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revert: builtins.c (fold_builtin_memory_op): Use the alias oracle to query if the memory regions for memmove overlap.

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2009-09-02  Richard Guenther  <rguenther@suse.de>

        Revert
        2009-08-31  Richard Guenther  <rguenther@suse.de>

        * builtins.c (fold_builtin_memory_op): Use the alias oracle
        to query if the memory regions for memmove overlap.
        * tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Relax the
        asserts on pointers, instead deal with odd trees.
        (ptr_derefs_may_alias_p): Likewise.
        (refs_may_alias_p_1): Constructor bases also never alias.

From-SVN: r151320
This commit is contained in:
Richard Guenther 2009-09-02 11:58:27 +00:00 committed by Richard Biener
parent 42c089971e
commit 638381579b
3 changed files with 82 additions and 18 deletions
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12
gcc/ChangeLog
View File

@ -1,3 +1,15 @@
2009-09-02 Richard Guenther <rguenther@suse.de>
Revert
2009-08-31 Richard Guenther <rguenther@suse.de>
* builtins.c (fold_builtin_memory_op): Use the alias oracle
to query if the memory regions for memmove overlap.
* tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Relax the
asserts on pointers, instead deal with odd trees.
(ptr_derefs_may_alias_p): Likewise.
(refs_may_alias_p_1): Constructor bases also never alias.
2009-08-01 Christian Bruel <christian.bruel@st.com>
Revert:

58
gcc/builtins.c
View File

@ -8990,8 +8990,6 @@ fold_builtin_memory_op (location_t loc, tree dest, tree src,
if (endp == 3)
{
ao_ref srcref, destref;
src_align = get_pointer_alignment (src, BIGGEST_ALIGNMENT);
dest_align = get_pointer_alignment (dest, BIGGEST_ALIGNMENT);
@ -9014,16 +9012,62 @@ fold_builtin_memory_op (location_t loc, tree dest, tree src,
}
/* If *src and *dest can't overlap, optimize into memcpy as well. */
ao_ref_init_from_ptr_and_size (&srcref, src, len);
ao_ref_init_from_ptr_and_size (&destref, dest, len);
if (!refs_may_alias_p_1 (&srcref, &destref, false))
srcvar = build_fold_indirect_ref_loc (loc, src);
destvar = build_fold_indirect_ref_loc (loc, dest);
if (srcvar
&& !TREE_THIS_VOLATILE (srcvar)
&& destvar
&& !TREE_THIS_VOLATILE (destvar))
{
tree fn = implicit_built_in_decls[BUILT_IN_MEMCPY];
tree src_base, dest_base, fn;
HOST_WIDE_INT src_offset = 0, dest_offset = 0;
HOST_WIDE_INT size = -1;
HOST_WIDE_INT maxsize = -1;
src_base = srcvar;
if (handled_component_p (src_base))
src_base = get_ref_base_and_extent (src_base, &src_offset,
&size, &maxsize);
dest_base = destvar;
if (handled_component_p (dest_base))
dest_base = get_ref_base_and_extent (dest_base, &dest_offset,
&size, &maxsize);
if (host_integerp (len, 1))
{
maxsize = tree_low_cst (len, 1);
if (maxsize
> INTTYPE_MAXIMUM (HOST_WIDE_INT) / BITS_PER_UNIT)
maxsize = -1;
else
maxsize *= BITS_PER_UNIT;
}
else
maxsize = -1;
if (SSA_VAR_P (src_base)
&& SSA_VAR_P (dest_base))
{
if (operand_equal_p (src_base, dest_base, 0)
&& ranges_overlap_p (src_offset, maxsize,
dest_offset, maxsize))
return NULL_TREE;
}
else if (TREE_CODE (src_base) == INDIRECT_REF
&& TREE_CODE (dest_base) == INDIRECT_REF)
{
if (! operand_equal_p (TREE_OPERAND (src_base, 0),
TREE_OPERAND (dest_base, 0), 0)
|| ranges_overlap_p (src_offset, maxsize,
dest_offset, maxsize))
return NULL_TREE;
}
else
return NULL_TREE;
fn = implicit_built_in_decls[BUILT_IN_MEMCPY];
if (!fn)
return NULL_TREE;
return build_call_expr_loc (loc, fn, 3, dest, src, len);
}
return NULL_TREE;
}

30
gcc/tree-ssa-alias.c
View File

@ -168,9 +168,12 @@ ptr_deref_may_alias_decl_p (tree ptr, tree decl)
{
struct ptr_info_def *pi;
gcc_assert (TREE_CODE (decl) == VAR_DECL
|| TREE_CODE (decl) == PARM_DECL
|| TREE_CODE (decl) == RESULT_DECL);
gcc_assert ((TREE_CODE (ptr) == SSA_NAME
|| TREE_CODE (ptr) == ADDR_EXPR
|| TREE_CODE (ptr) == INTEGER_CST)
&& (TREE_CODE (decl) == VAR_DECL
|| TREE_CODE (decl) == PARM_DECL
|| TREE_CODE (decl) == RESULT_DECL));
/* Non-aliased variables can not be pointed to. */
if (!may_be_aliased (decl))
@ -194,9 +197,9 @@ ptr_deref_may_alias_decl_p (tree ptr, tree decl)
return true;
}
/* We can end up with dereferencing non-SSA name pointers.
/* We can end up with dereferencing constant pointers.
Just bail out in this case. */
if (TREE_CODE (ptr) != SSA_NAME)
if (TREE_CODE (ptr) == INTEGER_CST)
return true;
/* If we do not have useful points-to information for this pointer
@ -217,6 +220,13 @@ ptr_derefs_may_alias_p (tree ptr1, tree ptr2)
{
struct ptr_info_def *pi1, *pi2;
gcc_assert ((TREE_CODE (ptr1) == SSA_NAME
|| TREE_CODE (ptr1) == ADDR_EXPR
|| TREE_CODE (ptr1) == INTEGER_CST)
&& (TREE_CODE (ptr2) == SSA_NAME
|| TREE_CODE (ptr2) == ADDR_EXPR
|| TREE_CODE (ptr2) == INTEGER_CST));
/* ADDR_EXPR pointers either just offset another pointer or directly
specify the pointed-to set. */
if (TREE_CODE (ptr1) == ADDR_EXPR)
@ -244,10 +254,10 @@ ptr_derefs_may_alias_p (tree ptr1, tree ptr2)
return true;
}
/* We can end up with dereferencing non-SSA name pointers.
/* We can end up with dereferencing constant pointers.
Just bail out in this case. */
if (TREE_CODE (ptr1) != SSA_NAME
|| TREE_CODE (ptr2) != SSA_NAME)
if (TREE_CODE (ptr1) == INTEGER_CST
|| TREE_CODE (ptr2) == INTEGER_CST)
return true;
/* We may end up with two empty points-to solutions for two same pointers.
@ -771,9 +781,7 @@ refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p)
if (TREE_CODE (base1) == SSA_NAME
|| TREE_CODE (base2) == SSA_NAME
|| is_gimple_min_invariant (base1)
|| is_gimple_min_invariant (base2)
|| TREE_CODE (base1) == CONSTRUCTOR
|| TREE_CODE (base2) == CONSTRUCTOR)
|| is_gimple_min_invariant (base2))
return false;
/* Defer to simple offset based disambiguation if we have