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 f2377279a63c407f8a45124f4ac72c346ff7d601..6d3cfcc664e214dfe1977c1f19bf2c9c56ebdecb 100644 (file)
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -13886,7 +13886,8 @@ 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