This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

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

On 7/12/19 3:35 AM, Richard Biener wrote:
On Thu, Jul 11, 2019 at 7:43 PM Martin Sebor <> 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.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]