[patch] support (ifield enum) in instruction formats

[Doug Evans <dje at sebabeach dot org>]

Hi.

Instruction formats support "ifield enums", e.g. (+ OP1_4 OP2_3 dr sr),
but one can't do (+ (f-op1 OP1_4) (f-op2 OP2_3) dr sr),
which seems unnecessarily restrictive.

[The "play.cpu" file is just to play around with.
I have a testsuite in the works.  When it's checked in
I think it'll be time to retire play.{cpu.opc}.]

2009-07-07  Doug Evans  <dje@sebabeach.org>

	* cpu/play.cpu (add): Use (ifield enum) for one format element.
	* cpu/play.opc: New file.

	Allow arbitrary enums in instruction formats, e.g. (f-op1 OP1_4).
	* insn.scm (-parse-insn-format-ifield-spec): Recognize (ifield enum).
	* doc/rtl.texi (Instructions): Update.

Index: insn.scm
===================================================================
RCS file: /cvs/src/src/cgen/insn.scm,v
retrieving revision 1.16
diff -u -p -r1.16 insn.scm
--- insn.scm	24 Jun 2009 15:03:09 -0000	1.16
+++ insn.scm	7 Jul 2009 18:38:46 -0000
@@ -546,9 +546,15 @@
     ; ??? This use to allow (ifield-name operand-name).  That's how
     ; `operand-name' elements are handled, but there's no current need
     ; to handle (ifield-name operand-name).
-    (if (not (integer? value))
-	(parse-error errtxt "ifield value not an integer" ifld-spec))
-    (ifld-new-value ifld value))
+    (cond ((integer? value)
+	   (ifld-new-value ifld value))
+	  ((symbol? value)
+	   (let ((e (enum-lookup-val value)))
+	     (if (not e)
+		 (parse-error errtxt "symbolic ifield value not an enum" ifld-spec))
+	     (ifld-new-value ifld (car e))))
+	  (else
+	   (parse-error errtxt "ifield value not an integer or enum" ifld-spec))))
 )
 
 ; Subroutine of -parse-insn-format to parse an
Index: cpu/play.cpu
===================================================================
RCS file: /cvs/src/src/cgen/cpu/play.cpu,v
retrieving revision 1.3
diff -u -p -r1.3 play.cpu
--- cpu/play.cpu	22 Dec 2002 02:06:47 -0000	1.3
+++ cpu/play.cpu	7 Jul 2009 18:38:46 -0000
@@ -175,7 +175,8 @@
 (dni add "add"
      ()
      "add $dr,$sr"
-     (+ OP1_4 OP2_0 dr sr)
+     ; Use (f-op1 OP1_4) to exercise it.
+     (+ (f-op1 OP1_4) OP2_0 dr sr)
      (sequence ()
 	       (set vbit (add-oflag dr sr (const 0)))
 	       (set cbit (add-cflag dr sr (const 0)))
Index: cpu/play.opc
===================================================================
RCS file: cpu/play.opc
diff -N cpu/play.opc
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ cpu/play.opc	7 Jul 2009 18:38:46 -0000
@@ -0,0 +1,18 @@
+/* Play opcode support.  -*- C -*-
+   Copyright (C) 2009 Red Hat, Inc.
+   This file is part of CGEN.  */
+
+/* This file is an addendum to play.cpu.  Heavy use of C code isn't
+   appropriate in .cpu files, so it resides here.  This especially applies
+   to assembly/disassembly where parsing/printing can be quite involved.
+   Such things aren't really part of the specification of the cpu, per se,
+   so .cpu files provide the general framework and .opc files handle the
+   nitty-gritty details as necessary.
+
+   Each section is delimited with start and end markers.
+
+   <arch>-opc.h additions use: "-- opc.h"
+   <arch>-opc.c additions use: "-- opc.c"
+   <arch>-asm.c additions use: "-- asm.c"
+   <arch>-dis.c additions use: "-- dis.c"
+   <arch>-ibd.h additions use: "-- ibd.h"  */
Index: doc/rtl.texi
===================================================================
RCS file: /cvs/src/src/cgen/doc/rtl.texi,v
retrieving revision 1.24
diff -u -p -r1.24 rtl.texi
--- doc/rtl.texi	21 Jun 2009 06:54:49 -0000	1.24
+++ doc/rtl.texi	7 Jul 2009 18:38:47 -0000
@@ -1867,9 +1867,10 @@ The ordering of the fields is not import
 Format elements can be any of:
 
 @itemize @bullet
-@item instruction field specifiers with a value (e.g. @code{(f-r1 14)})
-@item an instruction field enum, as in @code{OP1_4}
-@item an operand
+@item an instruction field name with an integer, e.g. @code{(f-op1 4)}
+@item an instruction field name with an enum, e.g. @code{(f-op1 OP1_4)}
+@item an instruction field enum, e.g. @code{OP1_4}
+@item an operand name, e.g. @code{dr}
 @end itemize
 
 @subsection semantics