This patch should fix the bug in pr50193.
The problem is that the arith_shiftsi pattern accepted any arbitrary
constant as the shift amount (via the shift_amount_operand predicate)
where in fact the constant must be in the range 0..32.
This patch fixes the problem by merely checking that the
On Thu, 1 Sep 2011, Andrew Stubbs wrote:
> This patch fixes the problem by merely checking that the constant is positive.
> I've confirmed that values larger than the mode-size are not a problem because
> the compiler optimizes those away earlier, even at -O0.
Do you mean that you have observed f
On 01/09/11 14:21, Joseph S. Myers wrote:
On Thu, 1 Sep 2011, Andrew Stubbs wrote:
This patch fixes the problem by merely checking that the constant is positive.
I've confirmed that values larger than the mode-size are not a problem because
the compiler optimizes those away earlier, even at -O0
On 01/09/11 16:26, Andrew Stubbs wrote:
OK, fair enough, redundant or not, here's a patch with belt and braces.
OK now?
And again, with the patch
Andrew
2011-09-01 Andrew Stubbs
gcc/
* config/arm/predicates.md (shift_amount_operand): Ensure shift
amount is in the range 1..mode_siz
On Thu, Sep 01, 2011 at 04:29:25PM +0100, Andrew Stubbs wrote:
> On 01/09/11 16:26, Andrew Stubbs wrote:
> >OK, fair enough, redundant or not, here's a patch with belt and braces.
> >
> >OK now?
>
> And again, with the patch
>
> Andrew
> 2011-09-01 Andrew Stubbs
>
> gcc/
> *
On 01/09/11 16:51, Jakub Jelinek wrote:
IN_RANGE (INTVAL (op), 0, GET_MODE_PRECISION (mode) - 1) ?
Ok, I can make that change.
1) shift by 0 is well defined (though not sure if arm backend
supports it)
Yeah, I suppose I could allow 0, but I don't know why it would be
helpful? I mean, i
On 01/09/11 17:21, Andrew Stubbs wrote:
I wasn't sure how to find the mode of shift operand in the predicate
though, so I've assumed they're always the same size. How would one find
the proper mode in a predicate?
OK, no reply, so I'm just going to assume we're dealing with 32-bit
registers.
On 5 September 2011 18:07, Andrew Stubbs wrote:
> On 01/09/11 17:21, Andrew Stubbs wrote:
>>
>> I wasn't sure how to find the mode of shift operand in the predicate
>> though, so I've assumed they're always the same size. How would one find
>> the proper mode in a predicate?
>
> OK, no reply, so I
On 01/09/11 16:51, Jakub Jelinek wrote:
> 1) shift by 0 is well defined (though not sure if arm backend
>supports it)
The canonical form of
( (x) (const_int 0))
is just
(x)
So while it's well defined, it's also useless.
