[PATCH] docs: Add documentation for TARGET_HAS_FMV_TARGET_ATTRIBUTE macro

[alfie.richards]

From: Alfie Richards <alfie.richa...@arm.com>

Hi all,

I sent this previously after Richard S noted that this hook was lacking
comments but it seemingly got lost in the period where I broke my send-mail
config.

This describes the hook as it will be after my FMV patch series lands, so wont
commit until thats in.

Reg tested on Aarch64.

Okay for master after FMV patch series lands?

Thanks,
Alfie

-- >8 --

Adds documentation for the TARGET_HAS_FMV_TARGET_ATTRIBUTE macro hook.

gcc/ChangeLog:

        * doc/tm.texi: Regenerate.
        * doc/tm.texi.in: Add documentation for TARGET_HAS_FMV_TARGET_ATTRIBUTE.
---
 gcc/doc/tm.texi    | 10 ++++++++++
 gcc/doc/tm.texi.in | 10 ++++++++++
 2 files changed, 20 insertions(+)

diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 37642680f42..b4d9e2d3ada 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -10924,6 +10924,16 @@ the function declaration to hold a pointer to a 
target-specific
 @code{struct cl_target_option} structure.
 @end deftypefn
 
+@defmac TARGET_HAS_FMV_TARGET_ATTRIBUTE
+Define this macro to zero to use @code{target_version} attributes for function
+multiversioning (FMV) rather than @code{target} attributes.
+
+Targets using @code{target_version} attributes will also have
+"target_version" FMV semantics, which allow for FMV sets defined across TU's
+and using a combination of @code{target_version} and @code{target_clones}
+attributed declarations in the definition of a FMV function set.
+@end defmac
+
 @defmac TARGET_CLONES_ATTR_SEPARATOR
 Define this char-typed macro to select a character that separates each
 target specific attributes from the @code{attribute(target_clones("..."))}
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index c3ed9a9fd7c..cd83315be16 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -7121,6 +7121,16 @@ on this implementation detail.
 
 @hook TARGET_OPTION_VALID_VERSION_ATTRIBUTE_P
 
+@defmac TARGET_HAS_FMV_TARGET_ATTRIBUTE
+Define this macro to zero to use @code{target_version} attributes for function
+multiversioning (FMV) rather than @code{target} attributes.
+
+Targets using @code{target_version} attributes will also have
+"target_version" FMV semantics, which allow for FMV sets defined across TU's
+and using a combination of @code{target_version} and @code{target_clones}
+attributed declarations in the definition of a FMV function set.
+@end defmac
+
 @defmac TARGET_CLONES_ATTR_SEPARATOR
 Define this char-typed macro to select a character that separates each
 target specific attributes from the @code{attribute(target_clones("..."))}
-- 
2.34.1