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* Missing pointer dereference in tree-affine.c
@ 2016-05-05 14:19 Richard Sandiford
  2016-05-06 10:41 ` Richard Biener
  0 siblings, 1 reply; 2+ messages in thread
From: Richard Sandiford @ 2016-05-05 14:19 UTC (permalink / raw)
  To: gcc-patches

wide_int_constant_multiple_p used:

      if (*mult_set && mult != 0)
        return false;

to check whether we had previously seen a nonzero multiple, but "mult" is
a pointer to the previous value rather than the previous value itself.

Noticed by inspection while working on another patch, so I don't have a
testcase.  I tried adding an assert for combinations that were wrongly
rejected before but it didn't trigger during a bootstrap and regtest.

Tested on x86_64-linux-gnu.  OK to install?

Thanks,
Richard


gcc/
	* tree-affine.c (wide_int_constant_multiple_p): Add missing
	pointer dereference.

diff --git a/gcc/tree-affine.c b/gcc/tree-affine.c
index 32f2301..4884241 100644
--- a/gcc/tree-affine.c
+++ b/gcc/tree-affine.c
@@ -769,7 +769,7 @@ wide_int_constant_multiple_p (const widest_int &val, const widest_int &div,
 
   if (val == 0)
     {
-      if (*mult_set && mult != 0)
+      if (*mult_set && *mult != 0)
 	return false;
       *mult_set = true;
       *mult = 0;

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

* Re: Missing pointer dereference in tree-affine.c
  2016-05-05 14:19 Missing pointer dereference in tree-affine.c Richard Sandiford
@ 2016-05-06 10:41 ` Richard Biener
  0 siblings, 0 replies; 2+ messages in thread
From: Richard Biener @ 2016-05-06 10:41 UTC (permalink / raw)
  To: GCC Patches, richard.sandiford

On Thu, May 5, 2016 at 4:19 PM, Richard Sandiford
<richard.sandiford@arm.com> wrote:
> wide_int_constant_multiple_p used:
>
>       if (*mult_set && mult != 0)
>         return false;
>
> to check whether we had previously seen a nonzero multiple, but "mult" is
> a pointer to the previous value rather than the previous value itself.
>
> Noticed by inspection while working on another patch, so I don't have a
> testcase.  I tried adding an assert for combinations that were wrongly
> rejected before but it didn't trigger during a bootstrap and regtest.
>
> Tested on x86_64-linux-gnu.  OK to install?

Ok.

Richard.

> Thanks,
> Richard
>
>
> gcc/
>         * tree-affine.c (wide_int_constant_multiple_p): Add missing
>         pointer dereference.
>
> diff --git a/gcc/tree-affine.c b/gcc/tree-affine.c
> index 32f2301..4884241 100644
> --- a/gcc/tree-affine.c
> +++ b/gcc/tree-affine.c
> @@ -769,7 +769,7 @@ wide_int_constant_multiple_p (const widest_int &val, const widest_int &div,
>
>    if (val == 0)
>      {
> -      if (*mult_set && mult != 0)
> +      if (*mult_set && *mult != 0)
>         return false;
>        *mult_set = true;
>        *mult = 0;
>

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

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