opcodes: microblaze: Add new bit-field instructions

This patches adds new bsefi and bsifi instructions.
BSEFI- The instruction shall extract a bit field from a
register and place it right-adjusted in the destination register.
The other bits in the destination register shall be set to zero.
BSIFI- The instruction shall insert a right-adjusted bit field
from a register at another position in the destination register.
The rest of the bits in the destination register shall be unchanged.

Further documentation of these instructions can be found here:
https://docs.xilinx.com/v/u/en-US/ug984-vivado-microblaze-ref

With version 6 of the patch, no new relocation types are added as
this was unnecessary for adding the bsefi and bsifi instructions.

FIXED: Segfault caused by incorrect termination of microblaze_opcodes.

Signed-off-by: nagaraju <[email protected]>
Signed-off-by: Ibai Erkiaga <[email protected]>
Signed-off-by: Neal Frager <[email protected]>
Signed-off-by: Michael J. Eager <[email protected]>

Author: nealfrager

gas/config/tc-microblaze.c

@@ -915,7 +915,7 @@ md_assemble (char * str)
   unsigned reg2;
   unsigned reg3;
   unsigned isize;
-  unsigned int immed = 0, temp;
+  unsigned int immed = 0, immed2 = 0, temp;
   expressionS exp;
   char name[20];
 
@@ -1177,6 +1177,87 @@ md_assemble (char * str)
       inst |= (immed << IMM_LOW) & IMM5_MASK;
       break;
 
+    case INST_TYPE_RD_R1_IMMW_IMMS:
+      if (strcmp (op_end, ""))
+	op_end = parse_reg (op_end + 1, &reg1);  /* Get rd.  */
+      else
+	{
+	  as_fatal (_("Error in statement syntax"));
+	  reg1 = 0;
+	}
+
+      if (strcmp (op_end, ""))
+	op_end = parse_reg (op_end + 1, &reg2);  /* Get r1.  */
+      else
+	{
+	  as_fatal (_("Error in statement syntax"));
+	  reg2 = 0;
+	}
+
+      /* Check for spl registers.  */
+      if (check_spl_reg (&reg1))
+	as_fatal (_("Cannot use special register with this instruction"));
+      if (check_spl_reg (&reg2))
+	as_fatal (_("Cannot use special register with this instruction"));
+
+      /* Width immediate value.  */
+      if (strcmp (op_end, ""))
+	op_end = parse_imm (op_end + 1, &exp, MIN_IMM_WIDTH, MAX_IMM_WIDTH);
+      else
+	as_fatal (_("Error in statement syntax"));
+
+      if (exp.X_op != O_constant)
+	{
+	  as_warn (_(
+	  "Symbol used as immediate width value for bit field instruction"));
+	  immed = 1;
+	}
+      else
+	immed = exp.X_add_number;
+
+      if (opcode->instr == bsefi && immed > 31)
+	as_fatal (_("Width value must be less than 32"));
+
+      /* Shift immediate value.  */
+      if (strcmp (op_end, ""))
+	op_end = parse_imm (op_end + 1, &exp, MIN_IMM, MAX_IMM);
+      else
+	as_fatal (_("Error in statement syntax"));
+
+      if (exp.X_op != O_constant)
+	{
+	  as_warn (_(
+	  "Symbol used as immediate shift value for bit field instruction"));
+	  immed2 = 0;
+	}
+      else
+	{
+	  output = frag_more (isize);
+	  immed2 = exp.X_add_number;
+	}
+
+      if (immed2 != (immed2 % 32))
+	{
+	  as_warn (_("Shift value greater than 32. using <value %% 32>"));
+	  immed2 = immed2 % 32;
+	}
+
+      /* Check combined value.  */
+      if (immed + immed2 > 32)
+	as_fatal (_("Width value + shift value must not be greater than 32"));
+
+      inst |= (reg1 << RD_LOW) & RD_MASK;
+      inst |= (reg2 << RA_LOW) & RA_MASK;
+
+      if (opcode->instr == bsefi)
+	inst |= (immed & IMM5_MASK) << IMM_WIDTH_LOW; /* bsefi */
+      else
+	inst |= ((immed + immed2 - 1) & IMM5_MASK)
+		<< IMM_WIDTH_LOW; /* bsifi */
+
+      inst |= (immed2 << IMM_LOW) & IMM5_MASK;
+      break;
+
     case INST_TYPE_R1_R2:
       if (strcmp (op_end, ""))
         op_end = parse_reg (op_end + 1, &reg1);  /* Get r1.  */

