Merge pull request #7476 from tkelman/openblas-noavx

Add OPENBLAS_NO_AVX build option to disable AVX kernels

README.md

@@ -163,7 +163,7 @@ Now you should be able to build using the generic Linux instructions. These inst
 
  Problem              | Possible Solution
 ------------------------|---------------------
- OpenBLAS build failure | Set one of the following build options in `Make.user` and build again: <ul><li> `OPENBLAS_TARGET_ARCH=BARCELONA` (AMD CPUs) or `OPENBLAS_TARGET_ARCH=NEHALEM` (Intel CPUs)<ul>Set `OPENBLAS_DYNAMIC_ARCH = 0` to disable compiling multiple architectures in a single binary.</ul></li><li> `USE_SYSTEM_BLAS=1` uses the system provided `libblas` <ul><li>Set `LIBBLAS=-lopenblas` and `LIBBLASNAME=libopenblas` to force the use of the system provided OpenBLAS when multiple BLAS versions are installed </li></ul></li></ul>
+ OpenBLAS build failure | Set one of the following build options in `Make.user` and build again: <ul><li> `OPENBLAS_TARGET_ARCH=BARCELONA` (AMD CPUs) or `OPENBLAS_TARGET_ARCH=NEHALEM` (Intel CPUs)<ul>Set `OPENBLAS_DYNAMIC_ARCH = 0` to disable compiling multiple architectures in a single binary.</ul></li><li> `OPENBLAS_NO_AVX = 1` disables AVX instructions, allowing OpenBLAS to compile with `OPENBLAS_DYNAMIC_ARCH = 1` using old versions of binutils </li><li> `USE_SYSTEM_BLAS=1` uses the system provided `libblas` <ul><li>Set `LIBBLAS=-lopenblas` and `LIBBLASNAME=libopenblas` to force the use of the system provided OpenBLAS when multiple BLAS versions are installed </li></ul></li></ul>
  Illegal Instruction error | Check if your CPU supports AVX while your OS does not (e.g. through virtualization, as described in [this issue](https://github.com/JuliaLang/julia/issues/3263)), and try installing LLVM 3.3 instead of LLVM 3.2.
 
 ### OS X

deps/Makefile

@@ -788,6 +788,11 @@ ifeq ($(OPENBLAS_DEBUG), 1)
 OPENBLAS_BUILD_OPTS += DEBUG=1
 endif
 
+# Allow disabling AVX for older binutils
+ifeq ($(OPENBLAS_NO_AVX), 1)
+OPENBLAS_BUILD_OPTS += NO_AVX=1
+endif
+
 openblas-$(OPENBLAS_VER).tar.gz:
 	$(JLDOWNLOAD) $@ https://github.com/xianyi/OpenBLAS/tarball/$(OPENBLAS_VER) 
 openblas-$(OPENBLAS_VER)/config.status: openblas-$(OPENBLAS_VER).tar.gz