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Whitespace cleanup and function reshuffling in tree-ssa-operands.c
- From: Diego Novillo <dnovillo at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Wed, 01 Mar 2006 11:11:32 -0500
- Subject: Whitespace cleanup and function reshuffling in tree-ssa-operands.c
No functional changes. The patch just moves most of the helper
functions forward to avoid having to forward declare them. The only one
that needs forward declaration is get_expr_operands.
Tested on x86.
2006-03-01 Diego Novillo <dnovillo@redhat.com>
* tree-ssa-operands.c: Cleanup whitespace.
(get_asm_expr_operands): Move before first invocation.
(get_indirect_ref_operands): Likewise.
(get_tmr_operands): Likewise.
(get_call_expr_operands): Likewise.
(append_def): Likewise.
(append_use): Likewise.
(append_v_may_def): Likewise.
(append_v_must_def): Likewise.
(add_call_clobber_ops): Likewise.
(add_call_read_ops): Likewise.
(add_stmt_operand): Likewise.
(add_virtual_operand): Likewise.
(build_ssa_operands): Likewise.
Index: tree-ssa-operands.c
===================================================================
--- tree-ssa-operands.c (revision 111602)
+++ tree-ssa-operands.c (working copy)
@@ -74,10 +74,7 @@ Boston, MA 02110-1301, USA. */
i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new operand
vector for VUSE, then the new vector will also be modified such that
- it contains 'a_5' rather than 'a'.
-
-*/
-
+ it contains 'a_5' rather than 'a'. */
/* Flags to describe operand properties in helpers. */
@@ -103,7 +100,6 @@ Boston, MA 02110-1301, USA. */
to distinguish "reset the world" events from explicit MODIFY_EXPRs. */
#define opf_non_specific (1 << 3)
-
/* Array for building all the def operands. */
static VEC(tree,heap) *build_defs;
@@ -119,7 +115,6 @@ static VEC(tree,heap) *build_vuses;
/* Array for building all the v_must_def operands. */
static VEC(tree,heap) *build_v_must_defs;
-
/* These arrays are the cached operand vectors for call clobbered calls. */
static bool ops_active = false;
@@ -127,23 +122,7 @@ static GTY (()) struct ssa_operand_memor
static unsigned operand_memory_index;
static void get_expr_operands (tree, tree *, int);
-static void get_asm_expr_operands (tree);
-static void get_indirect_ref_operands (tree, tree, int, tree, HOST_WIDE_INT,
- HOST_WIDE_INT, bool);
-static void get_tmr_operands (tree, tree, int);
-static void get_call_expr_operands (tree, tree);
-static inline void append_def (tree *);
-static inline void append_use (tree *);
-static void append_v_may_def (tree);
-static void append_v_must_def (tree);
-static void add_call_clobber_ops (tree, tree);
-static void add_call_read_ops (tree, tree);
-static void add_stmt_operand (tree *, stmt_ann_t, int);
-static void add_virtual_operand (tree, stmt_ann_t, int, tree,
- HOST_WIDE_INT, HOST_WIDE_INT,
- bool);
-static void build_ssa_operands (tree stmt);
-
+
static def_optype_p free_defs = NULL;
static use_optype_p free_uses = NULL;
static vuse_optype_p free_vuses = NULL;
@@ -162,6 +141,7 @@ get_name_decl (tree t)
return DECL_UID (SSA_NAME_VAR (t));
}
+
/* Comparison function for qsort used in operand_build_sort_virtual. */
static int
@@ -181,6 +161,7 @@ operand_build_cmp (const void *p, const
return (u1 > u2 ? 1 : -1);
}
+
/* Sort the virtual operands in LIST from lowest DECL_UID to highest. */
static inline void
@@ -209,7 +190,6 @@ operand_build_sort_virtual (VEC(tree,hea
}
-
/* Return true if the ssa operands cache is active. */
bool
@@ -218,8 +198,10 @@ ssa_operands_active (void)
return ops_active;
}
+
/* Structure storing statistics on how many call clobbers we have, and
how many where avoided. */
+
static struct
{
/* Number of call-clobbered ops we attempt to add to calls in
@@ -246,6 +228,7 @@ static struct
unsigned int static_readonly_clobbers_avoided;
} clobber_stats;
+
/* Initialize the operand cache routines. */
void
@@ -291,12 +274,18 @@ fini_ssa_operands (void)
if (dump_file && (dump_flags & TDF_STATS))
{
- fprintf (dump_file, "Original clobbered vars:%d\n", clobber_stats.clobbered_vars);
- fprintf (dump_file, "Static write clobbers avoided:%d\n", clobber_stats.static_write_clobbers_avoided);
- fprintf (dump_file, "Static read clobbers avoided:%d\n", clobber_stats.static_read_clobbers_avoided);
- fprintf (dump_file, "Unescapable clobbers avoided:%d\n", clobber_stats.unescapable_clobbers_avoided);
- fprintf (dump_file, "Original readonly clobbers:%d\n", clobber_stats.readonly_clobbers);
- fprintf (dump_file, "Static readonly clobbers avoided:%d\n", clobber_stats.static_readonly_clobbers_avoided);
+ fprintf (dump_file, "Original clobbered vars:%d\n",
+ clobber_stats.clobbered_vars);
+ fprintf (dump_file, "Static write clobbers avoided:%d\n",
+ clobber_stats.static_write_clobbers_avoided);
+ fprintf (dump_file, "Static read clobbers avoided:%d\n",
+ clobber_stats.static_read_clobbers_avoided);
+ fprintf (dump_file, "Unescapable clobbers avoided:%d\n",
+ clobber_stats.unescapable_clobbers_avoided);
+ fprintf (dump_file, "Original readonly clobbers:%d\n",
+ clobber_stats.readonly_clobbers);
+ fprintf (dump_file, "Static readonly clobbers avoided:%d\n",
+ clobber_stats.static_readonly_clobbers_avoided);
}
}
@@ -352,7 +341,8 @@ correct_use_link (use_operand_p ptr, tre
if (root == *(ptr->use))
return;
}
- /* Its in the wrong list if we reach here. */
+
+ /* It is in the wrong list if we reach here. */
delink_imm_use (ptr);
link_imm_use (ptr, *(ptr->use));
}
@@ -362,6 +352,7 @@ correct_use_link (use_operand_p ptr, tre
sure the stmt pointer is set to the current stmt. Virtual uses do not need
the overhead of correct_use_link since they cannot be directly manipulated
like a real use can be. (They don't exist in the TREE_OPERAND nodes.) */
+
static inline void
set_virtual_use_link (use_operand_p ptr, tree stmt)
{
@@ -375,7 +366,6 @@ set_virtual_use_link (use_operand_p ptr,
}
-
#define FINALIZE_OPBUILD build_defs
#define FINALIZE_OPBUILD_BASE(I) (tree *)VEC_index (tree, \
build_defs, (I))
@@ -400,12 +390,12 @@ static void
finalize_ssa_defs (tree stmt)
{
unsigned int num = VEC_length (tree, build_defs);
+
/* There should only be a single real definition per assignment. */
gcc_assert ((stmt && TREE_CODE (stmt) != MODIFY_EXPR) || num <= 1);
/* If there is an old list, often the new list is identical, or close, so
find the elements at the beginning that are the same as the vector. */
-
finalize_ssa_def_ops (stmt);
VEC_truncate (tree, build_defs, 0);
}
@@ -630,7 +620,6 @@ finalize_ssa_v_must_defs (tree stmt)
all must-defs in a statement belong to subvars if there is more than one
MUST-def, so we don't do it. Suffice to say, if you reach here without
having subvars, and have num >1, you have hit a bug. */
-
finalize_ssa_v_must_def_ops (stmt);
VEC_truncate (tree, build_v_must_defs, 0);
}
@@ -735,319 +724,740 @@ append_v_must_def (tree var)
}
-/* Parse STMT looking for operands. OLD_OPS is the original stmt operand
- cache for STMT, if it existed before. When finished, the various build_*
- operand vectors will have potential operands. in them. */
-
-static void
-parse_ssa_operands (tree stmt)
-{
- enum tree_code code;
+/* REF is a tree that contains the entire pointer dereference
+ expression, if available, or NULL otherwise. ALIAS is the variable
+ we are asking if REF can access. OFFSET and SIZE come from the
+ memory access expression that generated this virtual operand.
+ FOR_CLOBBER is true is this is adding a virtual operand for a call
+ clobber. */
- code = TREE_CODE (stmt);
- switch (code)
+static bool
+access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset,
+ HOST_WIDE_INT size)
+{
+ bool offsetgtz = offset > 0;
+ unsigned HOST_WIDE_INT uoffset = (unsigned HOST_WIDE_INT) offset;
+ tree base = ref ? get_base_address (ref) : NULL;
+
+ /* If ALIAS is an SFT, it can't be touched if the offset
+ and size of the access is not overlapping with the SFT offset and
+ size. This is only true if we are accessing through a pointer
+ to a type that is the same as SFT_PARENT_VAR. Otherwise, we may
+ be accessing through a pointer to some substruct of the
+ structure, and if we try to prune there, we will have the wrong
+ offset, and get the wrong answer.
+ i.e., we can't prune without more work if we have something like
+
+ struct gcc_target
+ {
+ struct asm_out
+ {
+ const char *byte_op;
+ struct asm_int_op
+ {
+ const char *hi;
+ } aligned_op;
+ } asm_out;
+ } targetm;
+
+ foo = &targetm.asm_out.aligned_op;
+ return foo->hi;
+
+ SFT.1, which represents hi, will have SFT_OFFSET=32 because in
+ terms of SFT_PARENT_VAR, that is where it is.
