From ee351cb74d905368195ad5c663581e646241f90b Mon Sep 17 00:00:00 2001 From: Brecht Van Lommel Date: Wed, 5 Aug 2020 14:45:54 +0200 Subject: Fix T78869: denoising performance regression on Windows Optimization was disabled in this function to work around a bug in MSVC, use a different solution that does not come with such a big performance regression. --- intern/cycles/util/util_math_fast.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/intern/cycles/util/util_math_fast.h b/intern/cycles/util/util_math_fast.h index 4f92d2f10d3..07b0878e3d5 100644 --- a/intern/cycles/util/util_math_fast.h +++ b/intern/cycles/util/util_math_fast.h @@ -445,12 +445,10 @@ ccl_device_inline float fast_expf(float x) return fast_exp2f(x / M_LN2_F); } -#ifndef __KERNEL_GPU__ -/* MSVC seems to have a code-gen bug here in at least SSE41/AVX - * see T78047 for details. */ -# ifdef _MSC_VER -# pragma optimize("", off) -# endif +#if defined(__KERNEL_CPU__) && !defined(_MSC_VER) +/* MSVC seems to have a code-gen bug here in at least SSE41/AVX, see + * T78047 and T78869 for details. Just disable for now, it only makes + * a small difference in denoising performance. */ ccl_device float4 fast_exp2f4(float4 x) { const float4 one = make_float4(1.0f); @@ -466,14 +464,16 @@ ccl_device float4 fast_exp2f4(float4 x) r = madd4(x, r, make_float4(1.0f)); return __int4_as_float4(__float4_as_int4(r) + (m << 23)); } -# ifdef _MSC_VER -# pragma optimize("", on) -# endif ccl_device_inline float4 fast_expf4(float4 x) { return fast_exp2f4(x / M_LN2_F); } +#else +ccl_device_inline float4 fast_expf4(float4 x) +{ + return make_float4(fast_expf(x.x), fast_expf(x.y), fast_expf(x.z), fast_expf(x.w)); +} #endif ccl_device_inline float fast_exp10(float x) -- cgit v1.2.3