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-rw-r--r--src/core/SkNx.h10
-rw-r--r--src/effects/gradients/SkRadialGradient.cpp5
-rw-r--r--src/opts/SkNx_neon.h47
-rw-r--r--src/opts/SkNx_sse.h12
-rw-r--r--tests/SkNxTest.cpp4
5 files changed, 29 insertions, 49 deletions
diff --git a/src/core/SkNx.h b/src/core/SkNx.h
index 4cfc6e3d9a..65b5b97a83 100644
--- a/src/core/SkNx.h
+++ b/src/core/SkNx.h
@@ -119,11 +119,7 @@ public:
}
SkNf sqrt() const { return SkNf(fLo. sqrt(), fHi. sqrt()); }
-
- // Generally, increasing precision, increasing cost.
- SkNf rsqrt0() const { return SkNf(fLo.rsqrt0(), fHi.rsqrt0()); }
- SkNf rsqrt1() const { return SkNf(fLo.rsqrt1(), fHi.rsqrt1()); }
- SkNf rsqrt2() const { return SkNf(fLo.rsqrt2(), fHi.rsqrt2()); }
+ SkNf rsqrt() const { return SkNf(fLo.rsqrt(), fHi.rsqrt()); }
SkNf invert() const { return SkNf(fLo. invert(), fHi. invert()); }
SkNf approxInvert() const { return SkNf(fLo.approxInvert(), fHi.approxInvert()); }
@@ -211,9 +207,7 @@ public:
static SkNf Max(const SkNf& l, const SkNf& r) { return SkNf(SkTMax(l.fVal, r.fVal)); }
SkNf sqrt() const { return SkNf(Sqrt(fVal)); }
- SkNf rsqrt0() const { return SkNf((T)1 / Sqrt(fVal)); }
- SkNf rsqrt1() const { return this->rsqrt0(); }
- SkNf rsqrt2() const { return this->rsqrt1(); }
+ SkNf rsqrt() const { return SkNf((T)1 / Sqrt(fVal)); }
SkNf invert() const { return SkNf((T)1 / fVal); }
SkNf approxInvert() const { return this->invert(); }
diff --git a/src/effects/gradients/SkRadialGradient.cpp b/src/effects/gradients/SkRadialGradient.cpp
index 80562dece8..bf3c821f6b 100644
--- a/src/effects/gradients/SkRadialGradient.cpp
+++ b/src/effects/gradients/SkRadialGradient.cpp
@@ -377,9 +377,10 @@ void shadeSpan_radial_clamp(SkScalar sfx, SkScalar sdx,
}
}
+// TODO: can we get away with 0th approximatino of inverse-sqrt (i.e. faster than rsqrt)?
+// seems like ~10bits is more than enough for our use, since we want a byte-index
static inline Sk4f fast_sqrt(const Sk4f& R) {
- // R * R.rsqrt0() is much faster, but it's non-monotonic, which isn't so pretty for gradients.
- return R * R.rsqrt1();
+ return R * R.rsqrt();
}
static inline Sk4f sum_squares(const Sk4f& a, const Sk4f& b) {
diff --git a/src/opts/SkNx_neon.h b/src/opts/SkNx_neon.h
index f27c2b3856..6b216827a8 100644
--- a/src/opts/SkNx_neon.h
+++ b/src/opts/SkNx_neon.h
@@ -81,21 +81,20 @@ public:
static SkNf Min(const SkNf& l, const SkNf& r) { return vmin_f32(l.fVec, r.fVec); }
static SkNf Max(const SkNf& l, const SkNf& r) { return vmax_f32(l.fVec, r.fVec); }
- SkNf rsqrt0() const { return vrsqrte_f32(fVec); }
- SkNf rsqrt1() const {
- float32x2_t est0 = this->rsqrt0().fVec;
- return vmul_f32(vrsqrts_f32(fVec, vmul_f32(est0, est0)), est0);
- }
- SkNf rsqrt2() const {
- float32x2_t est1 = this->rsqrt1().fVec;
- return vmul_f32(vrsqrts_f32(fVec, vmul_f32(est1, est1)), est1);
+ SkNf rsqrt() const {
+ float32x2_t est0 = vrsqrte_f32(fVec),
+ est1 = vmul_f32(vrsqrts_f32(fVec, vmul_f32(est0, est0)), est0);
+ return est1;
}
SkNf sqrt() const {
#if defined(SK_CPU_ARM64)
return vsqrt_f32(fVec);
#else
- return *this * this->rsqrt2();
+ float32x2_t est1 = this->rsqrt().fVec,
+ // An extra step of Newton's method to refine the estimate of 1/sqrt(this).