+ However, the access through the foo pointer will be at offset 0. */
+ if (size != -1
+ && TREE_CODE (alias) == STRUCT_FIELD_TAG
+ && base
+ && TREE_TYPE (base) == TREE_TYPE (SFT_PARENT_VAR (alias))
+ && !overlap_subvar (offset, size, alias, NULL))
{
- case MODIFY_EXPR:
- /* First get operands from the RHS. For the LHS, we use a V_MAY_DEF if
- either only part of LHS is modified or if the RHS might throw,
- otherwise, use V_MUST_DEF.
+#ifdef ACCESS_DEBUGGING
+ fprintf (stderr, "Access to ");
+ print_generic_expr (stderr, ref, 0);
+ fprintf (stderr, " may not touch ");
+ print_generic_expr (stderr, alias, 0);
+ fprintf (stderr, " in function %s\n", get_name (current_function_decl));
+#endif
+ return false;
+ }
- ??? If it might throw, we should represent somehow that it is killed
- on the fallthrough path. */
- {
- tree lhs = TREE_OPERAND (stmt, 0);
- int lhs_flags = opf_is_def;
+ /* Without strict aliasing, it is impossible for a component access
+ through a pointer to touch a random variable, unless that
+ variable *is* a structure or a pointer.
- get_expr_operands (stmt, &TREE_OPERAND (stmt, 1), opf_none);
+ That is, given p->c, and some random global variable b,
+ there is no legal way that p->c could be an access to b.
+
+ Without strict aliasing on, we consider it legal to do something
+ like:
- /* If the LHS is a VIEW_CONVERT_EXPR, it isn't changing whether
- or not the entire LHS is modified; that depends on what's
- inside the VIEW_CONVERT_EXPR. */
- if (TREE_CODE (lhs) == VIEW_CONVERT_EXPR)
- lhs = TREE_OPERAND (lhs, 0);
+ struct foos { int l; };
+ int foo;
+ static struct foos *getfoo(void);
+ int main (void)
+ {
+ struct foos *f = getfoo();
+ f->l = 1;
+ foo = 2;
+ if (f->l == 1)
+ abort();
+ exit(0);
+ }
+ static struct foos *getfoo(void)
+ { return (struct foos *)&foo; }
+
+ (taken from 20000623-1.c)
+ */
+ else if (ref
+ && flag_strict_aliasing
+ && TREE_CODE (ref) != INDIRECT_REF
+ && !MTAG_P (alias)
+ && !AGGREGATE_TYPE_P (TREE_TYPE (alias))
+ && TREE_CODE (TREE_TYPE (alias)) != COMPLEX_TYPE
+ && !POINTER_TYPE_P (TREE_TYPE (alias)))
+ {
+#ifdef ACCESS_DEBUGGING
+ fprintf (stderr, "Access to ");
+ print_generic_expr (stderr, ref, 0);
+ fprintf (stderr, " may not touch ");
+ print_generic_expr (stderr, alias, 0);
+ fprintf (stderr, " in function %s\n", get_name (current_function_decl));
+#endif
+ return false;
+ }
- if (TREE_CODE (lhs) != ARRAY_RANGE_REF
- && TREE_CODE (lhs) != BIT_FIELD_REF)
- lhs_flags |= opf_kill_def;
+ /* If the offset of the access is greater than the size of one of
+ the possible aliases, it can't be touching that alias, because it
+ would be past the end of the structure. */
+ else if (ref
+ && flag_strict_aliasing
+ && TREE_CODE (ref) != INDIRECT_REF
+ && !MTAG_P (alias)
+ && !POINTER_TYPE_P (TREE_TYPE (alias))
+ && offsetgtz
+ && DECL_SIZE (alias)
+ && TREE_CODE (DECL_SIZE (alias)) == INTEGER_CST
+ && uoffset > TREE_INT_CST_LOW (DECL_SIZE (alias)))
+ {
+#ifdef ACCESS_DEBUGGING
+ fprintf (stderr, "Access to ");
+ print_generic_expr (stderr, ref, 0);
+ fprintf (stderr, " may not touch ");
+ print_generic_expr (stderr, alias, 0);
+ fprintf (stderr, " in function %s\n", get_name (current_function_decl));
+#endif
+ return false;
+ }
- get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), lhs_flags);
- }
- break;
+ return true;
+}
- case COND_EXPR:
- get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_none);
- break;
- case SWITCH_EXPR:
- get_expr_operands (stmt, &SWITCH_COND (stmt), opf_none);
- break;
+/* Add VAR to the virtual operands array. FLAGS is as in
+ get_expr_operands. FULL_REF is a tree that contains the entire
+ pointer dereference expression, if available, or NULL otherwise.
+ OFFSET and SIZE come from the memory access expression that
+ generated this virtual operand. FOR_CLOBBER is true is this is
+ adding a virtual operand for a call clobber. */
- case ASM_EXPR:
- get_asm_expr_operands (stmt);
- break;
+static void
+add_virtual_operand (tree var, stmt_ann_t s_ann, int flags,
+ tree full_ref, HOST_WIDE_INT offset,
+ HOST_WIDE_INT size, bool for_clobber)
+{
+ VEC(tree,gc) *aliases;
+ tree sym;
+ var_ann_t v_ann;
+
+ sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
+ v_ann = var_ann (sym);
+
+ /* Mark statements with volatile operands. Optimizers should back
+ off from statements having volatile operands. */
+ if (TREE_THIS_VOLATILE (sym) && s_ann)
+ s_ann->has_volatile_ops = true;
- case RETURN_EXPR:
- get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), opf_none);
- break;
+ /* If the variable cannot be modified and this is a V_MAY_DEF change
+ it into a VUSE. This happens when read-only variables are marked
+ call-clobbered and/or aliased to writable variables. So we only
+ check that this only happens on non-specific stores.
- case GOTO_EXPR:
- get_expr_operands (stmt, &GOTO_DESTINATION (stmt), opf_none);
- break;
+ Note that if this is a specific store, i.e. associated with a
+ modify_expr, then we can't suppress the V_MAY_DEF, lest we run
+ into validation problems.
- case LABEL_EXPR:
- get_expr_operands (stmt, &LABEL_EXPR_LABEL (stmt), opf_none);
- break;
+ This can happen when programs cast away const, leaving us with a
+ store to read-only memory. If the statement is actually executed
+ at runtime, then the program is ill formed. If the statement is
+ not executed then all is well. At the very least, we cannot ICE. */
+ if ((flags & opf_non_specific) && unmodifiable_var_p (var))
+ flags &= ~(opf_is_def | opf_kill_def);
+
+ /* The variable is not a GIMPLE register. Add it (or its aliases) to
+ virtual operands, unless the caller has specifically requested
+ not to add virtual operands (used when adding operands inside an
+ ADDR_EXPR expression). */
+ if (flags & opf_no_vops)
+ return;
+
+ aliases = v_ann->may_aliases;
+ if (aliases == NULL)
+ {
+ /* The variable is not aliased or it is an alias tag. */
+ if (flags & opf_is_def)
+ {
+ if (flags & opf_kill_def)
+ {
+ /* V_MUST_DEF for non-aliased, non-GIMPLE register
+ variable definitions. */
+ gcc_assert (!MTAG_P (var)
+ || TREE_CODE (var) == STRUCT_FIELD_TAG);
+ append_v_must_def (var);
+ }
+ else
+ {
+ /* Add a V_MAY_DEF for call-clobbered variables and
+ memory tags. */
+ append_v_may_def (var);
+ }
+ }
+ else
+ append_vuse (var);
+ }
+ else
+ {
+ unsigned i;
+ tree al;
+
+ /* The variable is aliased. Add its aliases to the virtual
+ operands. */
+ gcc_assert (VEC_length (tree, aliases) != 0);
+
+ if (flags & opf_is_def)
+ {
+
+ bool none_added = true;
- /* These nodes contain no variable references. */
- case BIND_EXPR:
- case CASE_LABEL_EXPR:
- case TRY_CATCH_EXPR:
- case TRY_FINALLY_EXPR:
- case EH_FILTER_EXPR:
- case CATCH_EXPR:
- case RESX_EXPR:
- break;
+ for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
+ {
+ if (!access_can_touch_variable (full_ref, al, offset, size))
+ continue;
+
+ none_added = false;
+ append_v_may_def (al);
+ }
- default:
- /* Notice that if get_expr_operands tries to use &STMT as the operand
- pointer (which may only happen for USE operands), we will fail in
- append_use. This default will handle statements like empty
- statements, or CALL_EXPRs that may appear on the RHS of a statement
- or as statements themselves. */
- get_expr_operands (stmt, &stmt, opf_none);
- break;
+ /* If the variable is also an alias tag, add a virtual
+ operand for it, otherwise we will miss representing
+ references to the members of the variable's alias set.
+ This fixes the bug in gcc.c-torture/execute/20020503-1.c.
