diff options
| -rw-r--r-- | bench/MathBench.cpp | 12 | ||||
| -rw-r--r-- | include/private/SkFloatingPoint.h | 6 |
2 files changed, 5 insertions, 13 deletions
diff --git a/bench/MathBench.cpp b/bench/MathBench.cpp index 05a5f8a2d5..541a1052dc 100644 --- a/bench/MathBench.cpp +++ b/bench/MathBench.cpp @@ -126,23 +126,13 @@ private: typedef MathBench INHERITED; }; -static inline float SkFastInvSqrt(float x) { - float xhalf = 0.5f*x; - uint32_t i = *SkTCast<uint32_t*>(&x); - i = 0x5f3759df - (i>>1); - x = *SkTCast<float*>(&i); - x = x*(1.5f-xhalf*x*x); -// x = x*(1.5f-xhalf*x*x); // this line takes err from 10^-3 to 10^-6 - return x; -} - class FastISqrtMathBench : public MathBench { public: FastISqrtMathBench() : INHERITED("fastIsqrt") {} protected: void performTest(float* SK_RESTRICT dst, const float* SK_RESTRICT src, int count) override { for (int i = 0; i < count; ++i) { - dst[i] = SkFastInvSqrt(src[i]); + dst[i] = sk_float_rsqrt(src[i]); } } private: diff --git a/include/private/SkFloatingPoint.h b/include/private/SkFloatingPoint.h index 8d8843eb58..6a6edf3651 100644 --- a/include/private/SkFloatingPoint.h +++ b/include/private/SkFloatingPoint.h @@ -107,9 +107,11 @@ static const uint32_t kIEEENotANumber = 0x7fffffff; static inline float sk_float_rsqrt_portable(float x) { // Get initial estimate. - int i = *SkTCast<int*>(&x); + int i; + memcpy(&i, &x, 4); i = 0x5F1FFFF9 - (i>>1); - float estimate = *SkTCast<float*>(&i); + float estimate; + memcpy(&estimate, &i, 4); // One step of Newton's method to refine. const float estimate_sq = estimate*estimate; |