From b15e3b3fa9a4fb5da6e30685c0813a62cee5dd3f Mon Sep 17 00:00:00 2001
From: Gian-Carlo Pascutto <gcp@sjeng.org>
Date: Tue, 9 Feb 2021 14:05:35 +0100
Subject: [PATCH] Disable ThinLTO when using Clang.

Benchmarking with current Clang 12 shows that
and ThinLTO is a pessimization, see issue #3341.

closes https://github.com/official-stockfish/Stockfish/pull/3345

No functional change.
---
 src/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Makefile b/src/Makefile
index 55139a1f..827ce6bb 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -590,7 +590,7 @@ endif
 ifeq ($(optimize),yes)
 ifeq ($(debug), no)
 	ifeq ($(comp),clang)
-		CXXFLAGS += -flto=thin
+		CXXFLAGS += -flto
 		ifneq ($(findstring MINGW,$(KERNEL)),)
 			CXXFLAGS += -fuse-ld=lld
 		else ifneq ($(findstring MSYS,$(KERNEL)),)
@@ -610,7 +610,7 @@ ifeq ($(debug), no)
 			LDFLAGS += -save-temps
 		endif
 	else
-		CXXFLAGS += -flto=thin
+		CXXFLAGS += -flto
 		LDFLAGS += $(CXXFLAGS)
 	endif
 
-- 
2.39.2