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re PR tree-optimization/47179 (SPU: errno misoptimization around malloc call)

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2011-01-14  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/47179
	* target.def (ref_may_alias_errno): New target hook.
	* targhooks.h (default_ref_may_alias_errno): Declare.
	* targhooks.c: Include tree-ssa-alias.h and tree-flow.h.
	(default_ref_may_alias_errno): New function.
	* target.h (struct ao_ref_s): Declare.
	* tree-ssa-alias.c: Include target.h.
	(call_may_clobber_ref_p_1): Use the ref_may_alias_errno target hook.
	* Makefile.in (tree-ssa-alias.o): Adjust dependencies.
	(targhooks.o): Likewise.
	* doc/tm.texi.in (TARGET_REF_MAY_ALIAS_ERRNO): Document.
	* doc/tm.texi (TARGET_REF_MAY_ALIAS_ERRNO): Copy documentation.

From-SVN: r168788
This commit is contained in:
Richard Guenther 2011-01-14 15:02:20 +00:00 committed by Richard Biener
parent 9a6c928887
commit 7352c01332
9 changed files with 72 additions and 19 deletions
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15
gcc/ChangeLog
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@ -1,3 +1,18 @@
2011-01-14 Richard Guenther <rguenther@suse.de>
PR tree-optimization/47179
* target.def (ref_may_alias_errno): New target hook.
* targhooks.h (default_ref_may_alias_errno): Declare.
* targhooks.c: Include tree-ssa-alias.h and tree-flow.h.
(default_ref_may_alias_errno): New function.
* target.h (struct ao_ref_s): Declare.
* tree-ssa-alias.c: Include target.h.
(call_may_clobber_ref_p_1): Use the ref_may_alias_errno target hook.
* Makefile.in (tree-ssa-alias.o): Adjust dependencies.
(targhooks.o): Likewise.
* doc/tm.texi.in (TARGET_REF_MAY_ALIAS_ERRNO): Document.
* doc/tm.texi (TARGET_REF_MAY_ALIAS_ERRNO): Copy documentation.
2011-01-14 Richard Guenther <rguenther@suse.de>
* tree-ssa-structalias.c (new_var_info): Use DECL_HARD_REGISTER.

5
gcc/Makefile.in
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@ -2614,7 +2614,7 @@ tree-ssa-alias.o : tree-ssa-alias.c $(TREE_FLOW_H) $(CONFIG_H) $(SYSTEM_H) \
$(TREE_H) $(TM_P_H) $(EXPR_H) $(GGC_H) $(TREE_INLINE_H) $(FLAGS_H) \
$(FUNCTION_H) $(TIMEVAR_H) convert.h $(TM_H) coretypes.h langhooks.h \
$(TREE_DUMP_H) $(TREE_PASS_H) $(PARAMS_H) $(BASIC_BLOCK_H) $(DIAGNOSTIC_H) \
$(GIMPLE_H) $(VEC_H) \
$(GIMPLE_H) $(VEC_H) $(TARGET_H) \
$(IPA_TYPE_ESCAPE_H) vecprim.h pointer-set.h alloc-pool.h \
tree-pretty-print.h
tree-ssa-reassoc.o : tree-ssa-reassoc.c $(TREE_FLOW_H) $(CONFIG_H) \
@ -2796,7 +2796,8 @@ opts-common.o : opts-common.c $(OPTS_H) $(FLAGS_H) $(CONFIG_H) $(SYSTEM_H) \
targhooks.o : targhooks.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TREE_H) \
$(EXPR_H) $(TM_H) $(RTL_H) $(TM_P_H) $(FUNCTION_H) output.h $(DIAGNOSTIC_CORE_H) \
$(MACHMODE_H) $(TARGET_DEF_H) $(TARGET_H) $(GGC_H) gt-targhooks.h \
$(OPTABS_H) $(RECOG_H) reload.h hard-reg-set.h intl.h $(OPTS_H)
$(OPTABS_H) $(RECOG_H) reload.h hard-reg-set.h intl.h $(OPTS_H) \
tree-ssa-alias.h $(TREE_FLOW_H)
bversion.h: s-bversion; @true
s-bversion: BASE-VER

4
gcc/doc/tm.texi
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@ -4295,6 +4295,10 @@ with machine mode @var{mode}. The default version of this
hook returns true for both @code{ptr_mode} and @code{Pmode}.
@end deftypefn
@deftypefn {Target Hook} bool TARGET_REF_MAY_ALIAS_ERRNO (struct ao_ref_s *@var{ref})
Define this to return nonzero if the memory reference @var{ref} may alias with the system C library errno location. The default version of this hook assumes the system C library errno location is either a declaration of type int or accessed by dereferencing a pointer to int.
@end deftypefn
@deftypefn {Target Hook} bool TARGET_SCALAR_MODE_SUPPORTED_P (enum machine_mode @var{mode})
Define this to return nonzero if the port is prepared to handle
insns involving scalar mode @var{mode}. For a scalar mode to be

