[Bf-blender-cvs] [5b45715f8a] master: Cycles: Correct isfinite check used in integrator

[Sergey Sharybin]

Commit: 5b45715f8a98c8577bc1f0dcbe95d58124475d2c
Author: Sergey Sharybin
Date:   Fri Mar 24 15:22:27 2017 +0100
Branches: master
https://developer.blender.org/rB5b45715f8a98c8577bc1f0dcbe95d58124475d2c

Cycles: Correct isfinite check used in integrator

Use fast-math friendly version of this function.

We should probably avoid unsafe fast math, but this is to be done with
real care with all the benchmarks properly done.

For now comitting much safer fix.

===================================================================

M	intern/cycles/kernel/kernel_accumulate.h
M	intern/cycles/util/util_math.h

===================================================================

diff --git a/intern/cycles/kernel/kernel_accumulate.h b/intern/cycles/kernel/kernel_accumulate.h
index 6c3ee6b809..c589c112cc 100644
--- a/intern/cycles/kernel/kernel_accumulate.h
+++ b/intern/cycles/kernel/kernel_accumulate.h
@@ -399,7 +399,7 @@ ccl_device_inline float3 path_radiance_clamp_and_sum(KernelGlobals *kg, PathRadi
 		float sum = fabsf((L_sum).x) + fabsf((L_sum).y) + fabsf((L_sum).z);
 
 		/* Reject invalid value */
-		if(!isfinite(sum)) {
+		if(!isfinite_safe(sum)) {
 			kernel_assert(!"Non-finite sum in path_radiance_clamp_and_sum!");
 			L_sum = make_float3(0.0f, 0.0f, 0.0f);
 
@@ -468,7 +468,7 @@ ccl_device_inline float3 path_radiance_clamp_and_sum(KernelGlobals *kg, PathRadi
 
 	/* Reject invalid value */
 	float sum = fabsf((L_sum).x) + fabsf((L_sum).y) + fabsf((L_sum).z);
-	if(!isfinite(sum)) {
+	if(!isfinite_safe(sum)) {
 		kernel_assert(!"Non-finite final sum in path_radiance_clamp_and_sum!");
 		L_sum = make_float3(0.0f, 0.0f, 0.0f);
 	}
diff --git a/intern/cycles/util/util_math.h b/intern/cycles/util/util_math.h
index a41beab628..2af0e56325 100644
--- a/intern/cycles/util/util_math.h
+++ b/intern/cycles/util/util_math.h
@@ -1241,19 +1241,6 @@ ccl_device_inline float __uint_as_float(uint i)
 	return u.f;
 }
 
-/* Versions of functions which are safe for fast math. */
-ccl_device_inline bool isnan_safe(float f)
-{
-	unsigned int x = __float_as_uint(f);
-	return (x << 1) > 0xff000000u;
-}
-
-ccl_device_inline bool isfinite_safe(float f)
-{
-	/* By IEEE 754 rule, 2*Inf equals Inf */
-	unsigned int x = __float_as_uint(f);
-	return (f == f) && (x == 0 || (f != 2.0f*f));
-}
 
 /* Interpolation */
 
@@ -1271,6 +1258,20 @@ ccl_device_inline float triangle_area(const float3& v1, const float3& v2, const
 
 #endif
 
+/* Versions of functions which are safe for fast math. */
+ccl_device_inline bool isnan_safe(float f)
+{
+	unsigned int x = __float_as_uint(f);
+	return (x << 1) > 0xff000000u;
+}
+
+ccl_device_inline bool isfinite_safe(float f)
+{
+	/* By IEEE 754 rule, 2*Inf equals Inf */
+	unsigned int x = __float_as_uint(f);
+	return (f == f) && (x == 0 || (f != 2.0f*f)) && !((x << 1) > 0xff000000u);
+}
+
 /* Orthonormal vectors */
 
 ccl_device_inline void make_orthonormals(const float3 N, float3 *a, float3 *b)