Fused Multiply Add or Multiply-Accumulate
The Fused Multiply Add (also known as Multiply Accumulate) operation is when a multiplication followed by an addition or subtraction is done in a single operation with only one rounding at the end.
For example:
x = a * b + c
Would normally be done using two roundings without Fused-Multiply Add. (one after a * b and one after a * b + c)
Fused Multiply Add combines the two operations into a single operation thereby increasing accuracy in the computed result.
Supported Architectures include:
- PowerPC
- Intel x86 (via FMA3 instruction set)
- AMD x86 (via FMA4 instruction set)
