{
struct ptr_info_def *pi;
- /* ??? During SCCVN/PRE we can end up with *&x during valueizing
- operands. Likewise we can end up with dereferencing constant
- pointers. Just bail out in these cases for now. */
- if (TREE_CODE (ptr) == ADDR_EXPR
- || TREE_CODE (ptr) == INTEGER_CST)
- return true;
-
- gcc_assert (TREE_CODE (ptr) == SSA_NAME
+ 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));
if (!may_be_aliased (decl))
return false;
+ /* ADDR_EXPR pointers either just offset another pointer or directly
+ specify the pointed-to set. */
+ if (TREE_CODE (ptr) == ADDR_EXPR)
+ {
+ tree base = get_base_address (TREE_OPERAND (ptr, 0));
+ if (base
+ && INDIRECT_REF_P (base))
+ ptr = TREE_OPERAND (base, 0);
+ else if (base
+ && SSA_VAR_P (base))
+ return operand_equal_p (base, decl, 0);
+ else if (base
+ && CONSTANT_CLASS_P (base))
+ return false;
+ else
+ return true;
+ }
+
+ /* We can end up with dereferencing constant pointers.
+ Just bail out in this case. */
+ if (TREE_CODE (ptr) == INTEGER_CST)
+ return true;
+
/* If we do not have useful points-to information for this pointer
we cannot disambiguate anything else. */
pi = SSA_NAME_PTR_INFO (ptr);
{
struct ptr_info_def *pi1, *pi2;
- /* ??? During SCCVN/PRE we can end up with *&x during valueizing
- operands. Likewise we can end up with dereferencing constant
- pointers. Just bail out in these cases for now. */
- if (TREE_CODE (ptr1) == ADDR_EXPR
- || TREE_CODE (ptr1) == INTEGER_CST
- || TREE_CODE (ptr2) == ADDR_EXPR
+ 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)
+ {
+ tree base = get_base_address (TREE_OPERAND (ptr1, 0));
+ if (base
+ && INDIRECT_REF_P (base))
+ ptr1 = TREE_OPERAND (base, 0);
+ else if (base
+ && SSA_VAR_P (base))
+ return ptr_deref_may_alias_decl_p (ptr2, base);
+ else
+ return true;
+ }
+ if (TREE_CODE (ptr2) == ADDR_EXPR)
+ {
+ tree base = get_base_address (TREE_OPERAND (ptr2, 0));
+ if (base
+ && INDIRECT_REF_P (base))
+ ptr2 = TREE_OPERAND (base, 0);
+ else if (base
+ && SSA_VAR_P (base))
+ return ptr_deref_may_alias_decl_p (ptr1, base);
+ else
+ return true;
+ }
+
+ /* We can end up with dereferencing constant pointers.
+ Just bail out in this case. */
+ if (TREE_CODE (ptr1) == INTEGER_CST
|| TREE_CODE (ptr2) == INTEGER_CST)
return true;
- gcc_assert (TREE_CODE (ptr1) == SSA_NAME
- && TREE_CODE (ptr2) == SSA_NAME);
-
/* We may end up with two empty points-to solutions for two same pointers.
In this case we still want to say both pointers alias, so shortcut
that here. */
if (!pi1 || !pi2)
return true;
+ /* If both pointers are restrict-qualified try to disambiguate
+ with restrict information. */
+ if (TYPE_RESTRICT (TREE_TYPE (ptr1))
+ && TYPE_RESTRICT (TREE_TYPE (ptr2))
+ && !pt_solutions_same_restrict_base (&pi1->pt, &pi2->pt))
+ return false;
+
/* ??? This does not use TBAA to prune decls from the intersection
that not both pointers may access. */
return pt_solutions_intersect (&pi1->pt, &pi2->pt);
}
-/* Return true if STMT is an "escape" site from the current function. Escape
- sites those statements which might expose the address of a variable
- outside the current function. STMT is an escape site iff:
-
- 1- STMT is a function call, or
- 2- STMT is an __asm__ expression, or
- 3- STMT is an assignment to a non-local variable, or
- 4- STMT is a return statement.
-
- Return the type of escape site found, if we found one, or NO_ESCAPE
- if none. */
+/* Return true if dereferencing PTR may alias *REF.