2
gcc/doc/tm.texi.in
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@ -4283,6 +4283,8 @@ with machine mode @var{mode}. The default version of this
hook returns true for both @code{ptr_mode} and @code{Pmode}.
@end deftypefn
@hook TARGET_REF_MAY_ALIAS_ERRNO
@hook TARGET_SCALAR_MODE_SUPPORTED_P
Define this to return nonzero if the port is prepared to handle
insns involving scalar mode @var{mode}. For a scalar mode to be

11
gcc/target.def
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@ -1519,6 +1519,17 @@ DEFHOOK
bool, (enum machine_mode mode),
default_valid_pointer_mode)
/* Disambiguate with errno. */
DEFHOOK
(ref_may_alias_errno,
"Define this to return nonzero if the memory reference @var{ref}\
may alias with the system C library errno location. The default\
version of this hook assumes the system C library errno location\
is either a declaration of type int or accessed by dereferencing\
a pointer to int.",
bool, (struct ao_ref_s *ref),
default_ref_may_alias_errno)
/* Support for named address spaces. */
#undef HOOK_PREFIX
#define HOOK_PREFIX "TARGET_ADDR_SPACE_"

3
gcc/target.h
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@ -100,6 +100,9 @@ struct ddg;
/* This is defined in cfgloop.h . */
struct loop;
/* This is defined in tree-ssa-alias.h. */
struct ao_ref_s;
/* Assembler instructions for creating various kinds of integer object. */
struct asm_int_op

29
gcc/targhooks.c
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@ -69,6 +69,8 @@ along with GCC; see the file COPYING3. If not see
#include "recog.h"
#include "intl.h"
#include "opts.h"
#include "tree-flow.h"
#include "tree-ssa-alias.h"
bool
@ -1035,6 +1037,33 @@ default_valid_pointer_mode (enum machine_mode mode)
return (mode == ptr_mode || mode == Pmode);
}
/* Determine whether the memory reference specified by REF may alias
the C libraries errno location. */
bool
default_ref_may_alias_errno (ao_ref *ref)
{
tree base = ao_ref_base (ref);
/* The default implementation assumes the errno location is
a declaration of type int or is always accessed via a
pointer to int. We assume that accesses to errno are
not deliberately obfuscated (even in conforming ways). */
if (TYPE_UNSIGNED (TREE_TYPE (base))
|| TYPE_MODE (TREE_TYPE (base)) != TYPE_MODE (integer_type_node))
return false;
/* The default implementation assumes an errno location
declaration is never defined in the current compilation unit. */
if (DECL_P (base)
&& !TREE_STATIC (base))
return true;
else if (TREE_CODE (base) == MEM_REF
&& TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
{
struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
return !pi || pi->pt.anything || pi->pt.nonlocal;
}
return false;
}
/* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
for the generic address space only. */

1
gcc/targhooks.h
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@ -143,6 +143,7 @@ extern bool default_target_option_valid_attribute_p (tree, tree, tree, int);
extern bool default_target_option_pragma_parse (tree, tree);
extern bool default_target_can_inline_p (tree, tree);
extern bool default_valid_pointer_mode (enum machine_mode);
extern bool default_ref_may_alias_errno (struct ao_ref_s *);
extern enum machine_mode default_addr_space_pointer_mode (addr_space_t);
extern enum machine_mode default_addr_space_address_mode (addr_space_t);
extern bool default_addr_space_valid_pointer_mode (enum machine_mode,

21
gcc/tree-ssa-alias.c
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@ -25,6 +25,7 @@ along with GCC; see the file COPYING3. If not see
#include "tm.h"
#include "tree.h"
#include "tm_p.h"
#include "target.h"
#include "basic-block.h"
#include "timevar.h"
#include "ggc.h"
@ -1417,24 +1418,10 @@ call_may_clobber_ref_p_1 (gimple call, ao_ref *ref)
being the definition point for the pointer. */
case BUILT_IN_MALLOC:
case BUILT_IN_CALLOC:
/* Unix98 specifies that errno is set on allocation failure.
Until we properly can track the errno location assume it
is not a local decl but external or anonymous storage in
a different translation unit. Also assume it is of
type int as required by the standard. */
/* Unix98 specifies that errno is set on allocation failure. */
if (flag_errno_math
&& TREE_TYPE (base) == integer_type_node)
{
struct ptr_info_def *pi;
if (DECL_P (base)
&& !TREE_STATIC (base))
return true;
else if ((INDIRECT_REF_P (base)
|| TREE_CODE (base) == MEM_REF)
&& TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME
&& (pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0))))
return pi->pt.anything || pi->pt.nonlocal;
}
&& targetm.ref_may_alias_errno (ref))
return true;
return false;
/* Freeing memory kills the pointed-to memory. More importantly
the call has to serve as a barrier for moving loads and stores