+
+ It is also necessary to add bare defs on clobbers for
+ TMT's, so that bare TMT uses caused by pruning all the
+ aliases will link up properly with calls. In order to
+ keep the number of these bare defs we add down to the
+ minimum necessary, we keep track of which TMT's were used
+ alone in statement defs or vuses. */
+ if (v_ann->is_aliased
+ || none_added
+ || (TREE_CODE (var) == TYPE_MEMORY_TAG && for_clobber
+ && TMT_USED_ALONE (var)))
+ {
+ /* Every bare tmt def we add should have TMT_USED_ALONE
+ set on it, or else we will get the wrong answer on
+ clobbers. */
+
+ if (none_added && !updating_used_alone && aliases_computed_p
+ && TREE_CODE (var) == TYPE_MEMORY_TAG)
+ gcc_assert (TMT_USED_ALONE (var));
+
+ append_v_may_def (var);
+ }
+ }
+ else
+ {
+ bool none_added = true;
+ for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
+ {
+ if (!access_can_touch_variable (full_ref, al, offset, size))
+ continue;
+ none_added = false;
+ append_vuse (al);
+ }
+
+ /* Similarly, append a virtual uses for VAR itself, when
+ it is an alias tag. */
+ if (v_ann->is_aliased || none_added)
+ append_vuse (var);
+ }
}
}
-/* Create an operands cache for STMT. */
+
+/* Add *VAR_P to the appropriate operand array for S_ANN. FLAGS is as in
+ get_expr_operands. If *VAR_P is a GIMPLE register, it will be added to
+ the statement's real operands, otherwise it is added to virtual
+ operands. */
static void
-build_ssa_operands (tree stmt)
+add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags)
{
- stmt_ann_t ann = get_stmt_ann (stmt);
-
- /* Initially assume that the statement has no volatile operands. */
- if (ann)
- ann->has_volatile_ops = false;
+ bool is_real_op;
+ tree var, sym;
+ var_ann_t v_ann;
- start_ssa_stmt_operands ();
+ var = *var_p;
+ gcc_assert (SSA_VAR_P (var));
- parse_ssa_operands (stmt);
- operand_build_sort_virtual (build_vuses);
- operand_build_sort_virtual (build_v_may_defs);
- operand_build_sort_virtual (build_v_must_defs);
+ is_real_op = is_gimple_reg (var);
- finalize_ssa_stmt_operands (stmt);
-}
+ /* If this is a real operand, the operand is either an SSA name or a
+ decl. Virtual operands may only be decls. */
+ gcc_assert (is_real_op || DECL_P (var));
+ sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
+ v_ann = var_ann (sym);
-/* Free any operands vectors in OPS. */
-void
-free_ssa_operands (stmt_operands_p ops)
-{
- ops->def_ops = NULL;
- ops->use_ops = NULL;
- ops->maydef_ops = NULL;
- ops->mustdef_ops = NULL;
- ops->vuse_ops = NULL;
+ /* Mark statements with volatile operands. Optimizers should back
+ off from statements having volatile operands. */
+ if (TREE_THIS_VOLATILE (sym) && s_ann)
+ s_ann->has_volatile_ops = true;
+
+ if (is_real_op)
+ {
+ /* The variable is a GIMPLE register. Add it to real operands. */
+ if (flags & opf_is_def)
+ append_def (var_p);
+ else
+ append_use (var_p);
+ }
+ else
+ add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1, false);
}
-/* Get the operands of statement STMT. Note that repeated calls to
- get_stmt_operands for the same statement will do nothing until the
- statement is marked modified by a call to mark_stmt_modified(). */
+/* A subroutine of get_expr_operands to handle INDIRECT_REF,
+ ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF.
-void
-update_stmt_operands (tree stmt)
+ STMT is the statement being processed, EXPR is the INDIRECT_REF
+ that got us here.
+
+ FLAGS is as in get_expr_operands.
+
+ FULL_REF contains the full pointer dereference expression, if we
+ have it, or NULL otherwise.
+
+ OFFSET and SIZE are the location of the access inside the
+ dereferenced pointer, if known.
+
+ RECURSE_ON_BASE should be set to true if we want to continue
+ calling get_expr_operands on the base pointer, and false if
+ something else will do it for us. */
+
+static void
+get_indirect_ref_operands (tree stmt, tree expr, int flags,
+ tree full_ref,
+ HOST_WIDE_INT offset, HOST_WIDE_INT size,
+ bool recurse_on_base)
{
- stmt_ann_t ann = get_stmt_ann (stmt);
- /* If get_stmt_operands is called before SSA is initialized, dont
- do anything. */
- if (!ssa_operands_active ())
- return;
- /* The optimizers cannot handle statements that are nothing but a
- _DECL. This indicates a bug in the gimplifier. */
- gcc_assert (!SSA_VAR_P (stmt));
+ tree *pptr = &TREE_OPERAND (expr, 0);
+ tree ptr = *pptr;
+ stmt_ann_t s_ann = stmt_ann (stmt);
- gcc_assert (ann->modified);
+ /* Stores into INDIRECT_REF operands are never killing definitions. */
+ flags &= ~opf_kill_def;
- timevar_push (TV_TREE_OPS);
+ if (SSA_VAR_P (ptr))
+ {
+ struct ptr_info_def *pi = NULL;
- build_ssa_operands (stmt);
+ /* If PTR has flow-sensitive points-to information, use it. */
+ if (TREE_CODE (ptr) == SSA_NAME
+ && (pi = SSA_NAME_PTR_INFO (ptr)) != NULL
+ && pi->name_mem_tag)
+ {
+ /* PTR has its own memory tag. Use it. */
+ add_virtual_operand (pi->name_mem_tag, s_ann, flags,
+ full_ref, offset, size, false);
+ }
+ else
+ {
+ /* If PTR is not an SSA_NAME or it doesn't have a name
+ tag, use its type memory tag. */
+ var_ann_t v_ann;
- /* Clear the modified bit for STMT. Subsequent calls to
- get_stmt_operands for this statement will do nothing until the
- statement is marked modified by a call to mark_stmt_modified(). */
- ann->modified = 0;
+ /* If we are emitting debugging dumps, display a warning if
+ PTR is an SSA_NAME with no flow-sensitive alias
+ information. That means that we may need to compute
+ aliasing again. */
+ if (dump_file
+ && TREE_CODE (ptr) == SSA_NAME
+ && pi == NULL)
+ {
+ fprintf (dump_file,
+ "NOTE: no flow-sensitive alias info for ");
+ print_generic_expr (dump_file, ptr, dump_flags);
+ fprintf (dump_file, " in ");
+ print_generic_stmt (dump_file, stmt, dump_flags);
+ }
- timevar_pop (TV_TREE_OPS);
-}
+ if (TREE_CODE (ptr) == SSA_NAME)
+ ptr = SSA_NAME_VAR (ptr);
+ v_ann = var_ann (ptr);
-
-/* Copies virtual operands from SRC to DST. */
+ if (v_ann->type_mem_tag)
+ add_virtual_operand (v_ann->type_mem_tag, s_ann, flags,
+ full_ref, offset, size, false);
+ }
+ }
+ else if (TREE_CODE (ptr) == INTEGER_CST)
+ {
+ /* If a constant is used as a pointer, we can't generate a real
+ operand for it but we mark the statement volatile to prevent
+ optimizations from messing things up. */
+ if (s_ann)
+ s_ann->has_volatile_ops = true;
+ return;
+ }
+ else
+ {
+ /* Ok, this isn't even is_gimple_min_invariant. Something's broke. */
+ gcc_unreachable ();
+ }
-void
-copy_virtual_operands (tree dest, tree src)
-{
- tree t;
- ssa_op_iter iter, old_iter;
- use_operand_p use_p, u2;
- def_operand_p def_p, d2;
+ /* If requested, add a USE operand for the base pointer. */
+ if (recurse_on_base)
+ get_expr_operands (stmt, pptr, opf_none);
+}
- build_ssa_operands (dest);
- /* Copy all the virtual fields. */
- FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VUSE)
- append_vuse (t);
- FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMAYDEF)
- append_v_may_def (t);
- FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMUSTDEF)
- append_v_must_def (t);
+/* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */
- if (VEC_length (tree, build_vuses) == 0
- && VEC_length (tree, build_v_may_defs) == 0
- && VEC_length (tree, build_v_must_defs) == 0)
- return;
+static void
+get_tmr_operands (tree stmt, tree expr, int flags)
+{
+ tree tag = TMR_TAG (expr), ref;
+ HOST_WIDE_INT offset, size, maxsize;
+ subvar_t svars, sv;
+ stmt_ann_t s_ann = stmt_ann (stmt);
- /* Now commit the virtual operands to this stmt. */
- finalize_ssa_v_must_defs (dest);
- finalize_ssa_v_may_defs (dest);
- finalize_ssa_vuses (dest);
+ /* First record the real operands. */
+ get_expr_operands (stmt, &TMR_BASE (expr), opf_none);
+ get_expr_operands (stmt, &TMR_INDEX (expr), opf_none);
- /* Finally, set the field to the same values as then originals. */
+ /* MEM_REFs should never be killing. */
+ flags &= ~opf_kill_def;
-
- t = op_iter_init_tree (&old_iter, src, SSA_OP_VUSE);
