[PATCH]: Dump rtl in assembly

[Stephane Carrez <Stephane dot Carrez at worldnet dot fr>]

Hi!

While developping the 68hc11 port, I found that it was quite useful
to be able to dump the RTL in the assembly file, as an assembly comment.
By doing so, it becomes easier to find a problem in the generated code
(because you directly see the asm instruction with the rtl pattern above it;
 then you switch to other RTL dump to find out the problem).

The following patch introduces a new option -dZ (??? need some debug letter)
do dump the RTL in the assembly file.  It's easy in fact, we just have to
print the ASM_COMMENT_START at beginning of each rtl line.  In final_scan_insn,
we configure 'print-rtl' to do that, dump the insn in the asm file and
restore 'print-rtl' (for normal dumps).

To avoid major changes in the print_rtl operation, I've added a simple
string global variable 'print_rtx_head' which is empty by default and
set to ASM_COMMENT_START by final_prescan_insn.

The asm rtl dump is not generated even when you specify -da (I thought it was
better).  It must be explicitly activated.

Do you agree to integrate this patch?

	Stephane

ChangeLog for gcc/ChangeLog

2000-08-06  Stephane Carrez  <Stephane.Carrez@worldnet.fr>

	* flags.h (flag_dump_rtl_in_asm): Declare.
	* toplev.c (flag_dump_rtl_in_asm): Define.
	(decode_d_option): Set flag_dump_rtl_in_asm if -dZ is specified.
	* rtl.h (print_rtx_head): Declare.
	* print-rtl.c (print_rtx_head): Define.
	(print_rtx): Print the string pointed to by print_rtx_head
	at beginning of each dump line.
	(print_rtl): Likewise.
	(print_rtl_single): Likewise.
	* final.c (final_scan_insn): Dump the insn in the assembly
	file for debugging.
diff -Nrup --exclude-from=gcc-exclude.lst /src/gnu/cygnus/gcc/gcc/rtl.h gcc/gcc/rtl.h
--- /src/gnu/cygnus/gcc/gcc/rtl.h	Sun Aug  6 11:38:37 2000
+++ gcc/gcc/rtl.h	Sun Aug  6 12:09:31 2000
@@ -1728,6 +1761,7 @@ extern void schedule_insns		PARAMS ((FIL
 extern void fix_sched_param		PARAMS ((const char *, const char *));
 
 /* In print-rtl.c */
+extern char *print_rtx_head;
 extern void debug_rtx			PARAMS ((rtx));
 extern void debug_rtx_list		PARAMS ((rtx, int));
 extern void debug_rtx_range		PARAMS ((rtx, rtx));
diff -Nrup --exclude-from=gcc-exclude.lst /src/gnu/cygnus/gcc/gcc/final.c gcc/gcc/final.c
--- /src/gnu/cygnus/gcc/gcc/final.c	Sun Aug  6 11:35:24 2000
+++ gcc/gcc/final.c	Sun Aug  6 12:09:26 2000
@@ -2924,6 +2926,14 @@ final_scan_insn (insn, file, optimize, p
 	extract_insn (insn);
 	cleanup_subreg_operands (insn);
 
+       /* Dump the insn in the assembly for debugging.  */
+       if (flag_dump_rtl_in_asm)
+         {
+           print_rtx_head = ASM_COMMENT_START;
+           print_rtl_single (asm_out_file, insn);
+           print_rtx_head = "";
+         }
+       
 	if (! constrain_operands (1))
 	  fatal_insn_not_found (insn);
 
diff -Nrup --exclude-from=gcc-exclude.lst /src/gnu/cygnus/gcc/gcc/flags.h gcc/gcc/flags.h
--- /src/gnu/cygnus/gcc/gcc/flags.h	Tue Aug  1 23:10:30 2000
+++ gcc/gcc/flags.h	Sun Aug  6 12:09:26 2000
@@ -462,6 +462,8 @@ extern int flag_verbose_asm;
 
 extern int flag_debug_asm;
 
