EN.adoc
[2]: https://github.com/loongson/la-softdev-convention/blob/v0.1/la-softdev-convention.adoc
Reviewed By: xen0n, wangleiat
Differential Revision: https://reviews.llvm.org/D155824
As described in [1][2], `-mtune=` is used to select the type of target
microarchitecture, defaults to the value of `-march`. The set of
possible values should be a superset of `-march` values. Currently
possible values of `-march=` and `-mtune=` are `native`, `loongarch64`
and `la464`.
D136146 has supported `-march={loongarch64,la464}` and this patch adds
support for `-march=native` and `-mtune=`.
A new ProcessorModel called `loongarch64` is defined in LoongArch.td
to support `-mtune=loongarch64`.
`llvm::sys::getHostCPUName()` returns `generic` on unknown or future
LoongArch CPUs, e.g. the not yet added `la664`, leading to
`llvm::LoongArch::isValidArchName()` failing to parse the arch name.
In this case, use `loongarch64` as the default arch name for 64-bit
CPUs.
And these two preprocessor macros are defined:
- __loongarch_arch
- __loongarch_tune
[1]: https://github.com/loongson/LoongArch-Documentation/blob/2023.04.20/docs/LoongArch-toolchain-conventions-EN.adoc
[2]: https://github.com/loongson/la-softdev-convention/blob/v0.1/la-softdev-convention.adoc
Differential Revision: https://reviews.llvm.org/D155824
Change the return type of `getClobbers` function from `const char*`
to `std::string_view`. Update the function usages in CodeGen module.
The reasoning of these changes is to remove unsafe `const char*`
strings and prevent unnecessary allocations for constructing the
`std::string` in usages of `getClobbers()` function.
Differential Revision: https://reviews.llvm.org/D148799
This avoids recomputing string length that is already known at compile time.
It has a slight impact on preprocessing / compile time, see
https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u
This a recommit of e953ae5bbc313fd0cc980ce021d487e5b5199ea4 and the subsequent fixes caa713559bd38f337d7d35de35686775e8fb5175 and 06b90e2e9c991e211fecc97948e533320a825470.
The above patchset caused some version of GCC to take eons to compile clang/lib/Basic/Targets/AArch64.cpp, as spotted in aa171833ab0017d9732e82b8682c9848ab25ff9e.
The fix is to make BuiltinInfo tables a compilation unit static variable, instead of a private static variable.
Differential Revision: https://reviews.llvm.org/D139881
Define below macros according to LoongArch toolchain conventions [1].
* `__loongarch_grlen`
* `__loongarch_frlen`
* `__loongarch_lp64`
* `__loongarch_hard_float`
* `__loongarch_soft_float`
* `__loongarch_single_float`
* `__loongarch_double_float`
Note:
1. `__loongarch__` has been defined in earlier patch.
2. `__loongarch_arch` is not defined because I don't know how `TargetInfo` can get the arch name specified by `-march`.
3. `__loongarch_tune` will be defined in future.
[1]: https://loongson.github.io/LoongArch-Documentation/LoongArch-toolchain-conventions-EN.html
Depends on D136146
Differential Revision: https://reviews.llvm.org/D136413
Reference: https://gcc.gnu.org/onlinedocs/gccint/Machine-Constraints.html
k: A memory operand whose address is formed by a base register and
(optionally scaled) index register.
m: A memory operand whose address is formed by a base register and
offset that is suitable for use in instructions with the same
addressing mode as st.w and ld.w.
ZB: An address that is held in a general-purpose register. The offset
is zero.
ZC: A memory operand whose address is formed by a base register and
offset that is suitable for use in instructions with the same
addressing mode as ll.w and sc.w.
Note:
The INLINEASM SDNode flags in below tests are updated because the new
introduced enum `Constraint_k` is added before `Constraint_m`.
llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-inline-asm.ll
llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-inline-asm.ll
llvm/test/CodeGen/X86/callbr-asm-kill.mir
This patch passes `ninja check-all` on a X86 machine with all official
targets and the LoongArch target enabled.
Differential Revision: https://reviews.llvm.org/D134638
This reverts commit b7baddc7557e5c35a0f6a604a134d849265a99d4.
Broke CodeGen/X86/callbr-asm-kill.mir
We shall pay attention when adding new constraints.
k: A memory operand whose address is formed by a base register and
(optionally scaled) index register.
m: A memory operand whose address is formed by a base register and
offset that is suitable for use in instructions with the same
addressing mode as st.w and ld.w.
ZB: An address that is held in a general-purpose register. The offset
is zero.
ZC: A memory operand whose address is formed by a base register and
offset that is suitable for use in instructions with the same
addressing mode as ll.w and sc.w.
Differential Revision: https://reviews.llvm.org/D134638
Reuse most of RISCV's implementation with several exceptions:
1. Assign signext/zeroext attribute to args passed in stack.
On RISCV, integer scalars passed in registers have signext/zeroext
when promoted, but are anyext if passed on the stack. This is defined
in early RISCV ABI specification. But after this change [1], integers
should also be signext/zeroext if passed on the stack. So I think
RISCV's ABI lowering should be updated [2].
While in LoongArch ABI spec, we can see that integer scalars narrower
than GRLEN bits are zero/sign-extended no matter passed in registers
or on the stack.
2. Zero-width bit fields are ignored.
This matches GCC's behavior but it hasn't been documented in ABI sepc.
See https://gcc.gnu.org/r12-8294.
3. `char` is signed by default.
There is another difference worth mentioning is that `char` is signed
by default on LoongArch while it is unsigned on RISCV.
This patch also adds `_BitInt` type support to LoongArch and handle it
in LoongArchABIInfo::classifyArgumentType.
[1] cec39a064e
[2] https://github.com/llvm/llvm-project/issues/57261
Differential Revision: https://reviews.llvm.org/D132285
With the initial support added, clang can compile `helloworld` C
to executable file for loongarch64. For example:
```
$ cat hello.c
int main() {
printf("Hello, world!\n");
return 0;
}
$ clang --target=loongarch64-unknown-linux-gnu --gcc-toolchain=xxx --sysroot=xxx hello.c
```
The output a.out can run within qemu or native machine. For example:
```
$ file ./a.out
./a.out: ELF 64-bit LSB pie executable, LoongArch, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-loongarch-lp64d.so.1, for GNU/Linux 5.19.0, with debug_info, not stripped
$ ./a.out
Hello, world!
```
Currently gcc toolchain and sysroot can be found here:
https://github.com/loongson/build-tools/releases/download/2022.08.11/loongarch64-clfs-5.1-cross-tools-gcc-glibc.tar.xz
Reference: https://github.com/loongson/LoongArch-Documentation
The last commit hash (main branch) is:
99016636af64d02dee05e39974d4c1e55875c45b
Note loongarch32 is not fully tested because there is no reference
gcc toolchain yet.
Differential Revision: https://reviews.llvm.org/D130255
