/* Miscellaneous SSA utility functions.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
+ Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
This file is part of GCC.
#include "tm.h"
#include "tree.h"
#include "flags.h"
-#include "rtl.h"
#include "tm_p.h"
#include "target.h"
#include "ggc.h"
#include "langhooks.h"
-#include "hard-reg-set.h"
#include "basic-block.h"
#include "output.h"
-#include "expr.h"
#include "function.h"
-#include "diagnostic.h"
+#include "tree-pretty-print.h"
+#include "gimple-pretty-print.h"
#include "bitmap.h"
#include "pointer-set.h"
#include "tree-flow.h"
#include "gimple.h"
#include "tree-inline.h"
-#include "varray.h"
#include "timevar.h"
#include "hashtab.h"
#include "tree-dump.h"
if (!MAY_HAVE_DEBUG_STMTS)
return;
- /* First of all, check whether there are debug stmts that reference
- this variable and, if there are, decide whether we should use a
- debug temp. */
+ /* If this name has already been registered for replacement, do nothing
+ as anything that uses this name isn't in SSA form. */
+ if (name_registered_for_update_p (var))
+ return;
+
+ /* Check whether there are debug stmts that reference this variable and,
+ if there are, decide whether we should use a debug temp. */
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, var)
{
stmt = USE_STMT (use_p);
if (verify_ssa_name (ssa_name, is_virtual))
goto err;
+ if (TREE_CODE (SSA_NAME_VAR (ssa_name)) == RESULT_DECL
+ && DECL_BY_REFERENCE (SSA_NAME_VAR (ssa_name)))
+ {
+ error ("RESULT_DECL should be read only when DECL_BY_REFERENCE is set.");
+ goto err;
+ }
+
if (definition_block[SSA_NAME_VERSION (ssa_name)])
{
error ("SSA_NAME created in two different blocks %i and %i",
/* Verify common invariants in the SSA web.
TODO: verify the variable annotations. */
-void
+DEBUG_FUNCTION void
verify_ssa (bool check_modified_stmt)
{
size_t i;
void
init_tree_ssa (struct function *fn)
{
- fn->gimple_df = GGC_CNEW (struct gimple_df);
+ fn->gimple_df = ggc_alloc_cleared_gimple_df ();
fn->gimple_df->referenced_vars = htab_create_ggc (20, uid_decl_map_hash,
uid_decl_map_eq, NULL);
fn->gimple_df->default_defs = htab_create_ggc (20, uid_ssaname_map_hash,
uid_ssaname_map_eq, NULL);
pt_solution_reset (&fn->gimple_df->escaped);
- pt_solution_reset (&fn->gimple_df->callused);
init_ssanames (fn, 0);
init_phinodes ();
}
htab_delete (cfun->gimple_df->default_defs);
cfun->gimple_df->default_defs = NULL;
pt_solution_reset (&cfun->gimple_df->escaped);
- pt_solution_reset (&cfun->gimple_df->callused);
if (cfun->gimple_df->decls_to_pointers != NULL)
pointer_map_destroy (cfun->gimple_df->decls_to_pointers);
cfun->gimple_df->decls_to_pointers = NULL;
!= TYPE_ADDR_SPACE (TREE_TYPE (inner_type)))
return false;
+ /* Do not lose casts to restrict qualified pointers. */
+ if ((TYPE_RESTRICT (outer_type)
+ != TYPE_RESTRICT (inner_type))
+ && TYPE_RESTRICT (outer_type))
+ return false;
+
/* If the outer type is (void *) or a pointer to an incomplete
record type or a pointer to an unprototyped function,
then the conversion is not necessary. */
&& useless_type_conversion_p (TREE_TYPE (TREE_TYPE (outer_type)),
TREE_TYPE (TREE_TYPE (inner_type)))))
return true;
-
- /* Do not lose casts to restrict qualified pointers. */
- if ((TYPE_RESTRICT (outer_type)
- != TYPE_RESTRICT (inner_type))
- && TYPE_RESTRICT (outer_type))
- return false;
}
/* From now on qualifiers on value types do not matter. */
else if (POINTER_TYPE_P (inner_type)
&& POINTER_TYPE_P (outer_type))
{
- /* Don't lose casts between pointers to volatile and non-volatile
- qualified types. Doing so would result in changing the semantics
- of later accesses. For function types the volatile qualifier
- is used to indicate noreturn functions. */
- if (TREE_CODE (TREE_TYPE (outer_type)) != FUNCTION_TYPE
- && TREE_CODE (TREE_TYPE (outer_type)) != METHOD_TYPE
