v1: https://lists.nongnu.org/archive/html/qemu-devel/2018-03/msg05908.html
Changes from v1:
- Rename series from "hostfloat" to "hardfloat". The series already uses
"host" as an option for fp-test, so this change should make things clearer
- Rebase on top of master (4c2c101590).
- Move code from fpu/hostfloat.c to fpu/softfloat.c. I am not mentioning
anything about the license; I read the softfloat-2a license and I'm OK
with it. [ Laurent: thanks for the clarification on this. ]
- Fix target-m68k build breakage
- Merge is_normal and is_denormal additions into a single commit
- Add tricore patch to use float32_is_denormal
- Keep the flatten attribute for the soft-fp implementations that
have now become a slow path
- Add the noinline attribute to the soft-fp primitives. Not doing
this reduces performance significantly
- Add a comment about why dealing with denormals in hardfloat is
a bad idea
- Keep separate float32 and float64 implementations for most ops. This
improves performance as shown in the commit logs.
+ I'm keeping the macro-based definitions to make testing easier.
+ In v1 I wrongly reported similar float/double results for fp-bench;
I noticed that in my testing I forgot to set -p single/double, so I was
benchmarking only with the default precision (single). Ouch!
- Update commit logs with fresh (correct) numbers from fp-bench.
- Move some zero-input detection (addsub/div) *after* checking for
<= min_normal. This makes the common case (i.e. not all inputs are zero)
faster, still allowing us to handle the 0-input cases in hardfloat
- Update the commit log of the comparison patch to mention that
int64_to_float32/64 are still in soft-fp and take quite a bit of
execution time for fp-bench -o cmp.
- fp-test:
+ add *.txt to fp-test/.gitignore instead of just whitelist.txt
- fp-bench
+ generate only positive numbers for testing sqrt
+ add -o cmp
+ use g_strjoinv to print the list of available ops in the
help message
+ remove libc headers except math.h
+ use qemu/timer.h's get_clock_realtime instead of open-coding it
+ add entry to tests/Makefile.include to call fp-test/Makefile
when building anything in tests/fp-test/
Perf numbers are in the last patch. They are a little different than
last week; I cannot replicate last week's performance (even with
the very same binaries; might have to reboot the machine I'm using
soon), but as of today v2 is certainly faster than v1 (e.g. 5% faster
for nbench-fp).
I have checked all checkpatch warnings; they're all false positives.
You can fetch the series from:
https://github.com/cota/qemu/tree/hardfloat-v2
Thanks,
Emilio
diffstat:
configure | 2 +
fpu/softfloat.c | 619 ++++++++++++++++++--
include/fpu/softfloat.h | 20 +
target/tricore/fpu_helper.c | 9 +-
tests/.gitignore | 2 +
tests/Makefile.include | 6 +-
tests/fp-bench.c | 334 +++++++++++
tests/fp-test/.gitignore | 3 +
tests/fp-test/Makefile | 34 ++
tests/fp-test/fp-test.c | 1183 ++++++++++++++++++++++++++++++++++++++
tests/fp-test/muladd.fptest | 51 ++
11 files changed, 2212 insertions(+), 51 deletions(-)
create mode 100644 tests/fp-bench.c
create mode 100644 tests/fp-test/.gitignore
create mode 100644 tests/fp-test/Makefile
create mode 100644 tests/fp-test/fp-test.c
create mode 100644 tests/fp-test/muladd.fptest
