Add riscv64 support

'-mabi=lp64d’ means that ‘long’ and pointers are 64-bit (implicitly defining ‘int’ to be 32-bit), and that floating-point values up to 64 bits wide are passed in F registers.

[1] https://gcc.gnu.org/onlinedocs/gcc/RISC-V-Options.html

Co-authored-by: Glenn Strauss <[email protected]>

github: closes #89

Author: sunmin89

UnixBench/Makefile

@@ -89,15 +89,17 @@ else
 
   ## OS detection.  Comment out if gmake syntax not supported by other 'make'. 
   OSNAME:=$(shell uname -s)
-  ARCH := $(shell uname -p)
+  ARCH := $(shell uname -m)
   ifeq ($(OSNAME),Linux)
     # Not all CPU architectures support "-march" or "-march=native".
-    #   - Supported    : x86, x86_64, ARM, AARCH64, etc..
-    #   - Not Supported: RISC-V, IBM Power, etc...
-    ifneq ($(ARCH),$(filter $(ARCH),ppc64 ppc64le))
-        OPTON += -march=native -mtune=native
-    else
+    #   - Supported    : x86, x86_64, ARM, AARCH64, riscv64, etc..
+    #   - Not Supported: IBM Power, etc...
+    ifeq ($(ARCH),$(filter $(ARCH),ppc64 ppc64le))
         OPTON += -mcpu=native -mtune=native
+    else ifeq ($(ARCH),riscv64)
+        OPTON += -march=rv64g -mabi=lp64d
+    else
+        OPTON += -march=native -mtune=native
     endif
   endif