v_may_defs = V_MAY_DEF_OPS (ann);
for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++)
- print_generic_expr (stderr, V_MAY_DEF_OP (v_may_defs, i), 0);
+ @{
+ print_generic_expr (stderr, V_MAY_DEF_OP (v_may_defs, i), 0);
+ print_generic_expr (stderr, V_MAY_DEF_RESULT (v_may_defs, i), 0);
+ @}
v_must_defs = V_MUST_DEF_OPS (ann);
for (i = 0; i < NUM_V_MUST_DEFS (v_must_defs); i++)
modified by a call to @code{modify_stmt}. So, if your pass replaces
operands in a statement, make sure to call @code{modify_stmt}.
+@subsection Operand Iterators
+@cindex Operand Iterators
+
+There is an alternative to iterating over the operands in a statement.
+It is especially useful when you wish to perform the same operation on
+more than one type of operand. The previous example could be
+rewritten as follows:
+
+@smallexample
+void
+print_ops (tree stmt)
+@{
+ ssa_op_iter;
+ tree var;
+
+ get_stmt_operands (stmt);
+ FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_OPERANDS)
+ print_generic_expr (stderr, var, 0);
+@}
+@end smallexample
+
+
+@enumerate
+@item Determine whether you are need to see the operand pointers, or just the
+ trees, and choose the appropriate macro:
+
+@smallexample
+Need Macro:
+---- -------
+use_operand_p FOR_EACH_SSA_USE_OPERAND
+def_operand_p FOR_EACH_SSA_DEF_OPERAND
+tree FOR_EACH_SSA_TREE_OPERAND
+@end smallexample
+
+@item You need to declare a variable of the type you are interested
+ in, and an ssa_op_iter structure which serves as the loop
+ controlling variable.
+
+@item Determine which operands you wish to use, and specify the flags of
+ those you are interested in. They are documented in
+ @file{tree-ssa-operands.h}:
+
+@smallexample
+#define SSA_OP_USE 0x01 /* Real USE operands. */
+#define SSA_OP_DEF 0x02 /* Real DEF operands. */
+#define SSA_OP_VUSE 0x04 /* VUSE operands. */
+#define SSA_OP_VMAYUSE 0x08 /* USE portion of V_MAY_DEFS. */
+#define SSA_OP_VMAYDEF 0x10 /* DEF portion of V_MAY_DEFS. */
+#define SSA_OP_VMUSTDEF 0x20 /* V_MUST_DEF definitions. */
+
+/* These are commonly grouped operand flags. */
+#define SSA_OP_VIRTUAL_USES (SSA_OP_VUSE | SSA_OP_VMAYUSE)
+#define SSA_OP_VIRTUAL_DEFS (SSA_OP_VMAYDEF | SSA_OP_VMUSTDEF)
+#define SSA_OP_ALL_USES (SSA_OP_VIRTUAL_USES | SSA_OP_USE)
+#define SSA_OP_ALL_DEFS (SSA_OP_VIRTUAL_DEFS | SSA_OP_DEF)
+#define SSA_OP_ALL_OPERANDS (SSA_OP_ALL_USES | SSA_OP_ALL_DEFS)
+@end smallexample
+@end enumerate
+
+So if you want to look at the use pointers for all the @code{USE} and
+@code{VUSE} operands, you would do something like:
+
+@smallexample
+ use_operand_p use_p;
+ ssa_op_iter iter;
+
+ FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, (SSA_OP_USE | SSA_OP_VUSE))
+ @{
+ process_use_ptr (use_p);
+ @}
+@end smallexample
+
+The @code{_TREE_} macro is basically the same as the @code{USE} and
+@code{DEF} macros, only with the use or def dereferenced via
+@code{USE_FROM_PTR (use_p)} and @code{DEF_FROM_PTR (def_p)}. Since we
+aren't using operand pointers, use and defs flags can be mixed.
+
+@smallexample
+ tree var;
+ ssa_op_iter iter;
+
+ FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_VUSE | SSA_OP_VMUSTDEF)
+ @{
+ print_generic_expr (stderr, var, TDF_SLIM);
+ @}
+@end smallexample
+
+Note that @code{V_MAY_DEFS} are broken into 2 flags, one for the
+@code{DEF} portion (@code{SSA_OP_VMAYDEF}) and one for the USE portion
+(@code{SSA_OP_VMAYUSE}). If all you want to look at are the
+@code{V_MAY_DEFS} together, there is a fourth iterator macro for this,
+which returns both a def_operand_p and a use_operand_p for each
+@code{V_MAY_DEF} in the statement. Note that you don't need any flags for
+this one.
+
+@smallexample
+ use_operand_p use_p;
+ def_operand_p def_p;
+ ssa_op_iter iter;
+
+ FOR_EACH_SSA_MAYDEF_OPERAND (def_p, use_p, stmt, iter)
+ @{
+ my_code;
+ @}
+@end smallexample
+
+
+There are many examples in the code as well, as well as the
+documentation in @file{tree-ssa-operands.h}.
+
@node SSA
@section Static Single Assignment
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