[Qemu-devel] [PATCH 00/24] re-factor and add fp16 using glibc soft-fp
As discussed on list, the structure and inline function solution that Alex and I have been writing from scratch introduces a sizeable performance regression. Alex and I have done some work earlier in the week that improved things some, but not enough. Which leaves us with a bit of a problem. The were two existing code bases that we originally considered: There's softfloat v3, which would need a large structural reorg in order to be able to handle multiple float_status contexts. But when Alex communicated with upstream they weren't ready to accept patches. Or there's the code from glibc. I know Peter didn't like the idea; debugging this code is fairly painful -- the massive preprocessor macros mean that you can't step through anything. But at least we have a good relationship with glibc, so merging patches back and forth should be easy. The result seems to perform slightly better than mainline. With an aarch64 guest and a i7-8550U host, nbench gives - FLOATING-POINT INDEX: 3.095 + FLOATING-POINT INDEX: 3.438 I've also run this through my usual set of aarch64 RISU tests. Thoughts? r~ Alex Bennée (9): fpu/softfloat: implement float16_squash_input_denormal include/fpu/softfloat: remove USE_SOFTFLOAT_STRUCT_TYPES fpu/softfloat-types: new header to prevent excessive re-builds target/*/cpu.h: remove softfloat.h include/fpu/softfloat: implement float16_abs helper include/fpu/softfloat: implement float16_chs helper include/fpu/softfloat: implement float16_set_sign helper include/fpu/softfloat: add some float16 constants fpu/softfloat: improve comments on ARM NaN propagation Richard Henderson (15): fpu/soft-fp: Import soft-fp from glibc fpu/soft-fp: Adjust soft-fp types fpu/soft-fp: Add ties_away and to_odd rounding modes fpu/soft-fp: Add arithmetic macros to half.h fpu/soft-fp: Adjust _FP_CMP_CHECK_NAN fpu: Implement add/sub/mul/div with soft-fp.h fpu: Implement float_to_int/uint with soft-fp.h fpu: Implement int/uint_to_float with soft-fp.h fpu: Implement compares with soft-fp.h fpu: Implement min/max with soft-fp.h fpu: Implement sqrt with soft-fp.h fpu: Implement scalbn with soft-fp.h fpu: Implement float_to_float with soft-fp.h fpu: Implement muladd with soft-fp.h fpu: Implement round_to_int with soft-fp.h Makefile.target |5 + fpu/double.h| 321 +++ fpu/half.h | 180 ++ fpu/op-1.h | 369 +++ fpu/op-2.h | 705 ++ fpu/op-4.h | 875 +++ fpu/op-8.h |1 + fpu/op-common.h | 2154 + fpu/quad.h | 328 +++ fpu/sfp-machine.h | 222 ++ fpu/single.h| 197 ++ fpu/soft-fp-specialize.h| 254 ++ fpu/soft-fp.h | 379 +++ fpu/softfloat-specialize.h | 273 +-- include/fpu/softfloat-types.h | 179 ++ include/fpu/softfloat.h | 254 +- include/qemu/bswap.h|2 +- target/alpha/cpu.h |2 - target/arm/cpu.h|2 - target/hppa/cpu.h |1 - target/i386/cpu.h |4 - target/m68k/cpu.h |1 - target/microblaze/cpu.h |2 +- target/moxie/cpu.h |1 - target/nios2/cpu.h |1 - target/openrisc/cpu.h |1 - target/ppc/cpu.h|1 - target/s390x/cpu.h |2 - target/sh4/cpu.h|2 - target/sparc/cpu.h |2 - target/tricore/cpu.h|1 - target/unicore32/cpu.h |1 - target/xtensa/cpu.h |1 - fpu/float128.c | 35 + fpu/float16.c | 43 + fpu/float32.c | 35 + fpu/float64.c | 35 + fpu/floatconv.c | 154 ++ fpu/floatxx.inc.c | 541 + fpu/softfloat.c | 5092 +-- target/arm/cpu.c|1 + target/arm/helper-a64.c |1 + target/arm/helper.c |1 + target/arm/neon_helper.c|1 + target/hppa/cpu.c |1 + target/hppa/op_helper.c |1 + target/i386/fpu_helper.c|1 + target/m68k/cpu.c |2 +- target/m68k/fpu_helper.c|1 + target/m68k/helper.c|1 + target/m68k/translate.c |2 + target/microblaze/cpu.c |1 + target/microblaze/op_helper.c |1 + target/openrisc/fpu_helper.c|1 + target/ppc/fpu_helper.c |1 + target/ppc/int_helper.c |1 + target/ppc/translate_init.c |1 + target/s390x/cpu.c |1 + target/s390x/fpu_helper.c |1 + target/sh4/cpu.c|1 + target/sh4/op_helper.c |1 + target/sparc/fop_helper.c |1 +
Re: [Qemu-devel] [PATCH 00/24] re-factor and add fp16 using glibc soft-fp
