RISC-V: fold redundant code in riscv_ip()

The parsing of 'F' and 'O' .insn operands is pretty redundant. Have only a
single instance each of common code, with the inner switch()es merely
handling the actual value insertion. This in particular simplifies the
addition of new sub-forms.

Reviewed-by: Jiawei <jiawei@iscas.ac.cn>

diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
index b5acc8a1712918df27c9c3f60410843d3bffdcac..75e5542eb9b3f3884f4aabe6486f6efff7af629e 100644 (file)
--- a/gas/config/tc-riscv.c
+++ b/gas/config/tc-riscv.c
@@ -3193,72 +3193,47 @@ riscv_ip (char *str, struct riscv_cl_insn *ip, expressionS *imm_expr,
                  INSERT_OPERAND (CRS2, *ip, regno);
                  continue;
                case 'F':
-                 switch (*++oparg)
+                 if (!ISDIGIT (*++oparg))
+                   goto unknown_riscv_ip_operand;
+
+                 /* (Ab)use "regno" here.  */
+                 regno = *oparg - '0';
+                 if (my_getSmallExpression (imm_expr, imm_reloc, asarg, p)
+                     || imm_expr->X_op != O_constant
+                     || imm_expr->X_add_number < 0
+                     || imm_expr->X_add_number >= (1U << regno))
                    {
-                     case '6':
-                       if (my_getSmallExpression (imm_expr, imm_reloc, asarg, p)
-                           || imm_expr->X_op != O_constant
-                           || imm_expr->X_add_number < 0
-                           || imm_expr->X_add_number >= 64)
-                         {
-                           as_bad (_("bad value for compressed funct6 "
-                                     "field, value must be 0...63"));
-                           break;
-                         }
-                       INSERT_OPERAND (CFUNCT6, *ip, imm_expr->X_add_number);
-                       imm_expr->X_op = O_absent;
-                       asarg = expr_parse_end;
-                       continue;
+                     as_bad (_("bad value for compressed funct%u "
+                               "field, value must be 0...%u"),
+                             regno, (1U << regno) - 1);
+                     break;
+                   }
 
-                     case '4':
-                       if (my_getSmallExpression (imm_expr, imm_reloc, asarg, p)
-                           || imm_expr->X_op != O_constant
-                           || imm_expr->X_add_number < 0
-                           || imm_expr->X_add_number >= 16)
-                         {
-                           as_bad (_("bad value for compressed funct4 "
-                                     "field, value must be 0...15"));
-                           break;
-                         }
-                       INSERT_OPERAND (CFUNCT4, *ip, imm_expr->X_add_number);
-                       imm_expr->X_op = O_absent;
-                       asarg = expr_parse_end;
-                       continue;
+                 switch (regno)
+                   {
+                   case 6:
+                     INSERT_OPERAND (CFUNCT6, *ip, imm_expr->X_add_number);
+                     break;
 
-                     case '3':
-                       if (my_getSmallExpression (imm_expr, imm_reloc, asarg, p)
-                           || imm_expr->X_op != O_constant
-                           || imm_expr->X_add_number < 0
-                           || imm_expr->X_add_number >= 8)
-                         {
-                           as_bad (_("bad value for compressed funct3 "
-                                     "field, value must be 0...7"));
-                           break;
-                         }
-                       INSERT_OPERAND (CFUNCT3, *ip, imm_expr->X_add_number);
-                       imm_expr->X_op = O_absent;
-                       asarg = expr_parse_end;
-                       continue;
+                   case 4:
+                     INSERT_OPERAND (CFUNCT4, *ip, imm_expr->X_add_number);
+                     break;
 
-                     case '2':
-                       if (my_getSmallExpression (imm_expr, imm_reloc, asarg, p)
-                           || imm_expr->X_op != O_constant
-                           || imm_expr->X_add_number < 0
-                           || imm_expr->X_add_number >= 4)
-                         {
-                           as_bad (_("bad value for compressed funct2 "
-                                     "field, value must be 0...3"));
-                           break;
-                         }
-                       INSERT_OPERAND (CFUNCT2, *ip, imm_expr->X_add_number);
-                       imm_expr->X_op = O_absent;
-                       asarg = expr_parse_end;
-                       continue;
+                   case 3:
+                     INSERT_OPERAND (CFUNCT3, *ip, imm_expr->X_add_number);
+                     break;
 
-                     default:
-                       goto unknown_riscv_ip_operand;
+                   case 2:
+                     INSERT_OPERAND (CFUNCT2, *ip, imm_expr->X_add_number);
+                     break;
+
+                   default:
+                     goto unknown_riscv_ip_operand;
                    }
-                 break;
+
+                 imm_expr->X_op = O_absent;
+                 asarg = expr_parse_end;
+                 continue;
 
                default:
                  goto unknown_riscv_ip_operand;
@@ -3709,97 +3684,80 @@ riscv_ip (char *str, struct riscv_cl_insn *ip, expressionS *imm_expr,
              continue;
 
