Fix one bug of spike varch elen

According to the ISA, the zve32/zve64 xdf decides the elen of the
RVV. Thus we should pick up extension instead of xlen for spike
varch generation.

Signed-off-by: Pan Li <[email protected]>

Author: Incarnation-p-lee

scripts/march-to-cpu-opt

@@ -41,6 +41,7 @@ SPIKE_EXT_NOT_ALLOWED = [
 CPU_OPTIONS = {
   "xlen":            "",
   "vlen":            "",
+  "elen":            "",
   "extensions":      [],
 }
 
@@ -146,6 +147,14 @@ def get_vlen(ext_dict):
             vlen = max(vlen, zvelen)
     return vlen
 
+def get_elen(ext_dict):
+    elen = 32
+
+    if "zve64x" in ext_dict or "zve64f" in ext_dict or "zve64d" in ext_dict:
+        elen = 64
+
+    return elen
+
 def print_qemu_cpu():
     cpu_options = []
     cpu_options.append("rv{0}".format(CPU_OPTIONS['xlen']))
@@ -186,7 +195,7 @@ def print_spike_varch():
     if not CPU_OPTIONS['vlen']:
         return ""
 
-    return "vlen:{0},elen:{1}".format(CPU_OPTIONS['vlen'], CPU_OPTIONS['xlen'])
+    return "vlen:{0},elen:{1}".format(CPU_OPTIONS['vlen'], CPU_OPTIONS['elen'])
 
 class TestArchStringParse(unittest.TestCase):
     def _test(self, arch, expected_arch_list, expected_vlen=0):
@@ -256,6 +265,7 @@ def parse_elf_file(elf_file_path):
 
     CPU_OPTIONS["extensions"] = extensions
     CPU_OPTIONS["vlen"] = get_vlen(extension_dict)
+    CPU_OPTIONS["elen"] = get_elen(extension_dict)
     CPU_OPTIONS["xlen"] = get_xlen(elf_file_path)
 
 def main(argv):