- FOR_EACH_SSA_USE_OPERAND (use_p, dest, iter, SSA_OP_VUSE)
+ if (TMR_SYMBOL (expr))
{
- gcc_assert (!op_iter_done (&old_iter));
- SET_USE (use_p, t);
- t = op_iter_next_tree (&old_iter);
+ stmt_ann_t ann = stmt_ann (stmt);
+ add_to_addressable_set (TMR_SYMBOL (expr), &ann->addresses_taken);
}
- gcc_assert (op_iter_done (&old_iter));
- op_iter_init_maydef (&old_iter, src, &u2, &d2);
- FOR_EACH_SSA_MAYDEF_OPERAND (def_p, use_p, dest, iter)
+ if (!tag)
{
- gcc_assert (!op_iter_done (&old_iter));
- SET_USE (use_p, USE_FROM_PTR (u2));
- SET_DEF (def_p, DEF_FROM_PTR (d2));
- op_iter_next_maymustdef (&u2, &d2, &old_iter);
+ /* Something weird, so ensure that we will be careful. */
+ stmt_ann (stmt)->has_volatile_ops = true;
+ return;
}
- gcc_assert (op_iter_done (&old_iter));
- op_iter_init_mustdef (&old_iter, src, &u2, &d2);
- FOR_EACH_SSA_MUSTDEF_OPERAND (def_p, use_p, dest, iter)
+ if (DECL_P (tag))
{
- gcc_assert (!op_iter_done (&old_iter));
- SET_USE (use_p, USE_FROM_PTR (u2));
- SET_DEF (def_p, DEF_FROM_PTR (d2));
- op_iter_next_maymustdef (&u2, &d2, &old_iter);
+ get_expr_operands (stmt, &tag, flags);
+ return;
}
- gcc_assert (op_iter_done (&old_iter));
+ ref = get_ref_base_and_extent (tag, &offset, &size, &maxsize);
+ gcc_assert (ref != NULL_TREE);
+ svars = get_subvars_for_var (ref);
+ for (sv = svars; sv; sv = sv->next)
+ {
+ bool exact;
+ if (overlap_subvar (offset, maxsize, sv->var, &exact))
+ {
+ int subvar_flags = flags;
+ if (!exact || size != maxsize)
+ subvar_flags &= ~opf_kill_def;
+ add_stmt_operand (&sv->var, s_ann, subvar_flags);
+ }
+ }
}
-/* Specifically for use in DOM's expression analysis. Given a store, we
- create an artificial stmt which looks like a load from the store, this can
- be used to eliminate redundant loads. OLD_OPS are the operands from the
- store stmt, and NEW_STMT is the new load which represents a load of the
- values stored. */
+/* Add clobbering definitions for .GLOBAL_VAR or for each of the call
+ clobbered variables in the function. */
-void
-create_ssa_artficial_load_stmt (tree new_stmt, tree old_stmt)
+static void
+add_call_clobber_ops (tree stmt, tree callee)
{
- stmt_ann_t ann;
- tree op;
- ssa_op_iter iter;
- use_operand_p use_p;
- unsigned x;
-
- ann = get_stmt_ann (new_stmt);
+ unsigned u;
+ bitmap_iterator bi;
+ stmt_ann_t s_ann = stmt_ann (stmt);
+ bitmap not_read_b, not_written_b;
+
+ /* Functions that are not const, pure or never return may clobber
+ call-clobbered variables. */
+ if (s_ann)
+ s_ann->makes_clobbering_call = true;
- /* process the stmt looking for operands. */
- start_ssa_stmt_operands ();
- parse_ssa_operands (new_stmt);
+ /* If we created .GLOBAL_VAR earlier, just use it. See compute_may_aliases
+ for the heuristic used to decide whether to create .GLOBAL_VAR or not. */
+ if (global_var)
+ {
+ add_stmt_operand (&global_var, s_ann, opf_is_def);
+ return;
+ }
- for (x = 0; x < VEC_length (tree, build_vuses); x++)
+ /* Get info for local and module level statics. There is a bit
+ set for each static if the call being processed does not read
+ or write that variable. */
+ not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL;
+ not_written_b = callee ? ipa_reference_get_not_written_global (callee) : NULL;
+ /* Add a V_MAY_DEF operand for every call clobbered variable. */
+ EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
{
- tree t = VEC_index (tree, build_vuses, x);
- if (TREE_CODE (t) != SSA_NAME)
+ tree var = referenced_var_lookup (u);
+ unsigned int escape_mask = var_ann (var)->escape_mask;
+ tree real_var = var;
+ bool not_read;
+ bool not_written;
+
+ /* Not read and not written are computed on regular vars, not
+ subvars, so look at the parent var if this is an SFT. */
+ if (TREE_CODE (var) == STRUCT_FIELD_TAG)
+ real_var = SFT_PARENT_VAR (var);
+
+ not_read = not_read_b ? bitmap_bit_p (not_read_b,
+ DECL_UID (real_var)) : false;
+ not_written = not_written_b ? bitmap_bit_p (not_written_b,
+ DECL_UID (real_var)) : false;
+ gcc_assert (!unmodifiable_var_p (var));
+
+ clobber_stats.clobbered_vars++;
+
+ /* See if this variable is really clobbered by this function. */
+
+ /* Trivial case: Things escaping only to pure/const are not
+ clobbered by non-pure-const, and only read by pure/const. */
+ if ((escape_mask & ~(ESCAPE_TO_PURE_CONST)) == 0)
{
- var_ann_t ann = var_ann (t);
- ann->in_vuse_list = 0;
+ tree call = get_call_expr_in (stmt);
+ if (call_expr_flags (call) & (ECF_CONST | ECF_PURE))
+ {
+ add_stmt_operand (&var, s_ann, opf_none);
+ clobber_stats.unescapable_clobbers_avoided++;
+ continue;
+ }
+ else
+ {
+ clobber_stats.unescapable_clobbers_avoided++;
+ continue;
+ }
}
+
+ if (not_written)
+ {
+ clobber_stats.static_write_clobbers_avoided++;
+ if (!not_read)
+ add_stmt_operand (&var, s_ann, opf_none);
+ else
+ clobber_stats.static_read_clobbers_avoided++;
+ }
+ else
+ add_virtual_operand (var, s_ann, opf_is_def,
+ NULL, 0, -1, true);
}
-
- for (x = 0; x < VEC_length (tree, build_v_may_defs); x++)
+
+}
+
+
+/* Add VUSE operands for .GLOBAL_VAR or all call clobbered variables in the
+ function. */
+
+static void
+add_call_read_ops (tree stmt, tree callee)
+{
+ unsigned u;
+ bitmap_iterator bi;
+ stmt_ann_t s_ann = stmt_ann (stmt);
+ bitmap not_read_b;
+
+ /* if the function is not pure, it may reference memory. Add
+ a VUSE for .GLOBAL_VAR if it has been created. See add_referenced_var
+ for the heuristic used to decide whether to create .GLOBAL_VAR. */
+ if (global_var)
{
- tree t = VEC_index (tree, build_v_may_defs, x);
- if (TREE_CODE (t) != SSA_NAME)
+ add_stmt_operand (&global_var, s_ann, opf_none);
+ return;
+ }
+
+ not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL;
+
+ /* Add a VUSE for each call-clobbered variable. */
+ EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
+ {
+ tree var = referenced_var (u);
+ tree real_var = var;
+ bool not_read;
+
+ clobber_stats.readonly_clobbers++;
+
+ /* Not read and not written are computed on regular vars, not
+ subvars, so look at the parent var if this is an SFT. */
+
+ if (TREE_CODE (var) == STRUCT_FIELD_TAG)
+ real_var = SFT_PARENT_VAR (var);
+
+ not_read = not_read_b ? bitmap_bit_p (not_read_b,
+ DECL_UID (real_var)) : false;
+
+ if (not_read)
{
- var_ann_t ann = var_ann (t);
- ann->in_v_may_def_list = 0;
+ clobber_stats.static_readonly_clobbers_avoided++;
+ continue;
}
+
+ add_stmt_operand (&var, s_ann, opf_none | opf_non_specific);
}
- /* Remove any virtual operands that were found. */
- VEC_truncate (tree, build_v_may_defs, 0);
- VEC_truncate (tree, build_v_must_defs, 0);
- VEC_truncate (tree, build_vuses, 0);
+}
- /* For each VDEF on the original statement, we want to create a
- VUSE of the V_MAY_DEF result or V_MUST_DEF op on the new
- statement. */
- FOR_EACH_SSA_TREE_OPERAND (op, old_stmt, iter,
- (SSA_OP_VMAYDEF | SSA_OP_VMUSTDEF))
- append_vuse (op);
-
- /* Now build the operands for this new stmt. */
- finalize_ssa_stmt_operands (new_stmt);
- /* All uses in this fake stmt must not be in the immediate use lists. */
- FOR_EACH_SSA_USE_OPERAND (use_p, new_stmt, iter, SSA_OP_ALL_USES)
- delink_imm_use (use_p);
+/* A subroutine of get_expr_operands to handle CALL_EXPR. */
+
+static void
+get_call_expr_operands (tree stmt, tree expr)
+{
+ tree op;
+ int call_flags = call_expr_flags (expr);
+
+ /* If aliases have been computed already, add V_MAY_DEF or V_USE
+ operands for all the symbols that have been found to be
+ call-clobbered.
+
+ Note that if aliases have not been computed, the global effects
+ of calls will not be included in the SSA web. This is fine
+ because no optimizer should run before aliases have been
+ computed. By not bothering with virtual operands for CALL_EXPRs
+ we avoid adding superfluous virtual operands, which can be a
+ significant compile time sink (See PR 15855). */
+ if (aliases_computed_p
+ && !bitmap_empty_p (call_clobbered_vars)
+ && !(call_flags & ECF_NOVOPS))
+ {
+ /* A 'pure' or a 'const' function never call-clobbers anything.
