rvv: make variable name match its meaning

zimm5 for unsigned and zero-extended
   simm5 for signed and signed-extended

   It is unsigned arithmetics

Signed-off-by: Chih-Min Chao <chihmin.chao@sifive.com>

riscv/decode.h

@@ -613,7 +613,7 @@ static inline bool is_overlapped(const int astart, const int asize,
 
 #define VI_U_PARAMS(x) \
   type_usew_t<x>::type &vd = P.VU.elt<type_usew_t<x>::type>(rd_num, i, true); \
-  type_usew_t<x>::type simm5 = (type_usew_t<x>::type)insn.v_zimm5(); \
+  type_usew_t<x>::type zimm5 = (type_usew_t<x>::type)insn.v_zimm5(); \
   type_usew_t<x>::type vs2 = P.VU.elt<type_usew_t<x>::type>(rs2_num, i);
 
 #define VV_PARAMS(x) \

riscv/insns/vsaddu_vi.h

@@ -1,4 +1,4 @@
-// vsaddu vd, vs2, zimm5
+// vsaddu vd, vs2, simm5
 VI_VI_ULOOP
 ({
   bool sat = false;

riscv/insns/vsrl_vi.h

@@ -1,5 +1,5 @@
 // vsrl.vi vd, vs2, zimm5
 VI_VI_ULOOP
 ({
-  vd = vs2 >> (simm5 & (sew - 1) & 0x1f);
+  vd = vs2 >> (zimm5 & (sew - 1) & 0x1f);
 })

riscv/insns/vssrl_vi.h

@@ -2,7 +2,7 @@
 VRM xrm = P.VU.get_vround_mode();
 VI_VI_ULOOP
 ({
-  int sh = simm5 & (sew - 1) & 0x1f;
+  int sh = zimm5 & (sew - 1) & 0x1f;
   uint128_t val = vs2;
 
   INT_ROUNDING(val, xrm, sh);