donot speed up program, but lower the cpu cost significantly

Makefile

@@ -1,76 +1,32 @@
-# choose your compiler, e.g. gcc/clang
-# example override to clang: make run CC=clang
-CC = gcc
+TARGET=run
 
-# the most basic way of building that is most likely to work on most systems
-.PHONY: run
-run: run.c
-	$(CC) -O3 -o run run.c -lm
-	$(CC) -O3 -o runq runq.c -lm
+ifeq (,$(TOOLCHAIN_PREFIX))
+$(error TOOLCHAIN_PREFIX is not set)
+endif
 
-# useful for a debug build, can then e.g. analyze with valgrind, example:
-# $ valgrind --leak-check=full ./run out/model.bin -n 3
-rundebug: run.c
-	$(CC) -g -o run run.c -lm
-	$(CC) -g -o runq runq.c -lm
+ifeq (,$(CFLAGS))
+$(error CFLAGS is not set)
+endif
 
-# https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
-# https://simonbyrne.github.io/notes/fastmath/
-# -Ofast enables all -O3 optimizations.
-# Disregards strict standards compliance.
-# It also enables optimizations that are not valid for all standard-compliant programs.
-# It turns on -ffast-math, -fallow-store-data-races and the Fortran-specific
-# -fstack-arrays, unless -fmax-stack-var-size is specified, and -fno-protect-parens.
-# It turns off -fsemantic-interposition.
-# In our specific application this is *probably* okay to use
-.PHONY: runfast
-runfast: run.c
-	$(CC) -Ofast -o run run.c -lm
-	$(CC) -Ofast -o runq runq.c -lm
+ifeq (,$(LDFLAGS))
+$(error LDFLAGS is not set)
+endif
 
-# additionally compiles with OpenMP, allowing multithreaded runs
-# make sure to also enable multiple threads when running, e.g.:
-# OMP_NUM_THREADS=4 ./run out/model.bin
-.PHONY: runomp
-runomp: run.c
-	$(CC) -Ofast -fopenmp -march=native run.c  -lm  -o run
-	$(CC) -Ofast -fopenmp -march=native runq.c  -lm  -o runq
+CC = $(TOOLCHAIN_PREFIX)gcc
 
-.PHONY: win64
-win64:
-	x86_64-w64-mingw32-gcc -Ofast -D_WIN32 -o run.exe -I. run.c win.c
-	x86_64-w64-mingw32-gcc -Ofast -D_WIN32 -o runq.exe -I. runq.c win.c
+CFLAGS += -I$(SYSROOT)/usr/include
+CFLAGS += -Ofast
 
-# compiles with gnu99 standard flags for amazon linux, coreos, etc. compatibility
-.PHONY: rungnu
-rungnu:
-	$(CC) -Ofast -std=gnu11 -o run run.c -lm
-	$(CC) -Ofast -std=gnu11 -o runq runq.c -lm
+LDFLAGS += -L$(SYSROOT)/lib
+LDFLAGS += -L$(SYSROOT)/usr/lib
 
-.PHONY: runompgnu
-runompgnu:
-	$(CC) -Ofast -fopenmp -std=gnu11 run.c  -lm  -o run
-	$(CC) -Ofast -fopenmp -std=gnu11 runq.c  -lm  -o runq
+$(TARGET): $(TARGET).c
 
-# run all tests
-.PHONY: test
-test:
-	pytest
-
-# run only tests for run.c C implementation (is a bit faster if only C code changed)
-.PHONY: testc
-testc:
-	pytest -k runc
-
-# run the C tests, without touching pytest / python
-# to increase verbosity level run e.g. as `make testcc VERBOSITY=1`
-VERBOSITY ?= 0
-.PHONY: testcc
-testcc:
-	$(CC) -DVERBOSITY=$(VERBOSITY) -O3 -o testc test.c -lm
-	./testc
+%.o: %.c
+	$(CC) $(CFLAGS) -o $@ -c $<
 
 .PHONY: clean
 clean:
-	rm -f run
-	rm -f runq
+	@rm *.o -rf
+	@rm $(OBJS) -rf
+	@rm $(TARGET)

envsetup.sh

@@ -0,0 +1,59 @@
+#!/bin/bash
+
+SDK_DIR=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &> /dev/null && pwd)
+echo "SDK_DIR: ${SDK_DIR}"
+
+MILKV_DUO_SDK=${SDK_DIR}/duo-sdk
+TOOLCHAIN_DIR=${MILKV_DUO_SDK}/riscv64-linux-musl-x86_64
+
+SDK_URL="https://github.com/milkv-duo/duo-app-sdk/releases/download/duo-app-sdk-v1.2.0/duo-sdk-v1.2.0.tar.gz"
+
+function get_duo_sdk()
+{
+  pushd ${SDK_DIR}
+
+  echo "SDK_URL: ${SDK_URL}"
+  sdk_file=${SDK_URL##*/}
+  echo "sdk_file: ${sdk_file}"
+
+  wget ${SDK_URL} -O ${sdk_file}
+  if [ $? -ne 0 ]; then
+    echo "Failed to download ${SDK_URL} !"
+    return 1
+  fi
+
+  if [ ! -f ${sdk_file} ]; then
+    echo "${sdk_file} not found!"
+    return 1
+  fi
+
+  echo "Extracting ${sdk_file}..."
+  tar -xf ${sdk_file}
+  if [ $? -ne 0 ]; then
+    echo "Extract ${sdk_file} failed!"
+    return 1
+  fi
+
+  [ -f ${sdk_file} ] && rm -rf ${sdk_file}
+
+  popd
+}
+
+if [ ! -d ${MILKV_DUO_SDK} ]; then
+  echo "SDK does not exist, download it now..."
+  get_duo_sdk
+  if [ $? -ne 0 ]; then
+    echo "Get SDK failed!"
+    return 1
+  fi
+fi
+
+export TOOLCHAIN_PREFIX=${TOOLCHAIN_DIR}/bin/riscv64-unknown-linux-musl-
+export SYSROOT=${MILKV_DUO_SDK}/rootfs
+
+export LDFLAGS="-mcpu=c906fdv -march=rv64imafdcv0p7xthead -mcmodel=medany -mabi=lp64d"
+# -Os
+export CFLAGS="-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64"
+
+echo "SDK environment is ready"
+