[PATCH] MIPS: fix loongson3 llsc workaround

[PATCH] MIPS: fix loongson3 llsc workaround

[YunQiang Su]

-mfix-looongson3-llsc may add sync instructions not needed on some
asm code with lots of debug info.

	PR: 30153
	* gas/config/tc-mips.c(fix_loongson3_llsc): clear logistic.
---
 gas/config/tc-mips.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index e911aaa904a..8a970ceada2 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -6942,10 +6942,6 @@ fix_loongson3_llsc (struct mips_cl_insn * ip)
       unsigned long lookback = ARRAY_SIZE (history);
       for (i = 0; i < lookback; i++)
 	{
-	  if (streq (history[i].insn_mo->name, "ll")
-	      || streq (history[i].insn_mo->name, "lld"))
-	    break;
-
 	  if (streq (history[i].insn_mo->name, "sc")
 	      || streq (history[i].insn_mo->name, "scd"))
 	    {
@@ -6953,8 +6949,8 @@ fix_loongson3_llsc (struct mips_cl_insn * ip)
 
 	      for (j = i + 1; j < lookback; j++)
 		{
-		  if (streq (history[i].insn_mo->name, "ll")
-		      || streq (history[i].insn_mo->name, "lld"))
+		  if (streq (history[j].insn_mo->name, "ll")
+		      || streq (history[j].insn_mo->name, "lld"))
 		    break;
 
 		  if (delayed_branch_p (&history[j]))
@@ -6993,7 +6989,7 @@ fix_loongson3_llsc (struct mips_cl_insn * ip)
 	      for (j = i + 1; j < lookback; j++)
 		{
 		  if (streq (history[j].insn_mo->name, "ll")
-		      || streq (history[i].insn_mo->name, "lld"))
+		      || streq (history[j].insn_mo->name, "lld"))
 		    break;
 		}
 
-- 
2.30.2

Re: [PATCH] MIPS: fix loongson3 llsc workaround

[YunQiang Su]

ping

YunQiang Su <yunqiang.su@cipunited.com> 于2023年3月23日周四 19:00写道：
>
> -mfix-looongson3-llsc may add sync instructions not needed on some
> asm code with lots of debug info.
>
>         PR: 30153
>         * gas/config/tc-mips.c(fix_loongson3_llsc): clear logistic.
> ---
>  gas/config/tc-mips.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
> index e911aaa904a..8a970ceada2 100644
> --- a/gas/config/tc-mips.c
> +++ b/gas/config/tc-mips.c
> @@ -6942,10 +6942,6 @@ fix_loongson3_llsc (struct mips_cl_insn * ip)
>        unsigned long lookback = ARRAY_SIZE (history);
>        for (i = 0; i < lookback; i++)
>         {
> -         if (streq (history[i].insn_mo->name, "ll")
> -             || streq (history[i].insn_mo->name, "lld"))
> -           break;
> -
>           if (streq (history[i].insn_mo->name, "sc")
>               || streq (history[i].insn_mo->name, "scd"))
>             {
> @@ -6953,8 +6949,8 @@ fix_loongson3_llsc (struct mips_cl_insn * ip)
>
>               for (j = i + 1; j < lookback; j++)
>                 {
> -                 if (streq (history[i].insn_mo->name, "ll")
> -                     || streq (history[i].insn_mo->name, "lld"))
> +                 if (streq (history[j].insn_mo->name, "ll")
> +                     || streq (history[j].insn_mo->name, "lld"))
>                     break;
>
>                   if (delayed_branch_p (&history[j]))
> @@ -6993,7 +6989,7 @@ fix_loongson3_llsc (struct mips_cl_insn * ip)
>               for (j = i + 1; j < lookback; j++)
>                 {
>                   if (streq (history[j].insn_mo->name, "ll")
> -                     || streq (history[i].insn_mo->name, "lld"))
> +                     || streq (history[j].insn_mo->name, "lld"))
>                     break;
>                 }
>
> --
> 2.30.2
>

Re: [PATCH] MIPS: fix loongson3 llsc workaround

[Maciej W. Rozycki]

On Thu, 23 Mar 2023, YunQiang Su wrote:

> -mfix-looongson3-llsc may add sync instructions not needed on some
> asm code with lots of debug info.

 I can see the change has been committed, but who has actually reviewed 
it?

 The change description doesn't say what the change actually does, so one 
can't say whether it is correct or not.  At least an example of incorrect 
code produced ought to be shown and how the change affects it.  As it 
stands I have no idea what is going on here, and surely no one who looks 
at it in a few year's time will.

 Change descriptions cannot be retrofitted, so I think the original fix 
ought to be reverted and, assuming it is indeed the correct one, reapplied 
with a correct change description (after a proper review).

  Maciej

Re: [PATCH] MIPS: fix loongson3 llsc workaround

[YunQiang Su]

Maciej W. Rozycki <macro@orcam.me.uk> 于2023年5月11日周四 08:01写道：
>
> On Thu, 23 Mar 2023, YunQiang Su wrote:
>
> > -mfix-looongson3-llsc may add sync instructions not needed on some
> > asm code with lots of debug info.
>
>  I can see the change has been committed, but who has actually reviewed
> it?
>
>  The change description doesn't say what the change actually does, so one
> can't say whether it is correct or not.  At least an example of incorrect
> code produced ought to be shown and how the change affects it.  As it
> stands I have no idea what is going on here, and surely no one who looks
> at it in a few year's time will.
>

In fact, it was a typo of i/j.

>  Change descriptions cannot be retrofitted, so I think the original fix
> ought to be reverted and, assuming it is indeed the correct one, reapplied
> with a correct change description (after a proper review).
>
>   Maciej