* Re: [COMMITTED] Remove pass counting in VRP.
[not found] <248800ec-0e0e-6cae-5aaa-a9c69cd5f46a@redhat.com>
@ 2023-10-03 17:02 ` David Malcolm
2023-10-03 17:11 ` Andrew MacLeod
0 siblings, 1 reply; 3+ messages in thread
From: David Malcolm @ 2023-10-03 17:02 UTC (permalink / raw)
To: Andrew MacLeod, gcc-patches; +Cc: jit
On Tue, 2023-10-03 at 10:32 -0400, Andrew MacLeod wrote:
> Pass counting in VRP is used to decide when to call early VRP, pass
> the
> flag to enable warnings, and when the final pass is.
>
> If you try to add additional passes, this becomes quite fragile. This
> patch simply chooses the pass based on the data pointer passed in,
> and
> remove the pass counter. The first FULL VRP pass invokes the
> warning
> code, and the flag passed in now represents the FINAL pass of VRP.
> There is no longer a global flag which, as it turns out, wasn't
> working
> well with the JIT compiler, but when undetected. (Thanks to dmalcolm
> for helping me sort out what was going on there)
>
>
> Bootstraps on x86_64-pc-linux-gnu with no regressions. Pushed.
[CCing jit mailing list]
I'm worried that this patch may have "papered over" an issue with
libgccjit. Specifically:
[...snip...]
> diff --git a/gcc/tree-vrp.cc b/gcc/tree-vrp.cc
> index d7b194f5904..05266dfe34a 100644
> --- a/gcc/tree-vrp.cc
> +++ b/gcc/tree-vrp.cc
> @@ -1120,36 +1120,44 @@ const pass_data pass_data_early_vrp =
> ( TODO_cleanup_cfg | TODO_update_ssa | TODO_verify_all ),
> };
>
> -static int vrp_pass_num = 0;
> +static bool run_warning_pass = true;
I see the global variable "run_warning_pass" starts out true here
> class pass_vrp : public gimple_opt_pass
> {
> public:
> pass_vrp (gcc::context *ctxt, const pass_data &data_)
> - : gimple_opt_pass (data_, ctxt), data (data_), warn_array_bounds_p (false),
> - my_pass (vrp_pass_num++)
> - {}
> + : gimple_opt_pass (data_, ctxt), data (data_),
> + warn_array_bounds_p (false), final_p (false)
> + {
> + // Only the frst VRP pass should run warnings.
> + if (&data == &pass_data_vrp)
> + {
> + warn_array_bounds_p = run_warning_pass;
> + run_warning_pass = false;
...and run_warning_pass affects the member data
pass_vrp::warn_array_bounds_p here, and then becomes false, but nothing
seems to ever reset run_warning_pass back to true.
It seems that with this patch, if libgccjit compiles more than one
gcc_jit_context in the same process, the first context compilation will
warn, whereas subsequent ones in that process won't.
Or did I miss something?
[...snip...]
Thoughts?
Dave
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [COMMITTED] Remove pass counting in VRP.
2023-10-03 17:02 ` [COMMITTED] Remove pass counting in VRP David Malcolm
@ 2023-10-03 17:11 ` Andrew MacLeod
2023-10-03 17:27 ` David Malcolm
0 siblings, 1 reply; 3+ messages in thread
From: Andrew MacLeod @ 2023-10-03 17:11 UTC (permalink / raw)
To: David Malcolm, gcc-patches; +Cc: jit
[-- Attachment #1: Type: text/plain, Size: 1090 bytes --]
On 10/3/23 13:02, David Malcolm wrote:
> On Tue, 2023-10-03 at 10:32 -0400, Andrew MacLeod wrote:
>> Pass counting in VRP is used to decide when to call early VRP, pass
>> the
>> flag to enable warnings, and when the final pass is.
>>
>> If you try to add additional passes, this becomes quite fragile. This
>> patch simply chooses the pass based on the data pointer passed in,
>> and
>> remove the pass counter. The first FULL VRP pass invokes the
>> warning
>> code, and the flag passed in now represents the FINAL pass of VRP.
>> There is no longer a global flag which, as it turns out, wasn't
>> working
>> well with the JIT compiler, but when undetected. (Thanks to dmalcolm
>> for helping me sort out what was going on there)
>>
>>
>> Bootstraps on x86_64-pc-linux-gnu with no regressions. Pushed.
> [CCing jit mailing list]
>
> I'm worried that this patch may have "papered over" an issue with
> libgccjit. Specifically:
well, that isnt the patch that was checked in :-P
Im not sure how the old version got into the commit note.
Attached is the version checked in.
[-- Attachment #2: pass.diff --]
[-- Type: text/x-patch, Size: 3887 bytes --]
commit 7eb5ce7f58ed4a48641e1786e4fdeb2f7fb8c5ff
Author: Andrew MacLeod <amacleod@redhat.com>
Date: Thu Sep 28 09:19:32 2023 -0400
Remove pass counting in VRP.
Rather than using a pass count to decide which parameters are passed to
VRP, makemit explicit.
* passes.def (pass_vrp): Pass "final pass" flag as parameter.
* tree-vrp.cc (vrp_pass_num): Remove.
(pass_vrp::my_pass): Remove.
(pass_vrp::pass_vrp): Add warn_p as a parameter.
(pass_vrp::final_p): New.
(pass_vrp::set_pass_param): Set final_p param.
(pass_vrp::execute): Call execute_range_vrp with no conditions.
(make_pass_vrp): Pass additional parameter.
