Skip to content

R
riscv-gcc-1
Commit 1f8c015b by Matthew Wahab Committed by Matthew Wahab
Options

invoke.texi (Aarch64 Options, -march): Split out arch and feature description... 

2015-06-29  Matthew Wahab  <matthew.wahab@arm.com>

	* doc/invoke.texi (Aarch64 Options, -march): Split out arch and
	feature description, split out the native option, add a link to
	the feature documentation, rearrange and slightly rewrite text.
	(Aarch64 options, -mcpu): Likewise.
	(Aarch64 options, Feature Modifiers): Add an anchor.  Mention
	+rdma implies Adv. SIMD.

From-SVN: r225118
parent b155cfd9
Showing with 49 additions and 37 deletions
gcc/ChangeLog
2015-06-29 Matthew Wahab <matthew.wahab@arm.com>
* doc/invoke.texi (Aarch64 Options, -march): Split out arch and
feature description, split out the native option, add a link to
the feature documentation, rearrange and slightly rewrite text.
(Aarch64 options, -mcpu): Likewise.
(Aarch64 options, Feature Modifiers): Add an anchor. Mention
+rdma implies Adv. SIMD.
2015-06-29 Marek Polacek <polacek@redhat.com>
PR c/66322
......
gcc/doc/invoke.texi
......@@ -12430,24 +12430,26 @@ corresponding flag to the linker.
@opindex march
Specify the name of the target architecture, optionally suffixed by one or
more feature modifiers. This option has the form
@option{-march=@var{arch}@r{@{}+@r{[}no@r{]}@var{feature}@r{@}*}}, where the
permissible values for @var{arch} are @samp{armv8-a} or @samp{armv8.1-a}.
The permissible values for @var{feature} are documented in the sub-section
below. Additionally on native AArch64 GNU/Linux systems the value
@option{-march=@var{arch}@r{@{}+@r{[}no@r{]}@var{feature}@r{@}*}}.
The permissible values for @var{arch} are @samp{armv8-a} or
@samp{armv8.1-a}.
For the permissible values for @var{feature}, see the sub-section on
@ref{aarch64-feature-modifiers,,@option{-march} and @option{-mcpu}
Feature Modifiers}. Where conflicting feature modifiers are
specified, the right-most feature is used.
Additionally on native AArch64 GNU/Linux systems the value
@samp{native} is available. This option causes the compiler to pick the
architecture of the host system. If the compiler is unable to recognize the
architecture of the host system this option has no effect.
Where conflicting feature modifiers are specified, the right-most feature is
used.
GCC uses this name to determine what kind of instructions it can emit when
generating assembly code.
Where @option{-march} is specified without either of @option{-mtune}
or @option{-mcpu} also being specified, the code is tuned to perform
well across a range of target processors implementing the target
architecture.
GCC uses @var{name} to determine what kind of instructions it can emit
when generating assembly code. If @option{-march} is specified
without either of @option{-mtune} or @option{-mcpu} also being
specified, the code is tuned to perform well across a range of target
processors implementing the target architecture.
@item -mtune=@var{name}
@opindex mtune
......@@ -12460,12 +12462,11 @@ Additionally, this option can specify that GCC should tune the performance
of the code for a big.LITTLE system. Permissible values for this
option are: @samp{cortex-a57.cortex-a53}, @samp{cortex-a72.cortex-a53}.
Additionally on native AArch64 GNU/Linux systems the value @samp{native}
is available.
This option causes the compiler to pick the architecture of and tune the
performance of the code for the processor of the host system.
If the compiler is unable to recognize the processor of the host system
this option has no effect.
Additionally on native AArch64 GNU/Linux systems the value
@samp{native} is available. This option causes the compiler to pick
the architecture of and tune the performance of the code for the
processor of the host system. If the compiler is unable to recognize
the processor of the host system this option has no effect.
Where none of @option{-mtune=}, @option{-mcpu=} or @option{-march=}
are specified, the code is tuned to perform well across a range
......@@ -12475,23 +12476,23 @@ This option cannot be suffixed by feature modifiers.
@item -mcpu=@var{name}
@opindex mcpu
Specify the name of the target processor, optionally suffixed by one or more
feature modifiers. This option has the form
@option{-mcpu=@var{cpu}@r{@{}+@r{[}no@r{]}@var{feature}@r{@}*}}, where the
permissible values for @var{cpu} are the same as those available for
@option{-mtune}. Additionally on native AArch64 GNU/Linux systems the
value @samp{native} is available.
This option causes the compiler to tune the performance of the code for the
processor of the host system. If the compiler is unable to recognize the
processor of the host system this option has no effect.
The permissible values for @var{feature} are documented in the sub-section
below.
Where conflicting feature modifiers are specified, the right-most feature is
used.
Specify the name of the target processor, optionally suffixed by one
or more feature modifiers. This option has the form
@option{-mcpu=@var{cpu}@r{@{}+@r{[}no@r{]}@var{feature}@r{@}*}}, where
the permissible values for @var{cpu} are the same as those available
for @option{-mtune}. The permissible values for @var{feature} are
documented in the sub-section on
@ref{aarch64-feature-modifiers,,@option{-march} and @option{-mcpu}
Feature Modifiers}. Where conflicting feature modifiers are
specified, the right-most feature is used.
Additionally on native AArch64 GNU/Linux systems the value
@samp{native} is available. This option causes the compiler to tune
the performance of the code for the processor of the host system. If
the compiler is unable to recognize the processor of the host system
this option has no effect.
GCC uses this name to determine what kind of instructions it can emit when
GCC uses @var{name} to determine what kind of instructions it can emit when
generating assembly code (as if by @option{-march}) and to determine
the target processor for which to tune for performance (as if
by @option{-mtune}). Where this option is used in conjunction
......@@ -12500,6 +12501,7 @@ over the appropriate part of this option.
@end table
@subsubsection @option{-march} and @option{-mcpu} Feature Modifiers
@anchor{aarch64-feature-modifiers}
@cindex @option{-march} feature modifiers
@cindex @option{-mcpu} feature modifiers
Feature modifiers used with @option{-march} and @option{-mcpu} can be any of
......@@ -12525,7 +12527,8 @@ Enable Privileged Access Never support.
@item lor
Enable Limited Ordering Regions support.
@item rdma
Enable ARMv8.1 Advanced SIMD instructions.
Enable ARMv8.1 Advanced SIMD instructions. This implies Advanced SIMD
is enabled.
@item -moverride=@var{string}
@opindex master
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment