[PING] Re: [PATCH v7 00/34] libgcc: Thumb-1 Floating-Point Assembly for Cortex M0
Hello,
Is there still any interest in merging this patch?
Thanks,
Daniel
On Mon, Oct 31, 2022, at 8:44 AM, Daniel Engel wrote:
> Hi Richard,
>
> I am re-submitting my libgcc patch from 2021:
>
> https://gcc.gnu.org/pipermail/gcc-patches/2021-January/563585.html
> https://gcc.gnu.org/pipermail/gcc-patches/2021-December/587383.html
>
> I believe I have finally made the stage1 window.
>
> Regards,
> Daniel
>
> ---
>
> Changes since v6:
>
> * Rebased and tested with gcc-13
>
> There are no regressions for -march={armv4t,armv6s-m,armv7-m,armv7-a}.
> Clean master:
>
> # of expected passes529397
> # of unexpected failures41160
> # of unexpected successes 12
> # of expected failures 3442
> # of unresolved testcases 978
> # of unsupported tests 28993
>
> Patched master:
>
> # of expected passes529397
> # of unexpected failures41160
> # of unexpected successes 12
> # of expected failures 3442
> # of unresolved testcases 978
> # of unsupported tests 28993
>
> ---
>
> This patch series adds an assembly-language implementation of IEEE-754
> compliant
> single-precision functions designed for the Cortex M0 (v6m) architecture.
> There
> are improvements to most of the EABI integer functions as well. This is the
> ibgcc component of a larger library project originally proposed in 2018:
>
> https://gcc.gnu.org/legacy-ml/gcc/2018-11/msg00043.html
>
> As one point of comparison, a test program [1] links 916 bytes from libgcc
> with
> the patched toolchain vs 10276 bytes with gcc-arm-none-eabi-9-2020-q2
> toolchain.
> That's a 90% size reduction.
>
> I have extensive test vectors [2], and this patch pass all tests on an
> STM32F051.
> These vectors were derived from UCB [3], Testfloat [4], and IEEECC754
> [5], plus
> many of my own generation.
>
> There may be some follow-on projects worth discussing:
>
> * The library is currently integrated into the ARM v6s-m multilib only.
> It
> is likely that some other architectures would benefit from these routines.
> However, I have NOT profiled the existing implementations (ieee754-sf.S)
> to
> estimate where improvements may be found.
>
> * GCC currently lacks test for some functions, such as
> __aeabi_[u]ldivmod().
> There may be useful bits in [1] that can be integrated.
>
> On Cortex M0, the library has (approximately) the following properties:
>
> Function(s) Size (bytes)Cycles
> Stack Accuracy
> __clzsi250 20
> 0 exact
> __clzsi2 (OPTIMIZE_SIZE)22 51
> 0 exact
> __clzdi28+__clzsi2 4+__clzsi2
> 0 exact
>
> __clrsbsi2 8+__clzsi2 6+__clzsi2
> 0 exact
> __clrsbdi2 18+__clzsi2 (8..10)+__clzsi2
> 0 exact
>
> __ctzsi252 21
> 0 exact
> __ctzsi2 (OPTIMIZE_SIZE)24 52
> 0 exact
> __ctzdi28+__ctzsi2 5+__ctzsi2
> 0 exact
>
> __ffssi28 6..(5+__ctzsi2)
> 0 exact
> __ffsdi214+__ctzsi2 9..(8+__ctzsi2)
> 0 exact
>
> __popcountsi2 52 25
> 0 exact
> __popcountsi2 (OPTIMIZE_SIZE) 14 9..201
> 0 exact
> __popcountdi2 34+__popcountsi246
> 0 exact
> __popcountdi2 (OPTIMIZE_SIZE) 12+__popcountsi217..401
> 0 exact
>
> __paritysi2 24 14
> 0 exact
> __paritysi2 (OPTIMIZE_SIZE) 16 38
> 0 exact
> __paritydi2 2+__paritysi2 1+__paritysi2
> 0 exact
>
> __umulsidi3 44 24
> 0 exact
> __mulsidi3 30+__umulsidi3 24+__umulsidi3
> 8 exact
> __muldi3 (__aeabi_lmul) 10+__umulsidi3 6+__umulsidi3
> 0 exact
> __ashldi3 (__aeabi_llsl)22 13
> 0 exact
> __lshrdi3 (__aeabi_llsr)22 13
> 0 exact
> __ashrdi3 (__aeabi_lasr)22 13
> 0 exact
>
> __aeabi_lcmp20 13
> 0 exact
> __aeabi_ulcmp 16 10
> 0 exact
>
> __udivsi3 (__aeabi_uidiv) 56 72..385
> 0 < 1 lsb
[PATCH v7 00/34] libgcc: Thumb-1 Floating-Point Assembly for Cortex M0
Hi Richard,
I am re-submitting my libgcc patch from 2021:
https://gcc.gnu.org/pipermail/gcc-patches/2021-January/563585.html
https://gcc.gnu.org/pipermail/gcc-patches/2021-December/587383.html
I believe I have finally made the stage1 window.