(make_pass_early_vrp): Ditto.
diff --git a/gcc/passes.def b/gcc/passes.def
index 4110a472914..2bafd60bbfb 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -221,7 +221,7 @@ along with GCC; see the file COPYING3. If not see
NEXT_PASS (pass_fre, true /* may_iterate */);
NEXT_PASS (pass_merge_phi);
NEXT_PASS (pass_thread_jumps_full, /*first=*/true);
- NEXT_PASS (pass_vrp, true /* warn_array_bounds_p */);
+ NEXT_PASS (pass_vrp, false /* final_p*/);
NEXT_PASS (pass_dse);
NEXT_PASS (pass_dce);
/* pass_stdarg is always run and at this point we execute
@@ -348,7 +348,7 @@ along with GCC; see the file COPYING3. If not see
NEXT_PASS (pass_dominator, false /* may_peel_loop_headers_p */);
NEXT_PASS (pass_strlen);
NEXT_PASS (pass_thread_jumps_full, /*first=*/false);
- NEXT_PASS (pass_vrp, false /* warn_array_bounds_p */);
+ NEXT_PASS (pass_vrp, true /* final_p */);
/* Run CCP to compute alignment and nonzero bits. */
NEXT_PASS (pass_ccp, true /* nonzero_p */);
NEXT_PASS (pass_warn_restrict);
diff --git a/gcc/tree-vrp.cc b/gcc/tree-vrp.cc
index d7b194f5904..4f8c7745461 100644
--- a/gcc/tree-vrp.cc
+++ b/gcc/tree-vrp.cc
@@ -1120,36 +1120,32 @@ const pass_data pass_data_early_vrp =
( TODO_cleanup_cfg | TODO_update_ssa | TODO_verify_all ),
};
-static int vrp_pass_num = 0;
class pass_vrp : public gimple_opt_pass
{
public:
- pass_vrp (gcc::context *ctxt, const pass_data &data_)
- : gimple_opt_pass (data_, ctxt), data (data_), warn_array_bounds_p (false),
- my_pass (vrp_pass_num++)
- {}
+ pass_vrp (gcc::context *ctxt, const pass_data &data_, bool warn_p)
+ : gimple_opt_pass (data_, ctxt), data (data_),
+ warn_array_bounds_p (warn_p), final_p (false)
+ { }
/* opt_pass methods: */
- opt_pass * clone () final override { return new pass_vrp (m_ctxt, data); }
+ opt_pass * clone () final override
+ { return new pass_vrp (m_ctxt, data, false); }
void set_pass_param (unsigned int n, bool param) final override
{
gcc_assert (n == 0);
- warn_array_bounds_p = param;
+ final_p = param;
}
bool gate (function *) final override { return flag_tree_vrp != 0; }
unsigned int execute (function *fun) final override
{
- // Early VRP pass.
- if (my_pass == 0)
- return execute_ranger_vrp (fun, /*warn_array_bounds_p=*/false, false);
-
- return execute_ranger_vrp (fun, warn_array_bounds_p, my_pass == 2);
+ return execute_ranger_vrp (fun, warn_array_bounds_p, final_p);
}
private:
const pass_data &data;
bool warn_array_bounds_p;
- int my_pass;
+ bool final_p;
}; // class pass_vrp
const pass_data pass_data_assumptions =
@@ -1219,13 +1215,13 @@ public:
gimple_opt_pass *
make_pass_vrp (gcc::context *ctxt)
{
- return new pass_vrp (ctxt, pass_data_vrp);
+ return new pass_vrp (ctxt, pass_data_vrp, true);
}
gimple_opt_pass *
make_pass_early_vrp (gcc::context *ctxt)
{
- return new pass_vrp (ctxt, pass_data_early_vrp);
+ return new pass_vrp (ctxt, pass_data_early_vrp, false);
}
gimple_opt_pass *
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [COMMITTED] Remove pass counting in VRP.
2023-10-03 17:11 ` Andrew MacLeod
@ 2023-10-03 17:27 ` David Malcolm
0 siblings, 0 replies; 3+ messages in thread
From: David Malcolm @ 2023-10-03 17:27 UTC (permalink / raw)
To: Andrew MacLeod, gcc-patches; +Cc: jit
On Tue, 2023-10-03 at 13:11 -0400, Andrew MacLeod wrote:
>
> On 10/3/23 13:02, David Malcolm wrote:
> > On Tue, 2023-10-03 at 10:32 -0400, Andrew MacLeod wrote:
> > > Pass counting in VRP is used to decide when to call early VRP,
> > > pass
> > > the
> > > flag to enable warnings, and when the final pass is.
> > >
> > > If you try to add additional passes, this becomes quite fragile.
> > > This
> > > patch simply chooses the pass based on the data pointer passed
> > > in,
> > > and
> > > remove the pass counter. The first FULL VRP pass invokes the
> > > warning
> > > code, and the flag passed in now represents the FINAL pass of
> > > VRP.
> > > There is no longer a global flag which, as it turns out, wasn't
> > > working
> > > well with the JIT compiler, but when undetected. (Thanks to
> > > dmalcolm
> > > for helping me sort out what was going on there)
> > >
> > >
> > > Bootstraps on x86_64-pc-linux-gnu with no regressions. Pushed.
> > [CCing jit mailing list]
> >
> > I'm worried that this patch may have "papered over" an issue with
> > libgccjit. Specifically:
>
> well, that isnt the patch that was checked in :-P
Aha! That makes much more sense. I took a look at
https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=7eb5ce7f58ed4a48641e1786e4fdeb2f7fb8c5ff
and yes, that looks like it will work with libgccjit
Thanks for clarifying (and for fixing the issue)
Dave
>
> Im not sure how the old version got into the commit note.
>
> Attached is the version checked in.
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-10-03 17:02 ` [COMMITTED] Remove pass counting in VRP David Malcolm
2023-10-03 17:11 ` Andrew MacLeod
2023-10-03 17:27 ` David Malcolm
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