+ est2 = vmul_f32(vrsqrts_f32(fVec, vmul_f32(est1, est1)), est1);
+ return vmul_f32(fVec, est2);
#endif
}
@@ -152,15 +151,10 @@ public:
static SkNf Max(const SkNf& l, const SkNf& r) { return vmaxq_f64(l.fVec, r.fVec); }
SkNf sqrt() const { return vsqrtq_f64(fVec); }
-
- SkNf rsqrt0() const { return vrsqrteq_f64(fVec); }
- SkNf rsqrt1() const {
- float32x4_t est0 = this->rsqrt0().fVec;
- return vmulq_f64(vrsqrtsq_f64(fVec, vmulq_f64(est0, est0)), est0);
- }
- SkNf rsqrt2() const {
- float32x4_t est1 = this->rsqrt1().fVec;
- return vmulq_f64(vrsqrtsq_f64(fVec, vmulq_f64(est1, est1)), est1);
+ SkNf rsqrt() const {
+ float64x2_t est0 = vrsqrteq_f64(fVec),
+ est1 = vmulq_f64(vrsqrtsq_f64(fVec, vmulq_f64(est0, est0)), est0);
+ return est1;
}
SkNf approxInvert() const {
@@ -275,21 +269,20 @@ public:
static SkNf Min(const SkNf& l, const SkNf& r) { return vminq_f32(l.fVec, r.fVec); }
static SkNf Max(const SkNf& l, const SkNf& r) { return vmaxq_f32(l.fVec, r.fVec); }
- SkNf rsqrt0() const { return vrsqrteq_f32(fVec); }
- SkNf rsqrt1() const {
- float32x4_t est0 = this->rsqrt0().fVec;
- return vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est0, est0)), est0);
- }
- SkNf rsqrt2() const {
- float32x4_t est1 = this->rsqrt1().fVec;
- return vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est1, est1)), est1);
+ SkNf rsqrt() const {
+ float32x4_t est0 = vrsqrteq_f32(fVec),
+ est1 = vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est0, est0)), est0);
+ return est1;
}
SkNf sqrt() const {
#if defined(SK_CPU_ARM64)
return vsqrtq_f32(fVec);
#else
- return *this * this->rsqrt2();
+ float32x4_t est1 = this->rsqrt().fVec,
+ // An extra step of Newton's method to refine the estimate of 1/sqrt(this).
+ est2 = vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est1, est1)), est1);
+ return vmulq_f32(fVec, est2);
#endif
}
diff --git a/src/opts/SkNx_sse.h b/src/opts/SkNx_sse.h
index cbe624ba2d..2608525bd0 100644
--- a/src/opts/SkNx_sse.h
+++ b/src/opts/SkNx_sse.h
@@ -82,9 +82,7 @@ public:
static SkNf Max(const SkNf& l, const SkNf& r) { return _mm_max_ps(l.fVec, r.fVec); }
SkNf sqrt() const { return _mm_sqrt_ps (fVec); }
- SkNf rsqrt0() const { return _mm_rsqrt_ps(fVec); }
- SkNf rsqrt1() const { return this->rsqrt0(); }
- SkNf rsqrt2() const { return this->rsqrt1(); }
+ SkNf rsqrt() const { return _mm_rsqrt_ps(fVec); }
SkNf invert() const { return SkNf(1) / *this; }
SkNf approxInvert() const { return _mm_rcp_ps(fVec); }
@@ -128,9 +126,7 @@ public:
static SkNf Max(const SkNf& l, const SkNf& r) { return _mm_max_pd(l.fVec, r.fVec); }
SkNf sqrt() const { return _mm_sqrt_pd(fVec); }
- SkNf rsqrt0() const { return _mm_cvtps_pd(_mm_rsqrt_ps(_mm_cvtpd_ps(fVec))); }
- SkNf rsqrt1() const { return this->rsqrt0(); }
- SkNf rsqrt2() const { return this->rsqrt1(); }
+ SkNf rsqrt() const { return _mm_cvtps_pd(_mm_rsqrt_ps(_mm_cvtpd_ps(fVec))); }
SkNf invert() const { return SkNf(1) / *this; }
SkNf approxInvert() const { return _mm_cvtps_pd(_mm_rcp_ps(_mm_cvtpd_ps(fVec))); }
@@ -214,9 +210,7 @@ public:
static SkNf Max(const SkNf& l, const SkNf& r) { return _mm_max_ps(l.fVec, r.fVec); }
SkNf sqrt() const { return _mm_sqrt_ps (fVec); }
- SkNf rsqrt0() const { return _mm_rsqrt_ps(fVec); }
- SkNf rsqrt1() const { return this->rsqrt0(); }
- SkNf rsqrt2() const { return this->rsqrt1(); }
+ SkNf rsqrt() const { return _mm_rsqrt_ps(fVec); }
SkNf invert() const { return SkNf(1) / *this; }
SkNf approxInvert() const { return _mm_rcp_ps(fVec); }
diff --git a/tests/SkNxTest.cpp b/tests/SkNxTest.cpp
index dec7329c2c..25ece3867b 100644
--- a/tests/SkNxTest.cpp
+++ b/tests/SkNxTest.cpp
@@ -50,9 +50,7 @@ static void test_Nf(skiatest::Reporter* r) {
SkNf<N,T> fours(4);
assert_eq(fours.sqrt(), 2,2,2,2);
- assert_nearly_eq(0.001, fours.rsqrt0(), 0.5, 0.5, 0.5, 0.5);
- assert_nearly_eq(0.001, fours.rsqrt1(), 0.5, 0.5, 0.5, 0.5);
- assert_nearly_eq(0.001, fours.rsqrt2(), 0.5, 0.5, 0.5, 0.5);
+ assert_nearly_eq(0.001, fours.rsqrt(), 0.5, 0.5, 0.5, 0.5);
assert_eq( fours. invert(), 0.25, 0.25, 0.25, 0.25);
assert_nearly_eq(0.001, fours.approxInvert(), 0.25, 0.25, 0.25, 0.25);
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-01 12:45:19 +0000