Regards,
Daniel
---
Changes since v6:
* Rebased and tested with gcc-13
There are no regressions for -march={armv4t,armv6s-m,armv7-m,armv7-a}.
Clean master:
# of expected passes529397
# of unexpected failures41160
# of unexpected successes 12
# of expected failures 3442
# of unresolved testcases 978
# of unsupported tests 28993
Patched master:
# of expected passes529397
# of unexpected failures41160
# of unexpected successes 12
# of expected failures 3442
# of unresolved testcases 978
# of unsupported tests 28993
---
This patch series adds an assembly-language implementation of IEEE-754 compliant
single-precision functions designed for the Cortex M0 (v6m) architecture. There
are improvements to most of the EABI integer functions as well. This is the
ibgcc component of a larger library project originally proposed in 2018:
https://gcc.gnu.org/legacy-ml/gcc/2018-11/msg00043.html
As one point of comparison, a test program [1] links 916 bytes from libgcc with
the patched toolchain vs 10276 bytes with gcc-arm-none-eabi-9-2020-q2 toolchain.
That's a 90% size reduction.
I have extensive test vectors [2], and this patch pass all tests on an
STM32F051.
These vectors were derived from UCB [3], Testfloat [4], and IEEECC754 [5], plus
many of my own generation.
There may be some follow-on projects worth discussing:
* The library is currently integrated into the ARM v6s-m multilib only. It
is likely that some other architectures would benefit from these routines.
However, I have NOT profiled the existing implementations (ieee754-sf.S) to
estimate where improvements may be found.
* GCC currently lacks test for some functions, such as __aeabi_[u]ldivmod().
There may be useful bits in [1] that can be integrated.
On Cortex M0, the library has (approximately) the following properties:
Function(s) Size (bytes)Cycles Stack
Accuracy
__clzsi250 20 0
exact
__clzsi2 (OPTIMIZE_SIZE)22 51 0
exact
__clzdi28+__clzsi2 4+__clzsi2 0
exact
__clrsbsi2 8+__clzsi2 6+__clzsi2 0
exact
__clrsbdi2 18+__clzsi2 (8..10)+__clzsi20
exact
__ctzsi252 21 0
exact
__ctzsi2 (OPTIMIZE_SIZE)24 52 0
exact
__ctzdi28+__ctzsi2 5+__ctzsi2 0
exact
__ffssi28 6..(5+__ctzsi2) 0
exact
__ffsdi214+__ctzsi2 9..(8+__ctzsi2) 0
exact
__popcountsi2 52 25 0
exact
__popcountsi2 (OPTIMIZE_SIZE) 14 9..201 0
exact
__popcountdi2 34+__popcountsi246 0
exact
__popcountdi2 (OPTIMIZE_SIZE) 12+__popcountsi217..401 0
exact
__paritysi2 24 14 0
exact
__paritysi2 (OPTIMIZE_SIZE) 16 38 0
exact
__paritydi2 2+__paritysi2 1+__paritysi2 0
exact
__umulsidi3 44 24 0
exact
__mulsidi3 30+__umulsidi3 24+__umulsidi3 8
exact
__muldi3 (__aeabi_lmul) 10+__umulsidi3 6+__umulsidi3 0
exact
__ashldi3 (__aeabi_llsl)22 13 0
exact
__lshrdi3 (__aeabi_llsr)22 13 0
exact
__ashrdi3 (__aeabi_lasr)22 13 0
exact
__aeabi_lcmp20 13 0
exact
__aeabi_ulcmp 16 10 0
exact
__udivsi3 (__aeabi_uidiv) 56 72..385 0
< 1 lsb
__divsi3 (__aeabi_idiv) 38+__udivsi326+__udivsi38
< 1 lsb
__udivdi3 (__aeabi_uldiv) 164 103..1394 16
< 1 lsb
__udivdi3 (OPTIMIZE_SIZE) 142 120..1392 16
< 1 lsb
__divdi3 (__aeabi_ldiv) 54+__udivdi336+__udivdi332
< 1 lsb
__shared_float