            case 'O':
-             switch (*++oparg)
+             if (!ISDIGIT (*++oparg))
+               goto unknown_riscv_ip_operand;
+
+             /* (Ab)use "regno" here.  */
+             regno = *oparg - '0';
+             if (my_getOpcodeExpression (imm_expr, imm_reloc, asarg)
+                 || imm_expr->X_op != O_constant
+                 || imm_expr->X_add_number < 0
+                 /* O2 encodes C opcodes, i.e. doesn't permit value 3.  */
+                 || imm_expr->X_add_number >= (1U << regno) - (regno == 2)
+                 || (regno > 2 && (imm_expr->X_add_number & 3) != 3))
+               {
+                 as_bad (_("bad value for opcode field, "
+                           "value must be 0...%u%s"),
+                         (1U << regno) - (regno == 2) - 1,
+                         regno > 2 ? _(" and lower 2 bits must be 0x3") : "");
+                 break;
+               }
+
+             switch (*oparg)
                {
                case '7':
-                 if (my_getOpcodeExpression (imm_expr, imm_reloc, asarg)
-                     || imm_expr->X_op != O_constant
-                     || imm_expr->X_add_number < 0
-                     || imm_expr->X_add_number >= 128
-                     || (imm_expr->X_add_number & 0x3) != 3)
-                   {
-                     as_bad (_("bad value for opcode field, "
-                               "value must be 0...127 and "
-                               "lower 2 bits must be 0x3"));
-                     break;
-                   }
                  INSERT_OPERAND (OP, *ip, imm_expr->X_add_number);
-                 imm_expr->X_op = O_absent;
-                 asarg = expr_parse_end;
-                 continue;
+                 break;
 
                case '2':
-                 if (my_getOpcodeExpression (imm_expr, imm_reloc, asarg)
-                     || imm_expr->X_op != O_constant
-                     || imm_expr->X_add_number < 0
-                     || imm_expr->X_add_number >= 3)
-                   {
-                     as_bad (_("bad value for opcode field, "
-                               "value must be 0...2"));
-                     break;
-                   }
                  INSERT_OPERAND (OP2, *ip, imm_expr->X_add_number);
-                 imm_expr->X_op = O_absent;
-                 asarg = expr_parse_end;
-                 continue;
+                 break;
 
                default:
                  goto unknown_riscv_ip_operand;
                }
-             break;
+
+             imm_expr->X_op = O_absent;
+             asarg = expr_parse_end;
+             continue;
 
            case 'F':
-             switch (*++oparg)
+             if (!ISDIGIT (*++oparg))
+               goto unknown_riscv_ip_operand;
+
+             /* (Ab)use "regno" here.  */
+             regno = *oparg - '0';
+             if (my_getSmallExpression (imm_expr, imm_reloc, asarg, p)
+                 || imm_expr->X_op != O_constant
+                 || imm_expr->X_add_number < 0
+                 || imm_expr->X_add_number >= (1U << regno))
                {
-               case '7':
-                 if (my_getSmallExpression (imm_expr, imm_reloc, asarg, p)
-                     || imm_expr->X_op != O_constant
-                     || imm_expr->X_add_number < 0
-                     || imm_expr->X_add_number >= 128)
-                   {
-                     as_bad (_("bad value for funct7 field, "
-                               "value must be 0...127"));
-                     break;
-                   }
+                 as_bad (_("bad value for funct%u field, "
+                           "value must be 0...%u"),
+                         regno, (1U << regno) - 1);
+                 break;
+               }
+             switch (regno)
+               {
+               case 7:
                  INSERT_OPERAND (FUNCT7, *ip, imm_expr->X_add_number);
-                 imm_expr->X_op = O_absent;
-                 asarg = expr_parse_end;
-                 continue;
+                 break;
 
-               case '3':
-                 if (my_getSmallExpression (imm_expr, imm_reloc, asarg, p)
-                     || imm_expr->X_op != O_constant
-                     || imm_expr->X_add_number < 0
-                     || imm_expr->X_add_number >= 8)
-                   {
-                     as_bad (_("bad value for funct3 field, "
-                               "value must be 0...7"));
-                     break;
-                   }
+               case 3:
                  INSERT_OPERAND (FUNCT3, *ip, imm_expr->X_add_number);
-                 imm_expr->X_op = O_absent;
-                 asarg = expr_parse_end;
-                 continue;
+                 break;
 
-               case '2':
-                 if (my_getSmallExpression (imm_expr, imm_reloc, asarg, p)
-                     || imm_expr->X_op != O_constant
-                     || imm_expr->X_add_number < 0
-                     || imm_expr->X_add_number >= 4)
-                   {
-                     as_bad (_("bad value for funct2 field, "
-                               "value must be 0...3"));
-                     break;
-                   }
+               case 2:
                  INSERT_OPERAND (FUNCT2, *ip, imm_expr->X_add_number);
-                 imm_expr->X_op = O_absent;
-                 asarg = expr_parse_end;
-                 continue;
+                 break;
 
                default:
                  goto unknown_riscv_ip_operand;
                }
-             break;
+
+             imm_expr->X_op = O_absent;
+             asarg = expr_parse_end;
+             continue;
 
            case 'y': /* bs immediate */
              my_getExpression (imm_expr, asarg, force_reloc);