- && TREE_CODE (TREE_TYPE (inner_type)) != FUNCTION_TYPE
- && TREE_CODE (TREE_TYPE (inner_type)) != METHOD_TYPE
- && (TYPE_VOLATILE (TREE_TYPE (outer_type))
- != TYPE_VOLATILE (TREE_TYPE (inner_type)))
- && TYPE_VOLATILE (TREE_TYPE (outer_type)))
- return false;
-
- /* We require explicit conversions from incomplete target types. */
- if (!COMPLETE_TYPE_P (TREE_TYPE (inner_type))
- && COMPLETE_TYPE_P (TREE_TYPE (outer_type)))
- return false;
-
- /* Do not lose casts between pointers that when dereferenced access
- memory with different alias sets. */
- if (get_deref_alias_set (inner_type) != get_deref_alias_set (outer_type))
+ /* Do not lose casts to function pointer types. */
+ if ((TREE_CODE (TREE_TYPE (outer_type)) == FUNCTION_TYPE
+ || TREE_CODE (TREE_TYPE (outer_type)) == METHOD_TYPE)
+ && !useless_type_conversion_p (TREE_TYPE (outer_type),
+ TREE_TYPE (inner_type)))
return false;
/* We do not care for const qualification of the pointed-to types
as const qualification has no semantic value to the middle-end. */
- /* Otherwise pointers/references are equivalent if their pointed
- to types are effectively the same. We can strip qualifiers
- on pointed-to types for further comparison, which is done in
- the callee. Note we have to use true compatibility here
- because addresses are subject to propagation into dereferences
- and thus might get the original type exposed which is equivalent
- to a reverse conversion. */
- return types_compatible_p (TREE_TYPE (outer_type),
- TREE_TYPE (inner_type));
+ /* Otherwise pointers/references are equivalent. */
+ return true;
}
/* Recurse for complex types. */
}
\f
-/* Return true if T, an SSA_NAME, has an undefined value. */
-
-bool
-ssa_undefined_value_p (tree t)
-{
- tree var = SSA_NAME_VAR (t);
-
- /* Parameters get their initial value from the function entry. */
- if (TREE_CODE (var) == PARM_DECL)
- return false;
-
- /* Hard register variables get their initial value from the ether. */
- if (TREE_CODE (var) == VAR_DECL && DECL_HARD_REGISTER (var))
- return false;
-
- /* The value is undefined iff its definition statement is empty. */
- return gimple_nop_p (SSA_NAME_DEF_STMT (t));
-}
-
/* Emit warnings for uninitialized variables. This is done in two passes.
The first pass notices real uses of SSA names with undefined values.
/* Emit a warning for T, an SSA_NAME, being uninitialized. The exact
warning text is in MSGID and LOCUS may contain a location or be null. */
-static void
+void
warn_uninit (tree t, const char *gmsgid, void *data)
{
tree var = SSA_NAME_VAR (t);
/* We do not care about LHS. */
if (wi->is_lhs)
{
- /* Except for operands of INDIRECT_REF. */
- if (!INDIRECT_REF_P (t))
+ /* Except for operands of dereferences. */
+ if (!INDIRECT_REF_P (t)
+ && TREE_CODE (t) != MEM_REF)
return NULL_TREE;
t = TREE_OPERAND (t, 0);
}
return NULL_TREE;
}
-/* Look for inputs to PHI that are SSA_NAMEs that have empty definitions
- and warn about them. */
-
-static void
-warn_uninitialized_phi (gimple phi)
-{
- size_t i, n = gimple_phi_num_args (phi);
-
- /* Don't look at memory tags. */
- if (!is_gimple_reg (gimple_phi_result (phi)))
- return;
-
- for (i = 0; i < n; ++i)
- {
- tree op = gimple_phi_arg_def (phi, i);
- if (TREE_CODE (op) == SSA_NAME)
- warn_uninit (op, "%qD may be used uninitialized in this function",
- NULL);
- }
-}
-
-static unsigned int
+unsigned int
warn_uninitialized_vars (bool warn_possibly_uninitialized)
{
gimple_stmt_iterator gsi;
data.warn_possibly_uninitialized = warn_possibly_uninitialized;
- calculate_dominance_info (CDI_POST_DOMINATORS);
FOR_EACH_BB (bb)
{
}
}
- /* Post-dominator information can not be reliably updated. Free it
- after the use. */
-
- free_dominance_info (CDI_POST_DOMINATORS);
return 0;
}
as possible, thus don't do it here. However, without
optimization we need to warn here about "may be uninitialized".
