x86: Document -fcf-protection requires i686 or newer

	PR target/98667
	* doc/invoke.texi: Document -fcf-protection requires i686 or
	new.

(cherry picked from commit 1373066a46d8d47abd97e46a005aef3b3dbfe94a)

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 93049d7a22f07fe38bced8d6d496efeac856b124..2eb874a7176d9ea316d9b1207cdfc871ee2541d0 100644 (file)
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -15123,7 +15123,8 @@ which functions and calls should be skipped from instrumentation
 (@pxref{Function Attributes}).
 
 Currently the x86 GNU/Linux target provides an implementation based
-on Intel Control-flow Enforcement Technology (CET).
+on Intel Control-flow Enforcement Technology (CET) which works for
+i686 processor or newer.
 
 @item -fstack-protector
 @opindex fstack-protector