On Thu, 6 Feb 2014, Jakub Jelinek wrote: > On Thu, Feb 06, 2014 at 02:21:01PM +0100, Richard Biener wrote: > > + /* We marking allocated storage local, we deal with it becoming > > + global by escaping and setting of vars_contains_escaped_heap. */ > > Did you mean By marking ..., or something else?
"We are marking ..." cut&pasted and fixed both cases. > > + extern int posix_memalign(void **memptr, > > + __SIZE_TYPE__ alignment, __SIZE_TYPE__ size); > > + > > + int foo (int *p) > > + { > > + int res = *p; > > + int *q; > > + posix_memalign ((void **)&q, 128, 128 * sizeof (int)); > > Do you really want to have strict aliasing violations in the testcase? > I think one has to take address of a void * variable and if you want > int *, then cast to int * afterwards. Sure, I'll fix that (it doesn't matter for GCC luckily ;)). I still expect user code to be lazy ... (which is why GCC treats all pointer types as having the same alias set) > Also, I think for posix_memalign > you really should be checking return value of the function. Yeah. Like the following - will commit after re-bootstrapping together with the 3rd followup. Richard. 2014-02-06 Richard Biener <rguent...@suse.de> PR middle-end/60092 * builtin-types.def (BT_FN_INT_PTRPTR_SIZE_SIZE): Add. * builtins.def (BUILT_IN_POSIX_MEMALIGN): Likewise. * tree-ssa-structalias.c (find_func_aliases_for_builtin_call): Handle BUILT_IN_POSIX_MEMALIGN. (find_func_clobbers): Likewise. * tree-ssa-alias.c (ref_maybe_used_by_call_p_1): Likewise. (call_may_clobber_ref_p_1): Likewise. * gcc.dg/tree-ssa/alias-30.c: New testcase. * gcc.dg/tree-ssa/alias-31.c: Likewise. Index: gcc/builtin-types.def =================================================================== *** gcc/builtin-types.def.orig 2014-02-06 12:43:09.585012064 +0100 --- gcc/builtin-types.def 2014-02-06 12:43:34.435010353 +0100 *************** DEF_FUNCTION_TYPE_3 (BT_FN_VOID_VPTR_I2_ *** 429,434 **** --- 429,435 ---- DEF_FUNCTION_TYPE_3 (BT_FN_VOID_VPTR_I4_INT, BT_VOID, BT_VOLATILE_PTR, BT_I4, BT_INT) DEF_FUNCTION_TYPE_3 (BT_FN_VOID_VPTR_I8_INT, BT_VOID, BT_VOLATILE_PTR, BT_I8, BT_INT) DEF_FUNCTION_TYPE_3 (BT_FN_VOID_VPTR_I16_INT, BT_VOID, BT_VOLATILE_PTR, BT_I16, BT_INT) + DEF_FUNCTION_TYPE_3 (BT_FN_INT_PTRPTR_SIZE_SIZE, BT_INT, BT_PTR_PTR, BT_SIZE, BT_SIZE) DEF_FUNCTION_TYPE_4 (BT_FN_SIZE_CONST_PTR_SIZE_SIZE_FILEPTR, BT_SIZE, BT_CONST_PTR, BT_SIZE, BT_SIZE, BT_FILEPTR) Index: gcc/builtins.def =================================================================== *** gcc/builtins.def.orig 2014-02-06 12:43:09.586012064 +0100 --- gcc/builtins.def 2014-02-06 15:06:39.716419267 +0100 *************** DEF_GCC_BUILTIN (BUILT_IN_POPCOUN *** 755,760 **** --- 755,761 ---- DEF_GCC_BUILTIN (BUILT_IN_POPCOUNTIMAX, "popcountimax", BT_FN_INT_UINTMAX, ATTR_CONST_NOTHROW_LEAF_LIST) DEF_GCC_BUILTIN (BUILT_IN_POPCOUNTL, "popcountl", BT_FN_INT_ULONG, ATTR_CONST_NOTHROW_LEAF_LIST) DEF_GCC_BUILTIN (BUILT_IN_POPCOUNTLL, "popcountll", BT_FN_INT_ULONGLONG, ATTR_CONST_NOTHROW_LEAF_LIST) + DEF_EXT_LIB_BUILTIN (BUILT_IN_POSIX_MEMALIGN, "posix_memalign", BT_FN_INT_PTRPTR_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF) DEF_GCC_BUILTIN (BUILT_IN_PREFETCH, "prefetch", BT_FN_VOID_CONST_PTR_VAR, ATTR_NOVOPS_LEAF_LIST) DEF_LIB_BUILTIN (BUILT_IN_REALLOC, "realloc", BT_FN_PTR_PTR_SIZE, ATTR_NOTHROW_LEAF_LIST) DEF_GCC_BUILTIN (BUILT_IN_RETURN, "return", BT_FN_VOID_PTR, ATTR_NORETURN_NOTHROW_LEAF_LIST) Index: gcc/tree-ssa-structalias.c =================================================================== *** gcc/tree-ssa-structalias.c.orig 2014-02-06 12:43:09.597012063 +0100 --- gcc/tree-ssa-structalias.c 2014-02-06 15:07:22.987416288 +0100 *************** handle_lhs_call (gimple stmt, tree lhs, *** 3982,3988 **** struct constraint_expr tmpc; rhsc.create (0); vi = make_heapvar ("HEAP"); ! /* We marking allocated storage local, we deal with it becoming global by escaping and setting of vars_contains_escaped_heap. */ DECL_EXTERNAL (vi->decl) = 0; vi->is_global_var = 0; --- 3982,3988 ---- struct constraint_expr tmpc; rhsc.create (0); vi = make_heapvar ("HEAP"); ! /* We are marking allocated storage local, we deal with