Give choice of ATLAS, MKL, and OpenBLAS (with option to override paths)

- configure build for ATLAS, MKL, or OpenBLAS on Linux and OSX
- allow overriding of the include or lib dirs
- replace magic numbers with BLAS names (atlas, mkl, open)

Follow-up from #305 and #325.

Makefile

@@ -109,8 +109,6 @@ TEST_ALL_BIN := $(TEST_BIN_DIR)/test_all.testbin
 ##############################
 CUDA_INCLUDE_DIR := $(CUDA_DIR)/include
 CUDA_LIB_DIR := $(CUDA_DIR)/lib64 $(CUDA_DIR)/lib
-BLAS_INCLUDE_DIR := $(BLAS_DIR)/include
-BLAS_LIB_DIR := $(BLAS_DIR)/lib 
 
 INCLUDE_DIRS += $(BUILD_INCLUDE_DIR)
 INCLUDE_DIRS += ./src ./include $(CUDA_INCLUDE_DIR)
@@ -176,31 +174,36 @@ else
 	COMMON_FLAGS := -DNDEBUG -O2
 endif
 
-# MKL switch (default = ATLAS)
-BLAS ?= 0
-ifeq ($(BLAS), 1)
+# BLAS configuration (default = ATLAS)
+BLAS ?= atlas
+ifeq ($(BLAS), mkl)
+	# MKL
 	LIBRARIES += mkl_rt
 	COMMON_FLAGS += -DUSE_MKL
-	INCLUDE_DIRS += $(BLAS_INCLUDE_DIR)
-	LIBRARY_DIRS += $(BLAS_LIB_DIR) $(BLAS_DIR)/lib/intel64
+	MKL_DIR = /opt/intel/mkl
+	BLAS_INCLUDE ?= $(MKL_DIR)/include
+	BLAS_LIB ?= $(MKL_DIR)/lib $(MKL_DIR)/lib/intel64
+else ifeq ($(BLAS), open)
+	# OpenBLAS
+	LIBRARIES += openblas
 else
+	# ATLAS
 	ifeq ($(LINUX), 1)
-              ifeq ($(BLAS), 0)
-		# Linux simply has cblas and atlas
-		LIBRARIES += cblas atlas
-              else ifeq ($(BLAS), 2)
-                LIBRARIES += openblas
-              endif
-        INCLUDE_DIRS += $(BLAS_INCLUDE_DIR)
-	LIBRARY_DIRS += $(BLAS_LIB_DIR) 
+		ifeq ($(BLAS), atlas)
+			# Linux simply has cblas and atlas
+			LIBRARIES += cblas atlas
+		endif
 	else ifeq ($(OSX), 1)
 		# OS X packages atlas as the vecLib framework
-		INCLUDE_DIRS += /System/Library/Frameworks/vecLib.framework/Versions/Current/Headers/
+		BLAS_INCLUDE ?= /System/Library/Frameworks/vecLib.framework/Versions/Current/Headers/
 		LIBRARIES += cblas
 		LDFLAGS += -framework vecLib
 	endif
 endif
+INCLUDE_DIRS += $(BLAS_INCLUDE)
+LIBRARY_DIRS += $(BLAS_LIB)
 
+# Complete build flags.
 COMMON_FLAGS += $(foreach includedir,$(INCLUDE_DIRS),-I$(includedir))
 CXXFLAGS += -pthread -fPIC $(COMMON_FLAGS)
 NVCCFLAGS := -ccbin=$(CXX) -Xcompiler -fPIC $(COMMON_FLAGS)

Makefile.config.example

@@ -10,13 +10,16 @@ CUDA_ARCH := -gencode arch=compute_20,code=sm_20 \
 		-gencode arch=compute_30,code=sm_30 \
 		-gencode arch=compute_35,code=sm_35
 
-# BLAS switch:
-# 0 for ATLAS BLAS (default)
-# 1 for MKL BLAS
-# 2 for OpenBlas
-BLAS := 0
-# (MKL/ATLAS/OpenBlas) directory contains include/ and lib/ directions that we need.
-#BLAS_DIR := /opt/intel/mkl
+# BLAS choice:
+# atlas for ATLAS (default)
+# mkl for MKL
+# open for OpenBlas
+BLAS := atlas
+# Custom (MKL/ATLAS/OpenBLAS) include and lib directories.
+# Leave commented to accept the defaults for your choice of BLAS
+# (which should work)!
+# BLAS_INCLUDE := /path/to/your/blas
+# BLAS_LIB := /path/to/your/blas
 
 # This is required only if you will compile the matlab interface.
 # MATLAB directory should contain the mex binary in /bin.

docs/installation.md

@@ -47,8 +47,10 @@ N.B. one can install the CUDA libraries without the CUDA driver in order to buil
     + OS X: already installed as the [Accelerate / vecLib Framework](https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man7/Accelerate.7.html).
 * [Intel MKL](http://software.intel.com/en-us/intel-mkl): commercial; however free trial or [student](http://software.intel.com/en-us/intel-education-offerings) licenses are available. Caffe was originally developed with MKL.
     1. Install MKL
-    2. Set `USE_MKL := 1` in `Makefile.config`
-* [OpenBLAS](http://www.openblas.net/): free and open source; this optimized BLAS is left as an exercise because it requires more effort to install, although it might offer a speedup.
+    2. Set `BLAS := mkl` in `Makefile.config`
+* [OpenBLAS](http://www.openblas.net/): free and open source; this optimized and parallel BLAS could require more effort to install, although it might offer a speedup.
+    1. Install OpenBLAS
+    2. Set `BLAS := open` in `Makefile.config`
 
 **The Rest**: you will also need other packages, most of which can be installed via apt-get using: