graphics/OpenEXR & gcc 4.6.3 ISSUE error: 'memset' was not declared in this scope

[awarecons]

libtool: compile:  g++46 -DHAVE_CONFIG_H -I. -I. -I../config
-D_THREAD_SAFE -I/usr/local/include/OpenEXR -I.. -I../config -O2 -pipe
-march=pentium4 -mtune=pentium4 -Wno-error -w -pipe -O2 -pipe
-march=pentium4 -mtune=pentium4 -Wl,-rpath=/usr/local/lib/gcc46
-fno-strict-aliasing -O2 -pipe -march=pentium4 -mtune=pentium4
-Wno-error -w -Wl,-rpath=/usr/local/lib/gcc46 -MT ImfChromaticities.lo
-MD -MP -MF .deps/ImfChromaticities.Tpo -c ImfChromaticities.cpp
-fPIC -DPIC -o .libs/ImfChromaticities.o
In file included from ./ImfChromaticities.h:47:0,
                 from ImfChromaticities.cpp:43:
/usr/local/include/OpenEXR/ImathMatrix.h: In constructor
'Imath::Matrix44<T>::Matrix44() [with T = float]':
ImfChromaticities.cpp:110:17:   instantiated from here
/usr/local/include/OpenEXR/ImathMatrix.h:1813:5: error: 'memset' was
not declared in this scope
gmake[2]: *** [ImfChromaticities.lo] Error 1
gmake[2]: Leaving directory
`/usr/ports/graphics/OpenEXR/work/openexr-1.7.0/IlmImf'
gmake[1]: *** [all] Error 2
gmake[1]: Leaving directory
`/usr/ports/graphics/OpenEXR/work/openexr-1.7.0/IlmImf'
gmake: *** [all-recursive] Error 1
*** Error code 1

Stop in /usr/ports/graphics/OpenEXR.
*** Error code 1

Stop in /usr/ports/graphics/OpenEXR.

Gcc 4.2+ works, but graphics/ilmbase should be compiled with 4.2+ either.