Enable x64 ASM Salsa20/12 on Linux.

make-linux.mk

@@ -83,9 +83,11 @@ CC_MACH=$(shell $(CC) -dumpmachine | cut -d '-' -f 1)
 ZT_ARCHITECTURE=0
 ifeq ($(CC_MACH),x86_64)
         ZT_ARCHITECTURE=2
+	ZT_USE_X64_ASM_SALSA2012=1
 endif
 ifeq ($(CC_MACH),amd64)
         ZT_ARCHITECTURE=2
+	ZT_USE_X64_ASM_SALSA2012=1
 endif
 ifeq ($(CC_MACH),i386)
         ZT_ARCHITECTURE=1
@@ -130,6 +132,12 @@ ifeq ($(ZT_ARCHITECTURE),4)
 	override DEFS+=-DZT_NO_TYPE_PUNNING
 endif
 
+# Use X64 ASM Salsa20/12 on X86_64 target
+ifeq ($(ZT_USE_X64_ASM_SALSA2012),1)
+	override DEFS+=-DZT_USE_X64_ASM_SALSA2012
+	override OBJS+=ext/x64-salsa2012-asm/salsa2012.o
+endif
+
 # Static builds, which are currently done for a number of Linux targets
 ifeq ($(ZT_STATIC),1)
 	override LDFLAGS+=-static