https://gcc.gnu.org/g:1162861439fd3c4b30fc3ccd49462e47e876f04a

commit r14-9840-g1162861439fd3c4b30fc3ccd49462e47e876f04a
Author: Martin Jambor <mjam...@suse.cz>
Date:   Mon Apr 8 18:53:23 2024 +0200

    ipa: Compare jump functions in ICF (PR 113907)
    
    In PR 113907 comment #58, Honza found a case where ICF thinks bodies
    of functions are equivalent but becaise of difference in aliases in a
    memory access, different aggregate jump functions are associated with
    supposedly equivalent call statements.  This patch adds a way to
    compare jump functions and plugs it into ICF to avoid the issue.
    
    gcc/ChangeLog:
    
    2024-03-20  Martin Jambor  <mjam...@suse.cz>
    
            PR ipa/113907
            * ipa-prop.h (class ipa_vr): Declare new overload of a member 
function
            equal_p.
            (ipa_jump_functions_equivalent_p): Declare.
            * ipa-prop.cc (ipa_vr::equal_p): New function.
            (ipa_agg_pass_through_jf_equivalent_p): Likewise.
            (ipa_agg_jump_functions_equivalent_p): Likewise.
            (ipa_jump_functions_equivalent_p): Likewise.
            * ipa-cp.h (values_equal_for_ipcp_p): Declare.
            * ipa-cp.cc (values_equal_for_ipcp_p): Make function public.
            * ipa-icf-gimple.cc: Include alloc-pool.h, symbol-summary.h, 
sreal.h,
            ipa-cp.h and ipa-prop.h.
            (func_checker::compare_gimple_call): Comapre jump functions.
    
    gcc/testsuite/ChangeLog:
    
    2024-03-20  Martin Jambor  <mjam...@suse.cz>
    
            PR ipa/113907
            * gcc.dg/lto/pr113907_0.c: New.
            * gcc.dg/lto/pr113907_1.c: Likewise.
            * gcc.dg/lto/pr113907_2.c: Likewise.

Diff:
---
 gcc/ipa-cp.cc                         |   2 +-
 gcc/ipa-cp.h                          |   2 +
 gcc/ipa-icf-gimple.cc                 |  30 ++++++
 gcc/ipa-prop.cc                       | 167 ++++++++++++++++++++++++++++++++++
 gcc/ipa-prop.h                        |   3 +
 gcc/testsuite/gcc.dg/lto/pr113907_0.c |  18 ++++
 gcc/testsuite/gcc.dg/lto/pr113907_1.c |  35 +++++++
 gcc/testsuite/gcc.dg/lto/pr113907_2.c |  11 +++
 8 files changed, 267 insertions(+), 1 deletion(-)

diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
index 2a1da631e9c..b7add455bd5 100644
--- a/gcc/ipa-cp.cc
+++ b/gcc/ipa-cp.cc
@@ -201,7 +201,7 @@ ipcp_lattice<valtype>::is_single_const ()
 
 /* Return true iff X and Y should be considered equal values by IPA-CP.  */
 
-static bool
+bool
 values_equal_for_ipcp_p (tree x, tree y)
 {
   gcc_checking_assert (x != NULL_TREE && y != NULL_TREE);
diff --git a/gcc/ipa-cp.h b/gcc/ipa-cp.h
index 0b3cfe4b526..7ff74fb5c98 100644
--- a/gcc/ipa-cp.h
+++ b/gcc/ipa-cp.h
@@ -289,4 +289,6 @@ public:
   bool virt_call = false;
 };
 
+bool values_equal_for_ipcp_p (tree x, tree y);
+
 #endif /* IPA_CP_H */
diff --git a/gcc/ipa-icf-gimple.cc b/gcc/ipa-icf-gimple.cc
index 8c2df7a354e..17f62bec068 100644
--- a/gcc/ipa-icf-gimple.cc
+++ b/gcc/ipa-icf-gimple.cc
@@ -41,7 +41,12 @@ along with GCC; see the file COPYING3.  If not see
 #include "gimple-walk.h"
 
