On Wed, 21 Dec 2011, Jakub Jelinek wrote:
> Hi!
>
> The following testcases fail on the trunk, because at -O0
> we don't decide to copy the finally stmts if there is more than one
> destination. That is of course desirable for debugging reasons if
> there are any real stmts, but if the try/finally has been created only to
> hold gimple_clobber_p stmts that will not result in any code generated
> in those spots, we really should duplicate those.
> The second hunk is to use the right costs for the clobber stmts, they
> are expanded to nothing. Without that for -O2 and perhaps many clobber
> stmts we could still decide not to duplicate. I guess it should help
> inlining too if the costs much better the reality.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok
Thanks,
Richard.
> 2011-12-21 Jakub Jelinek <ja...@redhat.com>
>
> PR middle-end/51644
> PR middle-end/51647
> * tree-eh.c (decide_copy_try_finally): At -O0, return true
> even when ndests is not 1, if there are only gimple_clobber_p
> (or debug) stmts in the finally sequence.
> * tree-inline.c (estimate_num_insns): Return 0 for gimple_clobber_p
> stmts.
>
> * gcc.dg/pr51644.c: New test.
> * g++.dg/warn/Wreturn-4.C: New test.
>
> --- gcc/tree-eh.c.jj 2011-12-14 08:11:03.000000000 +0100
> +++ gcc/tree-eh.c 2011-12-21 12:15:49.749301513 +0100
> @@ -1538,7 +1538,20 @@ decide_copy_try_finally (int ndests, boo
> }
>
> if (!optimize)
> - return ndests == 1;
> + {
> + gimple_stmt_iterator gsi;
> +
> + if (ndests == 1)
> + return true;
> +
> + for (gsi = gsi_start (finally); !gsi_end_p (gsi); gsi_next (&gsi))
> + {
> + gimple stmt = gsi_stmt (gsi);
> + if (!is_gimple_debug (stmt) && !gimple_clobber_p (stmt))
> + return false;
> + }
> + return true;
> + }
>
> /* Finally estimate N times, plus N gotos. */
> f_estimate = count_insns_seq (finally, &eni_size_weights);
> --- gcc/tree-inline.c.jj 2011-12-14 08:11:03.000000000 +0100
> +++ gcc/tree-inline.c 2011-12-21 11:17:04.708413203 +0100
> @@ -3482,6 +3482,9 @@ estimate_num_insns (gimple stmt, eni_wei
> likely be a real store, so the cost of the GIMPLE_ASSIGN is the cost
> of moving something into "a", which we compute using the function
> estimate_move_cost. */
> + if (gimple_clobber_p (stmt))
> + return 0; /* ={v} {CLOBBER} stmt expands to nothing. */
> +
> lhs = gimple_assign_lhs (stmt);
> rhs = gimple_assign_rhs1 (stmt);
>
> --- gcc/testsuite/gcc.dg/pr51644.c.jj 2011-12-21 12:24:22.185537200 +0100
> +++ gcc/testsuite/gcc.dg/pr51644.c 2011-12-21 12:32:01.493946505 +0100
> @@ -0,0 +1,33 @@
> +/* PR middle-end/51644 */
> +/* { dg-do compile } */
> +/* { dg-options "-Wall -fexceptions" } */
> +
> +#include <stdarg.h>
> +
> +extern void baz (int, va_list) __attribute__ ((__noreturn__));
> +
> +__attribute__ ((__noreturn__))
> +void
> +foo (int s, ...)
> +{
> + va_list ap;
> + va_start (ap, s);
> + baz (s, ap);
> + va_end (ap);
> +} /* { dg-bogus "function does return" } */
> +
> +__attribute__ ((__noreturn__))
> +void
> +bar (int s, ...)
> +{
> + va_list ap1;
> + va_start (ap1, s);
> + {
> + va_list ap2;
> + va_start (ap2, s);
> + baz (s, ap1);
> + baz (s, ap2);
> + va_end (ap2);
> + }
> + va_end (ap1);
> +} /* { dg-bogus "function does return" } */
> --- gcc/testsuite/g++.dg/warn/Wreturn-4.C.jj 2011-12-21 12:33:33.328428381
> +0100
> +++ gcc/testsuite/g++.dg/warn/Wreturn-4.C 2011-12-21 12:32:44.000000000
> +0100
> @@ -0,0 +1,48 @@
> +// PR middle-end/51647
> +// { dg-do compile }
> +// { dg-options "-Wall" }
> +
> +enum PropertyAttributes { NONE = 1 };
> +enum PropertyType { NORMAL = 0, FIELD = 1 };
> +class LookupResult;
> +
> +template <typename T>
> +struct Handle
> +{
> + inline explicit Handle (T *obj) __attribute__ ((always_inline)) {}
> + inline T *operator-> () const __attribute__ ((always_inline)) { return 0; }
> +};
> +
> +struct JSObject
> +{
> + bool IsGlobalObject () { return false; }
> +};
> +
> +struct Isolate
> +{
> + LookupResult *top_lookup_result () { return 0; }
> +};
> +
> +struct LookupResult
> +{
> + explicit LookupResult (Isolate *isolate) {}
> + JSObject *holder () { return 0; }
> + PropertyType type () { return NORMAL; }
> +};
> +
> +int
> +test (LookupResult *lookup)
> +{
> + Handle <JSObject> holder (lookup->holder ());
> + switch (lookup->type ())
> + {
> + case NORMAL:
> + if (holder->IsGlobalObject ())
> + return 2;
> + else
> + return 3;
> + break;
> + default:
> + return 4;
> + }
> +} // { dg-bogus "control reaches end of non-void function" }
>
> Jakub
>
>
--
Richard Guenther <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
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