From: Alexander Monakov <amonakov@ispras.ru>
Date: Wed, 16 Nov 2022 13:33:11 +0000 (+0300)
Subject: doc: fix description of -mrelax-cmpxchg-loop [PR 107676]
X-Git-Tag: basepoints/gcc-14~3113
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=85966f0d20baf50a767ac1110f537395441604a9;p=thirdparty%2Fgcc.git

doc: fix description of -mrelax-cmpxchg-loop [PR 107676]

gcc/ChangeLog:

	PR target/107676
	* doc/invoke.texi (-mrelax-cmpxchg-loop): Reword description.
---

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index cbfe1102bd20..96f0b6d08bdf 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -33561,10 +33561,11 @@ registers.
 
 @item -mrelax-cmpxchg-loop
 @opindex mrelax-cmpxchg-loop
-Relax cmpxchg loop by emitting an early load and compare before cmpxchg,
-execute pause if load value is not expected. This reduces excessive
-cachline bouncing when and works for all atomic logic fetch builtins
-that generates compare and swap loop.
+When emitting a compare-and-swap loop for @ref{__sync Builtins}
+and @ref{__atomic Builtins} lacking a native instruction, optimize
+for the highly contended case by issuing an atomic load before the
+@code{CMPXCHG} instruction, and using the @code{PAUSE} instruction
+to save CPU power when restarting the loop.
 
 @item -mindirect-branch=@var{choice}
 @opindex mindirect-branch