public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
* [PATCH] Fix a pasto in lra-remat.c (reg_overlap_for_remat_p)
@ 2017-09-01 20:33 Jakub Jelinek
  2017-09-02 12:38 ` Richard Biener
  0 siblings, 1 reply; 2+ messages in thread
From: Jakub Jelinek @ 2017-09-01 20:33 UTC (permalink / raw)
  To: Vladimir Makarov, Jeff Law, Bernd Schmidt; +Cc: gcc-patches

Hi!

This is something that has been reported privately to me.
This is in code introduced in
https://gcc.gnu.org/ml/gcc-patches/2016-03/msg00660.html
and looks indeed like a pasto to me, before the loop there is
a very similar set of stmts without the 2 suffix, and unless
regno being a hard reg (after possible reg_renumber) implies
that regno2 (after possible reg_renumber) is a hard reg, if
unlucky we might access out of bounds.

I don't have a testcase for this, but have bootstrapped/regtested
it on x86_64-linux and i686-linux, ok for trunk?

2017-09-01  Jakub Jelinek  <jakub@redhat.com>

	* lra-remat.c (reg_overlap_for_remat_p): Fix a pasto.

--- gcc/lra-remat.c.jj	2017-05-25 10:37:00.000000000 +0200
+++ gcc/lra-remat.c	2017-09-01 19:42:07.615291583 +0200
@@ -684,7 +684,7 @@ reg_overlap_for_remat_p (lra_insn_reg *r
 
 	if (regno2 >= FIRST_PSEUDO_REGISTER && reg_renumber[regno2] >= 0)
 	  regno2 = reg_renumber[regno2];
-	if (regno >= FIRST_PSEUDO_REGISTER)
+	if (regno2 >= FIRST_PSEUDO_REGISTER)
 	  nregs2 = 1;
 	else
 	  nregs2 = hard_regno_nregs[regno2][reg->biggest_mode];

	Jakub

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] Fix a pasto in lra-remat.c (reg_overlap_for_remat_p)
  2017-09-01 20:33 [PATCH] Fix a pasto in lra-remat.c (reg_overlap_for_remat_p) Jakub Jelinek
@ 2017-09-02 12:38 ` Richard Biener
  0 siblings, 0 replies; 2+ messages in thread
From: Richard Biener @ 2017-09-02 12:38 UTC (permalink / raw)
  To: Jakub Jelinek, Vladimir Makarov, Jeff Law, Bernd Schmidt; +Cc: gcc-patches

On September 1, 2017 10:33:10 PM GMT+02:00, Jakub Jelinek <jakub@redhat.com> wrote:
>Hi!
>
>This is something that has been reported privately to me.
>This is in code introduced in
>https://gcc.gnu.org/ml/gcc-patches/2016-03/msg00660.html
>and looks indeed like a pasto to me, before the loop there is
>a very similar set of stmts without the 2 suffix, and unless
>regno being a hard reg (after possible reg_renumber) implies
>that regno2 (after possible reg_renumber) is a hard reg, if
>unlucky we might access out of bounds.
>
>I don't have a testcase for this, but have bootstrapped/regtested
>it on x86_64-linux and i686-linux, ok for trunk?

OK. 

Richard. 

>2017-09-01  Jakub Jelinek  <jakub@redhat.com>
>
>	* lra-remat.c (reg_overlap_for_remat_p): Fix a pasto.
>
>--- gcc/lra-remat.c.jj	2017-05-25 10:37:00.000000000 +0200
>+++ gcc/lra-remat.c	2017-09-01 19:42:07.615291583 +0200
>@@ -684,7 +684,7 @@ reg_overlap_for_remat_p (lra_insn_reg *r
> 
> 	if (regno2 >= FIRST_PSEUDO_REGISTER && reg_renumber[regno2] >= 0)
> 	  regno2 = reg_renumber[regno2];
>-	if (regno >= FIRST_PSEUDO_REGISTER)
>+	if (regno2 >= FIRST_PSEUDO_REGISTER)
> 	  nregs2 = 1;
> 	else
> 	  nregs2 = hard_regno_nregs[regno2][reg->biggest_mode];
>
>	Jakub

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2017-09-02 12:38 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-09-01 20:33 [PATCH] Fix a pasto in lra-remat.c (reg_overlap_for_remat_p) Jakub Jelinek
2017-09-02 12:38 ` Richard Biener

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).