Fix size_t -> int -> size_t round trip in Cycles

There are two things achieved by this change:

- No possible downcast of size_t to int when calculating motion steps.
- Disambiguate call to min() which was for some reason considered
  ambiguous on 32bit platforms `min(int, unsigned int)`.

On an implementation side the `min()` is defined for a fixed width
integer type to disambiguate uint from size_t on 32bit platforms,
and yet be able to use it for 32bit operands on 64bit platforms without
upcast.

Fixes 32bit platforms (such as i386) in Debian package build system.

Differential Revision: https://developer.blender.org/D13992

1 files changed, 6 insertions, 1 deletions

diff --git a/intern/cycles/util/math.h b/intern/cycles/util/math.h
index 605a19aaef0..a580a21c28b 100644
--- a/intern/cycles/util/math.h
+++ b/intern/cycles/util/math.h
@@ -124,7 +124,12 @@ ccl_device_inline int min(int a, int b)
   return (a < b) ? a : b;
 }
 
-ccl_device_inline uint min(uint a, uint b)
+ccl_device_inline uint32_t min(uint32_t a, uint32_t b)
+{
+  return (a < b) ? a : b;
+}
+
+ccl_device_inline uint64_t min(uint64_t a, uint64_t b)
 {
   return (a < b) ? a : b;
 }