 #include "tree-ssa-alias-compare.h"
+#include "alloc-pool.h"
+#include "symbol-summary.h"
 #include "ipa-icf-gimple.h"
+#include "sreal.h"
+#include "ipa-cp.h"
+#include "ipa-prop.h"
 
 namespace ipa_icf_gimple {
 
@@ -714,6 +719,31 @@ func_checker::compare_gimple_call (gcall *s1, gcall *s2)
       && !compatible_types_p (TREE_TYPE (t1), TREE_TYPE (t2)))
     return return_false_with_msg ("GIMPLE internal call LHS type mismatch");
 
+  if (!gimple_call_internal_p (s1))
+    {
+      cgraph_edge *e1 = cgraph_node::get (m_source_func_decl)->get_edge (s1);
+      cgraph_edge *e2 = cgraph_node::get (m_target_func_decl)->get_edge (s2);
+      class ipa_edge_args *args1 = ipa_edge_args_sum->get (e1);
+      class ipa_edge_args *args2 = ipa_edge_args_sum->get (e2);
+      if ((args1 != nullptr) != (args2 != nullptr))
+       return return_false_with_msg ("ipa_edge_args mismatch");
+      if (args1)
+       {
+         int n1 = ipa_get_cs_argument_count (args1);
+         int n2 = ipa_get_cs_argument_count (args2);
+         if (n1 != n2)
+           return return_false_with_msg ("ipa_edge_args nargs mismatch");
+         for (int i = 0; i < n1; i++)
+           {
+             struct ipa_jump_func *jf1 = ipa_get_ith_jump_func (args1, i);
+             struct ipa_jump_func *jf2 = ipa_get_ith_jump_func (args2, i);
+             if (((jf1 != nullptr) != (jf2 != nullptr))
+                 || (jf1 && !ipa_jump_functions_equivalent_p (jf1, jf2)))
+               return return_false_with_msg ("jump function mismatch");
+           }
+       }
+    }
+
   return compare_operand (t1, t2, get_operand_access_type (&map, t1));
 }
 
diff --git a/gcc/ipa-prop.cc b/gcc/ipa-prop.cc
index e8e4918d5a8..374e998aa64 100644
--- a/gcc/ipa-prop.cc
+++ b/gcc/ipa-prop.cc
@@ -156,6 +156,20 @@ ipa_vr::equal_p (const vrange &r) const
   return (types_compatible_p (m_type, r.type ()) && m_storage->equal_p (r));
 }
 
+bool
+ipa_vr::equal_p (const ipa_vr &o) const
+{
+  if (!known_p ())
+    return !o.known_p ();
+
+  if (!types_compatible_p (m_type, o.m_type))
+    return false;
+
+  Value_Range r;
+  o.get_vrange (r);
+  return m_storage->equal_p (r);
+}
+
 void
 ipa_vr::get_vrange (Value_Range &r) const
 {
@@ -6057,4 +6071,157 @@ ipa_prop_cc_finalize (void)
   ipa_node_params_sum = NULL;
 }
 
