From: Sadoon Albader <sadoon@soulserv.xyz>
Date: Fri, 8 Sep 2023 14:47:41 +0000 (+0300)
Subject: verilator optimizations up to 25% speedup
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=844de1745beb7f484239f0f5d443e5457744f09c;p=microwatt.git

verilator optimizations up to 25% speedup
---

diff --git a/Makefile b/Makefile
index b764793..cca51a6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,14 @@
 GHDL ?= ghdl
 GHDLFLAGS=--std=08 -frelaxed
 CFLAGS=-O3 -Wall
+
+ifeq ($(shell uname -m),ppc64le)
+CFLAG_ARCH_OPT=-mcpu=native
+else
+CFLAG_ARCH_OPT=-march=native
+endif
+
+CFLAGS=-O3 -Wall $(CFLAG_ARCH_OPT) -mtune=native
 CXXFLAGS=-g -g
 
 GHDLSYNTH ?= ghdl.so
@@ -250,6 +258,7 @@ microwatt.v: $(synth_files) $(RAM_INIT_FILE)
 	$(YOSYS) -m $(GHDLSYNTH) -p "ghdl --std=08 --no-formal $(GHDL_IMAGE_GENERICS) $(GHDL_TARGET_GENERICS) $(synth_files) -e toplevel; write_verilog $@"
 
 THREADS=1 # How many threads should be used for verilator binary
+THREADS=3 # How many threads should be used for verilator binary, 3 is optimal
 # Need to investigate why yosys is hitting verilator warnings, and eventually turn on -Wall
 # --top-module toplevel
 microwatt-verilator: microwatt.v verilator/microwatt-verilator.cpp verilator/uart-verilator.c
@@ -266,6 +275,11 @@ microwatt-verilator: microwatt.v verilator/microwatt-verilator.cpp verilator/uar
 	    -Wno-WIDTH \
 	 --savable \
 	 --trace \
+	 --threads-dpi all --x-initial fast \
+	 -CFLAGS $(CFLAG_ARCH_OPT) \
+	 -CFLAGS -mtune=native \
+	 -CFLAGS -O3 \
+	# -CFLAGS -flto #disabled for now, no measured performance benefit \
 	#    --unroll-count 256 \
 	#    --output-split 5000 \
 	#    --output-split-cfuncs 500 \