procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Improve documentation of noinline and noipa attributes [PR108470]

Browse source 
gcc/ChangeLog
	PR ipa/108470
	* doc/extend.texi (Common Function Attributes): Document that
	noinline also disables some interprocedural optimizations and
	improve flow to the part about using inline asm instead to
	disable calls from being optimized away completely.  Remove the
	sentence that says noipa is mainly for internal compiler testing.
This commit is contained in:
Sandra Loosemore 2024-01-18 23:19:39 +00:00
parent 0c7c65c4c3
commit 9b6b7d6155
1 changed files with 10 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
gcc/doc/extend.texi
View file

@ -3666,13 +3666,17 @@ propagation.
@cindex @code{noinline} function attribute
@item noinline
This function attribute prevents a function from being considered for
inlining.
inlining. It also disables some other interprocedural optimizations; it's
preferable to use the more comprehensive @code{noipa} attribute instead
if that is your goal.
@c Don't enumerate the optimizations by name here; we try to be
@c future-compatible with this mechanism.
If the function does not have side effects, there are optimizations
other than inlining that cause function calls to be optimized away,
although the function call is live. To keep such calls from being
optimized away, put
Even if a function is declared with the @code{noinline} attribute,
there are optimizations other than inlining that can cause calls to be
optimized away if it does not have side effects, although the function
call is live. To keep such calls from being optimized away, put
@smallexample
asm ("");
@end smallexample
@ -3691,8 +3695,7 @@ the body. This attribute implies @code{noinline}, @code{noclone} and
to a combination of other attributes, because its purpose is to suppress
existing and future optimizations employing interprocedural analysis,
including those that do not have an attribute suitable for disabling
them individually. This attribute is supported mainly for the purpose
of testing the compiler.
them individually.
@cindex @code{nonnull} function attribute
@cindex functions with non-null pointer arguments