AuroraMiddleware/skia2
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

f16<->f32 ftz is an optional thing for speed.

Browse Source 
The ARMv8 asm path actually does it right... that should be okay.

My Nexus 5x fails `dm -m _finite_ftz` before this and passes after it.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2276533002

TBR=msarett@google.com

Review-Url: https://codereview.chromium.org/2276533002
This commit is contained in:
mtklein 2016-08-23 08:58:12 -07:00 committed by Commit bot
parent a97a1ab571
commit a2d2f38600
2 changed files with 14 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
src/core/SkHalf.h
View File

@ -26,8 +26,8 @@ float SkHalfToFloat(SkHalf h);
SkHalf SkFloatToHalf(float f);
// Convert between half and single precision floating point,
// assuming inputs and outputs are both finite, and
// flushing values which would be denormal half floats to zero.
// assuming inputs and outputs are both finite, and may
// flush values which would be denormal half floats to zero.
static inline Sk4f SkHalfToFloat_finite_ftz(uint64_t);
static inline Sk4h SkFloatToHalf_finite_ftz(const Sk4f&);

19
tests/Float16Test.cpp
View File

@ -70,10 +70,13 @@ DEF_TEST(SkHalfToFloat_finite_ftz, r) {
continue;
}
// _finite_ftz() flushes denorms to zero. 0.0f will compare == with both +0.0f and -0.0f.
float expected = is_denorm(h) ? 0.0f : SkHalfToFloat(h);
// _finite_ftz() may flush denorms to zero. 0.0f will compare == with both +0.0f and -0.0f.
float expected = SkHalfToFloat(h),
alternate = is_denorm(h) ? 0.0f : expected;
REPORTER_ASSERT(r, SkHalfToFloat_finite_ftz(h)[0] == expected);
float actual = SkHalfToFloat_finite_ftz(h)[0];
REPORTER_ASSERT(r, actual == expected || actual == alternate);
}
}
@ -94,13 +97,15 @@ DEF_TEST(SkFloatToHalf_finite_ftz, r) {
continue;
}
uint16_t alternate = expected;
if (is_denorm(expected)) {
// _finite_ftz() flushes denorms to zero, and happens to keep the sign bit.
expected = signbit(f) ? 0x8000 : 0x0000;
// _finite_ftz() may flush denorms to zero, and happens to keep the sign bit.
alternate = signbit(f) ? 0x8000 : 0x0000;
}
uint16_t actual = SkFloatToHalf_finite_ftz(Sk4f{f})[0];
// _finite_ftz() truncates instead of rounding, so it may be one too small.
REPORTER_ASSERT(r, actual == expected || actual == expected - 1);
// _finite_ftz() may truncate instead of rounding, so it may be one too small.
REPORTER_ASSERT(r, actual == expected || actual == expected - 1 ||
actual == alternate || actual == alternate - 1);
}
}