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invoke.texi (RS/6000 and PowerPC Options): Document that -mlongcall does not guarantee all calls will be long.

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* doc/invoke.texi (RS/6000 and PowerPC Options): Document that
	-mlongcall does not guarantee all calls will be long.
	* doc/extend.texi (long_call/short_call): Document that longcall
	does not guarantee a long call will be used.
	(longcall/shortcall): Likewise.

From-SVN: r115582
This commit is contained in:
Nathan Sidwell 2006-07-19 06:45:34 +00:00 • committed by Nathan Sidwell
parent 2e0d61d983
commit 87c365a481
3 changed files with 25 additions and 14 deletions
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8
gcc/ChangeLog
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@ -1,3 +1,11 @@
2006-07-17 Nathan Sidwell <nathan@codesourcery.com>
* doc/invoke.texi (RS/6000 and PowerPC Options): Document that
-mlongcall does not guarantee all calls will be long.
* doc/extend.texi (long_call/short_call): Document that longcall
does not guarantee a long call will be used.
(longcall/shortcall): Likewise.
2006-07-18 Roger Sayle <roger@eyesopen.com>
PR middle-end/28283

19
gcc/doc/extend.texi
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@ -1962,20 +1962,21 @@ from the USP register in the function prologue.
This attribute specifies how a particular function is called on
ARM@. Both attributes override the @option{-mlong-calls} (@pxref{ARM Options})
command line switch and @code{#pragma long_calls} settings. The
@code{long_call} attribute causes the compiler to always call the
function by first loading its address into a register and then using the
contents of that register. The @code{short_call} attribute always places
@code{long_call} attribute indicates that the function might be far
away from the call site and require a different (more expensive)
calling sequence. The @code{short_call} attribute always places
the offset to the function from the call site into the @samp{BL}
instruction directly.
@item longcall/shortcall
@cindex functions called via pointer on the RS/6000 and PowerPC
On the Blackfin, RS/6000 and PowerPC, the @code{longcall} attribute causes
the compiler to always call this function via a pointer, just as it would if
the @option{-mlongcall} option had been specified. The @code{shortcall}
attribute causes the compiler not to do this. These attributes override
both the @option{-mlongcall} switch and, on the RS/6000 and PowerPC, the
@code{#pragma longcall} setting.
On the Blackfin, RS/6000 and PowerPC, the @code{longcall} attribute
indicates that the function might be far away from the call site and
require a different (more expensive) calling sequence. The
@code{shortcall} attribute indicates that the function is always close
enough for the shorter calling sequence to be used. These attributes
override both the @option{-mlongcall} switch and, on the RS/6000 and
PowerPC, the @code{#pragma longcall} setting.
@xref{RS/6000 and PowerPC Options}, for more information on whether long
calls are necessary.

12
gcc/doc/invoke.texi
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@ -11906,11 +11906,13 @@ names in the assembly language output using symbolic forms.
@itemx -mno-longcall
@opindex mlongcall
@opindex mno-longcall
Default to making all function calls indirectly, using a register, so
that functions which reside further than 32 megabytes (33,554,432
bytes) from the current location can be called. This setting can be
overridden by the @code{shortcall} function attribute, or by
@code{#pragma longcall(0)}.
By default assume that all calls are far away so that a longer more
expensive calling sequence is required. This is required for calls
further than 32 megabytes (33,554,432 bytes) from the current location.
A short call will be generated if the compiler knows
the call cannot be that far away. This setting can be overridden by
the @code{shortcall} function attribute, or by @code{#pragma
longcall(0)}.
Some linkers are capable of detecting out-of-range calls and generating
glue code on the fly. On these systems, long calls are unnecessary and