[PATCH] Alternative number in output_asm_name

[PATCH] Alternative number in output_asm_name

[Ye, Joey]

It is well known which_alternative is from 0 to N-1. Where as in .s file
generated with option -dp, alternative number is from 1 to N. This is
very confusing. 

For example, i386.md has
(define_insn "*movsf_1"
...
switch (which_alternative)
...
case 7: case 8:
      return "movss\t{%1, %0|%0, %1}";

But the output .s is:
movss   %xmm0, (%rax)   # 10    *movsf_1/9      [length = 4]
                                                               ^^^
Confusing

I'd suggest to follow C convention to output 0 to N-1 in .s file. OK to
mainline?

Thanks - Joey

2008-05-21 Joey Ye <joey.ye@intel.com>

	* final.c (output_asm_name): Don't plus one to
which_alternative.

Index: gcc/final.c
===================================================================
--- gcc/final.c	(revision 134775)
+++ gcc/final.c	(working copy)
@@ -3000,7 +3000,7 @@ output_asm_name (void)
 	       ASM_COMMENT_START, INSN_UID (debug_insn),
 	       insn_data[num].name);
       if (insn_data[num].n_alternatives > 1)
-	fprintf (asm_out_file, "/%d", which_alternative + 1);
+	fprintf (asm_out_file, "/%d", which_alternative);
 #ifdef HAVE_ATTR_length
       fprintf (asm_out_file, "\t[length = %d]",
 	       get_attr_length (debug_insn));

Re: [PATCH] Alternative number in output_asm_name

[H.J. Lu]

On Wed, May 21, 2008 at 2:06 AM, Ye, Joey <joey.ye@intel.com> wrote:
> It is well known which_alternative is from 0 to N-1. Where as in .s file
> generated with option -dp, alternative number is from 1 to N. This is
> very confusing.
>
> For example, i386.md has
> (define_insn "*movsf_1"
> ...
> switch (which_alternative)
> ...
> case 7: case 8:
>      return "movss\t{%1, %0|%0, %1}";
>
> But the output .s is:
> movss   %xmm0, (%rax)   # 10    *movsf_1/9      [length = 4]
>                                                               ^^^
> Confusing
>
> I'd suggest to follow C convention to output 0 to N-1 in .s file. OK to
> mainline?
>
> Thanks - Joey
>
> 2008-05-21 Joey Ye <joey.ye@intel.com>
>
>        * final.c (output_asm_name): Don't plus one to
> which_alternative.
>

It also bothers me when I am comparing the alternative indicated
in the assembly code with alternatives in md files. I think it is a
good idea to make 2 consistent. Are they any objections to this
simple and useful change?

Thanks.


H.J.