[AArch64][SVE 15/32] Add {insert,extract}_all_fields helpers

Several of the SVE operands use the aarch64_operand fields array
to store the fields that make up the operand, rather than hard-coding
the names in the C code.  This patch adds helpers for inserting and
extracting those fields.

opcodes/
	* aarch64-asm.c: Include libiberty.h.
	(insert_fields): New function.
	(aarch64_ins_imm): Use it.
	* aarch64-dis.c (extract_fields): New function.
	(aarch64_ext_imm): Use it.

3 files changed, 50 insertions, 14 deletions

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 9f44e97..fd24116 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,5 +1,13 @@
 2016-09-21  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* aarch64-asm.c: Include libiberty.h.
+	(insert_fields): New function.
+	(aarch64_ins_imm): Use it.
+	* aarch64-dis.c (extract_fields): New function.
+	(aarch64_ext_imm): Use it.
+
+2016-09-21  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* aarch64-opc.c (aarch64_logical_immediate_p): Replace is32
 	with an esize parameter.
 	(operand_general_constraint_met_p): Update accordingly.
diff --git a/opcodes/aarch64-asm.c b/opcodes/aarch64-asm.c
index 8fbd66f..3b0a383 100644
--- a/opcodes/aarch64-asm.c
+++ b/opcodes/aarch64-asm.c
@@ -20,6 +20,7 @@
 
 #include "sysdep.h"
 #include <stdarg.h>
+#include "libiberty.h"
 #include "aarch64-asm.h"
 
 /* Utilities.  */
@@ -55,6 +56,25 @@ insert_fields (aarch64_insn *code, aarch64_insn value, aarch64_insn mask, ...)
   va_end (va);
 }
 
+/* Insert a raw field value VALUE into all fields in SELF->fields.
+   The least significant bit goes in the final field.  */
+
+static void
+insert_all_fields (const aarch64_operand *self, aarch64_insn *code,
+		   aarch64_insn value)
+{
+  unsigned int i;
+  enum aarch64_field_kind kind;
+
+  for (i = ARRAY_SIZE (self->fields); i-- > 0; )
+    if (self->fields[i] != FLD_NIL)
+      {
+	kind = self->fields[i];
+	insert_field (kind, code, value, 0);
+	value >>= fields[kind].width;
+      }
+}
+
 /* Operand inserters.  */
 
 /* Insert register number.  */
@@ -318,17 +338,11 @@ aarch64_ins_imm (const aarch64_operand *self, const aarch64_opnd_info *info,
 		 const aarch64_inst *inst ATTRIBUTE_UNUSED)
 {
   int64_t imm;
-  /* Maximum of two fields to insert.  */
-  assert (self->fields[2] == FLD_NIL);
 
   imm = info->imm.value;
   if (operand_need_shift_by_two (self))
     imm >>= 2;
-  if (self->fields[1] == FLD_NIL)
-    insert_field (self->fields[0], code, imm, 0);
-  else
-    /* e.g. TBZ b5:b40.  */
-    insert_fields (code, imm, 0, 2, self->fields[1], self->fields[0]);
+  insert_all_fields (self, code, imm);
   return NULL;
 }
 
diff --git a/opcodes/aarch64-dis.c b/opcodes/aarch64-dis.c
index 9ffc713..67daa66 100644
--- a/opcodes/aarch64-dis.c
+++ b/opcodes/aarch64-dis.c
@@ -145,6 +145,26 @@ extract_fields (aarch64_insn code, aarch64_insn mask, ...)
   return value;
 }
 
+/* Extract the value of all fields in SELF->fields from instruction CODE.
+   The least significant bit comes from the final field.  */
+
+static aarch64_insn
+extract_all_fields (const aarch64_operand *self, aarch64_insn code)
+{
+  aarch64_insn value;
+  unsigned int i;
+  enum aarch64_field_kind kind;
+
+  value = 0;
+  for (i = 0; i < ARRAY_SIZE (self->fields) && self->fields[i] != FLD_NIL; ++i)
+    {
+      kind = self->fields[i];
+      value <<= fields[kind].width;
+      value |= extract_field (kind, code, 0);
+    }
+  return value;
+}
+
 /* Sign-extend bit I of VALUE.  */
 static inline int32_t
 sign_extend (aarch64_insn value, unsigned i)
@@ -575,14 +595,8 @@ aarch64_ext_imm (const aarch64_operand *self, aarch64_opnd_info *info,
 		 const aarch64_inst *inst ATTRIBUTE_UNUSED)
 {
   int64_t imm;
-  /* Maximum of two fields to extract.  */
-  assert (self->fields[2] == FLD_NIL);
 
-  if (self->fields[1] == FLD_NIL)
-    imm = extract_field (self->fields[0], code, 0);
-  else
-    /* e.g. TBZ b5:b40.  */
-    imm = extract_fields (code, 0, 2, self->fields[0], self->fields[1]);
+  imm = extract_all_fields (self, code);
 
   if (info->type == AARCH64_OPND_FPIMM)
     info->imm.is_fp = 1;