+ A 'noreturn' function might, but since we don't return anyway
+ there is no point in recording that. */
+ if (TREE_SIDE_EFFECTS (expr)
+ && !(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN)))
+ add_call_clobber_ops (stmt, get_callee_fndecl (expr));
+ else if (!(call_flags & ECF_CONST))
+ add_call_read_ops (stmt, get_callee_fndecl (expr));
+ }
+
+ /* Find uses in the called function. */
+ get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none);
+
+ for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op))
+ get_expr_operands (stmt, &TREE_VALUE (op), opf_none);
+
+ get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
}
-void
-swap_tree_operands (tree stmt, tree *exp0, tree *exp1)
+
+/* Scan operands in the ASM_EXPR stmt referred to in INFO. */
+
+static void
+get_asm_expr_operands (tree stmt)
{
- tree op0, op1;
- op0 = *exp0;
- op1 = *exp1;
+ stmt_ann_t s_ann = stmt_ann (stmt);
+ int noutputs = list_length (ASM_OUTPUTS (stmt));
+ const char **oconstraints
+ = (const char **) alloca ((noutputs) * sizeof (const char *));
+ int i;
+ tree link;
+ const char *constraint;
+ bool allows_mem, allows_reg, is_inout;
- /* If the operand cache is active, attempt to preserve the relative positions
- of these two operands in their respective immediate use lists. */
- if (ssa_operands_active () && op0 != op1)
+ for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link))
{
- use_optype_p use0, use1, ptr;
- use0 = use1 = NULL;
- /* Find the 2 operands in the cache, if they are there. */
- for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
- if (USE_OP_PTR (ptr)->use == exp0)
- {
- use0 = ptr;
- break;
- }
- for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
- if (USE_OP_PTR (ptr)->use == exp1)
- {
- use1 = ptr;
- break;
- }
- /* If both uses don't have operand entries, there isn't much we can do
- at this point. Presumably we dont need to worry about it. */
- if (use0 && use1)
- {
- tree *tmp = USE_OP_PTR (use1)->use;
- USE_OP_PTR (use1)->use = USE_OP_PTR (use0)->use;
- USE_OP_PTR (use0)->use = tmp;
+ oconstraints[i] = constraint
+ = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
+ parse_output_constraint (&constraint, i, 0, 0,
+ &allows_mem, &allows_reg, &is_inout);
+
+ /* This should have been split in gimplify_asm_expr. */
+ gcc_assert (!allows_reg || !is_inout);
+
+ /* Memory operands are addressable. Note that STMT needs the
+ address of this operand. */
+ if (!allows_reg && allows_mem)
+ {
+ tree t = get_base_address (TREE_VALUE (link));
+ if (t && DECL_P (t) && s_ann)
+ add_to_addressable_set (t, &s_ann->addresses_taken);
}
+
+ get_expr_operands (stmt, &TREE_VALUE (link), opf_is_def);
}
- /* Now swap the data. */
- *exp0 = op1;
- *exp1 = op0;
+ for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
+ {
+ constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
+ parse_input_constraint (&constraint, 0, 0, noutputs, 0,
+ oconstraints, &allows_mem, &allows_reg);
+
+ /* Memory operands are addressable. Note that STMT needs the
+ address of this operand. */
+ if (!allows_reg && allows_mem)
+ {
+ tree t = get_base_address (TREE_VALUE (link));
+ if (t && DECL_P (t) && s_ann)
+ add_to_addressable_set (t, &s_ann->addresses_taken);
+ }
+
+ get_expr_operands (stmt, &TREE_VALUE (link), 0);
+ }
+
+
+ /* Clobber memory for asm ("" : : : "memory"); */
+ for (link = ASM_CLOBBERS (stmt); link; link = TREE_CHAIN (link))
+ if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
+ {
+ unsigned i;
+ bitmap_iterator bi;
+
+ /* Clobber all call-clobbered variables (or .GLOBAL_VAR if we
+ decided to group them). */
+ if (global_var)
+ add_stmt_operand (&global_var, s_ann, opf_is_def);
+ else
+ EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi)
+ {
+ tree var = referenced_var (i);
+ add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
+ }
+
+ /* Now clobber all addressables. */
+ EXECUTE_IF_SET_IN_BITMAP (addressable_vars, 0, i, bi)
+ {
+ tree var = referenced_var (i);
+
+ /* Subvars are explicitly represented in this list, so
+ we don't need the original to be added to the clobber
+ ops, but the original *will* be in this list because
+ we keep the addressability of the original
+ variable up-to-date so we don't screw up the rest of
+ the backend. */
+ if (var_can_have_subvars (var)
+ && get_subvars_for_var (var) != NULL)
+ continue;
+
+ add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
+ }
+
+ break;
+ }
}
@@ -1326,608 +1736,335 @@ get_expr_operands (tree stmt, tree *expr
fprintf (stderr, "unhandled expression in get_expr_operands():\n");
debug_tree (expr);
fputs ("\n", stderr);
- internal_error ("internal error");
#endif
gcc_unreachable ();
}
-/* Scan operands in the ASM_EXPR stmt referred to in INFO. */
-
+/* Parse STMT looking for operands. OLD_OPS is the original stmt operand
+ cache for STMT, if it existed before. When finished, the various build_*
+ operand vectors will have potential operands. in them. */
+
static void
-get_asm_expr_operands (tree stmt)
+parse_ssa_operands (tree stmt)
{
- stmt_ann_t s_ann = stmt_ann (stmt);
- int noutputs = list_length (ASM_OUTPUTS (stmt));
- const char **oconstraints
- = (const char **) alloca ((noutputs) * sizeof (const char *));
- int i;
- tree link;
- const char *constraint;
- bool allows_mem, allows_reg, is_inout;
+ enum tree_code code;
- for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link))
+ code = TREE_CODE (stmt);
+ switch (code)
{
- oconstraints[i] = constraint
- = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
- parse_output_constraint (&constraint, i, 0, 0,
- &allows_mem, &allows_reg, &is_inout);
+ case MODIFY_EXPR:
+ /* First get operands from the RHS. For the LHS, we use a V_MAY_DEF if
+ either only part of LHS is modified or if the RHS might throw,
+ otherwise, use V_MUST_DEF.
- /* This should have been split in gimplify_asm_expr. */
- gcc_assert (!allows_reg || !is_inout);
+ ??? If it might throw, we should represent somehow that it is killed
+ on the fallthrough path. */
+ {
+ tree lhs = TREE_OPERAND (stmt, 0);
+ int lhs_flags = opf_is_def;
- /* Memory operands are addressable. Note that STMT needs the
- address of this operand. */
- if (!allows_reg && allows_mem)
- {
- tree t = get_base_address (TREE_VALUE (link));
- if (t && DECL_P (t) && s_ann)
- add_to_addressable_set (t, &s_ann->addresses_taken);
- }
+ get_expr_operands (stmt, &TREE_OPERAND (stmt, 1), opf_none);
- get_expr_operands (stmt, &TREE_VALUE (link), opf_is_def);
- }
+ /* If the LHS is a VIEW_CONVERT_EXPR, it isn't changing whether
+ or not the entire LHS is modified; that depends on what's
+ inside the VIEW_CONVERT_EXPR. */
+ if (TREE_CODE (lhs) == VIEW_CONVERT_EXPR)
+ lhs = TREE_OPERAND (lhs, 0);
- for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
- {
- constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
- parse_input_constraint (&constraint, 0, 0, noutputs, 0,
- oconstraints, &allows_mem, &allows_reg);
+ if (TREE_CODE (lhs) != ARRAY_RANGE_REF
+ && TREE_CODE (lhs) != BIT_FIELD_REF)
+ lhs_flags |= opf_kill_def;
- /* Memory operands are addressable. Note that STMT needs the
- address of this operand. */
- if (!allows_reg && allows_mem)
- {
- tree t = get_base_address (TREE_VALUE (link));
- if (t && DECL_P (t) && s_ann)
- add_to_addressable_set (t, &s_ann->addresses_taken);
- }
+ get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), lhs_flags);
+ }
+ break;
- get_expr_operands (stmt, &TREE_VALUE (link), 0);
- }
+ case COND_EXPR:
+ get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_none);
+ break;
+ case SWITCH_EXPR:
+ get_expr_operands (stmt, &SWITCH_COND (stmt), opf_none);
+ break;
- /* Clobber memory for asm ("" : : : "memory"); */
- for (link = ASM_CLOBBERS (stmt); link; link = TREE_CHAIN (link))
- if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
- {
- unsigned i;
- bitmap_iterator bi;
+ case ASM_EXPR:
+ get_asm_expr_operands (stmt);
+ break;
- /* Clobber all call-clobbered variables (or .GLOBAL_VAR if we
- decided to group them). */
- if (global_var)
- add_stmt_operand (&global_var, s_ann, opf_is_def);
- else
- EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi)
- {
- tree var = referenced_var (i);
- add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
- }
+ case RETURN_EXPR:
+ get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), opf_none);
+ break;
- /* Now clobber all addressables. */
- EXECUTE_IF_SET_IN_BITMAP (addressable_vars, 0, i, bi)
- {
- tree var = referenced_var (i);
+ case GOTO_EXPR:
+ get_expr_operands (stmt, &GOTO_DESTINATION (stmt), opf_none);
+ break;
- /* Subvars are explicitly represented in this list, so
- we don't need the original to be added to the clobber
- ops, but the original *will* be in this list because
- we keep the addressability of the original
- variable up-to-date so we don't screw up the rest of
- the backend. */
- if (var_can_have_subvars (var)
- && get_subvars_for_var (var) != NULL)
- continue;
+ case LABEL_EXPR:
+ get_expr_operands (stmt, &LABEL_EXPR_LABEL (stmt), opf_none);
+ break;
- add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific);
- }
+ /* These nodes contain no variable references. */
+ case BIND_EXPR:
+ case CASE_LABEL_EXPR:
+ case TRY_CATCH_EXPR:
+ case TRY_FINALLY_EXPR:
+ case EH_FILTER_EXPR:
+ case CATCH_EXPR:
+ case RESX_EXPR:
+ break;
- break;
- }
+ default:
+ /* Notice that if get_expr_operands tries to use &STMT as the operand
+ pointer (which may only happen for USE operands), we will fail in
+ append_use. This default will handle statements like empty
+ statements, or CALL_EXPRs that may appear on the RHS of a statement
+ or as statements themselves. */
+ get_expr_operands (stmt, &stmt, opf_none);
+ break;
+ }
}
-/* A subroutine of get_expr_operands to handle INDIRECT_REF,
- ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF.