+ The caller is responsible for applying TBAA to see if PTR
+ may access *REF at all. */
-enum escape_type
-is_escape_site (gimple stmt)
+static bool
+ptr_deref_may_alias_ref_p_1 (tree ptr, ao_ref *ref)
{
- if (is_gimple_call (stmt))
- {
- if (gimple_call_flags (stmt) & (ECF_PURE | ECF_CONST))
- return ESCAPE_TO_PURE_CONST;
-
- return ESCAPE_TO_CALL;
- }
- else if (gimple_code (stmt) == GIMPLE_ASM)
- return ESCAPE_TO_ASM;
- else if (is_gimple_assign (stmt))
- {
- tree lhs = gimple_assign_lhs (stmt);
-
- /* Get to the base of _REF nodes. */
- if (TREE_CODE (lhs) != SSA_NAME)
- lhs = get_base_address (lhs);
+ tree base = ao_ref_base (ref);
- /* If we couldn't recognize the LHS of the assignment, assume that it
- is a non-local store. */
- if (lhs == NULL_TREE)
- return ESCAPE_UNKNOWN;
+ if (INDIRECT_REF_P (base))
+ return ptr_derefs_may_alias_p (ptr, TREE_OPERAND (base, 0));
+ else if (SSA_VAR_P (base))
+ return ptr_deref_may_alias_decl_p (ptr, base);
- if (gimple_assign_cast_p (stmt))
- {
- tree from = TREE_TYPE (gimple_assign_rhs1 (stmt));
- tree to = TREE_TYPE (lhs);
-
- /* If the RHS is a conversion between a pointer and an integer, the
- pointer escapes since we can't track the integer. */
- if (POINTER_TYPE_P (from) && !POINTER_TYPE_P (to))
- return ESCAPE_BAD_CAST;
- }
-
- /* If the LHS is an SSA name, it can't possibly represent a non-local
- memory store. */
- if (TREE_CODE (lhs) == SSA_NAME)
- return NO_ESCAPE;
-
- /* If the LHS is a non-global decl, it isn't a non-local memory store.
- If the LHS escapes, the RHS escape is dealt with in the PTA solver. */
- if (DECL_P (lhs)
- && !is_global_var (lhs))
- return NO_ESCAPE;
-
- /* FIXME: LHS is not an SSA_NAME. Even if it's an assignment to a
- local variables we cannot be sure if it will escape, because we
- don't have information about objects not in SSA form. Need to
- implement something along the lines of
-
- J.-D. Choi, M. Gupta, M. J. Serrano, V. C. Sreedhar, and S. P.
- Midkiff, ``Escape analysis for java,'' in Proceedings of the
- Conference on Object-Oriented Programming Systems, Languages, and
- Applications (OOPSLA), pp. 1-19, 1999. */
- return ESCAPE_STORED_IN_GLOBAL;
- }
- else if (gimple_code (stmt) == GIMPLE_RETURN)
- return ESCAPE_TO_RETURN;
-
- return NO_ESCAPE;
+ return true;
}
return ref->ref_alias_set;
}
+/* Init an alias-oracle reference representation from a gimple pointer
+ PTR and a gimple size SIZE in bytes. If SIZE is NULL_TREE the the
+ size is assumed to be unknown. The access is assumed to be only
+ to or after of the pointer target, not before it. */
+
+void
+ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size)
+{
+ HOST_WIDE_INT t1, t2;
+ ref->ref = NULL_TREE;
+ if (TREE_CODE (ptr) == ADDR_EXPR)
+ ref->base = get_ref_base_and_extent (TREE_OPERAND (ptr, 0),
+ &ref->offset, &t1, &t2);
+ else
+ {
+ ref->base = build1 (INDIRECT_REF, char_type_node, ptr);
+ ref->offset = 0;
+ }
+ if (size
+ && host_integerp (size, 0)
+ && TREE_INT_CST_LOW (size) * 8 / 8 == TREE_INT_CST_LOW (size))
+ ref->max_size = ref->size = TREE_INT_CST_LOW (size) * 8;
+ else
+ ref->max_size = ref->size = -1;
+ ref->ref_alias_set = 0;
+ ref->base_alias_set = 0;
+}
+
/* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the
purpose of TBAA. Return 0 if they are distinct and -1 if we cannot
decide. */
/* Now search for the type1 in the access path of ref2. This
would be a common base for doing offset based disambiguation on. */
- /* Skip the outermost ref - we would have caught that earlier. */
- refp = &TREE_OPERAND (ref2, 0);
