On Wed, Sep 7, 2011 at 7:18 PM, Martin Jambor <mjam...@suse.cz> wrote:
> Hi,
>
> the patch below should fix PR 50287 (and its many duplicates) by
> simply never attempting to create new default-defs for unused
> non-register parameters and using their DECL when calling the split
> function. Note that all of this is relevant only in the case when
> there is some other reason why we cannot change the function's
> signature (typically because there are function attributes).
> Otherwise, parameters that are not used or referenced in any way are
> not passed on to the split function.
>
> This is correct because it does not really matter what actual value we
> pass to the split function for any non-register parameter because all
> statements that are going to end up in the split function are checked
> by mark_nonssa_use which makes sure it does not use, store or take
> address of any such PARM_DECL.
>
> The patch passes bootstrap and testing on x86_64-linux, it has
> successfully LTO-built Firefox and I'm LTO-building a few SPEC 2006
> benchmarks with it right now. Of course it fixes the ICE when
> compiling the testcase (and I have verified that the 4.6 version also
> fixes the ICE when compiling the reduced testcase of PR 50295). OK for
> trunk (and then for the 4.6 branch)?
Ok.
Thanks,
Richard.
> Thanks,
>
> Martin
>
>
> 2011-09-06 Martin Jambor <mjam...@suse.cz>
>
> PR tree-optimization/50287
> * ipa-split.c (split_function): Do not create SSA names for
> non-gimple-registers.
>
> * testsuite/gcc.dg/torture/pr50287.c: New test.
>
>
> Index: src/gcc/testsuite/gcc.dg/torture/pr50287.c
> ===================================================================
> --- /dev/null
> +++ src/gcc/testsuite/gcc.dg/torture/pr50287.c
> @@ -0,0 +1,109 @@
> +/* { dg-do compile } */
> +
> +struct PMC {
> + unsigned flags;
> +};
> +
> +struct PVC {
> + unsigned flags, other_stuff;
> +};
> +
> +
> +typedef struct Pcc_cell
> +{
> + struct PMC *p;
> + long bla;
> + long type;
> +} Pcc_cell;
> +
> +int gi;
> +int cond;
> +
> +struct PVC g_pvc;
> +
> +extern void abort ();
> +extern void never_ever(int interp, struct PMC *pmc)
> + __attribute__((noinline,noclone));
> +
> +void never_ever (int interp, struct PMC *pmc)
> +{
> + abort ();
> +}
> +
> +static void mark_cell(int * interp, Pcc_cell *c, struct PVC pvc)
> + __attribute__((__nonnull__(1)));
> +
> +static void
> +mark_cell(int * interp, Pcc_cell *c, struct PVC pvc)
> +{
> + if (!cond)
> + return;
> +
> + if (c && c->type == 4 && c->p
> + && !(c->p->flags & (1<<8)))
> + never_ever(gi + 1, c->p);
> + if (c && c->type == 4 && c->p
> + && !(c->p->flags & (1<<7)))
> + never_ever(gi + 2, c->p);
> + if (c && c->type == 4 && c->p
> + && !(c->p->flags & (1<<6)))
> + never_ever(gi + 3, c->p);
> + if (c && c->type == 4 && c->p
> + && !(c->p->flags & (1<<5)))
> + never_ever(gi + 4, c->p);
> + if (c && c->type == 4 && c->p
> + && !(c->p->flags & (1<<4)))
> + never_ever(gi + 5, c->p);
> + if (c && c->type == 4 && c->p
> + && !(c->p->flags & (1<<3)))
> + never_ever(gi + 6, c->p);
> + if (c && c->type == 4 && c->p
> + && !(c->p->flags & (1<<2)))
> + never_ever(gi + 7, c->p);
> + if (c && c->type == 4 && c->p
> + && !(c->p->flags & (1<<1)))
> + never_ever(gi + 8, c->p);
> + if (c && c->type == 4 && c->p
> + && !(c->p->flags & (1<<9)))
> + never_ever(gi + 9, c->p);
> +}
> +
> +static void
> +foo(int * interp, Pcc_cell *c)
> +{
> + mark_cell(interp, c, g_pvc);
> +}
> +
> +static struct Pcc_cell *
> +__attribute__((noinline,noclone))
> +getnull(void)
> +{
> + return (struct Pcc_cell *) 0;
> +}
> +
> +
> +int main()
> +{
> + int i;
> +
> + cond = 1;
> + for (i = 0; i < 100; i++)
> + foo (&gi, getnull ());
> + return 0;
> +}
> +
> +
> +void
> +bar_1 (int * interp, Pcc_cell *c)
> +{
> + c->bla += 1;
> + mark_cell(interp, c, g_pvc);
> +}
> +
> +void
> +bar_2 (int * interp, Pcc_cell *c, struct PVC pvc)
> +{
> + c->bla += 2;
> + mark_cell(interp, c, pvc);
> +}
> +
> Index: src/gcc/ipa-split.c
> ===================================================================
> --- src.orig/gcc/ipa-split.c
> +++ src/gcc/ipa-split.c
> @@ -985,15 +985,20 @@ split_function (struct split_point *spli
> bitmap_set_bit (args_to_skip, num);
> else
> {
> - arg = gimple_default_def (cfun, parm);
> - if (!arg)
> + /* This parm might not have been used up to now, but is going to be
> + used, hence register it. */
> + add_referenced_var (parm);
> + if (is_gimple_reg (parm))
> {
> - /* This parm wasn't used up to now, but is going to be used,
> - hence register it. */
> - add_referenced_var (parm);
> - arg = make_ssa_name (parm, gimple_build_nop ());
> - set_default_def (parm, arg);
> + arg = gimple_default_def (cfun, parm);
> + if (!arg)
> + {
> + arg = make_ssa_name (parm, gimple_build_nop ());
> + set_default_def (parm, arg);
> + }
> }
> + else
> + arg = parm;
>
> if (TYPE_MAIN_VARIANT (DECL_ARG_TYPE (parm))
> != TYPE_MAIN_VARIANT (TREE_TYPE (arg)))
>