On Sun, Feb 4, 2018 at 5:11 AM, Richard Henderson wrote: > As discussed on list, the structure and inline function solution that > Alex and I have been writing from scratch introduces a sizeable > performance regression. Alex and I have done some work earlier > in the week that improved things some, but not enough. > > Which leaves us with a bit of a problem. The were two existing > code bases that we originally considered: > > There's softfloat v3, which would need a large structural reorg in > order to be able to handle multiple float_status contexts. But when > Alex communicated with upstream they weren't ready to accept patches. > > Or there's the code from glibc. I know Peter didn't like the idea; > debugging this code is fairly painful -- the massive preprocessor > macros mean that you can't step through anything. But at least we > have a good relationship with glibc, so merging patches back and > forth should be easy. > > The result seems to perform slightly better than mainline. > With an aarch64 guest and a i7-8550U host, nbench gives > > - FLOATING-POINT INDEX: 3.095 > + FLOATING-POINT INDEX: 3.438 > > I've also run this through my usual set of aarch64 RISU tests. > > Thoughts? > > Hi, Thanks for looking into this. It seems this code does not build on OSX Sierra nor while cross compiling for Windows on Fedora 27: In file included from /Users/hsp/src/qemu-softfloatglibc/fpu/float16.c:20: /Users/hsp/src/qemu-softfloatglibc/fpu/soft-fp.h:50:4: error: "endianness not defined by sfp-machine.h" # error "endianness not defined by sfp-machine.h" Best, Howard
Re: [Qemu-devel] [PATCH 00/24] re-factor and add fp16 using glibc soft-fp
On 4 February 2018 at 04:11, Richard Henderson wrote: > Or there's the code from glibc. I know Peter didn't like the idea; > debugging this code is fairly painful -- the massive preprocessor > macros mean that you can't step through anything. But at least we > have a good relationship with glibc, so merging patches back and > forth should be easy. Yeah. I didn't like dealing with this code two decades ago when I first encountered it, and it hasn't improved any. It's pretty much write-only code, and it isn't going to be any fun for debugging. thanks -- PMM
Re: [Qemu-devel] [PATCH 00/24] re-factor and add fp16 using glibc soft-fp
Peter Maydell writes: > On 4 February 2018 at 04:11, Richard Henderson > wrote: >> Or there's the code from glibc. I know Peter didn't like the idea; >> debugging this code is fairly painful -- the massive preprocessor >> macros mean that you can't step through anything. But at least we >> have a good relationship with glibc, so merging patches back and >> forth should be easy. > > Yeah. I didn't like dealing with this code two decades ago > when I first encountered it, and it hasn't improved any. > It's pretty much write-only code, and it isn't going to be > any fun for debugging. I think I've managed to pull the performance back on softfloat-v4 thanks to the attribute(flatten) changes to addsub/div/mul/mulladd. -- Alex Bennée
Re: [Qemu-devel] [PATCH 00/24] re-factor and add fp16 using glibc soft-fp
Hi, This series seems to have some coding style problems. See output below for more information: Type: series Message-id: 20180204041136.17525-1-richard.hender...@linaro.org Subject: [Qemu-devel] [PATCH 00/24] re-factor and add fp16 using glibc soft-fp === TEST SCRIPT BEGIN === #!/bin/bash BASE=base n=1 total=$(git log --oneline $BASE.. | wc -l) failed=0 git config --local diff.renamelimit 0 git config --local diff.renames True commits="$(git log --format=%H --reverse $BASE..)" for c in $commits; do echo "Checking PATCH $n/$total: $(git log -n 1 --format=%s $c)..." if ! git show $c --format=email | ./scripts/checkpatch.pl --mailback -; then failed=1 echo fi n=$((n+1)) done exit $failed === TEST SCRIPT END === Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384 error: RPC failed; curl 18 transfer closed with outstanding read data remaining fatal: The remote end hung up unexpectedly error: Could not fetch 3c8cf5a9c21ff8782164d1def7f44bd888713384 Traceback (most recent call last): File "/usr/bin/patchew", line 442, in test_one git_clone_repo(clone, r["repo"], r["head"], logf) File "/usr/bin/patchew", line 48, in git_clone_repo stdout=logf, stderr=logf) File "/usr/lib64/python3.6/subprocess.py", line 291, in check_call raise CalledProcessError(retcode, cmd) subprocess.CalledProcessError: Command '['git', 'remote', 'add', '-f', '--mirror=fetch', '3c8cf5a9c21ff8782164d1def7f44bd888713384', 'https://github.com/patchew-project/qemu']' returned non-zero exit status 1. --- Email generated automatically by Patchew [http://patchew.org/]. Please send your feedback to patchew-de...@freelists.org
Re: [Qemu-devel] [PATCH 00/24] re-factor and add fp16 using glibc soft-fp
