zum Verständniss, bin kein englischsprachiger Informatiker .....
|
Quellcode
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
-mfpmath=unit
Generate floating point arithmetics for selected unit unit. The choices for unit are:
`sse'
Use scalar floating point instructions present in the SSE instruction set. This instruction set is
supported by Pentium3 and newer chips, in the AMD line by Athlon-4, Athlon-xp and Athlon-mp chips.
The earlier version of SSE instruction set supports only single precision arithmetics, thus the double and
extended precision arithmetics is still done using 387. Later version, present only in Pentium4 and the future AMD x86-64 chips supports double precision arithmetics too.
For the i386 compiler, you need to use -march=cpu-type, -msse or -msse2 switches to enable SSE extensions and make this option effective. For the x86-64 compiler, these extensions are enabled by
default.
The resulting code should be considerably faster in the majority of cases and avoid the numerical instability problems of 387 code, but may break some existing code that expects temporaries to be 80bit.
This is the default choice for the x86-64 compiler.
|
würde für meine Architektur folgendes bedeuten:
- da ich -march=athlon64 bei den CFLAGS stehen habe, verwende ich automatisch den x86-64 Compiler?
- würde weiter bedeuten, das ich msse2 nicht angeben muss, da es per Voreinstellung an ist
- der übersetzte Code ist mit sse schneller
was macht dann -mfpmath=sse ?????
ein etwas verwirrter 64Biteinsteiger.....