Re: [PATCH] add --param ssa-name-def-chain-limit

[Martin Sebor <msebor@gmail.com>]

On 7/12/19 3:35 AM, Richard Biener wrote:
> On Thu, Jul 11, 2019 at 7:43 PM Martin Sebor <msebor@gmail.com> wrote:
>>
>> Attached is a patch that adds a new parameter to limit the number
>> of SSA_NAME assignments for GCC to follow in iterative or recursive
>> algorithms.  Purely as a proof of concept the patch introduces
>> the parameter into -Warray-bounds where the warning follows
>> POINTER_PLUS (and ASSERT_EXPR) assignments to get at the DECL
>> the final pointer points to.
>>
>> With this "infrastructure" in place the parameter can start to be
>> introduced wherever else it might be necessary.  I don't know of
>> any pathological cases where it actually is necessary (i.e., one
>> the 512 default keeps from going off the rails) so the test I have
>> put together for it is artificial.  A better test case involving
>> one of the known recursive algorithms would be helpful.
> 
> The docs talk about diagnostics so I wonder if the param
> name should include that as well, otherwise OK.

I committed the patch as is for now.  The parameter's effect is
on both, optimization and diagnostics, so a generic name seems
like a good fit.  Plus, I couldn't off hand think of a better
name.  We can always change it if you or someone else comes up
with one.

Martin