+ refp = &ref2;
while (handled_component_p (*refp)
&& same_type_for_tbaa (TREE_TYPE (*refp), type1) == 0)
refp = &TREE_OPERAND (*refp, 0);
return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
}
/* If we didn't find a common base, try the other way around. */
- refp = &TREE_OPERAND (ref1, 0);
+ refp = &ref1;
while (handled_component_p (*refp)
&& same_type_for_tbaa (TREE_TYPE (*refp), type2) == 0)
refp = &TREE_OPERAND (*refp, 0);
}
/* Return true if two memory references based on the variables BASE1
- and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1[ and
- [OFFSET2, OFFSET2 + MAX_SIZE2[ may alias. */
+ and BASE2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
+ [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. */
static bool
decl_refs_may_alias_p (tree base1,
}
/* Return true if an indirect reference based on *PTR1 constrained
- to [OFFSET1, OFFSET1 + MAX_SIZE1[ may alias a variable based on BASE2
- constrained to [OFFSET2, OFFSET2 + MAX_SIZE2[. *PTR1 and BASE2 have
+ to [OFFSET1, OFFSET1 + MAX_SIZE1) may alias a variable based on BASE2
+ constrained to [OFFSET2, OFFSET2 + MAX_SIZE2). *PTR1 and BASE2 have
the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
in which case they are computed on-demand. REF1 and REF2
if non-NULL are the complete memory reference trees. */
}
/* Return true if two indirect references based on *PTR1
- and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1[ and
- [OFFSET2, OFFSET2 + MAX_SIZE2[ may alias. *PTR1 and *PTR2 have
+ and *PTR2 constrained to [OFFSET1, OFFSET1 + MAX_SIZE1) and
+ [OFFSET2, OFFSET2 + MAX_SIZE2) may alias. *PTR1 and *PTR2 have
the alias sets BASE1_ALIAS_SET and BASE2_ALIAS_SET which can be -1
in which case they are computed on-demand. REF1 and REF2
if non-NULL are the complete memory reference trees. */
/* Return true, if the two memory references REF1 and REF2 may alias. */
-static bool
+bool
refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p)
{
tree base1, base2;
|| is_gimple_min_invariant (base2))
return false;
+ /* We can end up refering to code via function decls. As we likely
+ do not properly track code aliases conservatively bail out. */
+ if (TREE_CODE (base1) == FUNCTION_DECL
+ || TREE_CODE (base2) == FUNCTION_DECL)
+ return true;
+
/* Defer to simple offset based disambiguation if we have
references based on two decls. Do this before defering to
TBAA to handle must-alias cases in conformance with the
otherwise return false. */
static bool
-ref_maybe_used_by_call_p_1 (gimple call, tree ref)
+ref_maybe_used_by_call_p_1 (gimple call, ao_ref *ref)
{
- tree base;
+ tree base, callee;
unsigned i;
int flags = gimple_call_flags (call);
&& (flags & (ECF_CONST|ECF_NOVOPS)))
goto process_args;
- /* If the reference is not based on a decl give up.
- ??? Handle indirect references by intersecting the call-used
- solution with that of the pointer. */
- base = get_base_address (ref);
- if (!base
- || !DECL_P (base))
+ base = ao_ref_base (ref);
+ if (!base)
return true;
/* If the reference is based on a decl that is not aliased the call
&& !is_global_var (base))
goto process_args;
+ callee = gimple_call_fndecl (call);
+
+ /* Handle those builtin functions explicitly that do not act as
+ escape points. See tree-ssa-structalias.c:find_func_aliases
+ for the list of builtins we might need to handle here. */
+ if (callee != NULL_TREE
+ && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
+ switch (DECL_FUNCTION_CODE (callee))
+ {
+ /* All the following functions clobber memory pointed to by
+ their first argument. */
