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
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.
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
The author of the following files is licongtian <licongtian@loongson.cn>:
- clang/lib/Basic/Targets/LoongArch.cpp
- llvm/lib/Target/LoongArch/LoongArchAsmPrinter.cpp
- llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
The files mentioned above implement InlineAsm for LSX and LASX as follows:
- Enable clang parsing LSX/LASX register name, such as $vr0.
- Support the case which operand type is 128bit or 256bit when the
constraints is 'f'.
- Support the way of specifying LSX/LASX register by using constraint,
such as "={$xr0}".
- Support the operand modifiers 'u' and 'w'.
- Support and legalize the data types and register classes involved in
LSX/LASX in the lowering process.
Reviewed By: xen0n, SixWeining
Differential Revision: https://reviews.llvm.org/D154931
Currenlty there is a mismatch between LoongArch gcc and clang about
handling register name in inlineasm, i.e. gcc allows both `$`-prefixed
and non-prefiexed names for GPRs while clang only allows `$`-prefixed
one. This patch fixes this mismatch by adding non-prefixed GPR names
in clang.
Take `$r4` for example. With this patch, clang accepts `$r4`, `r4`,
`$a0` and `a0` like what gcc does.
Reviewed By: xen0n
Differential Revision: https://reviews.llvm.org/D136436
Reorganize clang::Builtin::Info to have them naturally align on 4 bytes
boundaries.
Instead of storing builtin headers as a straight char pointer, enumerate
them and store the enum. It allows to use a small enum instead of a
pointer to reference them.
On a 64 bit machine, this brings sizeof(clang::Builtin::Info) from 56
down to 48 bytes.
On a release build on my Linux 64 bit machine, it shrinks the size of
libclang-cpp.so by 193kB.
The impact on performance is negligible in terms of instruction count,
but the wall time seems better, see
https://llvm-compile-time-tracker.com/compare.php?from=b3d8639f3536a4876b511aca9fb7948ff9266cee&to=a89b56423f98b550260a58c41e64aff9e56b76be&stat=task-clock
Differential Revision: https://reviews.llvm.org/D142024
The CACOP instruction is mainly used for cache initialization
and cache-consistency maintenance.
Depends on D140872
Reviewed By: SixWeining
Differential Revision: https://reviews.llvm.org/D140527
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
This patch adds support for constraints `f`, `l`, `I`, `K` according
to [1]. The remain constraints (`k`, `m`, `ZB`, `ZC`) will be added
later as they are a little more complex than the others.
f: A floating-point register (if available).
l: A signed 16-bit constant.
I: A signed 12-bit constant (for arithmetic instructions).
K: An unsigned 12-bit constant (for logic instructions).
For now, no need to support register alias (e.g. `$a0`) in llvm as
clang will correctly decode the usage of register name aliases into
their official names. And AFAIK, the not yet upstreamed `rustc` for
LoongArch will always use official register names (e.g. `$r4`).
[1] https://gcc.gnu.org/onlinedocs/gccint/Machine-Constraints.html
Differential Revision: https://reviews.llvm.org/D134157
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