Hi, This series failed docker-mingw@fedora build test. Please find the testing commands and their output below. If you have Docker installed, you can probably reproduce it locally. Type: series Message-id: 20180204041136.17525-1-richard.hender...@linaro.org Subject: [Qemu-devel] [PATCH 00/24] re-factor and add fp16 using glibc soft-fp === TEST SCRIPT BEGIN === #!/bin/bash set -e git submodule update --init dtc # Let docker tests dump environment info export SHOW_ENV=1 export J=8 time make docker-test-mingw@fedora === TEST SCRIPT END === Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384 Switched to a new branch 'test' 54bfdc61a5 fpu: Implement round_to_int with soft-fp.h cea1e682ca fpu: Implement muladd with soft-fp.h 70b4528db0 fpu: Implement float_to_float with soft-fp.h b4c110b84f fpu: Implement scalbn with soft-fp.h 5b30da2aa0 fpu: Implement sqrt with soft-fp.h a4e5a62d79 fpu: Implement min/max with soft-fp.h 14c4d2bcdf fpu: Implement compares with soft-fp.h f54c32c68c fpu: Implement int/uint_to_float with soft-fp.h a8f491ad0e fpu: Implement float_to_int/uint with soft-fp.h 6d17d64dde fpu: Implement add/sub/mul/div with soft-fp.h 017e0c5da1 fpu/soft-fp: Adjust _FP_CMP_CHECK_NAN 4017e90c32 fpu/soft-fp: Add arithmetic macros to half.h b60dd3e9a3 fpu/soft-fp: Add ties_away and to_odd rounding modes 207fb14412 fpu/soft-fp: Adjust soft-fp types c319fb5b30 fpu/soft-fp: Import soft-fp from glibc c45db50d7c fpu/softfloat: improve comments on ARM NaN propagation 1e8300958f include/fpu/softfloat: add some float16 constants c1f9b7e53d include/fpu/softfloat: implement float16_set_sign helper b592870a92 include/fpu/softfloat: implement float16_chs helper 6044c4568a include/fpu/softfloat: implement float16_abs helper e08ee277b9 target/*/cpu.h: remove softfloat.h 5e9ee7ddaa fpu/softfloat-types: new header to prevent excessive re-builds 7f1df09de5 include/fpu/softfloat: remove USE_SOFTFLOAT_STRUCT_TYPES ed6075583d fpu/softfloat: implement float16_squash_input_denormal === OUTPUT BEGIN === Submodule 'dtc' (git://git.qemu-project.org/dtc.git) registered for path 'dtc' Cloning into '/var/tmp/patchew-tester-tmp-cgiev8vr/src/dtc'... Submodule path 'dtc': checked out 'e54388015af1fb4bf04d0bca99caba1074d9cc42' BUILD fedora GEN /var/tmp/patchew-tester-tmp-cgiev8vr/src/docker-src.2018-02-08-16.06.27.17466/qemu.tar Cloning into '/var/tmp/patchew-tester-tmp-cgiev8vr/src/docker-src.2018-02-08-16.06.27.17466/qemu.tar.vroot'... done. Checking out files: 29% (1729/5796) Checking out files: 30% (1739/5796) Checking out files: 31% (1797/5796) Checking out files: 32% (1855/5796) Checking out files: 33% (1913/5796) Checking out files: 34% (1971/5796) Checking out files: 35% (2029/5796) Checking out files: 36% (2087/5796) Checking out files: 37% (2145/5796) Checking out files: 38% (2203/5796) Checking out files: 39% (2261/5796) Checking out files: 40% (2319/5796) Checking out files: 41% (2377/5796) Checking out files: 42% (2435/5796) Checking out files: 43% (2493/5796) Checking out files: 44% (2551/5796) Checking out files: 45% (2609/5796) Checking out files: 46% (2667/5796) Checking out files: 47% (2725/5796) Checking out files: 48% (2783/5796) Checking out files: 49% (2841/5796) Checking out files: 50% (2898/5796) Checking out files: 51% (2956/5796) Checking out files: 52% (3014/5796) Checking out files: 53% (3072/5796) Checking out files: 54% (3130/5796) Checking out files: 55% (3188/5796) Checking out files: 56% (3246/5796) Checking out files: 57% (3304/5796) Checking out files: 58% (3362/5796) Checking out files: 59% (3420/5796) Checking out files: 60% (3478/5796) Checking out files: 61% (3536/5796) Checking out files: 62% (3594/5796) Checking out files: 63% (3652/5796) Checking out files: 64% (3710/5796) Checking out files: 65% (3768/5796) Checking out files: 66% (3826/5796) Checking out files: 67% (3884/5796) Checking out files: 68% (3942/5796) Checking out files: 69% (4000/5796) Checking out files: 70% (4058/5796) Checking out files: 71% (4116/5796) Checking out files: 72% (4174/5796) Checking out files: 73% (4232/5796) Checking out files: 74% (4290/5796) Checking out files: 75% (4347/5796) Checking out files: 76% (4405/5796) Checking out files: 77% (4463/5796) Checking out files: 78% (4521/5796) Checking out files: 79% (4579/5796) Checking out files: 80% (4637/5796) Checking out files: 81% (4695/5796) Checking out files: 82% (4753/5796) Checking out files: 83% (4811/5796) Checking out files: 84% (4869/5796) Checking out files: 85% (4927/5796) Checking out files: 86% (4985/5796) Checking out files: 87% (5043/5796) Checking out files: 88% (5101/5796) Checking out files: 89% (5159/5796) Checking out files
