Merge pull request #728 from jeromerobert/fix-no-stack-alloc

Fix make MAX_STACK_ALLOC=0

Makefile.rule

@@ -163,10 +163,11 @@ COMMON_PROF = -pg
 # Build Debug version
 # DEBUG = 1
 
-# Improve GEMV and GER for small matrices by stack allocation.
-# For details, https://github.com/xianyi/OpenBLAS/pull/482
+# Set maximum stack allocation.
+# The default value is 2048. 0 disable stack allocation a may reduce GER and GEMV
+# performance. For details, https://github.com/xianyi/OpenBLAS/pull/482
 #
- MAX_STACK_ALLOC=2048
+# MAX_STACK_ALLOC = 0
 
 # Add a prefix or suffix to all exported symbol names in the shared library.
 # Avoid conflicts with other BLAS libraries, especially when using

Makefile.system

@@ -328,7 +328,8 @@ ifdef SANITY_CHECK
 CCOMMON_OPT	+= -DSANITY_CHECK -DREFNAME=$(*F)f$(BU)
 endif
 
-ifdef MAX_STACK_ALLOC
+MAX_STACK_ALLOC ?= 2048
+ifneq ($(MAX_STACK_ALLOC), 0)
 CCOMMON_OPT	+= -DMAX_STACK_ALLOC=$(MAX_STACK_ALLOC)
 endif
 

interface/gemv.c

@@ -270,10 +270,11 @@ void CNAME(enum CBLAS_ORDER order,
 
   }
 #endif
-// stack overflow check
-assert(stack_check==3.14159265358979323846);
 
 #ifdef MAX_STACK_ALLOC
+  // stack overflow check
+  assert(stack_check==3.14159265358979323846);
+
   if(!stack_alloc_size){
     blas_memory_free(buffer);
   }