[2/3,AArch64,nofp] Clarify docs for +nofp/-mgeneral-regs-only

James Greenhalgh wrote:
> 
>> -Generate code which uses only the general registers.
>> +Generate code which uses only the general registers.  Equivalent to feature
> 
> The ARMARM uses "general-purpose registers" to refer to these registers,
> we should match that style.
> 
> s/Equivalent to feature/This is equivalent to the feature/

Done.

>> -Feature modifiers used with @option{-march} and @option{-mcpu} can be one
>> -the following:
>> +Feature modifiers used with @option{-march} and @option{-mcpu} can be any of
>> +the following, or their inverses @option{no@var{feature}}:
> 
> s/inverses/inverse/

The grammar is quite difficult here, so have gone for "and their inverses" as 
the set of possibilities definitely includes 3 inverses.

>>  
>> +As stated above, @option{crypto} implies @option{simd} implies @option{fp}.
> 
> Drop the "As stated above".

To my eye, beginning a sentence in lowercase looks very odd in pdf, and still a 
bit odd in html. Have changed to "That is"...?

Tested with make pdf & make html.

gcc/ChangeLog (unchanged):

	* doc/invoke.texi: Clarify AArch64 feature modifiers (no)fp, (no)simd
	and (no)crypto.

On Tue, Jun 23, 2015 at 05:03:13PM +0100, Alan Lawrence wrote:
> James Greenhalgh wrote:
<<snip>>

> To my eye, beginning a sentence in lowercase looks very odd in pdf, and still a 
> bit odd in html. Have changed to "That is"...?
> 
> Tested with make pdf & make html.
> 
> gcc/ChangeLog (unchanged):
> 
> 	* doc/invoke.texi: Clarify AArch64 feature modifiers (no)fp, (no)simd
> 	and (no)crypto.

OK.

Thanks,
James

> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index d8e982c3aa338819df3785696c493a66c1f5b674..0579bf2ecf993bb56987e0bb9686925537ab61e3 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -12359,7 +12359,10 @@ Generate big-endian code.  This is the default when GCC is configured for an
>  
>  @item -mgeneral-regs-only
>  @opindex mgeneral-regs-only
> -Generate code which uses only the general registers.
> +Generate code which uses only the general-purpose registers.  This is equivalent
> +to feature modifier @option{nofp} of @option{-march} or @option{-mcpu}, except
> +that @option{-mgeneral-regs-only} takes precedence over any conflicting feature
> +modifier regardless of sequence.
>  
>  @item -mlittle-endian
>  @opindex mlittle-endian
> @@ -12498,20 +12501,22 @@ over the appropriate part of this option.
>  @subsubsection @option{-march} and @option{-mcpu} Feature Modifiers
>  @cindex @option{-march} feature modifiers
>  @cindex @option{-mcpu} feature modifiers
> -Feature modifiers used with @option{-march} and @option{-mcpu} can be one
> -the following:
> +Feature modifiers used with @option{-march} and @option{-mcpu} can be any of
> +the following and their inverses @option{no@var{feature}}:
>  
>  @table @samp
>  @item crc
>  Enable CRC extension.
>  @item crypto
> -Enable Crypto extension.  This implies Advanced SIMD is enabled.
> +Enable Crypto extension.  This also enables Advanced SIMD and floating-point
> +instructions.
>  @item fp
> -Enable floating-point instructions.
> +Enable floating-point instructions.  This is on by default for all possible
> +values for options @option{-march} and @option{-mcpu}.
>  @item simd
> -Enable Advanced SIMD instructions.  This implies floating-point instructions
> -are enabled.  This is the default for all current possible values for options
> -@option{-march} and @option{-mcpu=}.
> +Enable Advanced SIMD instructions.  This also enables floating-point
> +instructions.  This is on by default for all possible values for options
> +@option{-march} and @option{-mcpu}.
>  @item lse
>  Enable Large System Extension instructions.
>  @item pan
> @@ -12522,6 +12527,10 @@ Enable Limited Ordering Regions support.
>  Enable ARMv8.1 Advanced SIMD instructions.
>  @end table
>  
> +That is, @option{crypto} implies @option{simd} implies @option{fp}.
> +Conversely, @option{nofp} (or equivalently, @option{-mgeneral-regs-only})
> +implies @option{nosimd} implies @option{nocrypto}.
> +
>  @node Adapteva Epiphany Options
>  @subsection Adapteva Epiphany Options
>