From 2c7143459f0003d918975d683542d66588325a78 Mon Sep 17 00:00:00 2001
From: Jerome Robert <jeromerobert@gmx.com>
Date: Thu, 31 Dec 2015 13:32:53 +0000
Subject: [PATCH 1/2] Let make MAX_STACK_ALLOC=0 do what expected

It's no longer required to modify Makefile.rule to disable
stack allocation. It's now possible to run:

make MAX_STACK_ALLOC=0
---
 Makefile.rule   | 7 ++++---
 Makefile.system | 3 ++-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/Makefile.rule b/Makefile.rule
index 0d7c45ead..4a6e4e9f1 100644
--- a/Makefile.rule
+++ b/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
diff --git a/Makefile.system b/Makefile.system
index 9de9232ad..b3e83e2dd 100644
--- a/Makefile.system
+++ b/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
 

From f9890a6452b2807200ea4b0ee2b2874e189fcbba Mon Sep 17 00:00:00 2001
From: Jerome Robert <jeromerobert@gmx.com>
Date: Thu, 31 Dec 2015 13:36:22 +0000
Subject: [PATCH 2/2] Fix compilation when MAX_STACK_ALLOC is not set

Close #722
---
 interface/gemv.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/interface/gemv.c b/interface/gemv.c
index 97c68bf2d..206390ed9 100644
--- a/interface/gemv.c
+++ b/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);
   }