opcodes/microblaze-dis.c

@@ -90,6 +90,21 @@ get_field_imm5_mbar (struct string_buf *buf, long instr)
   return p;
 }
 
+static char *
+get_field_immw (struct string_buf *buf, long instr)
+{
+  char *p = strbuf (buf);
+
+  if (instr & 0x00004000)
+    sprintf (p, "%d", (short)(((instr & IMM5_WIDTH_MASK)
+				>> IMM_WIDTH_LOW))); /* bsefi */
+  else
+    sprintf (p, "%d", (short)(((instr & IMM5_WIDTH_MASK) >>
+				IMM_WIDTH_LOW) - ((instr & IMM5_MASK) >>
+				IMM_LOW) + 1)); /* bsifi */
+  return p;
+}
+
 static char *
 get_field_rfsl (struct string_buf *buf, long instr)
 {
@@ -427,6 +442,14 @@ print_insn_microblaze (bfd_vma memaddr, struct disassemble_info * info)
 	  /* For mbar 16 or sleep insn.  */
 	case INST_TYPE_NONE:
 	  break;
+	  /* For bit field insns.  */
+	case INST_TYPE_RD_R1_IMMW_IMMS:
+	  print_func (stream, "\t%s, %s, %s, %s",
+		      get_field_rd (&buf, inst),
+		      get_field_r1 (&buf, inst),
+		      get_field_immw (&buf, inst),
+		      get_field_imm5 (&buf, inst));
+	  break;
 	  /* For tuqula instruction */
 	case INST_TYPE_RD:
 	  print_func (stream, "\t%s", get_field_rd (&buf, inst));

opcodes/microblaze-opc.h

@@ -59,6 +59,9 @@
 /* For mbar.  */
 #define INST_TYPE_IMM5 20
 
+/* For bsefi and bsifi */
+#define INST_TYPE_RD_R1_IMMW_IMMS  21
+
 #define INST_TYPE_NONE 25
 
 
@@ -90,6 +93,7 @@
 #define OPCODE_MASK_H1234 0xFFFFFFFF /* All 32 bits.  */
 #define OPCODE_MASK_H3    0xFC000600 /* High 6 bits and bits 21, 22.  */
 #define OPCODE_MASK_H32   0xFC00FC00 /* High 6 bits and bit 16-21.  */
+#define OPCODE_MASK_H32B  0xFC00C000 /* High 6 bits and bit 16, 17.  */
 #define OPCODE_MASK_H34B  0xFC0000FF /* High 6 bits and low 8 bits.  */
 #define OPCODE_MASK_H35B  0xFC0004FF /* High 6 bits and low 9 bits.  */
 #define OPCODE_MASK_H34C  0xFC0007E0 /* High 6 bits and bits 21-26.  */
@@ -102,7 +106,7 @@
 #define DELAY_SLOT 1
 #define NO_DELAY_SLOT 0
 