- STMT is the statement being processed, EXPR is the INDIRECT_REF
- that got us here.
-
- FLAGS is as in get_expr_operands.
-
- FULL_REF contains the full pointer dereference expression, if we
- have it, or NULL otherwise.
-
- OFFSET and SIZE are the location of the access inside the
- dereferenced pointer, if known.
-
- RECURSE_ON_BASE should be set to true if we want to continue
- calling get_expr_operands on the base pointer, and false if
- something else will do it for us. */
+/* Create an operands cache for STMT. */
static void
-get_indirect_ref_operands (tree stmt, tree expr, int flags,
- tree full_ref,
- HOST_WIDE_INT offset, HOST_WIDE_INT size,
- bool recurse_on_base)
+build_ssa_operands (tree stmt)
{
- tree *pptr = &TREE_OPERAND (expr, 0);
- tree ptr = *pptr;
- stmt_ann_t s_ann = stmt_ann (stmt);
-
- /* Stores into INDIRECT_REF operands are never killing definitions. */
- flags &= ~opf_kill_def;
-
- if (SSA_VAR_P (ptr))
- {
- struct ptr_info_def *pi = NULL;
+ stmt_ann_t ann = get_stmt_ann (stmt);
+
+ /* Initially assume that the statement has no volatile operands. */
+ if (ann)
+ ann->has_volatile_ops = false;
- /* If PTR has flow-sensitive points-to information, use it. */
- if (TREE_CODE (ptr) == SSA_NAME
- && (pi = SSA_NAME_PTR_INFO (ptr)) != NULL
- && pi->name_mem_tag)
- {
- /* PTR has its own memory tag. Use it. */
- add_virtual_operand (pi->name_mem_tag, s_ann, flags,
- full_ref, offset, size, false);
- }
- else
- {
- /* If PTR is not an SSA_NAME or it doesn't have a name
- tag, use its type memory tag. */
- var_ann_t v_ann;
+ start_ssa_stmt_operands ();
- /* If we are emitting debugging dumps, display a warning if
- PTR is an SSA_NAME with no flow-sensitive alias
- information. That means that we may need to compute
- aliasing again. */
- if (dump_file
- && TREE_CODE (ptr) == SSA_NAME
- && pi == NULL)
- {
- fprintf (dump_file,
- "NOTE: no flow-sensitive alias info for ");
- print_generic_expr (dump_file, ptr, dump_flags);
- fprintf (dump_file, " in ");
- print_generic_stmt (dump_file, stmt, dump_flags);
- }
+ parse_ssa_operands (stmt);
+ operand_build_sort_virtual (build_vuses);
+ operand_build_sort_virtual (build_v_may_defs);
+ operand_build_sort_virtual (build_v_must_defs);
- if (TREE_CODE (ptr) == SSA_NAME)
- ptr = SSA_NAME_VAR (ptr);
- v_ann = var_ann (ptr);
+ finalize_ssa_stmt_operands (stmt);
+}
- if (v_ann->type_mem_tag)
- add_virtual_operand (v_ann->type_mem_tag, s_ann, flags,
- full_ref, offset, size, false);
- }
- }
- else if (TREE_CODE (ptr) == INTEGER_CST)
- {
- /* If a constant is used as a pointer, we can't generate a real
- operand for it but we mark the statement volatile to prevent
- optimizations from messing things up. */
- if (s_ann)
- s_ann->has_volatile_ops = true;
- return;
- }
- else
- {
- /* Ok, this isn't even is_gimple_min_invariant. Something's broke. */
- gcc_unreachable ();
- }
- /* If requested, add a USE operand for the base pointer. */
- if (recurse_on_base)
- get_expr_operands (stmt, pptr, opf_none);
+/* Free any operands vectors in OPS. */
+void
+free_ssa_operands (stmt_operands_p ops)
+{
+ ops->def_ops = NULL;
+ ops->use_ops = NULL;
+ ops->maydef_ops = NULL;
+ ops->mustdef_ops = NULL;
+ ops->vuse_ops = NULL;
}
-/* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */
+/* Get the operands of statement STMT. Note that repeated calls to
+ get_stmt_operands for the same statement will do nothing until the
+ statement is marked modified by a call to mark_stmt_modified(). */
-static void
-get_tmr_operands (tree stmt, tree expr, int flags)
+void
+update_stmt_operands (tree stmt)
{
- tree tag = TMR_TAG (expr), ref;
- HOST_WIDE_INT offset, size, maxsize;
- subvar_t svars, sv;
- stmt_ann_t s_ann = stmt_ann (stmt);
+ stmt_ann_t ann = get_stmt_ann (stmt);
- /* First record the real operands. */
- get_expr_operands (stmt, &TMR_BASE (expr), opf_none);
- get_expr_operands (stmt, &TMR_INDEX (expr), opf_none);
+ /* If get_stmt_operands is called before SSA is initialized, dont
+ do anything. */
+ if (!ssa_operands_active ())
+ return;
- /* MEM_REFs should never be killing. */
- flags &= ~opf_kill_def;
+ /* The optimizers cannot handle statements that are nothing but a
+ _DECL. This indicates a bug in the gimplifier. */
+ gcc_assert (!SSA_VAR_P (stmt));
- if (TMR_SYMBOL (expr))
- {
- stmt_ann_t ann = stmt_ann (stmt);
- add_to_addressable_set (TMR_SYMBOL (expr), &ann->addresses_taken);
- }
+ gcc_assert (ann->modified);
- if (!tag)
- {
- /* Something weird, so ensure that we will be careful. */
- stmt_ann (stmt)->has_volatile_ops = true;
- return;
- }
+ timevar_push (TV_TREE_OPS);
- if (DECL_P (tag))
- {
- get_expr_operands (stmt, &tag, flags);
- return;
- }
+ build_ssa_operands (stmt);
- ref = get_ref_base_and_extent (tag, &offset, &size, &maxsize);
- gcc_assert (ref != NULL_TREE);
- svars = get_subvars_for_var (ref);
- for (sv = svars; sv; sv = sv->next)
- {
- bool exact;
- if (overlap_subvar (offset, maxsize, sv->var, &exact))
- {
- int subvar_flags = flags;
- if (!exact || size != maxsize)
- subvar_flags &= ~opf_kill_def;
- add_stmt_operand (&sv->var, s_ann, subvar_flags);
- }
- }
-}
+ /* Clear the modified bit for STMT. Subsequent calls to
+ get_stmt_operands for this statement will do nothing until the
+ statement is marked modified by a call to mark_stmt_modified(). */
+ ann->modified = 0;
+ timevar_pop (TV_TREE_OPS);
+}
-/* A subroutine of get_expr_operands to handle CALL_EXPR. */
+
+/* Copies virtual operands from SRC to DST. */
-static void
-get_call_expr_operands (tree stmt, tree expr)
+void
+copy_virtual_operands (tree dest, tree src)
{
- tree op;
- int call_flags = call_expr_flags (expr);
-
- /* If aliases have been computed already, add V_MAY_DEF or V_USE
- operands for all the symbols that have been found to be
- call-clobbered.
-
- Note that if aliases have not been computed, the global effects
- of calls will not be included in the SSA web. This is fine
- because no optimizer should run before aliases have been
- computed. By not bothering with virtual operands for CALL_EXPRs
- we avoid adding superfluous virtual operands, which can be a
- significant compile time sink (See PR 15855). */
- if (aliases_computed_p
- && !bitmap_empty_p (call_clobbered_vars)
- && !(call_flags & ECF_NOVOPS))
- {
- /* A 'pure' or a 'const' function never call-clobbers anything.
- A 'noreturn' function might, but since we don't return anyway
- there is no point in recording that. */
- if (TREE_SIDE_EFFECTS (expr)
- && !(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN)))
- add_call_clobber_ops (stmt, get_callee_fndecl (expr));
- else if (!(call_flags & ECF_CONST))
- add_call_read_ops (stmt, get_callee_fndecl (expr));
- }
-
- /* Find uses in the called function. */
- get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none);
-
- for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op))
- get_expr_operands (stmt, &TREE_VALUE (op), opf_none);
-
- get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none);
+ tree t;
+ ssa_op_iter iter, old_iter;
+ use_operand_p use_p, u2;
+ def_operand_p def_p, d2;
-}
+ build_ssa_operands (dest);
-/* REF is a tree that contains the entire pointer dereference
- expression, if available, or NULL otherwise. ALIAS is the variable
- we are asking if REF can access. OFFSET and SIZE come from the
- memory access expression that generated this virtual operand.
- FOR_CLOBBER is true is this is adding a virtual operand for a call
- clobber. */
+ /* Copy all the virtual fields. */
+ FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VUSE)
+ append_vuse (t);
+ FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMAYDEF)
+ append_v_may_def (t);
+ FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMUSTDEF)
+ append_v_must_def (t);
-static bool
-access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset,
- HOST_WIDE_INT size)
-{
- bool offsetgtz = offset > 0;
- unsigned HOST_WIDE_INT uoffset = (unsigned HOST_WIDE_INT) offset;
- tree base = ref ? get_base_address (ref) : NULL;
+ if (VEC_length (tree, build_vuses) == 0
+ && VEC_length (tree, build_v_may_defs) == 0
+ && VEC_length (tree, build_v_must_defs) == 0)
+ return;
- /* If ALIAS is an SFT, it can't be touched if the offset
- and size of the access is not overlapping with the SFT offset and
- size. This is only true if we are accessing through a pointer
- to a type that is the same as SFT_PARENT_VAR. Otherwise, we may
- be accessing through a pointer to some substruct of the
- structure, and if we try to prune there, we will have the wrong
- offset, and get the wrong answer.