+/* Return true if the two pass_through components of two jump functions are
+   known to be equivalent.  AGG_JF denotes whether they are part of aggregate
+   functions or not.  The function can be used before the IPA phase of IPA-CP
+   or inlining because it cannot cope with refdesc changes these passes can
+   carry out.  */
+
+static bool
+ipa_agg_pass_through_jf_equivalent_p (ipa_pass_through_data *ipt1,
+                                     ipa_pass_through_data *ipt2,
+                                     bool agg_jf)
+
+{
+  gcc_assert (agg_jf ||
+             (!ipt1->refdesc_decremented && !ipt2->refdesc_decremented));
+  if (ipt1->operation != ipt2->operation
+      || ipt1->formal_id != ipt2->formal_id
+      || (!agg_jf && (ipt1->agg_preserved != ipt2->agg_preserved)))
+    return false;
+  if (((ipt1->operand != NULL_TREE) != (ipt2->operand != NULL_TREE))
+      || (ipt1->operand
+         && !values_equal_for_ipcp_p (ipt1->operand, ipt2->operand)))
+    return false;
+  return true;
+}
+
+/* Return true if the two aggregate jump functions are known to be equivalent.
+   The function can be used before the IPA phase of IPA-CP or inlining because
+   it cannot cope with refdesc changes these passes can carry out.  */
+
+static bool
+ipa_agg_jump_functions_equivalent_p (ipa_agg_jf_item *ajf1,
+                                    ipa_agg_jf_item *ajf2)
+{
+  if (ajf1->offset != ajf2->offset
+      || ajf1->jftype != ajf2->jftype
+      || !types_compatible_p (ajf1->type, ajf2->type))
+    return false;
+
+  switch (ajf1->jftype)
+    {
+    case IPA_JF_CONST:
+      if (!values_equal_for_ipcp_p (ajf1->value.constant,
+                                   ajf2->value.constant))
+       return false;
+      break;
+    case IPA_JF_PASS_THROUGH:
+      {
+       ipa_pass_through_data *ipt1 = &ajf1->value.pass_through;
+       ipa_pass_through_data *ipt2 = &ajf2->value.pass_through;
+       if (!ipa_agg_pass_through_jf_equivalent_p (ipt1, ipt2, true))
+         return false;
+      }
+      break;
+    case IPA_JF_LOAD_AGG:
+      {
+       ipa_load_agg_data *ila1 = &ajf1->value.load_agg;
+       ipa_load_agg_data *ila2 = &ajf2->value.load_agg;
+       if (!ipa_agg_pass_through_jf_equivalent_p (&ila1->pass_through,
+                                                  &ila2->pass_through, true))
+         return false;
+       if (ila1->offset != ila2->offset
+           || ila1->by_ref != ila2->by_ref
+           || !types_compatible_p (ila1->type, ila2->type))
+         return false;
+      }
+      break;
+    default:
+       gcc_unreachable ();
+    }
+  return true;
+}
+
+/* Return true if the two jump functions are known to be equivalent.  The
+   function can be used before the IPA phase of IPA-CP or inlining because it
+   cannot cope with refdesc changes these passes can carry out.  */
+
+bool
+ipa_jump_functions_equivalent_p (ipa_jump_func *jf1, ipa_jump_func *jf2)
+{
+  if (jf1->type != jf2->type)
+    return false;
+
+  switch (jf1->type)
+    {
+    case IPA_JF_UNKNOWN:
+      break;
+    case IPA_JF_CONST:
+      {
+       tree cst1 = ipa_get_jf_constant (jf1);
+       tree cst2 = ipa_get_jf_constant (jf2);
+       if (!values_equal_for_ipcp_p (cst1, cst2))
+         return false;
+
+       ipa_cst_ref_desc *rd1 = jfunc_rdesc_usable (jf1);
+       ipa_cst_ref_desc *rd2 = jfunc_rdesc_usable (jf2);
+       if (rd1 && rd2)
+         {
+           gcc_assert (rd1->refcount == 1
+                       && rd2->refcount == 1);
+           gcc_assert (!rd1->next_duplicate && !rd2->next_duplicate);
+         }
+       else if (rd1)
+         return false;
+       else if (rd2)
+         return false;
+      }
+      break;
+    case IPA_JF_PASS_THROUGH:
+      {
+       ipa_pass_through_data *ipt1 = &jf1->value.pass_through;
+       ipa_pass_through_data *ipt2 = &jf2->value.pass_through;
+       if (!ipa_agg_pass_through_jf_equivalent_p (ipt1, ipt2, false))
+         return false;
+      }
+      break;
+    case IPA_JF_ANCESTOR:
+      {
+       ipa_ancestor_jf_data *ia1 = &jf1->value.ancestor;
+       ipa_ancestor_jf_data *ia2 = &jf2->value.ancestor;
+
+       if (ia1->formal_id != ia2->formal_id
+           || ia1->agg_preserved != ia2->agg_preserved
+           || ia1->keep_null != ia2->keep_null
+           || ia1->offset != ia2->offset)
+         return false;
+      }
+      break;
+    default:
+      gcc_unreachable ();
+    }
+
+  if (((jf1->m_vr != nullptr) != (jf2->m_vr != nullptr))
+      || (jf1->m_vr && !jf1->m_vr->equal_p (*jf2->m_vr)))
+    return false;
+
+  unsigned alen = vec_safe_length (jf1->agg.items);
+  if (vec_safe_length (jf2->agg.items) != alen)
+    return false;
+
+  if (!alen)
+    return true;
+
+  if (jf1->agg.by_ref != jf2->agg.by_ref)
+    return false;
+
+  for (unsigned i = 0 ; i < alen; i++)
+    if (!ipa_agg_jump_functions_equivalent_p (&(*jf1->agg.items)[i],
+                                             &(*jf2->agg.items)[i]))
+      return false;
+
+  return true;
+}
+
 #include "gt-ipa-prop.h"
diff --git a/gcc/ipa-prop.h b/gcc/ipa-prop.h
index ee3c0006add..93d1b87b1f7 100644
--- a/gcc/ipa-prop.h
+++ b/gcc/ipa-prop.h
@@ -308,6 +308,7 @@ public:
   tree type () const { return m_type; }
   void get_vrange (Value_Range &) const;
   bool equal_p (const vrange &) const;
+  bool equal_p (const ipa_vr &) const;
   const vrange_storage *storage () const { return m_storage; }
   void streamer_read (lto_input_block *, class data_in *);
   void streamer_write (output_block *) const;
@@ -1278,5 +1279,7 @@ ipa_range_set_and_normalize (vrange &r, tree val)
 
