From: Henrik Gramner <henrik@gramner.com>
Date: Thu, 20 Apr 2017 17:16:51 +0000 (+0200)
Subject: x86inc: Make REP_RET identical to RET in SSSE3+ functions
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=46a489b5e21cae3b4fea5d41cc285dcaf79d19e3;p=libx264

x86inc: Make REP_RET identical to RET in SSSE3+ functions

There's no point in emitting a rep prefix before ret on modern CPUs.
---

diff --git a/common/x86/x86inc.asm b/common/x86/x86inc.asm
index 6c2edf9a..7c146e54 100644
--- a/common/x86/x86inc.asm
+++ b/common/x86/x86inc.asm
@@ -624,7 +624,7 @@ DECLARE_ARG 7, 8, 9, 10, 11, 12, 13, 14
 ; We can automatically detect "follows a branch", but not a branch target.
 ; (SSSE3 is a sufficient condition to know that your cpu doesn't have this problem.)
 %macro REP_RET 0
-    %if has_epilogue
+    %if has_epilogue || cpuflag(ssse3)
         RET
     %else
         rep ret