diff options
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index b6398ff..e185178 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -20355,9 +20355,14 @@ hardware instructions. The VSX instruction set (@option{-mvsx}, @option{-mcpu=power7}, or @option{-mcpu=power8}) must be enabled to use the @option{-mfloat128} -option. The @code{-mfloat128} option only works on PowerPC 64-bit +option. The @option{-mfloat128} option only works on PowerPC 64-bit Linux systems. +If you use the ISA 3.0 instruction set (@option{-mcpu=power9}), the +@option{-mfloat128} option will also enable the generation of ISA 3.0 +IEEE 128-bit floating point instructions. Otherwise, IEEE 128-bit +floating point will be done with software emulation. + @item -mfloat128-hardware @itemx -mno-float128-hardware @opindex mfloat128-hardware @@ -20365,6 +20370,13 @@ Linux systems. Enable/disable using ISA 3.0 hardware instructions to support the @var{__float128} data type. +If you use @option{-mfloat128-hardware}, it will enable the option +@option{-mfloat128} as well. + +If you select ISA 3.0 instructions with @option{-mcpu=power9}, but do +not use either @option{-mfloat128} or @option{-mfloat128-hardware}, +the IEEE 128-bit floating point support will not be enabled. + @item -mmodulo @itemx -mno-modulo @opindex mmodulo |