| Message ID | 20100904134204.GC31380@kam.mff.cuni.cz |
|---|---|
| State | New |
| Headers | show |
On Sat, 4 Sep 2010, Jan Hubicka wrote: > Hi > this patch fixes missed folding of tree_code_type[6] into 2 in the testcase > attached. The problem is that the constant is discovered by VRP, not CCP and > gimple_fold makes no attempt to fold the constant vars references into > constants except for string. > > Moving code folding strings into fold_const_aggregate_ref is also needed > to avoid one missed constant folding during Ada bootstrap I don't know how > to produce testcase for. > > Bootstrapped/regtested x86_64-linux, OK? Ok. Thanks, Richard. > Honza > > /* { dg-do compile } */ > /* { dg-options "-O2 -fdump-tree-optimized" } */ > typedef const union tree_node *const_tree; > typedef struct > { > } > double_int; > double_int double_int_zext (double_int, unsigned); > enum tree_code > { ERROR_MARK, IDENTIFIER_NODE, TREE_LIST, BLOCK, ENUMERAL_TYPE, BOOLEAN_TYPE, > INTEGER_TYPE, ARRAY_TYPE, INTEGER_CST, VAR_DECL, PARM_DECL, RESULT_DECL, > }; > enum tree_code_class > { tcc_exceptional, tcc_constant, tcc_type, tcc_declaration, tcc_reference, }; > struct tree_base > { > __extension__ enum tree_code code:16; > unsigned unsigned_flag:1; > }; > struct tree_type > { > unsigned int precision:10; > union tree_type_symtab > { > } symtab; > }; > union tree_node > { > struct tree_base base; > struct tree_type type; > }; > const enum tree_code_class tree_code_type[] = > { tcc_exceptional, 1, 0, 0, 0, 0, 2, }; > > int_fits_type_p (const_tree c, const_tree type) > { > double_int dc, dd; > { > if (((enum tree_code) (type)->base.code) == INTEGER_TYPE && (( > { > __typeof > (type) __t > = (type); > if > (tree_code_type > [(int) > (((enum > tree_code) > (__t)-> > base. > code))] > != > (tcc_type)) > tree_class_check_failed > (__t, > __FUNCTION__); > __t;})-> > base. > unsigned_flag)) > dd = double_int_zext (dd, (( > { > __typeof (type) __t = (type); > if (tree_code_type > [(int) > (((enum tree_code) (__t)->base. > code))] != > (tcc_type)) > tree_class_check_failed (__t, > __FUNCTION__); > __t;} > )->type.precision)); > } > } > /* The switch should be switch converted and later constant propagated. */ > /* { dg-final { scan-tree-dump-not "tree_code_type.6" "optimized"} } */ > /* { dg-final { cleanup-tree-dump "optimized" } } */ > > * gimple-fold.c (maybe_fold_reference): Use fold_const_aggregate_ref. > * tree-ssa-ccp.c (fold_const_aggregate_ref): Use > fold_read_from_constant_string. > Index: gimple-fold.c > =================================================================== > --- gimple-fold.c (revision 163859) > +++ gimple-fold.c (working copy) > @@ -462,14 +474,11 @@ static tree > maybe_fold_reference (tree expr, bool is_lhs) > { > tree *t = &expr; > + tree result; > > - if (TREE_CODE (expr) == ARRAY_REF > - && !is_lhs) > - { > - tree tem = fold_read_from_constant_string (expr); > - if (tem) > - return tem; > - } > + if (!is_lhs > + && (result = fold_const_aggregate_ref (expr))) > + return result; > > /* ??? We might want to open-code the relevant remaining cases > to avoid using the generic fold. */ > Index: tree-ssa-ccp.c > =================================================================== > --- tree-ssa-ccp.c (revision 163859) > +++ tree-ssa-ccp.c (working copy) > @@ -1325,6 +1325,10 @@ fold_const_aggregate_ref (tree t) > if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration) > return get_symbol_constant_value (t); > > + tem = fold_read_from_constant_string (t); > + if (tem) > + return tem; > + > switch (TREE_CODE (t)) > { > case ARRAY_REF: > >
Index: gimple-fold.c =================================================================== --- gimple-fold.c (revision 163859) +++ gimple-fold.c (working copy) @@ -462,14 +474,11 @@ static tree maybe_fold_reference (tree expr, bool is_lhs) { tree *t = &expr; + tree result; - if (TREE_CODE (expr) == ARRAY_REF - && !is_lhs) - { - tree tem = fold_read_from_constant_string (expr); - if (tem) - return tem; - } + if (!is_lhs + && (result = fold_const_aggregate_ref (expr))) + return result; /* ??? We might want to open-code the relevant remaining cases to avoid using the generic fold. */ Index: tree-ssa-ccp.c =================================================================== --- tree-ssa-ccp.c (revision 163859) +++ tree-ssa-ccp.c (working copy) @@ -1325,6 +1325,10 @@ fold_const_aggregate_ref (tree t) if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration) return get_symbol_constant_value (t); + tem = fold_read_from_constant_string (t); + if (tem) + return tem; + switch (TREE_CODE (t)) { case ARRAY_REF:
Hi this patch fixes missed folding of tree_code_type[6] into 2 in the testcase attached. The problem is that the constant is discovered by VRP, not CCP and gimple_fold makes no attempt to fold the constant vars references into constants except for string. Moving code folding strings into fold_const_aggregate_ref is also needed to avoid one missed constant folding during Ada bootstrap I don't know how to produce testcase for. Bootstrapped/regtested x86_64-linux, OK? Honza /* { dg-do compile } */ /* { dg-options "-O2 -fdump-tree-optimized" } */ typedef const union tree_node *const_tree; typedef struct { } double_int; double_int double_int_zext (double_int, unsigned); enum tree_code { ERROR_MARK, IDENTIFIER_NODE, TREE_LIST, BLOCK, ENUMERAL_TYPE, BOOLEAN_TYPE, INTEGER_TYPE, ARRAY_TYPE, INTEGER_CST, VAR_DECL, PARM_DECL, RESULT_DECL, }; enum tree_code_class { tcc_exceptional, tcc_constant, tcc_type, tcc_declaration, tcc_reference, }; struct tree_base { __extension__ enum tree_code code:16; unsigned unsigned_flag:1; }; struct tree_type { unsigned int precision:10; union tree_type_symtab { } symtab; }; union tree_node { struct tree_base base; struct tree_type type; }; const enum tree_code_class tree_code_type[] = { tcc_exceptional, 1, 0, 0, 0, 0, 2, }; int_fits_type_p (const_tree c, const_tree type) { double_int dc, dd; { if (((enum tree_code) (type)->base.code) == INTEGER_TYPE && (( { __typeof (type) __t = (type); if (tree_code_type [(int) (((enum tree_code) (__t)-> base. code))] != (tcc_type)) tree_class_check_failed (__t, __FUNCTION__); __t;})-> base. unsigned_flag)) dd = double_int_zext (dd, (( { __typeof (type) __t = (type); if (tree_code_type [(int) (((enum tree_code) (__t)->base. code))] != (tcc_type)) tree_class_check_failed (__t, __FUNCTION__); __t;} )->type.precision)); } } /* The switch should be switch converted and later constant propagated. */ /* { dg-final { scan-tree-dump-not "tree_code_type.6" "optimized"} } */ /* { dg-final { cleanup-tree-dump "optimized" } } */ * gimple-fold.c (maybe_fold_reference): Use fold_const_aggregate_ref. * tree-ssa-ccp.c (fold_const_aggregate_ref): Use fold_read_from_constant_string.