*/
- warn_uninitialized_vars (/*warn_possibly_uninitialized=*/!optimize);
- return 0;
-}
-
-static unsigned int
-execute_late_warn_uninitialized (void)
-{
- basic_block bb;
- gimple_stmt_iterator gsi;
+ calculate_dominance_info (CDI_POST_DOMINATORS);
- /* Re-do the plain uninitialized variable check, as optimization may have
- straightened control flow. Do this first so that we don't accidentally
- get a "may be" warning when we'd have seen an "is" warning later. */
- warn_uninitialized_vars (/*warn_possibly_uninitialized=*/1);
+ warn_uninitialized_vars (/*warn_possibly_uninitialized=*/!optimize);
- FOR_EACH_BB (bb)
- for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
- warn_uninitialized_phi (gsi_stmt (gsi));
+ /* Post-dominator information can not be reliably updated. Free it
+ after the use. */
+ free_dominance_info (CDI_POST_DOMINATORS);
return 0;
}
}
};
-struct gimple_opt_pass pass_late_warn_uninitialized =
+
+/* If necessary, rewrite the base of the reference tree *TP from
+ a MEM_REF to a plain or converted symbol. */
+
+static void
+maybe_rewrite_mem_ref_base (tree *tp)
{
- {
- GIMPLE_PASS,
- "*late_warn_uninitialized", /* name */
- gate_warn_uninitialized, /* gate */
- execute_late_warn_uninitialized, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_NONE, /* tv_id */
- PROP_ssa, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- 0 /* todo_flags_finish */
- }
-};
+ tree sym;
+
+ while (handled_component_p (*tp))
+ tp = &TREE_OPERAND (*tp, 0);
+ if (TREE_CODE (*tp) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (*tp, 0)) == ADDR_EXPR
+ && integer_zerop (TREE_OPERAND (*tp, 1))
+ && (sym = TREE_OPERAND (TREE_OPERAND (*tp, 0), 0))
+ && DECL_P (sym)
+ && !TREE_ADDRESSABLE (sym)
+ && symbol_marked_for_renaming (sym))
+ {
+ if (!useless_type_conversion_p (TREE_TYPE (*tp),
+ TREE_TYPE (sym)))
+ *tp = build1 (VIEW_CONVERT_EXPR,
+ TREE_TYPE (*tp), sym);
+ else
+ *tp = sym;
+ }
+}
/* Compute TREE_ADDRESSABLE and DECL_GIMPLE_REG_P for local variables. */
{
tree lhs = gimple_get_lhs (stmt);
- /* We may not rewrite TMR_SYMBOL to SSA. */
- if (lhs && TREE_CODE (lhs) == TARGET_MEM_REF
- && TMR_SYMBOL (lhs))
- bitmap_set_bit (not_reg_needs, DECL_UID (TMR_SYMBOL (lhs)));
+ /* A plain decl does not need it set. */
+ if (lhs && !DECL_P (lhs))
+ {
+ if (handled_component_p (lhs))
+ lhs = get_base_address (lhs);
+
+ if (DECL_P (lhs))
+ bitmap_set_bit (not_reg_needs, DECL_UID (lhs));
+ else if (TREE_CODE (lhs) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (lhs, 0)) == ADDR_EXPR)
+ {
+ tree decl = TREE_OPERAND (TREE_OPERAND (lhs, 0), 0);
+ if (DECL_P (decl)
+ && (!integer_zerop (TREE_OPERAND (lhs, 1))
+ || (DECL_SIZE (decl)
+ != TYPE_SIZE (TREE_TYPE (lhs)))))
+ bitmap_set_bit (not_reg_needs, DECL_UID (decl));
+ }
+ }
+ }
+
+ if (gimple_assign_single_p (stmt))
+ {
+ tree rhs = gimple_assign_rhs1 (stmt);
/* A plain decl does not need it set. */