+extern int flag_dump_rtl_in_asm;
+
 /* -fgnu-linker specifies use of the GNU linker for initializations.
    -fno-gnu-linker says that collect will be used.  */
 extern int flag_gnu_linker;
diff -Nrup --exclude-from=gcc-exclude.lst /src/gnu/cygnus/gcc/gcc/print-rtl.c gcc/gcc/print-rtl.c
--- /src/gnu/cygnus/gcc/gcc/print-rtl.c	Sun Aug  6 11:37:41 2000
+++ gcc/gcc/print-rtl.c	Sun Aug  6 12:09:29 2000
@@ -55,6 +55,11 @@ static int indent;
 
 static void print_rtx		PARAMS ((rtx));
 
+/* String printed at beginning of each RTL when it is dumped.
+   This string is set to ASM_COMMENT_START when the RTL is dumped in
+   the assembly output file.  */
+char *print_rtx_head = "";
+
 /* Nonzero means suppress output of instruction numbers and line number
    notes in debugging dumps.
    This must be defined here so that programs like gencodes can be linked.  */
@@ -77,8 +82,9 @@ print_rtx (in_rtx)
 
   if (sawclose)
     {
-      fprintf (outfile, "\n%s",
-	       (xspaces + (sizeof xspaces - 1 - indent * 2)));
+      fprintf (outfile, "\n%s%s",
+               print_rtx_head,
+ 	       (xspaces + (sizeof xspaces - 1 - indent * 2)));
       sawclose = 0;
     }
 
@@ -253,7 +259,8 @@ print_rtx (in_rtx)
 	indent += 2;
 	if (sawclose)
 	  {
-	    fprintf (outfile, "\n%s",
+	    fprintf (outfile, "\n%s%s",
+                     print_rtx_head,
 		     (xspaces + (sizeof xspaces - 1 - indent * 2)));
 	    sawclose = 0;
 	  }
@@ -270,7 +277,8 @@ print_rtx (in_rtx)
 	    indent -= 2;
 	  }
 	if (sawclose)
-	  fprintf (outfile, "\n%s",
+	  fprintf (outfile, "\n%s%s",
+                   print_rtx_head,
 		   (xspaces + (sizeof xspaces - 1 - indent * 2)));
 
 	fputs ("] ", outfile);
@@ -566,7 +574,10 @@ print_rtl (outf, rtx_first)
   sawclose = 0;
 
   if (rtx_first == 0)
-    fputs ("(nil)\n", outf);
+    {
+      fputs (print_rtx_head, outf);
+      fputs ("(nil)\n", outf);
+    }
   else
     switch (GET_CODE (rtx_first))
       {
@@ -580,12 +591,14 @@ print_rtl (outf, rtx_first)
 	  if (! flag_dump_unnumbered
 	      || GET_CODE (tmp_rtx) != NOTE || NOTE_LINE_NUMBER (tmp_rtx) < 0)
 	    {
+              fputs (print_rtx_head, outfile);
 	      print_rtx (tmp_rtx);
 	      fprintf (outfile, "\n");
 	    }
 	break;
 
       default:
+        fputs (print_rtx_head, outfile);
 	print_rtx (rtx_first);
       }
 }
@@ -603,6 +616,7 @@ print_rtl_single (outf, x)
   if (! flag_dump_unnumbered
       || GET_CODE (x) != NOTE || NOTE_LINE_NUMBER (x) < 0)
     {
+      fputs (print_rtx_head, outfile);
       print_rtx (x);
       putc ('\n', outf);
       return 1;
diff -Nrup --exclude-from=gcc-exclude.lst /src/gnu/cygnus/gcc/gcc/toplev.c gcc/gcc/toplev.c
--- /src/gnu/cygnus/gcc/gcc/toplev.c	Sun Aug  6 11:39:18 2000
+++ gcc/gcc/toplev.c	Sun Aug  6 12:09:32 2000
@@ -779,6 +783,10 @@ int flag_verbose_asm = 0;
 
 int flag_debug_asm = 0;
 
+/* -dZ causes the rtl to be emited as a comment in assembly.  */
+
+int flag_dump_rtl_in_asm = 0;
+
 /* -fgnu-linker specifies use of the GNU linker for initializations.
    (Or, more generally, a linker that handles initializations.)
    -fno-gnu-linker says that collect2 will be used.  */
@@ -3930,6 +3939,9 @@ decode_d_option (arg)
       case 'A':
 	flag_debug_asm = 1;
 	break;
+      case 'Z':
+        flag_dump_rtl_in_asm = 1;
+        break;
       case 'm':
 	flag_print_mem = 1;
 	break;