PXOR user in code were causing the lowest SP float register to have NaN
values which made all math operations in that slot fail. Correct istruction
to clear float registers is XORPS which handles single precission floats
correctly.
Fixes progs/tests/fog in swrast SSE mode.
Now the correct commit instead of
66d09e4a2a6b770ddb which is not even close
of correct fix for the bug.
MOV_L( REGOFF(V4F_START, EDI), EDI ) /* ptr to first dest vertex */
ADD_L( EDI, ECX ) /* count += dest ptr */
+ XORPS( XMM0, XMM0 ) /* clean the working register */
ALIGNTEXT32
MOVSS ( M(0), XMM1 ) /* - | - | - | m0 */
MOV_L( REGOFF(V4F_START, EDI), EDI ) /* ptr to first dest vertex */
ADD_L( EDI, ECX ) /* count += dest ptr */
+ XORPS( XMM0, XMM0 ) /* clean the working register */
ALIGNTEXT32
MOVSS ( M(0), XMM1 ) /* - | - | - | m0 */