diff options
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 82 |
1 files changed, 42 insertions, 40 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 9947270db8f..5dcfd404719 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -11254,11 +11254,32 @@ option should only be used if you require compatibility with code for big-endian ARM processors generated by versions of the compiler prior to 2.8. This option is now deprecated. -@item -mcpu=@var{name} -@opindex mcpu -This specifies the name of the target ARM processor. GCC uses this name -to determine what kind of instructions it can emit when generating -assembly code. Permissible names are: @samp{arm2}, @samp{arm250}, +@item -march=@var{name} +@opindex march +This specifies the name of the target ARM architecture. GCC uses this +name to determine what kind of instructions it can emit when generating +assembly code. This option can be used in conjunction with or instead +of the @option{-mcpu=} option. Permissible names are: @samp{armv2}, +@samp{armv2a}, @samp{armv3}, @samp{armv3m}, @samp{armv4}, @samp{armv4t}, +@samp{armv5}, @samp{armv5t}, @samp{armv5e}, @samp{armv5te}, +@samp{armv6}, @samp{armv6j}, +@samp{armv6t2}, @samp{armv6z}, @samp{armv6zk}, @samp{armv6-m}, +@samp{armv7}, @samp{armv7-a}, @samp{armv7-r}, @samp{armv7-m}, @samp{armv7e-m} +@samp{armv8-a}, +@samp{iwmmxt}, @samp{iwmmxt2}, @samp{ep9312}. + +@option{-march=native} causes the compiler to auto-detect the architecture +of the build computer. At present, this feature is only supported on +Linux, and not all architectures are recognized. If the auto-detect is +unsuccessful the option has no effect. + +@item -mtune=@var{name} +@opindex mtune +This option specifies the name of the target ARM processor for +which GCC should tune the performance of the code. +For some ARM implementations better performance can be obtained by using +this option. +Permissible names are: @samp{arm2}, @samp{arm250}, @samp{arm3}, @samp{arm6}, @samp{arm60}, @samp{arm600}, @samp{arm610}, @samp{arm620}, @samp{arm7}, @samp{arm7m}, @samp{arm7d}, @samp{arm7dm}, @samp{arm7di}, @samp{arm7dmi}, @samp{arm70}, @samp{arm700}, @@ -11286,27 +11307,6 @@ assembly code. Permissible names are: @samp{arm2}, @samp{arm250}, @samp{fa526}, @samp{fa626}, @samp{fa606te}, @samp{fa626te}, @samp{fmp626}, @samp{fa726te}. - -@option{-mcpu=generic-@var{arch}} is also permissible, and is -equivalent to @option{-march=@var{arch} -mtune=generic-@var{arch}}. -See @option{-mtune} for more information. - -@option{-mcpu=native} causes the compiler to auto-detect the CPU -of the build computer. At present, this feature is only supported on -Linux, and not all architectures are recognized. If the auto-detect is -unsuccessful the option has no effect. - -@item -mtune=@var{name} -@opindex mtune -This option is very similar to the @option{-mcpu=} option, except that -instead of specifying the actual target processor type, and hence -restricting which instructions can be used, it specifies that GCC should -tune the performance of the code as if the target were of the type -specified in this option, but still choosing the instructions it -generates based on the CPU specified by a @option{-mcpu=} option. -For some ARM implementations better performance can be obtained by using -this option. - @option{-mtune=generic-@var{arch}} specifies that GCC should tune the performance for a blend of processors within architecture @var{arch}. The aim is to generate code that run well on the current most popular @@ -11319,21 +11319,23 @@ of the build computer. At present, this feature is only supported on Linux, and not all architectures are recognized. If the auto-detect is unsuccessful the option has no effect. -@item -march=@var{name} -@opindex march -This specifies the name of the target ARM architecture. GCC uses this -name to determine what kind of instructions it can emit when generating -assembly code. This option can be used in conjunction with or instead -of the @option{-mcpu=} option. Permissible names are: @samp{armv2}, -@samp{armv2a}, @samp{armv3}, @samp{armv3m}, @samp{armv4}, @samp{armv4t}, -@samp{armv5}, @samp{armv5t}, @samp{armv5e}, @samp{armv5te}, -@samp{armv6}, @samp{armv6j}, -@samp{armv6t2}, @samp{armv6z}, @samp{armv6zk}, @samp{armv6-m}, -@samp{armv7}, @samp{armv7-a}, @samp{armv7-r}, @samp{armv7-m}, -@samp{armv8-a}, -@samp{iwmmxt}, @samp{iwmmxt2}, @samp{ep9312}. +@item -mcpu=@var{name} +@opindex mcpu +This specifies the name of the target ARM processor. GCC uses this name +to derive the name of the target ARM architecture (as if specified +by @option{-march}) and the ARM processor type for which to tune for +performance (as if specified by @option{-mtune}). Where this option +is used in conjunction with @option{-march} or @option{-mtune}, +those options take precedence over the appropriate part of this option. -@option{-march=native} causes the compiler to auto-detect the architecture +Permissible names for this option are the same as those for +@option{-mtune}. + +@option{-mcpu=generic-@var{arch}} is also permissible, and is +equivalent to @option{-march=@var{arch} -mtune=generic-@var{arch}}. +See @option{-mtune} for more information. + +@option{-mcpu=native} causes the compiler to auto-detect the CPU of the build computer. At present, this feature is only supported on Linux, and not all architectures are recognized. If the auto-detect is unsuccessful the option has no effect. |