A.2.22 -fma[={none|fused}]

(SPARC) Enables automatic generation of floating-point, fused, multiply-add instructions. -fma=none disables generation of these instructions. -fma=fused allows the compiler to attempt to find opportunities to improve the performance of the code by using floating-point, fused, multiply-add instructions.

The default is -fma=none.

The minimum requirements are -xarch=sparcfmaf and an optimization level of at least -xO2 for the compiler to generate fused multiply-add instructions. The compiler marks the binary program if fused multiply-add instructions are generated in order to prevent the program from executing on platforms that do not support them.

Fused multiply-adds eliminate the intermediate rounding step between the multiply and the add. Consequently, programs may produce different results when compiled with -fma=fused, although precision will tend to be increased rather than decreased.