Use sane Makefile

If additional libraries are necessary, the user can always pass flags and
environment variables accordingly.

Makefile

@@ -1,74 +1,41 @@
 # Names of target, sources and object files
 BIN = benchmark
-SRC := timer.c utilities.c benchmark.c
+SRC = timer.c utilities.c benchmark.c opencl_fft.c
 
 # Dependencies
 DEP_OCLFFT = .deps/oclfft/src/liboclfft.so
 DEP_CLFFT = .deps/clFFT/src/library/libclFFT.so
-DEPS = $(DEP_OCLFFT)
+DEPS = $(DEP_OCLFFT) $(DEP_CLFFT)
 
 # Debug mode
 CC_MARK := @
+
 ifeq ($(V), 1)
 	override CC_MARK =
 endif
 
-# Get bits of OS
-ARCH := $(shell getconf LONG_BIT 2> /dev/null)
-ifeq ($(ARCH),32)
-	override ARCH = ''
-endif
-
 # Libs titiles
-LIBS_MSG    :=
+LIBS_MSG    =
 
 # Common flags definition
-CPPFLAGS    :=
-CFLAGS      := -O3 -Wall -Werror -Wno-unused-variable -std=c99 -fmessage-length=0
-LDFLAGS     := -lm
-
-# Detect OpenCL
-OPENCL_PATH := $(shell find /usr/lib$(ARCH) -type f -name "libOpenCL.so*" 2> /dev/null)
-
-ifneq ($(OPENCL_PATH),)
-	override LDFLAGS += -L/usr/lib$(ARCH) -lOpenCL
-	override SRC += $(wildcard opencl*.c)
-else
-$(error "OpenCL library cannot be found.")
-endif
+CPPFLAGS    =
+CFLAGS      ?= -O3 -Wall -Werror -Wno-unused-variable -fmessage-length=0
+CFLAGS 		+= -std=c99
+LDFLAGS     += -lm -lOpenCL
 
-# Detect CUDA FFT library
-CUDA_FFT := $(shell find $(CUDA_PATH)/ -maxdepth 2 -type f -name "libcufft.so*" 2> /dev/null)
-
-# If true then try to use CUDA, otherwise AMD
-ifneq ($(CUDA_FFT),)
+ifneq ($(CUDA_PATH),)
 	override CPPFLAGS += -DHAVE_CUDA_FFT
 	override CFLAGS += -I$(CUDA_PATH)/include
-	override LDFLAGS += -L$(CUDA_PATH)/lib$(ARCH) -lcufft -lcudart -Wl,-rpath=$(CUDA_PATH)/lib$(ARCH) 
+	override LDFLAGS += -L$(CUDA_PATH)/lib$(ARCH) -lcufft -lcudart -Wl,-rpath=$(CUDA_PATH)/lib$(ARCH)
 	override LIBS_MSG += " +cuda"
 	override SRC += $(wildcard cuda*.c)
-else
-	ifneq ($(AMDAPPSDKROOT),)
-		override CFLAGS += -I$(AMDAPPSDKROOT)/include
-	else
-$(error "SDKs paths cannot be found. Try setting CUDA_PATH for CUDA SDK or AMDAPPSDKROOT for AMD SDK.")
-	endif
 endif
 
 # AMD FFT library
-AMD_FFT_EXISTS = $(shell pkg-config --exists clFFT && echo "1" || echo "0")
-
-ifeq ($(AMD_FFT_EXISTS),1)
-	override CPPFLAGS += -DHAVE_AMD_FFT
-	override CFLAGS += $(shell pkg-config --cflags clFFT)
-	override LDFLAGS += $(shell pkg-config --libs clFFT) -Wl,-rpath=$(shell pkg-config --variable=libdir clFFT)
-	override LIBS_MSG += " +amd"
-else
-	override DEPS += $(DEP_CLFFT)
-	override CFLAGS += -I.deps/clFFT/src/include -DHAVE_AMD_FFT
-	override LDFLAGS += -L.deps/clFFT/src/library -lclFFT -Wl,-rpath=.deps/clFFT/src/library
-	override LIBS_MSG += " +amd"
-endif
+override DEPS += $(DEP_CLFFT)
+override CFLAGS += -I.deps/clFFT/src/include -DHAVE_AMD_FFT
+override LDFLAGS += -L.deps/clFFT/src/library -lclFFT -Wl,-rpath=.deps/clFFT/src/library
+override LIBS_MSG += " +amd"
 
 # Apple FFT library
 override CPPFLAGS += -DHAVE_APPLE_FFT
@@ -76,10 +43,6 @@ override CFLAGS += -I.deps/
 override LDFLAGS += -L.deps/oclfft/src -loclfft -Wl,-rpath=.deps/oclfft/src
 override LIBS_MSG += " +apple"
 
-ifneq ($(OPENCL_PATH),)
-	override LDFLAGS += -Wl,-rpath=/usr/lib$(ARCH)
-endif
-
 # FFTW library
 FFTW_EXISTS = $(shell pkg-config --exists fftw3 && echo "1" || echo "0")
 
@@ -132,4 +95,4 @@ $(DEP_OCLFFT):
 $(DEP_CLFFT):
 	@mkdir -p .deps
 	@git clone https://github.com/clMathLibraries/clFFT .deps/clFFT
-	@cd .deps/clFFT/src; cmake . -DOPENCL_ROOT=/usr; make
+	@cd .deps/clFFT/src; AMDAPPSDKROOT="" cmake . -DOPENCL_ROOT=/usr; AMDAPPSDKROOT="" make