-#define MAX_OPCODES 300
+#define MAX_OPCODES 291
 
 const struct op_code_struct
 {
@@ -159,6 +163,8 @@ const struct op_code_struct
   {"bslli", INST_TYPE_RD_R1_IMM5, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x64000400, OPCODE_MASK_H3, bslli, barrel_shift_inst },
   {"bsrai", INST_TYPE_RD_R1_IMM5, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x64000200, OPCODE_MASK_H3, bsrai, barrel_shift_inst },
   {"bsrli", INST_TYPE_RD_R1_IMM5, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x64000000, OPCODE_MASK_H3, bsrli, barrel_shift_inst },
+  {"bsefi", INST_TYPE_RD_R1_IMMW_IMMS, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x64004000, OPCODE_MASK_H32B, bsefi, barrel_shift_inst },
+  {"bsifi", INST_TYPE_RD_R1_IMMW_IMMS, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x64008000, OPCODE_MASK_H32B, bsifi, barrel_shift_inst },
   {"or",    INST_TYPE_RD_R1_R2, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x80000000, OPCODE_MASK_H4, microblaze_or, logical_inst },
   {"and",   INST_TYPE_RD_R1_R2, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x84000000, OPCODE_MASK_H4, microblaze_and, logical_inst },
   {"xor",   INST_TYPE_RD_R1_R2, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x88000000, OPCODE_MASK_H4, microblaze_xor, logical_inst },
@@ -418,7 +424,7 @@ const struct op_code_struct
   {"suspend",   INST_TYPE_NONE,  INST_PC_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0xBB020004, OPCODE_MASK_HN,   invalid_inst, special_inst }, /* translates to mbar 24.  */
   {"swapb",     INST_TYPE_RD_R1, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x900001E0, OPCODE_MASK_H4,   swapb,     arithmetic_inst },
   {"swaph",     INST_TYPE_RD_R1, INST_NO_OFFSET, NO_DELAY_SLOT, IMMVAL_MASK_NON_SPECIAL, 0x900001E2, OPCODE_MASK_H4,   swaph,     arithmetic_inst },
-  {"", 0, 0, 0, 0, 0, 0, 0, 0},
+  {NULL, 0, 0, 0, 0, 0, 0, 0, 0},
 };
 
 /* Prefix for register names.  */
@@ -438,5 +444,8 @@ char pvr_register_prefix[] = "rpvr";
 #define MIN_IMM5  ((int) 0x00000000)
 #define MAX_IMM5  ((int) 0x0000001f)
 
+#define MIN_IMM_WIDTH  ((int) 0x00000001)
+#define MAX_IMM_WIDTH  ((int) 0x00000020)
+
 #endif /* MICROBLAZE_OPC */
 

opcodes/microblaze-opcm.h

@@ -29,7 +29,7 @@ enum microblaze_instr
   addi, rsubi, addic, rsubic, addik, rsubik, addikc, rsubikc, mul,
   mulh, mulhu, mulhsu, swapb, swaph,
   idiv, idivu, bsll, bsra, bsrl, get, put, nget, nput, cget, cput,
-  ncget, ncput, muli, bslli, bsrai, bsrli, mului,
+  ncget, ncput, muli, bslli, bsrai, bsrli, bsefi, bsifi, mului,
   /* 'or/and/xor' are C++ keywords.  */
   microblaze_or, microblaze_and, microblaze_xor,
   andn, pcmpbf, pcmpbc, pcmpeq, pcmpne, sra, src, srl, sext8, sext16,
@@ -130,6 +130,7 @@ enum microblaze_instr_type
 #define RB_LOW  11 /* Low bit for RB.  */
 #define IMM_LOW  0 /* Low bit for immediate.  */
 #define IMM_MBAR 21 /* low bit for mbar instruction.  */
+#define IMM_WIDTH_LOW 6 /* Low bit for immediate width */
 
 #define RD_MASK 0x03E00000
 #define RA_MASK 0x001F0000
@@ -142,6 +143,9 @@ enum microblaze_instr_type
 /* Imm mask for mbar.  */
 #define IMM5_MBAR_MASK 0x03E00000
 
+/* Imm mask for extract/insert width. */
+#define IMM5_WIDTH_MASK 0x000007C0
+
 /* FSL imm mask for get, put instructions.  */
 #define  RFSL_MASK 0x000000F