Use AC_PATH_PROG to find nvcc's path

configure.ac

@@ -222,6 +222,8 @@ if test x$enable_cuda = xyes; then
 		NVCCFLAGS="${NVCCFLAGS} -m64"
 		AC_SUBST(NVCCFLAGS)
 	fi
+
+	AC_PATH_PROG([NVCC], [nvcc], [nvcc], [$cuda_dir/bin:$PATH:/usr/local/bin:/usr/bin:/bin], [AC_MSG_WARN(Cannot find nvcc.)])
 fi
 
 enable_magma=no

examples/Makefile.am

@@ -56,9 +56,6 @@ CLEANFILES += *.gcno *.gcda *.linkinfo
 
 if STARPU_USE_CUDA
 
-# TODO define NVCCFLAGS
-NVCC ?= nvcc
-
 .cu.cubin:
 	$(MKDIR_P) `dirname $@`
 	$(NVCC) -cubin $< -o $@ --compiler-options -fno-strict-aliasing  $(NVCCFLAGS)

examples/starpufft/Makefile.am

@@ -39,8 +39,6 @@ libstarpufft_la_LIBADD = $(top_builddir)/src/libstarpu.la $(FFTW_LIBS) $(FFTWF_L
 libstarpufft_la_CFLAGS = $(FFTWF_CFLAGS)
 
 if STARPU_USE_CUDA
-# TODO define NVCCFLAGS
-NVCC ?= nvcc
 NVCCFLAGS += -Xcompiler -fPIC -Xlinker -fPIC
 
 cudaf_kernels.o: cudaf_kernels.cu