CilkPlus sample

fib.cpp

#include <iostream>
#include <cassert>
#include <cstdlib>
#include <cilk/cilk.h>
#include <gmpxx.h>

using namespace std;

mpz_class fast_fib(unsigned int n) {
  if (n < 2) { return mpz_class(n); }
  mpz_class a(0), b(1);
  for (unsigned int i = 0; i < n; i++) {
    mpz_class t = a + b;
    swap(b, a);
    swap(a, t);
  }
  return a;
}

unsigned int fib(unsigned int n) {
  if (n < 2) { return n; }
  const unsigned int a = cilk_spawn fib(n - 1);
  const unsigned int b = fib(n - 2);
  cilk_sync;
  return a + b;
}

mpz_class fib(const mpz_class& n) {
  if (n < 2) { return n; }
  const mpz_class a = cilk_spawn fib(n - 1);
  const mpz_class b = fib(n - 2);
  cilk_sync;
  return a + b;
}

int main(int argc, const char **argv) {
  assert(argc >= 2);
  const unsigned int x = atoi(argv[1]);

  bool use_gmp = false;
  if (argc >= 3) {
    const string m = argv[2];
    if (m == "gmp") { use_gmp = true; }
  }

  const mpz_class verify = fast_fib(x);

  if (use_gmp) {
    cout << "use gmp" << endl;
    const mpz_class y(x);
    const mpz_class result = fib(y);
    cout << result << endl;
    assert(result == verify);
  } else {
    unsigned int result = fib(x);
    cout << result << endl;
    assert(result == verify);
  }
  return 0;
}

Makefile

GCC_VERSION := $(shell $(CXX) -dumpversion)
GCC_MAJOR_VERSION = $(shell echo $(GCC_VERSION) | cut -d '.' -f 1)
GCC_MINOR_VERSION = $(shell echo $(GCC_VERSION) | cut -d '.' -f 2)

CPPFLAGS = -Wall -Wextra -O3 -g3 -fcilkplus
LDFLAGS = -g3 -lcilkrts -lgmpxx -lgmp -lstdc++

TARGETs = fib

.PHONY: all clean precheck
all: precheck $(TARGETs)

clean:
	$(RM) $(TARGETs)

precheck:
	[ "$(findstring g++,$(CXX))" = "g++" ]
	[ $$($(CXX) -dumpversion | cut -d '.' -f 1) -ge 4 ]
	[ $$($(CXX) -dumpversion | cut -d '.' -f 2) -ge 9 ]

setenv.bash

# This bash script assumes gcc with CilkPlus is installed with
# configure script option '--prefix=${HOME}/cilkplus --program-suffix=-4.8-cp'.

export PATH=${HOME}/cilkplus/bin${PATH:+:${PATH}}
export CPATH=${HOME}/cilkplus/include${CPATH:+:${CPATH}}
export LIBRARY_PATH=${HOME}/cilkplus/lib${LIBRARY_PATH:+:${LIBRARY_PATH}}
export LD_LIBRARY_PATH=${HOME}/cilkplus/lib64${HOME}/cilkplus/lib${LD_LIBRARY_PATH:+:${LD_LIBRARY_PATH}}
export CC=${HOME}/cilkplus/bin/gcc-4.8-cp
export CXX=${HOME}/cilkplus/bin/g++-4.8-cp