- i.e., we can't prune without more work if we have something like
+ /* Now commit the virtual operands to this stmt. */
+ finalize_ssa_v_must_defs (dest);
+ finalize_ssa_v_may_defs (dest);
+ finalize_ssa_vuses (dest);
- struct gcc_target
- {
- struct asm_out
- {
- const char *byte_op;
- struct asm_int_op
- {
- const char *hi;
- } aligned_op;
- } asm_out;
- } targetm;
-
- foo = &targetm.asm_out.aligned_op;
- return foo->hi;
+ /* Finally, set the field to the same values as then originals. */
- SFT.1, which represents hi, will have SFT_OFFSET=32 because in
- terms of SFT_PARENT_VAR, that is where it is.
- However, the access through the foo pointer will be at offset 0. */
- if (size != -1
- && TREE_CODE (alias) == STRUCT_FIELD_TAG
- && base
- && TREE_TYPE (base) == TREE_TYPE (SFT_PARENT_VAR (alias))
- && !overlap_subvar (offset, size, alias, NULL))
+
+ t = op_iter_init_tree (&old_iter, src, SSA_OP_VUSE);
+ FOR_EACH_SSA_USE_OPERAND (use_p, dest, iter, SSA_OP_VUSE)
{
-#ifdef ACCESS_DEBUGGING
- fprintf (stderr, "Access to ");
- print_generic_expr (stderr, ref, 0);
- fprintf (stderr, " may not touch ");
- print_generic_expr (stderr, alias, 0);
- fprintf (stderr, " in function %s\n", get_name (current_function_decl));
-#endif
- return false;
+ gcc_assert (!op_iter_done (&old_iter));
+ SET_USE (use_p, t);
+ t = op_iter_next_tree (&old_iter);
}
+ gcc_assert (op_iter_done (&old_iter));
- /* Without strict aliasing, it is impossible for a component access
- through a pointer to touch a random variable, unless that
- variable *is* a structure or a pointer.
-
- That is, given p->c, and some random global variable b,
- there is no legal way that p->c could be an access to b.
-
- Without strict aliasing on, we consider it legal to do something
- like:
-
- struct foos { int l; };
- int foo;
- static struct foos *getfoo(void);
- int main (void)
- {
- struct foos *f = getfoo();
- f->l = 1;
- foo = 2;
- if (f->l == 1)
- abort();
- exit(0);
- }
- static struct foos *getfoo(void)
- { return (struct foos *)&foo; }
-
- (taken from 20000623-1.c)
- */
- else if (ref
- && flag_strict_aliasing
- && TREE_CODE (ref) != INDIRECT_REF
- && !MTAG_P (alias)
- && !AGGREGATE_TYPE_P (TREE_TYPE (alias))
- && TREE_CODE (TREE_TYPE (alias)) != COMPLEX_TYPE
- && !POINTER_TYPE_P (TREE_TYPE (alias)))
+ op_iter_init_maydef (&old_iter, src, &u2, &d2);
+ FOR_EACH_SSA_MAYDEF_OPERAND (def_p, use_p, dest, iter)
{
-#ifdef ACCESS_DEBUGGING
- fprintf (stderr, "Access to ");
- print_generic_expr (stderr, ref, 0);
- fprintf (stderr, " may not touch ");
- print_generic_expr (stderr, alias, 0);
- fprintf (stderr, " in function %s\n", get_name (current_function_decl));
-#endif
- return false;
+ gcc_assert (!op_iter_done (&old_iter));
+ SET_USE (use_p, USE_FROM_PTR (u2));
+ SET_DEF (def_p, DEF_FROM_PTR (d2));
+ op_iter_next_maymustdef (&u2, &d2, &old_iter);
}
+ gcc_assert (op_iter_done (&old_iter));
- /* If the offset of the access is greater than the size of one of
- the possible aliases, it can't be touching that alias, because it
- would be past the end of the structure. */
- else if (ref
- && flag_strict_aliasing
- && TREE_CODE (ref) != INDIRECT_REF
- && !MTAG_P (alias)
- && !POINTER_TYPE_P (TREE_TYPE (alias))
- && offsetgtz
- && DECL_SIZE (alias)
- && TREE_CODE (DECL_SIZE (alias)) == INTEGER_CST
- && uoffset > TREE_INT_CST_LOW (DECL_SIZE (alias)))
+ op_iter_init_mustdef (&old_iter, src, &u2, &d2);
+ FOR_EACH_SSA_MUSTDEF_OPERAND (def_p, use_p, dest, iter)
{
-#ifdef ACCESS_DEBUGGING
- fprintf (stderr, "Access to ");
- print_generic_expr (stderr, ref, 0);
- fprintf (stderr, " may not touch ");
- print_generic_expr (stderr, alias, 0);
- fprintf (stderr, " in function %s\n", get_name (current_function_decl));
-#endif
- return false;
- }
+ gcc_assert (!op_iter_done (&old_iter));
+ SET_USE (use_p, USE_FROM_PTR (u2));
+ SET_DEF (def_p, DEF_FROM_PTR (d2));
+ op_iter_next_maymustdef (&u2, &d2, &old_iter);
+ }
+ gcc_assert (op_iter_done (&old_iter));
- return true;
}
-/* Add VAR to the virtual operands array. FLAGS is as in
- get_expr_operands. FULL_REF is a tree that contains the entire
- pointer dereference expression, if available, or NULL otherwise.
- OFFSET and SIZE come from the memory access expression that
- generated this virtual operand. FOR_CLOBBER is true is this is
- adding a virtual operand for a call clobber. */
+/* Specifically for use in DOM's expression analysis. Given a store, we
+ create an artificial stmt which looks like a load from the store, this can
+ be used to eliminate redundant loads. OLD_OPS are the operands from the
+ store stmt, and NEW_STMT is the new load which represents a load of the
+ values stored. */
-static void
-add_virtual_operand (tree var, stmt_ann_t s_ann, int flags,
- tree full_ref, HOST_WIDE_INT offset,
- HOST_WIDE_INT size, bool for_clobber)
+void
+create_ssa_artficial_load_stmt (tree new_stmt, tree old_stmt)
{
- VEC(tree,gc) *aliases;
- tree sym;
- var_ann_t v_ann;
-
- sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
- v_ann = var_ann (sym);
-
- /* Mark statements with volatile operands. Optimizers should back
- off from statements having volatile operands. */
- if (TREE_THIS_VOLATILE (sym) && s_ann)
- s_ann->has_volatile_ops = true;
+ stmt_ann_t ann;
+ tree op;
+ ssa_op_iter iter;
+ use_operand_p use_p;
+ unsigned x;
- /* If the variable cannot be modified and this is a V_MAY_DEF change
- it into a VUSE. This happens when read-only variables are marked
- call-clobbered and/or aliased to writable variables. So we only
- check that this only happens on non-specific stores.
+ ann = get_stmt_ann (new_stmt);
- Note that if this is a specific store, i.e. associated with a
- modify_expr, then we can't suppress the V_MAY_DEF, lest we run
- into validation problems.
+ /* process the stmt looking for operands. */
+ start_ssa_stmt_operands ();
+ parse_ssa_operands (new_stmt);
- This can happen when programs cast away const, leaving us with a
- store to read-only memory. If the statement is actually executed
- at runtime, then the program is ill formed. If the statement is
- not executed then all is well. At the very least, we cannot ICE. */
- if ((flags & opf_non_specific) && unmodifiable_var_p (var))
- flags &= ~(opf_is_def | opf_kill_def);
-
- /* The variable is not a GIMPLE register. Add it (or its aliases) to
- virtual operands, unless the caller has specifically requested
- not to add virtual operands (used when adding operands inside an
- ADDR_EXPR expression). */
- if (flags & opf_no_vops)
- return;
-
- aliases = v_ann->may_aliases;
- if (aliases == NULL)
+ for (x = 0; x < VEC_length (tree, build_vuses); x++)
{
- /* The variable is not aliased or it is an alias tag. */
- if (flags & opf_is_def)
+ tree t = VEC_index (tree, build_vuses, x);
+ if (TREE_CODE (t) != SSA_NAME)
{
- if (flags & opf_kill_def)
- {
- /* V_MUST_DEF for non-aliased, non-GIMPLE register
- variable definitions. */
- gcc_assert (!MTAG_P (var)
- || TREE_CODE (var) == STRUCT_FIELD_TAG);
- append_v_must_def (var);
- }
- else
- {
- /* Add a V_MAY_DEF for call-clobbered variables and
- memory tags. */
- append_v_may_def (var);
- }
+ var_ann_t ann = var_ann (t);
+ ann->in_vuse_list = 0;
}
- else
- append_vuse (var);
}
- else
+
+ for (x = 0; x < VEC_length (tree, build_v_may_defs); x++)
{
- unsigned i;
- tree al;
-
- /* The variable is aliased. Add its aliases to the virtual
- operands. */
- gcc_assert (VEC_length (tree, aliases) != 0);
-
- if (flags & opf_is_def)
+ tree t = VEC_index (tree, build_v_may_defs, x);
+ if (TREE_CODE (t) != SSA_NAME)
{
-
- bool none_added = true;
-
- for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
- {
- if (!access_can_touch_variable (full_ref, al, offset, size))
- continue;
-
- none_added = false;
- append_v_may_def (al);
- }
-
- /* If the variable is also an alias tag, add a virtual
- operand for it, otherwise we will miss representing
- references to the members of the variable's alias set.
