Developer Guide and Reference

Contents

fma, Qfma

Determines whether the compiler generates fused multiply-add (FMA) instructions if such instructions exist on the target processor.

Syntax

Linux:
-fma
-no-fma
macOS:
-fma
-no-fma
Windows:
/Qfma
/Qfma-
Arguments
None
Default
-fma
or
/Qfma
If the instructions exist on the target processor, the compiler generates fused multiply-add (FMA) instructions.
However, if you specify
-fp-model strict
(Linux*
and
macOS*
)
or
/fp:strict
(Windows*)
, but do not explicitly specify
-fma
or
/Qfma
, the default is
-no-fma
or
/Qfma-
.
Description
This option determines whether the compiler generates fused multiply-add (FMA) instructions if such instructions exist on the target processor. When the
[Q]fma
option is specified, the compiler may generate FMA instructions for combining multiply and add operations. When the negative form of the
[Q]fma
option is specified, the compiler must generate separate multiply and add instructions with intermediate rounding.
This option has no effect unless setting CORE-AVX2 or higher is specified for option [Q]x,
-march
(Linux and