On Mon, 4 Nov 2013, Jakub Jelinek wrote:
> Hi!
>
> This patch fixes PR58984, where determine_known_aggregate_parts
> notices that o.f0 = 1 store (because of ESRA) and p.f0 = 1
> store (because the field isn't a bitfield) are known constants
> at offset 0 of the first parameter, but doesn't record the access
> of that size (8 bits) and happily replaces BIT_FIELD_REF <p, 32, 0>
> in the called function with 1 (which is wrong, because the f1 bitfield
> also contains 1). As the size isn't recorded explicitly, this patch
> looks at TYPE_SIZE of the constants we've recorded, if the IL was correct
> then the store to it should be a useless type conversion and thus have the
> same number of bits.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux (together with a short
> hack to record how many times this has changed compiler's behavior and the
> only case during bootstrap/regtest was on this testcase on x86_64-linux
> 64-bit).
>
> Ok for trunk/4.8?
Looks ok to me.
Thanks,
Richard.
> 2013-11-04 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/58984
> * ipa-prop.c (ipa_load_from_parm_agg_1): Add SIZE_P argument,
> set *SIZE_P if non-NULL on success.
> (ipa_load_from_parm_agg, ipa_analyze_indirect_call_uses): Adjust
> callers.
> (ipcp_transform_function): Likewise. Punt if size of access
> is different from TYPE_SIZE on v->value's type.
>
> * gcc.c-torture/execute/pr58984.c: New test.
>
> --- gcc/ipa-prop.c.jj 2013-11-01 12:41:34.000000000 +0100
> +++ gcc/ipa-prop.c 2013-11-04 15:47:36.373955817 +0100
> @@ -852,7 +852,7 @@ static bool
> ipa_load_from_parm_agg_1 (vec<ipa_param_descriptor_t> descriptors,
> struct param_analysis_info *parms_ainfo, gimple stmt,
> tree op, int *index_p, HOST_WIDE_INT *offset_p,
> - bool *by_ref_p)
> + HOST_WIDE_INT *size_p, bool *by_ref_p)
> {
> int index;
> HOST_WIDE_INT size, max_size;
> @@ -870,6 +870,8 @@ ipa_load_from_parm_agg_1 (vec<ipa_param_
> {
> *index_p = index;
> *by_ref_p = false;
> + if (size_p)
> + *size_p = size;
> return true;
> }
> return false;
> @@ -912,6 +914,8 @@ ipa_load_from_parm_agg_1 (vec<ipa_param_
> {
> *index_p = index;
> *by_ref_p = true;
> + if (size_p)
> + *size_p = size;
> return true;
> }
> return false;
> @@ -926,7 +930,7 @@ ipa_load_from_parm_agg (struct ipa_node_
> bool *by_ref_p)
> {
> return ipa_load_from_parm_agg_1 (info->descriptors, NULL, stmt, op,
> index_p,
> - offset_p, by_ref_p);
> + offset_p, NULL, by_ref_p);
> }
>
> /* Given that an actual argument is an SSA_NAME (given in NAME) and is a
> result
> @@ -1826,7 +1830,7 @@ ipa_analyze_indirect_call_uses (struct c
> if (gimple_assign_single_p (def)
> && ipa_load_from_parm_agg_1 (info->descriptors, parms_ainfo, def,
> gimple_assign_rhs1 (def), &index, &offset,
> - &by_ref))
> + NULL, &by_ref))
> {
> struct cgraph_edge *cs = ipa_note_param_call (node, index, call);
> cs->indirect_info->offset = offset;
> @@ -4567,7 +4571,7 @@ ipcp_transform_function (struct cgraph_n
> struct ipa_agg_replacement_value *v;
> gimple stmt = gsi_stmt (gsi);
> tree rhs, val, t;
> - HOST_WIDE_INT offset;
> + HOST_WIDE_INT offset, size;
> int index;
> bool by_ref, vce;
>
> @@ -4594,13 +4598,15 @@ ipcp_transform_function (struct cgraph_n
> continue;
>
> if (!ipa_load_from_parm_agg_1 (descriptors, parms_ainfo, stmt,
> - rhs, &index, &offset, &by_ref))
> + rhs, &index, &offset, &size, &by_ref))
> continue;
> for (v = aggval; v; v = v->next)
> if (v->index == index
> && v->offset == offset)
> break;
> - if (!v || v->by_ref != by_ref)
> + if (!v
> + || v->by_ref != by_ref
> + || tree_low_cst (TYPE_SIZE (TREE_TYPE (v->value)), 0) != size)
> continue;
>
> gcc_checking_assert (is_gimple_ip_invariant (v->value));
> --- gcc/testsuite/gcc.c-torture/execute/pr58984.c.jj 2013-11-04
> 15:49:48.657239937 +0100
> +++ gcc/testsuite/gcc.c-torture/execute/pr58984.c 2013-11-04
> 16:00:44.876785998 +0100
> @@ -0,0 +1,57 @@
> +/* PR tree-optimization/58984 */
> +
> +struct S { int f0 : 8; int : 6; int f1 : 5; };
> +struct T { char f0; int : 6; int f1 : 5; };
> +
> +int a, *c = &a, e, n, b, m;
> +
> +static int
> +foo (struct S p)
> +{
> + const unsigned short *f[36];
> + for (; e < 2; e++)
> + {
> + const unsigned short **i = &f[0];
> + *c ^= 1;
> + if (p.f1)
> + {
> + *i = 0;
> + return b;
> + }
> + }
> + return 0;
> +}
> +
> +static int
> +bar (struct T p)
> +{
> + const unsigned short *f[36];
> + for (; e < 2; e++)
> + {
> + const unsigned short **i = &f[0];
> + *c ^= 1;
> + if (p.f1)
> + {
> + *i = 0;
> + return b;
> + }
> + }
> + return 0;
> +}
> +
> +int
> +main ()
> +{
> + struct S o = { 1, 1 };
> + foo (o);
> + m = n || o.f0;
> + if (a != 1)
> + __builtin_abort ();
> + e = 0;
> + struct T p = { 1, 1 };
> + bar (p);
> + m |= n || p.f0;
> + if (a != 0)
> + __builtin_abort ();
> + return 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE / SUSE Labs
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