- This fixes the bug in gcc.c-torture/execute/20020503-1.c.
-
- It is also necessary to add bare defs on clobbers for
- TMT's, so that bare TMT uses caused by pruning all the
- aliases will link up properly with calls. In order to
- keep the number of these bare defs we add down to the
- minimum necessary, we keep track of which TMT's were used
- alone in statement defs or vuses. */
-
- if (v_ann->is_aliased
- || none_added
- || (TREE_CODE (var) == TYPE_MEMORY_TAG && for_clobber
- && TMT_USED_ALONE (var)))
- {
- /* Every bare tmt def we add should have TMT_USED_ALONE
- set on it, or else we will get the wrong answer on
- clobbers. */
+ var_ann_t ann = var_ann (t);
+ ann->in_v_may_def_list = 0;
+ }
+ }
- if (none_added && !updating_used_alone && aliases_computed_p
- && TREE_CODE (var) == TYPE_MEMORY_TAG)
- gcc_assert (TMT_USED_ALONE (var));
+ /* Remove any virtual operands that were found. */
+ VEC_truncate (tree, build_v_may_defs, 0);
+ VEC_truncate (tree, build_v_must_defs, 0);
+ VEC_truncate (tree, build_vuses, 0);
- append_v_may_def (var);
- }
- }
- else
- {
- bool none_added = true;
- for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
- {
- if (!access_can_touch_variable (full_ref, al, offset, size))
- continue;
- none_added = false;
- append_vuse (al);
- }
+ /* For each VDEF on the original statement, we want to create a
+ VUSE of the V_MAY_DEF result or V_MUST_DEF op on the new
+ statement. */
+ FOR_EACH_SSA_TREE_OPERAND (op, old_stmt, iter,
+ (SSA_OP_VMAYDEF | SSA_OP_VMUSTDEF))
+ append_vuse (op);
+
+ /* Now build the operands for this new stmt. */
+ finalize_ssa_stmt_operands (new_stmt);
- /* Similarly, append a virtual uses for VAR itself, when
- it is an alias tag. */
- if (v_ann->is_aliased || none_added)
- append_vuse (var);
- }
- }
+ /* All uses in this fake stmt must not be in the immediate use lists. */
+ FOR_EACH_SSA_USE_OPERAND (use_p, new_stmt, iter, SSA_OP_ALL_USES)
+ delink_imm_use (use_p);
}
-/* Add *VAR_P to the appropriate operand array for S_ANN. FLAGS is as in
- get_expr_operands. If *VAR_P is a GIMPLE register, it will be added to
- the statement's real operands, otherwise it is added to virtual
- operands. */
+/* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done
+ to test the validity of the swap operation. */
-static void
-add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags)
+void
+swap_tree_operands (tree stmt, tree *exp0, tree *exp1)
{
- bool is_real_op;
- tree var, sym;
- var_ann_t v_ann;
-
- var = *var_p;
- gcc_assert (SSA_VAR_P (var));
-
- is_real_op = is_gimple_reg (var);
+ tree op0, op1;
+ op0 = *exp0;
+ op1 = *exp1;
- /* If this is a real operand, the operand is either an SSA name or a
- decl. Virtual operands may only be decls. */
- gcc_assert (is_real_op || DECL_P (var));
+ /* If the operand cache is active, attempt to preserve the relative positions
+ of these two operands in their respective immediate use lists. */
+ if (ssa_operands_active () && op0 != op1)
+ {
+ use_optype_p use0, use1, ptr;
+ use0 = use1 = NULL;
- sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var);
- v_ann = var_ann (sym);
+ /* Find the 2 operands in the cache, if they are there. */
+ for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
+ if (USE_OP_PTR (ptr)->use == exp0)
+ {
+ use0 = ptr;
+ break;
+ }
- /* Mark statements with volatile operands. Optimizers should back
- off from statements having volatile operands. */
- if (TREE_THIS_VOLATILE (sym) && s_ann)
- s_ann->has_volatile_ops = true;
+ for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next)
+ if (USE_OP_PTR (ptr)->use == exp1)
+ {
+ use1 = ptr;
+ break;
+ }
- if (is_real_op)
- {
- /* The variable is a GIMPLE register. Add it to real operands. */
- if (flags & opf_is_def)
- append_def (var_p);
- else
- append_use (var_p);
+ /* If both uses don't have operand entries, there isn't much we can do
+ at this point. Presumably we dont need to worry about it. */
+ if (use0 && use1)
+ {
+ tree *tmp = USE_OP_PTR (use1)->use;
+ USE_OP_PTR (use1)->use = USE_OP_PTR (use0)->use;
+ USE_OP_PTR (use0)->use = tmp;
+ }
}
- else
- add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1, false);
+
+ /* Now swap the data. */
+ *exp0 = op1;
+ *exp1 = op0;
}
@@ -1976,144 +2113,6 @@ add_to_addressable_set (tree ref, bitmap
}
-/* Add clobbering definitions for .GLOBAL_VAR or for each of the call
- clobbered variables in the function. */
-
-static void
-add_call_clobber_ops (tree stmt, tree callee)
-{
- unsigned u;
- bitmap_iterator bi;
- stmt_ann_t s_ann = stmt_ann (stmt);
- bitmap not_read_b, not_written_b;
-
- /* Functions that are not const, pure or never return may clobber
- call-clobbered variables. */
- if (s_ann)
- s_ann->makes_clobbering_call = true;
-
- /* If we created .GLOBAL_VAR earlier, just use it. See compute_may_aliases
- for the heuristic used to decide whether to create .GLOBAL_VAR or not. */
- if (global_var)
- {
- add_stmt_operand (&global_var, s_ann, opf_is_def);
- return;
- }
-
- /* Get info for local and module level statics. There is a bit
- set for each static if the call being processed does not read
- or write that variable. */
- not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL;
- not_written_b = callee ? ipa_reference_get_not_written_global (callee) : NULL;
- /* Add a V_MAY_DEF operand for every call clobbered variable. */
- EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
- {
- tree var = referenced_var_lookup (u);
- unsigned int escape_mask = var_ann (var)->escape_mask;
- tree real_var = var;
- bool not_read;
- bool not_written;
-
- /* Not read and not written are computed on regular vars, not
- subvars, so look at the parent var if this is an SFT. */
- if (TREE_CODE (var) == STRUCT_FIELD_TAG)
- real_var = SFT_PARENT_VAR (var);
-
- not_read = not_read_b ? bitmap_bit_p (not_read_b,
- DECL_UID (real_var)) : false;
- not_written = not_written_b ? bitmap_bit_p (not_written_b,
- DECL_UID (real_var)) : false;
- gcc_assert (!unmodifiable_var_p (var));
-
- clobber_stats.clobbered_vars++;
-
- /* See if this variable is really clobbered by this function. */
-
- /* Trivial case: Things escaping only to pure/const are not
- clobbered by non-pure-const, and only read by pure/const. */
- if ((escape_mask & ~(ESCAPE_TO_PURE_CONST)) == 0)
- {
- tree call = get_call_expr_in (stmt);
- if (call_expr_flags (call) & (ECF_CONST | ECF_PURE))
- {
- add_stmt_operand (&var, s_ann, opf_none);
- clobber_stats.unescapable_clobbers_avoided++;
- continue;
- }
- else
- {
- clobber_stats.unescapable_clobbers_avoided++;
- continue;
- }
- }
-
- if (not_written)
- {
- clobber_stats.static_write_clobbers_avoided++;
- if (!not_read)
- add_stmt_operand (&var, s_ann, opf_none);
- else
- clobber_stats.static_read_clobbers_avoided++;
- }
- else
- add_virtual_operand (var, s_ann, opf_is_def,
- NULL, 0, -1, true);
- }
-
-}
-
-
-/* Add VUSE operands for .GLOBAL_VAR or all call clobbered variables in the
- function. */
-
-static void
-add_call_read_ops (tree stmt, tree callee)
-{
- unsigned u;
- bitmap_iterator bi;
- stmt_ann_t s_ann = stmt_ann (stmt);
- bitmap not_read_b;
-
- /* if the function is not pure, it may reference memory. Add
- a VUSE for .GLOBAL_VAR if it has been created. See add_referenced_var
- for the heuristic used to decide whether to create .GLOBAL_VAR. */
- if (global_var)
- {
- add_stmt_operand (&global_var, s_ann, opf_none);
- return;
- }
-
- not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL;
-
- /* Add a VUSE for each call-clobbered variable. */
- EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi)
- {
- tree var = referenced_var (u);
- tree real_var = var;
- bool not_read;
-
- clobber_stats.readonly_clobbers++;
-
- /* Not read and not written are computed on regular vars, not
- subvars, so look at the parent var if this is an SFT. */
-
- if (TREE_CODE (var) == STRUCT_FIELD_TAG)
- real_var = SFT_PARENT_VAR (var);
-
- not_read = not_read_b ? bitmap_bit_p (not_read_b,
- DECL_UID (real_var)) : false;
-
- if (not_read)
- {
- clobber_stats.static_readonly_clobbers_avoided++;
- continue;
- }
-
- add_stmt_operand (&var, s_ann, opf_none | opf_non_specific);
- }
-}
-
-
/* Scan the immediate_use list for VAR making sure its linked properly.
return RTUE iof there is a problem. */