Remove unused code in vsmul* (riscv-software-src#1069)

Author: ksco

riscv/insns/vsmul_vv.h

@@ -2,27 +2,19 @@
 VRM xrm = P.VU.get_vround_mode();
 int64_t int_max = INT64_MAX >> (64 - P.VU.vsew);
 int64_t int_min = INT64_MIN >> (64 - P.VU.vsew);
-int64_t sign_mask = uint64_t(1) << (P.VU.vsew - 1);
 
 VI_VV_LOOP
 ({
-  int64_t vs1_sign;
-  int64_t vs2_sign;
-  int64_t result_sign;
-
-  vs1_sign = vs1 & sign_mask;
-  vs2_sign = vs2 & sign_mask;
   bool overflow = vs1 == vs2 && vs1 == int_min;
-
   int128_t result = (int128_t)vs1 * (int128_t)vs2;
-  result_sign = (vs1_sign ^ vs2_sign) & sign_mask;
 
   // rounding
   INT_ROUNDING(result, xrm, sew - 1);
+
   // remove guard bits
   result = result >> (sew - 1);
 
-  // saturation
+  // max saturation
   if (overflow) {
     result = int_max;
     P_SET_OV(1);

riscv/insns/vsmul_vx.h

@@ -2,20 +2,11 @@
 VRM xrm = P.VU.get_vround_mode();
 int64_t int_max = INT64_MAX >> (64 - P.VU.vsew);
 int64_t int_min = INT64_MIN >> (64 - P.VU.vsew);
-int64_t sign_mask = uint64_t(1) << (P.VU.vsew - 1);
 
 VI_VX_LOOP
 ({
-  int64_t rs1_sign;
-  int64_t vs2_sign;
-  int64_t result_sign;
-
-  rs1_sign = rs1 & sign_mask;
-  vs2_sign = vs2 & sign_mask;
   bool overflow = rs1 == vs2 && rs1 == int_min;
-
   int128_t result = (int128_t)rs1 * (int128_t)vs2;
-  result_sign = (rs1_sign ^ vs2_sign) & sign_mask;
 
   // rounding
   INT_ROUNDING(result, xrm, sew - 1);