aarch64: Tweak insn sequence code

libopcodes has some code to check constraints across sequences
of consecutive instructions.  It was added to support MOVPRFX
sequences but is going to be useful for the Armv8.8-A MOPS
feature as well.

Currently the structure has one field to record the instruction
that started a sequence and another to record the remaining
instructions in the sequence.  It's more convenient for the
MOPS code if we put the instructions into a single array instead.

No functional change intended.

include/
	* opcode/aarch64.h (aarch64_instr_sequence): Replace num_insns
	and current_insns with num_added_insns and num_allocated_insns.

opcodes/
	* aarch64-opc.c (add_insn_to_sequence): New function.
	(init_insn_sequence): Update for new aarch64_instr_sequence layout.
	Add the first instruction to the inst array.
	(verify_constraints): Update for new aarch64_instr_sequence layout.
	Don't add the last instruction to the array.

1 files changed, 22 insertions, 26 deletions

diff --git a/opcodes/aarch64-opc.c b/opcodes/aarch64-opc.c
index b7076cd..289df9e 100644
--- a/opcodes/aarch64-opc.c
+++ b/opcodes/aarch64-opc.c
@@ -5403,6 +5403,15 @@ verify_elem_sd (const struct aarch64_inst *inst, const aarch64_insn insn,
   return ERR_OK;
 }
 
+/* Add INST to the end of INSN_SEQUENCE.  */
+
+static void
+add_insn_to_sequence (const struct aarch64_inst *inst,
+		      aarch64_instr_sequence *insn_sequence)
+{
+  insn_sequence->instr[insn_sequence->num_added_insns++] = *inst;
+}
+
 /* Initialize an instruction sequence insn_sequence with the instruction INST.
    If INST is NULL the given insn_sequence is cleared and the sequence is left
    uninitialized.  */
@@ -5412,16 +5421,11 @@ init_insn_sequence (const struct aarch64_inst *inst,
 		    aarch64_instr_sequence *insn_sequence)
 {
   int num_req_entries = 0;
-  insn_sequence->next_insn = 0;
-  insn_sequence->num_insns = num_req_entries;
-  if (insn_sequence->instr)
-    XDELETE (insn_sequence->instr);
-  insn_sequence->instr = NULL;
 
-  if (inst)
+  if (insn_sequence->instr)
     {
-      insn_sequence->instr = XNEW (aarch64_inst);
-      memcpy (insn_sequence->instr, inst, sizeof (aarch64_inst));
+      XDELETE (insn_sequence->instr);
+      insn_sequence->instr = NULL;
     }
 
   /* Handle all the cases here.  May need to think of something smarter than
@@ -5430,16 +5434,13 @@ init_insn_sequence (const struct aarch64_inst *inst,
   if (inst && inst->opcode->constraints & C_SCAN_MOVPRFX)
     num_req_entries = 1;
 
-  if (insn_sequence->current_insns)
-    XDELETEVEC (insn_sequence->current_insns);
-  insn_sequence->current_insns = NULL;
+  insn_sequence->num_added_insns = 0;
+  insn_sequence->num_allocated_insns = num_req_entries;
 
   if (num_req_entries != 0)
     {
-      size_t size = num_req_entries * sizeof (aarch64_inst);
-      insn_sequence->current_insns
-	= (aarch64_inst**) XNEWVEC (aarch64_inst, num_req_entries);
-      memset (insn_sequence->current_insns, 0, size);
+      insn_sequence->instr = XCNEWVEC (aarch64_inst, num_req_entries);
+      add_insn_to_sequence (inst, insn_sequence);
     }
 }
 
@@ -5715,17 +5716,12 @@ verify_constraints (const struct aarch64_inst *inst,
 	}
 
     done:
-      /* Add the new instruction to the sequence.  */
-      memcpy (insn_sequence->current_insns + insn_sequence->next_insn++,
-	      inst, sizeof (aarch64_inst));
-
-      /* Check if sequence is now full.  */
-      if (insn_sequence->next_insn >= insn_sequence->num_insns)
-	{
-	  /* Sequence is full, but we don't have anything special to do for now,
-	     so clear and reset it.  */
-	  init_insn_sequence (NULL, insn_sequence);
-	}
+      if (insn_sequence->num_added_insns == insn_sequence->num_allocated_insns)
+	/* We've checked the last instruction in the sequence and so
+	   don't need the sequence any more.  */
+	init_insn_sequence (NULL, insn_sequence);
+      else
+	add_insn_to_sequence (inst, insn_sequence);
     }
 
   return res;