+ case BUILT_IN_STRCPY:
+ case BUILT_IN_STRNCPY:
+ case BUILT_IN_BCOPY:
+ case BUILT_IN_MEMCPY:
+ case BUILT_IN_MEMMOVE:
+ case BUILT_IN_MEMPCPY:
+ case BUILT_IN_STPCPY:
+ case BUILT_IN_STPNCPY:
+ case BUILT_IN_STRCAT:
+ case BUILT_IN_STRNCAT:
+ {
+ ao_ref dref;
+ tree size = NULL_TREE;
+ if (gimple_call_num_args (call) == 3)
+ size = gimple_call_arg (call, 2);
+ ao_ref_init_from_ptr_and_size (&dref,
+ gimple_call_arg (call, 1),
+ size);
+ return refs_may_alias_p_1 (&dref, ref, false);
+ }
+ /* The following builtins do not read from memory. */
+ case BUILT_IN_FREE:
+ case BUILT_IN_MEMSET:
+ case BUILT_IN_FREXP:
+ case BUILT_IN_FREXPF:
+ case BUILT_IN_FREXPL:
+ case BUILT_IN_GAMMA_R:
+ case BUILT_IN_GAMMAF_R:
+ case BUILT_IN_GAMMAL_R:
+ case BUILT_IN_LGAMMA_R:
+ case BUILT_IN_LGAMMAF_R:
+ case BUILT_IN_LGAMMAL_R:
+ case BUILT_IN_MODF:
+ case BUILT_IN_MODFF:
+ case BUILT_IN_MODFL:
+ case BUILT_IN_REMQUO:
+ case BUILT_IN_REMQUOF:
+ case BUILT_IN_REMQUOL:
+ case BUILT_IN_SINCOS:
+ case BUILT_IN_SINCOSF:
+ case BUILT_IN_SINCOSL:
+ return false;
+
+ default:
+ /* Fallthru to general call handling. */;
+ }
+
/* Check if base is a global static variable that is not read
by the function. */
if (TREE_CODE (base) == VAR_DECL
&& TREE_STATIC (base)
&& !TREE_PUBLIC (base))
{
- tree callee = gimple_call_fndecl (call);
bitmap not_read;
if (callee != NULL_TREE
it may be used. */
if (flags & (ECF_PURE|ECF_CONST|ECF_LOOPING_CONST_OR_PURE|ECF_NOVOPS))
{
- if (is_call_used (base))
+ if (DECL_P (base))
+ {
+ if (is_call_used (base))
+ return true;
+ }
+ else if (INDIRECT_REF_P (base)
+ && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
+ {
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
+ if (!pi)
+ return true;
+
+ if (pt_solution_includes_global (&pi->pt)
+ || pt_solutions_intersect (&cfun->gimple_df->callused, &pi->pt)
+ || pt_solutions_intersect (&cfun->gimple_df->escaped, &pi->pt))
+ return true;
+ }
+ else
return true;
}
else
{
- if (is_call_clobbered (base))
+ if (DECL_P (base))
+ {
+ if (is_call_clobbered (base))
+ return true;
+ }
+ else if (INDIRECT_REF_P (base)
+ && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
+ {
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
+ if (!pi)
+ return true;
+
+ if (pt_solution_includes_global (&pi->pt)
+ || pt_solutions_intersect (&cfun->gimple_df->escaped, &pi->pt))
+ return true;
+ }
+ else
return true;
}
op = TREE_OPERAND (op, 0);
if (TREE_CODE (op) != SSA_NAME
- && !is_gimple_min_invariant (op)
- && refs_may_alias_p (op, ref))
- return true;
+ && !is_gimple_min_invariant (op))
+ {
+ ao_ref r;
+ ao_ref_init (&r, op);
+ if (refs_may_alias_p_1 (&r, ref, true))
+ return true;
+ }
}
return false;
static bool
ref_maybe_used_by_call_p (gimple call, tree ref)
{
- bool res = ref_maybe_used_by_call_p_1 (call, ref);
+ ao_ref r;
+ bool res;
+ ao_ref_init (&r, ref);
+ res = ref_maybe_used_by_call_p_1 (call, &r);
if (res)
++alias_stats.ref_maybe_used_by_call_p_may_alias;
else
call_may_clobber_ref_p_1 (gimple call, ao_ref *ref)
{
tree base;
+ tree callee;
/* If the call is pure or const it cannot clobber anything. */
if (gimple_call_flags (call)
|| !is_global_var (base)))
return false;
+ callee = gimple_call_fndecl (call);
+
+ /* Handle those builtin functions explicitly that do not act as
+ escape points. See tree-ssa-structalias.c:find_func_aliases
+ for the list of builtins we might need to handle here. */
+ if (callee != NULL_TREE
+ && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
+ switch (DECL_FUNCTION_CODE (callee))
+ {
