MinGW64 requires that the functions be prefixed with an underscore.  Visual C++ apparently doesn't


git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@125 632fc199-4ca6-4c93-a231-07263d6284db
diff --git a/simd/jsimdext.inc b/simd/jsimdext.inc
index d371a52..d0b47e6 100644
--- a/simd/jsimdext.inc
+++ b/simd/jsimdext.inc
@@ -47,7 +47,9 @@
 ;
 %define SEG_TEXT    .text  align=16 public use64 class=CODE
 %define SEG_CONST   .rdata align=16 public use64 class=CONST
-;%define EXTN(name)  name			; foo() -> foo
+%ifdef MSVC
+%define EXTN(name)  name			; foo() -> foo
+%endif
 
 %elifdef OBJ32	; ----(nasm -fobj -DOBJ32 ...)----------
 ; * Borland C++ (Win32)
diff --git a/win/Makerules b/win/Makerules
index 12e96fe..59a7d3a 100755
--- a/win/Makerules
+++ b/win/Makerules
@@ -30,9 +30,9 @@
 CFLAGS = -W3 -wd4996 -Iwin -I.
 CDEFINES = -DWIN32 -D_CRT_SECURE_NO_DEPRECATE
 ifeq ($(WIN64), yes)
-NAFLAGS = -fwin64 -DWIN64 -D__x86_64__ -Iwin/
+NAFLAGS = -fwin64 -DWIN64 -DMSVC -D__x86_64__ -Iwin/
 else
-NAFLAGS = -fwin32 -DWIN32 -Iwin/
+NAFLAGS = -fwin32 -DWIN32 -DMSVC -Iwin/
 endif
 ifeq ($(DEBUG), yes)
  CFLAGS := $(CFLAGS) -Od -MTd -Zi