Enable New Pass Manager for Clang.
authorGian-Carlo Pascutto <gcp@sjeng.org>
Tue, 9 Feb 2021 16:38:58 +0000 (17:38 +0100)
committerJoost VandeVondele <Joost.VandeVondele@gmail.com>
Wed, 10 Feb 2021 18:54:26 +0000 (19:54 +0100)
It's about 1% speedup for Stockfish.

Result of 100 runs
==================
base (...fish_clang12) =    1946851  +/- 3717
test (./stockfish    ) =    1967276  +/- 3408
diff                   =     +20425  +/- 2438

speedup        = +0.0105
P(speedup > 0) =  1.0000

Thanks to David Major for making me aware of this part
of LLVM development.

closes https://github.com/official-stockfish/Stockfish/pull/3346

No functional change

src/Makefile

index 827ce6bb9d838930708ab6542ce04b89c411e014..1ff03f8391acca25bc4e3c5af9938d3408aa062d 100644 (file)
@@ -481,6 +481,10 @@ ifeq ($(optimize),yes)
                        CXXFLAGS += -mdynamic-no-pic
                endif
        endif
                        CXXFLAGS += -mdynamic-no-pic
                endif
        endif
+
+       ifeq ($(comp),clang)
+               CXXFLAGS += -fexperimental-new-pass-manager
+       endif
 endif
 
 ### 3.4 Bits
 endif
 
 ### 3.4 Bits