- else if (lhs && handled_component_p (lhs))
- {
- var = get_base_address (lhs);
- if (DECL_P (var))
- bitmap_set_bit (not_reg_needs, DECL_UID (var));
+ if (!DECL_P (rhs))
+ {
+ tree base = rhs;
+ while (handled_component_p (base))
+ base = TREE_OPERAND (base, 0);
+
+ /* But watch out for MEM_REFs we cannot lower to a
+ VIEW_CONVERT_EXPR. */
+ if (TREE_CODE (base) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (base, 0)) == ADDR_EXPR)
+ {
+ tree decl = TREE_OPERAND (TREE_OPERAND (base, 0), 0);
+ if (DECL_P (decl)
+ && (!integer_zerop (TREE_OPERAND (base, 1))
+ || (DECL_SIZE (decl)
+ != TYPE_SIZE (TREE_TYPE (base)))))
+ bitmap_set_bit (not_reg_needs, DECL_UID (decl));
+ }
}
}
}
if (update_vops)
{
FOR_EACH_BB (bb)
- for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
- {
- gimple stmt = gsi_stmt (gsi);
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
- if (gimple_references_memory_p (stmt)
- || is_gimple_debug (stmt))
- update_stmt (stmt);
- }
+ /* Re-write TARGET_MEM_REFs of symbols we want to
+ rewrite into SSA form. */
+ if (gimple_assign_single_p (stmt))
+ {
+ tree lhs = gimple_assign_lhs (stmt);
+ tree rhs, *rhsp = gimple_assign_rhs1_ptr (stmt);
+ tree sym;
+
+ /* We shouldn't have any fancy wrapping of
+ component-refs on the LHS, but look through
+ VIEW_CONVERT_EXPRs as that is easy. */
+ while (TREE_CODE (lhs) == VIEW_CONVERT_EXPR)
+ lhs = TREE_OPERAND (lhs, 0);
+ if (TREE_CODE (lhs) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (lhs, 0)) == ADDR_EXPR
+ && integer_zerop (TREE_OPERAND (lhs, 1))
+ && (sym = TREE_OPERAND (TREE_OPERAND (lhs, 0), 0))
+ && DECL_P (sym)
+ && !TREE_ADDRESSABLE (sym)
+ && symbol_marked_for_renaming (sym))
+ lhs = sym;
+ else
+ lhs = gimple_assign_lhs (stmt);
+
+ /* Rewrite the RHS and make sure the resulting assignment
+ is validly typed. */
+ maybe_rewrite_mem_ref_base (rhsp);
+ rhs = gimple_assign_rhs1 (stmt);
+ if (gimple_assign_lhs (stmt) != lhs
+ && !useless_type_conversion_p (TREE_TYPE (lhs),
+ TREE_TYPE (rhs)))
+ rhs = fold_build1 (VIEW_CONVERT_EXPR,
+ TREE_TYPE (lhs), rhs);
+
+ if (gimple_assign_lhs (stmt) != lhs)
+ gimple_assign_set_lhs (stmt, lhs);
+
+ if (gimple_assign_rhs1 (stmt) != rhs)
+ {
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
+ gimple_assign_set_rhs_from_tree (&gsi, rhs);
+ }
+ }
+
+ if (gimple_code (stmt) == GIMPLE_ASM)
+ {
+ unsigned i;
+ for (i = 0; i < gimple_asm_noutputs (stmt); ++i)
+ {
+ tree link = gimple_asm_output_op (stmt, i);
+ maybe_rewrite_mem_ref_base (&TREE_VALUE (link));
+ }
+ for (i = 0; i < gimple_asm_ninputs (stmt); ++i)
+ {
+ tree link = gimple_asm_input_op (stmt, i);
+ maybe_rewrite_mem_ref_base (&TREE_VALUE (link));
+ }
+ }
+
+ if (gimple_references_memory_p (stmt)
+ || is_gimple_debug (stmt))
+ update_stmt (stmt);
+ }
/* Update SSA form here, we are called as non-pass as well. */
update_ssa (TODO_update_ssa);
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