+ /* All the following functions clobber memory pointed to by
+ their first argument. */
+ case BUILT_IN_STRCPY:
+ case BUILT_IN_STRNCPY:
+ case BUILT_IN_BCOPY:
+ case BUILT_IN_MEMCPY:
+ case BUILT_IN_MEMMOVE:
+ case BUILT_IN_MEMPCPY:
+ case BUILT_IN_STPCPY:
+ case BUILT_IN_STPNCPY:
+ case BUILT_IN_STRCAT:
+ case BUILT_IN_STRNCAT:
+ case BUILT_IN_MEMSET:
+ {
+ ao_ref dref;
+ tree size = NULL_TREE;
+ if (gimple_call_num_args (call) == 3)
+ size = gimple_call_arg (call, 2);
+ ao_ref_init_from_ptr_and_size (&dref,
+ gimple_call_arg (call, 0),
+ size);
+ 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. */
+ case BUILT_IN_FREE:
+ {
+ tree ptr = gimple_call_arg (call, 0);
+ return ptr_deref_may_alias_ref_p_1 (ptr, ref);
+ }
+ case BUILT_IN_GAMMA_R:
+ case BUILT_IN_GAMMAF_R:
+ case BUILT_IN_GAMMAL_R:
+ case BUILT_IN_LGAMMA_R:
+ case BUILT_IN_LGAMMAF_R:
+ case BUILT_IN_LGAMMAL_R:
+ {
+ tree out = gimple_call_arg (call, 1);
+ if (ptr_deref_may_alias_ref_p_1 (out, ref))
+ return true;
+ if (flag_errno_math)
+ break;
+ return false;
+ }
+ case BUILT_IN_FREXP:
+ case BUILT_IN_FREXPF:
+ case BUILT_IN_FREXPL:
+ case BUILT_IN_MODF:
+ case BUILT_IN_MODFF:
+ case BUILT_IN_MODFL:
+ {
+ tree out = gimple_call_arg (call, 1);
+ return ptr_deref_may_alias_ref_p_1 (out, ref);
+ }
+ case BUILT_IN_REMQUO:
+ case BUILT_IN_REMQUOF:
+ case BUILT_IN_REMQUOL:
+ {
+ tree out = gimple_call_arg (call, 2);
+ if (ptr_deref_may_alias_ref_p_1 (out, ref))
+ return true;
+ if (flag_errno_math)
+ break;
+ return false;
+ }
+ case BUILT_IN_SINCOS:
+ case BUILT_IN_SINCOSF:
+ case BUILT_IN_SINCOSL:
+ {
+ tree sin = gimple_call_arg (call, 1);
+ tree cos = gimple_call_arg (call, 2);
+ return (ptr_deref_may_alias_ref_p_1 (sin, ref)
+ || ptr_deref_may_alias_ref_p_1 (cos, ref));
+ }
+ default:
+ /* Fallthru to general call handling. */;
+ }
+
/* Check if base is a global static variable that is not written
by the function. */
- if (TREE_CODE (base) == VAR_DECL
+ if (callee != NULL_TREE
+ && TREE_CODE (base) == VAR_DECL
&& TREE_STATIC (base)
&& !TREE_PUBLIC (base))
{
- tree callee = gimple_call_fndecl (call);
bitmap not_written;
- if (callee != NULL_TREE
- && (not_written
- = ipa_reference_get_not_written_global (cgraph_node (callee)))
+ if ((not_written
+ = ipa_reference_get_not_written_global (cgraph_node (callee)))
&& bitmap_bit_p (not_written, DECL_UID (base)))
return false;
}
if (DECL_P (base))
return is_call_clobbered (base);
+ else if (INDIRECT_REF_P (base)
+ && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
+ {
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0));
+ if (!pi)
+ return true;
+
+ return (pt_solution_includes_global (&pi->pt)
+ || pt_solutions_intersect (&cfun->gimple_df->escaped, &pi->pt));
+ }
return true;
}
The function returns the number of statements walked. */
static unsigned int
-walk_aliased_vdefs_1 (tree ref, tree vdef,
- bool (*walker)(tree, tree, void *), void *data,
+walk_aliased_vdefs_1 (ao_ref *ref, tree vdef,
+ bool (*walker)(ao_ref *, tree, void *), void *data,
bitmap *visited, unsigned int cnt)
{
do
/* ??? Do we want to account this to TV_ALIAS_STMT_WALK? */
cnt++;
if ((!ref
- || stmt_may_clobber_ref_p (def_stmt, ref))
+ || stmt_may_clobber_ref_p_1 (def_stmt, ref))
&& (*walker) (ref, vdef, data))
return cnt;
}
unsigned int
-walk_aliased_vdefs (tree ref, tree vdef,
- bool (*walker)(tree, tree, void *), void *data,
+walk_aliased_vdefs (ao_ref *ref, tree vdef,
+ bool (*walker)(ao_ref *, tree, void *), void *data,
bitmap *visited)
{
bitmap local_visited = NULL;
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