 bool ipa_return_value_range (Value_Range &range, tree decl);
 void ipa_record_return_value_range (Value_Range val);
+bool ipa_jump_functions_equivalent_p (ipa_jump_func *jf1, ipa_jump_func *jf2);
+
 
 #endif /* IPA_PROP_H */
diff --git a/gcc/testsuite/gcc.dg/lto/pr113907_0.c 
b/gcc/testsuite/gcc.dg/lto/pr113907_0.c
new file mode 100644
index 00000000000..3c4dd475c01
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/lto/pr113907_0.c
@@ -0,0 +1,18 @@
+/* { dg-lto-do run } */
+/* { dg-lto-options {{-O3 -flto}} }  */
+
+struct bar {int a;};
+struct foo {int a;};
+struct barp {struct bar *f; struct bar *g;};
+extern struct foo **ptr;
+int test2 (void *);
+int test3 (void *);
+int
+testb(void)
+{
+  struct bar *fp;
+  test2 ((void *)&fp);
+  fp = (void *) 0;
+  (*ptr)++;
+  test3 ((void *)&fp);
+}
diff --git a/gcc/testsuite/gcc.dg/lto/pr113907_1.c 
b/gcc/testsuite/gcc.dg/lto/pr113907_1.c
new file mode 100644
index 00000000000..1c48bfd83a4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/lto/pr113907_1.c
@@ -0,0 +1,35 @@
+__attribute__((used)) int val,val2 = 1;
+
+struct foo {int a;};
+
+struct foo **ptr;
+
+__attribute__ ((noipa))
+int
+test2 (void *a)
+{
+  ptr = (struct foo **)a;
+}
+int test3 (void *a);
+
+int
+test(void)
+{
+  struct foo *fp;
+  test2 ((void *)&fp);
+  fp = (void *) 0;
+  (*ptr)++;
+  test3 ((void *)&fp);
+}
+
+int testb (void);
+
+int
+main()
+{
+  for (int i = 0; i < val2; i++)
+  if (val)
+    testb ();
+  else
+    test();
+}
diff --git a/gcc/testsuite/gcc.dg/lto/pr113907_2.c 
b/gcc/testsuite/gcc.dg/lto/pr113907_2.c
new file mode 100644
index 00000000000..172e86e8b0b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/lto/pr113907_2.c
@@ -0,0 +1,11 @@
+/* { dg-options "-O3 -flto -fno-strict-aliasing" }  */
+
+__attribute__ ((noinline))
+int
+test3 (void *a)
+{
+  if (!*(void **)a)
+          __builtin_abort ();
+  return 0;
+}
+

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