Refs #139. Added NO_AVX flag to use old Nehalem kernels on Sandy Bridge.

For example, make NO_AVX=1 or make DYNAMIC_ARCH=1 NO_AVX=1

Makefile.rule

@@ -71,6 +71,10 @@ VERSION = 0.2.3
 # If you want to disable CPU/Memory affinity on Linux.
 # NO_AFFINITY = 1
 
+# Don't use AVX kernel on Sandy Bridge. It is compatible with old compilers 
+# and OS. However, the performance is low.
+# NO_AVX = 1
+
 # If you would like to know minute performance report of GotoBLAS.
 # FUNCTION_PROFILE = 1
 

Makefile.system

@@ -57,6 +57,10 @@ GEMM_MULTITHREAD_THRESHOLD=50
 endif
 GETARCH_FLAGS	+= -DGEMM_MULTITHREAD_THRESHOLD=$(GEMM_MULTITHREAD_THRESHOLD) 
 
+ifeq ($(NO_AVX), 1)
+GETARCH_FLAGS	+= -DNO_AVX
+endif
+
 # This operation is expensive, so execution should be once.
 ifndef GOTOBLAS_MAKEFILE
 export GOTOBLAS_MAKEFILE = 1
@@ -247,11 +251,17 @@ endif
 ifeq ($(DYNAMIC_ARCH), 1)
 ifeq ($(ARCH), x86)
 DYNAMIC_CORE = KATMAI COPPERMINE NORTHWOOD PRESCOTT BANIAS \
-	       CORE2 PENRYN DUNNINGTON NEHALEM SANDYBRIDGE ATHLON OPTERON OPTERON_SSE3 BARCELONA BOBCAT ATOM NANO
+	       CORE2 PENRYN DUNNINGTON NEHALEM ATHLON OPTERON OPTERON_SSE3 BARCELONA BOBCAT ATOM NANO
+ifneq ($(NO_AVX), 1)
+DYNAMIC_CORE += SANDYBRIDGE 
+endif
 endif
 
 ifeq ($(ARCH), x86_64)
-DYNAMIC_CORE = PRESCOTT CORE2 PENRYN DUNNINGTON NEHALEM SANDYBRIDGE OPTERON OPTERON_SSE3 BARCELONA BOBCAT ATOM NANO
+DYNAMIC_CORE = PRESCOTT CORE2 PENRYN DUNNINGTON NEHALEM OPTERON OPTERON_SSE3 BARCELONA BOBCAT ATOM NANO
+ifneq ($(NO_AVX), 1)
+DYNAMIC_CORE += SANDYBRIDGE 
+endif
 endif
 
 ifndef DYNAMIC_CORE
@@ -562,6 +572,10 @@ ifeq ($(NO_LAPACKE), 1)
 CCOMMON_OPT	+= -DNO_LAPACKE
 endif
 
+ifeq ($(NO_AVX), 1)
+CCOMMON_OPT	+= -DNO_AVX
+endif
+
 ifdef SMP
 CCOMMON_OPT	+= -DSMP_SERVER
 

cpuid_x86.c

@@ -40,6 +40,11 @@
 #include <string.h>
 #include "cpuid.h"
 
+#ifdef NO_AVX
+#define CPUTYPE_SANDYBRIDGE CPUTYPE_NEHALEM
+#define CORE_SANDYBRIDGE CORE_NEHALEM
+#endif
+
 #ifndef CPUIDEMU
 
 #if defined(__APPLE__) && defined(__i386__)
@@ -189,7 +194,9 @@ int get_cputype(int gettype){
     if ((ecx & (1 <<  9)) != 0) feature |= HAVE_SSSE3;
     if ((ecx & (1 << 19)) != 0) feature |= HAVE_SSE4_1;
     if ((ecx & (1 << 20)) != 0) feature |= HAVE_SSE4_2;
+#ifndef NO_AVX
     if ((ecx & (1 << 28)) != 0) feature |= HAVE_AVX;
+#endif
 
     if (have_excpuid() >= 0x01) {
       cpuid(0x80000001, &eax, &ebx, &ecx, &edx);

driver/others/dynamic.c

@@ -60,8 +60,14 @@ extern gotoblas_t  gotoblas_NEHALEM;
 extern gotoblas_t  gotoblas_OPTERON;
 extern gotoblas_t  gotoblas_OPTERON_SSE3;
 extern gotoblas_t  gotoblas_BARCELONA;
-extern gotoblas_t  gotoblas_SANDYBRIDGE;
 extern gotoblas_t  gotoblas_BOBCAT;
+#ifndef NO_AVX
+extern gotoblas_t  gotoblas_SANDYBRIDGE;
+#else
+//Use NEHALEM kernels for sandy bridge
+#define gotoblas_SANDYBRIDGE gotoblas_NEHALEM
+#endif
+
 
 #define VENDOR_INTEL      1
 #define VENDOR_AMD        2