it becoming global by escaping and setting of vars_contains_escaped_heap. */ DECL_EXTERNAL (vi->decl) = 0; vi->is_global_var = 0; *************** find_func_aliases_for_builtin_call (gimp *** 4231,4236 **** --- 4231,4256 ---- lhsc.release (); return true; } + case BUILT_IN_POSIX_MEMALIGN: + { + tree ptrptr = gimple_call_arg (t, 0); + get_constraint_for (ptrptr, &lhsc); + do_deref (&lhsc); + varinfo_t vi = make_heapvar ("HEAP"); + /* We are marking allocated storage local, we deal with it becoming + global by escaping and setting of vars_contains_escaped_heap. */ + DECL_EXTERNAL (vi->decl) = 0; + vi->is_global_var = 0; + struct constraint_expr tmpc; + tmpc.var = vi->id; + tmpc.offset = 0; + tmpc.type = ADDRESSOF; + rhsc.safe_push (tmpc); + process_all_all_constraints (lhsc, rhsc); + lhsc.release (); + rhsc.release (); + return true; + } case BUILT_IN_ASSUME_ALIGNED: { tree res = gimple_call_lhs (t); *************** find_func_clobbers (gimple origt) *** 4960,4965 **** --- 4980,4986 ---- its argument. */ case BUILT_IN_MEMSET: case BUILT_IN_MEMSET_CHK: + case BUILT_IN_POSIX_MEMALIGN: { tree dest = gimple_call_arg (t, 0); unsigned i; Index: gcc/tree-ssa-alias.c =================================================================== *** gcc/tree-ssa-alias.c.orig 2014-02-06 12:43:09.598012063 +0100 --- gcc/tree-ssa-alias.c 2014-02-06 15:06:39.716419267 +0100 *************** ref_maybe_used_by_call_p_1 (gimple call, *** 1515,1520 **** --- 1515,1521 ---- /* The following builtins do not read from memory. */ case BUILT_IN_FREE: case BUILT_IN_MALLOC: + case BUILT_IN_POSIX_MEMALIGN: case BUILT_IN_CALLOC: case BUILT_IN_ALLOCA: case BUILT_IN_ALLOCA_WITH_ALIGN: *************** call_may_clobber_ref_p_1 (gimple call, a *** 1838,1843 **** --- 1839,1854 ---- case BUILT_IN_ALLOCA_WITH_ALIGN: case BUILT_IN_ASSUME_ALIGNED: return false; + /* But posix_memalign stores a pointer into the memory pointed to + by its first argument. */ + case BUILT_IN_POSIX_MEMALIGN: + { + tree ptrptr = gimple_call_arg (call, 0); + ao_ref dref; + ao_ref_init_from_ptr_and_size (&dref, ptrptr, + TYPE_SIZE_UNIT (ptr_type_node)); + return refs_may_alias_p_1 (&dref, ref, false); + } /* Freeing memory kills the pointed-to memory. More importantly the call has to serve as a barrier for moving loads and stores across it. */ Index: gcc/testsuite/gcc.dg/tree-ssa/alias-30.c =================================================================== *** /dev/null 1970-01-01 00:00:00.000000000 +0000 --- gcc/testsuite/gcc.dg/tree-ssa/alias-30.c 2014-02-06 15:10:01.991405340 +0100 *************** *** 0 **** --- 1,22 ---- + /* { dg-do compile } */ + /* { dg-options "-O -fdump-tree-fre-details" } */ + + extern int posix_memalign(void **memptr, + __SIZE_TYPE__ alignment, __SIZE_TYPE__ size); + + int foo (int *p) + { + int res = *p; + int *q; + void *tem; + if (posix_memalign (&tem, 128, 128 * sizeof (int)) != 0) + return 0; + q = (int *)tem; + *q = 1; + return res + *p; + } + + /* We should be able to CSE the load from *p in the return stmt. */ + + /* { dg-final { scan-tree-dump "Replaced \\\*p" "fre1" } } */ + /* { dg-final { cleanup-tree-dump "fre1" } } */ Index: gcc/testsuite/gcc.dg/tree-ssa/alias-31.c =================================================================== *** /dev/null 1970-01-01 00:00:00.000000000 +0000 --- gcc/testsuite/gcc.dg/tree-ssa/alias-31.c 2014-02-06 15:11:55.881397499 +0100 *************** *** 0 **** --- 1,24 ---- + /* { dg-do compile } */ + /* { dg-options "-O2 -fdump-tree-cddce1" } */ + + extern int posix_memalign(void **memptr, + __SIZE_TYPE__ alignment, __SIZE_TYPE__ size); + + int foo (int *p) + { + int res = *p; + struct { void *q1; void *q2; } q; + if (posix_memalign (&q.q1, 128, 128 * sizeof (int)) != 0) + return 0; + if (posix_memalign (&q.q2, 128, 128 * sizeof (int)) != 0) + return 0; + *((int *)q.q1) = 1; + *((int *)q.q2) = 2; + return res + *p + *((int *)q.q1) + *((int *)q.q2); + } + + /* There should be only one load from *p left. All stores and all + other loads should be removed. */ + + /* { dg-final { scan-tree-dump-times "\\\*\[^ \]" 1 "cddce1" } } */ + /* { dg-final { cleanup-tree-dump "cddce1" } } */