Re: [PATCH, DOC] Enhance documentation of -fipa-ra option.

[Martin Liška <mliska at suse dot cz>]

On 07/19/2016 03:46 PM, Alexander Monakov wrote:
>> So I decided to also mention this alias.
>>
>> Thoughts?
> 
> I'd like the new ipa-ra text to go in, but perhaps you should consider leaving
> out option aliases out of this patch, especially given that it's non-trivial, as
> Andreas' comment has shown.
> 
> (I'd say it's rather confusing that -fprofile is quite different from
> -fprofile-generate; I doubt it's worthwhile to document this alias at all, but I
> won't argue much either way)
> 
> Thanks.
> Alexander
> 

Thanks Andreas, you are right.

Ok, so I'm sending third version which just explains documentation
of -fipa-ra option.

Martin

>From 2894c36014d726fa0bfaebff261642d42550622c Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Wed, 13 Jul 2016 18:25:09 +0200
Subject: [PATCH] Enhance documentation of -fipa-ra option.

gcc/ChangeLog:

2016-07-13  Martin Liska  <mliska@suse.cz>

	* doc/invoke.texi (-fipa-ra): Document when the option is
	disabled. Fix a typo.
---
 gcc/doc/invoke.texi | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 9a4db38..4435f54 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -7260,7 +7260,11 @@ any called function.  In that case it is not necessary to save and restore
 them around calls.  This is only possible if called functions are part of
 same compilation unit as current function and they are compiled before it.
 
-Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}.
+Enabled at levels @option{-O2}, @option{-O3}, @option{-Os}, however the option
+is disabled if generated code will be instrumented for profiling
+(@option{-p}, or @option{-pg}) or if callee's register usage cannot be known
+exactly (this happens on targets that do not expose prologues
+and epilogues in RTL).
 
 @item -fconserve-stack
 @opindex fconserve-stack
@@ -7280,7 +7284,7 @@ Perform code hoisting.  Code hoisting tries to move the
 evaluation of expressions executed on all paths to the function exit
 as early as possible.  This is especially useful as a code size
 optimization, but it often helps for code speed as well.
-This flag is enabled by defailt at @option{-O2} and higher.
+This flag is enabled by default at @option{-O2} and higher.
 
 @item -ftree-pre
 @opindex ftree-pre
-- 
2.9.0