PFACC
Usage: PFACC dest,src Modifies flags: None
Performs negative accumulation of the two doublewords of the 'dest' operand and the 'src' operand. Then stores the results in the low and high words of the 'dest' operand.
Packed Single-Precision FP Accumulate
PFACC mm1,mm2/m64 ; 0F 0F /r AE [PENT,3DNOW]
PFACC adds the two single-precision FP values from the destination operand together, then adds the two single-precision FP values from the source operand, and places the results in the low and high doublewords of the destination operand.
The operation is:
dst[0-31] := dst[0-31] + dst[32-63],
dst[32-63] := src[0-31] + src[32-63].
Both operands are single-precision, floating-point operands with 24-bit significands.
Example:
pfacc mm1 mm2
PFACC
Usage: PFACC dest,src Modifies flags: None
Performs negative accumulation of the two doublewords of the 'dest' operand and the 'src' operand. Then stores the results in the low and high words of the 'dest' operand.
Packed Single-Precision FP Accumulate
PFACC mm1,mm2/m64 ; 0F 0F /r AE [PENT,3DNOW]
PFACC adds the two single-precision FP values from the destination operand together, then adds the two single-precision FP values from the source operand, and places the results in the low and high doublewords of the destination operand.
The operation is:
dst[0-31] := dst[0-31] + dst[32-63],
dst[32-63] := src[0-31] + src[32-63].
Both operands are single-precision, floating-point operands with 24-bit significands.
Example:
pfacc mm1 mm2