re PR ipa/67056 (Wrong code generated)

	PR ipa/67056
	* ipa-polymorphic-call.c (possible_placement_new): If cur_offset
	is negative we don't know the type.
	(check_stmt_for_type_change): Skip constructors of non-polymorphic
	types as those won't help devirutalization.
	* g++.dg/ipa/pr67056.C: New testcase.

From-SVN: r229148

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 38ae32110db492b6fda6db6d7ab925d02d9682a3..bc3cfa7cb939f7c4399eac08c02ec45c7597afca 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2015-10-11  Jan Hubicka  <hubicka@ucw.cz>
+
+       PR ipa/67056
+       * ipa-polymorphic-call.c (possible_placement_new): If cur_offset
+       is negative we don't know the type.
+       (check_stmt_for_type_change): Skip constructors of non-polymorphic
+       types as those won't help devirutalization.
+
 2015-10-11  Jan Hubicka  <hubicka@ucw.cz>
 
        * fold-const.c (operand_equal_p): Add code matching empty

diff --git a/gcc/ipa-polymorphic-call.c b/gcc/ipa-polymorphic-call.c
index 99770dedf11ead24ba918b13c1823be2cc9ce81b..9ce86d1c7d49853b0fba8e64c2f48b916df7caa0 100644 (file)
--- a/gcc/ipa-polymorphic-call.c
+++ b/gcc/ipa-polymorphic-call.c
@@ -99,6 +99,8 @@ bool
 possible_placement_new (tree type, tree expected_type,
                        HOST_WIDE_INT cur_offset)
 {
+  if (cur_offset < 0)
+    return true;
   return ((TREE_CODE (type) != RECORD_TYPE
           || !TYPE_BINFO (type)
           || cur_offset >= POINTER_SIZE
@@ -1418,7 +1420,21 @@ check_stmt_for_type_change (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef, void *data)
            && TYPE_SIZE (type)
            && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
            && tree_fits_shwi_p (TYPE_SIZE (type))
-           && tree_to_shwi (TYPE_SIZE (type)) + offset > tci->offset)
+           && tree_to_shwi (TYPE_SIZE (type)) + offset > tci->offset
+           /* Some inlined constructors may look as follows:
+                 _3 = operator new (16);
+                 MEM[(struct  &)_3] ={v} {CLOBBER};
+                 MEM[(struct CompositeClass *)_3]._vptr.CompositeClass
+                   = &MEM[(void *)&_ZTV14CompositeClass + 16B];
+                 _7 = &MEM[(struct CompositeClass *)_3].object;
+                 EmptyClass::EmptyClass (_7);
+
+              When determining dynamic type of _3 and because we stop at first
+              dynamic type found, we would stop on EmptyClass::EmptyClass (_7).
+              In this case the emptyclass is not even polymorphic and we miss
+              it is contained in an outer type that is polymorphic.  */
+
+           && (tci->offset == offset || contains_polymorphic_type_p (type)))
          {
            record_known_type (tci, type, tci->offset - offset);
            return true;

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4637ae747e2059a2e273f7582128879ef4c5a6a3..d2a7da62e8ca598e59dd0eb1d131cacae0ca4c80 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-10-11  Jan Hubicka  <hubicka@ucw.cz>
+
+       PR ipa/67056
+       * g++.dg/ipa/pr67056.C: New testcase.
+
 2015-10-11  Jan Hubicka  <hubicka@ucw.cz>
 
        * gcc.dg/tree-ssa/operand-equal-1.c: Verify that empty constructors

diff --git a/gcc/testsuite/g++.dg/ipa/pr67056.C b/gcc/testsuite/g++.dg/ipa/pr67056.C
new file mode 100644 (file)
index 0000000..f47323b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ipa/pr67056.C
@@ -0,0 +1,39 @@
+/* { dg-do run } */
+/* { dg-options "-std=c++11 -O3 -fdump-ipa-cp"  } */
+/* { dg-additional-options "-fPIC" { target fpic } } */
+#include <memory>
+
+class EmptyClass {
+public:
+    EmptyClass();
+};
+
+EmptyClass::EmptyClass() {
+}
+
+class CompositeClass {
+public:
+    CompositeClass() {}
+    virtual ~CompositeClass() {}
+    EmptyClass object;
+    bool bool1;
+    bool bool2;
+};
+
+bool boolFunc() {
+    return true;
+}
+
+static bool staticBoolFunc(CompositeClass * ptr) {
+    std::unique_ptr<CompositeClass> up(ptr);
+    (void)up;
+
+    return boolFunc();
+}
+
+int main(int, char **) {
+    staticBoolFunc(new CompositeClass);
+    return 0;
+}
+
+/* { dg-final { scan-ipa-dump "Speculative outer type:struct CompositeClass" "cp"  } } */