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| author | Richard Biener <rguenther@suse.de> | 2019-05-03 07:07:28 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2019-05-03 07:07:28 +0000 |
| commit | 37f808c4a683a7431b7aa6d49f4c2e385cc0d707 (patch) | |
| tree | 17b318f02a0ab1defcde8d90f4cc17251ff68994 | |
| parent | c0f9d1fd7e54434e4f06b20b9a61a9d35c578223 (diff) | |
| download | gcc-37f808c4a683a7431b7aa6d49f4c2e385cc0d707.zip gcc-37f808c4a683a7431b7aa6d49f4c2e385cc0d707.tar.gz gcc-37f808c4a683a7431b7aa6d49f4c2e385cc0d707.tar.bz2 | |
re PR c++/89698 (Run-time error due to optimization of field access after cast at -Os/-O2 and higher)
2019-05-03 Richard Biener <rguenther@suse.de>
PR tree-optimization/89698
* gimple-fold.c (canonicalize_constructor_val): Early out
for constants, handle unfolded INTEGER_CSTs as they appear in
C++ virtual table ctors.
* g++.dg/tree-ssa/pr89698.C: New testcase.
From-SVN: r270833
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/gimple-fold.c | 14 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/tree-ssa/pr89698.C | 29 |
4 files changed, 53 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 65df011..5973192 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,12 @@ 2019-05-03 Richard Biener <rguenther@suse.de> + PR tree-optimization/89698 + * gimple-fold.c (canonicalize_constructor_val): Early out + for constants, handle unfolded INTEGER_CSTs as they appear in + C++ virtual table ctors. + +2019-05-03 Richard Biener <rguenther@suse.de> + * passes.c (execute_function_todo): Remove dead code. 2019-05-02 Segher Boessenkool <segher@kernel.crashing.org> diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index d3ef05b..1b10bae 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -207,6 +207,9 @@ create_tmp_reg_or_ssa_name (tree type, gimple *stmt) tree canonicalize_constructor_val (tree cval, tree from_decl) { + if (CONSTANT_CLASS_P (cval)) + return cval; + tree orig_cval = cval; STRIP_NOPS (cval); if (TREE_CODE (cval) == POINTER_PLUS_EXPR @@ -257,8 +260,15 @@ canonicalize_constructor_val (tree cval, tree from_decl) cval = fold_convert (TREE_TYPE (orig_cval), cval); return cval; } - if (TREE_OVERFLOW_P (cval)) - return drop_tree_overflow (cval); + /* In CONSTRUCTORs we may see unfolded constants like (int (*) ()) 0. */ + if (TREE_CODE (cval) == INTEGER_CST) + { + if (TREE_OVERFLOW_P (cval)) + cval = drop_tree_overflow (cval); + if (!useless_type_conversion_p (TREE_TYPE (orig_cval), TREE_TYPE (cval))) + cval = fold_convert (TREE_TYPE (orig_cval), cval); + return cval; + } return orig_cval; } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ad12005..660110d 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-05-03 Richard Biener <rguenther@suse.de> + + PR tree-optimization/89698 + * g++.dg/tree-ssa/pr89698.C: New testcase. + 2019-05-02 Iain Sandoe <iain@sandoe.co.uk> * g++.dg/ext/instantiate2.C: Remove special-casing for Darwin. diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr89698.C b/gcc/testsuite/g++.dg/tree-ssa/pr89698.C new file mode 100644 index 0000000..9d3b408 --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/pr89698.C @@ -0,0 +1,29 @@ +// { dg-do compile } +// { dg-options "-O -fdump-tree-fre1" } + +class A { + virtual void f(){}; +public: + int x; + A(int in): x(in) {}; +}; + +class B: public A { +public: + int y; + B(int in):A(in-1), y(in) {}; +}; + +void bar(void *); +void test() +{ + B b(2); + A* bp = &b; + void* vp = dynamic_cast<void*>(bp); + bar (vp); +} + +// We should be able to constant fold from the virtual table +// the offset added to bp for the dynamic cast and forward +// &b to the argument of bar +// { dg-final { scan-tree-dump "bar \\\(&b" "fre1" } } |