GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 2, or (at your option) any later
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
/* This file handles the generation of rtl code from tree structure
at the level of the function as a whole.
/* We always define `record_insns' even if it's not used so that we
can always export `prologue_epilogue_contains'. */
static void record_insns (rtx, VEC(int,heap) **) ATTRIBUTE_UNUSED;
-static int contains (rtx, VEC(int,heap) **);
+static int contains (const_rtx, VEC(int,heap) **);
#ifdef HAVE_return
static void emit_return_into_block (basic_block);
#endif
#if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
static rtx keep_stack_depressed (rtx);
#endif
-static void prepare_function_start (tree);
+static void prepare_function_start (void);
static void do_clobber_return_reg (rtx, void *);
static void do_use_return_reg (rtx, void *);
static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
struct function *p;
if (cfun == 0)
- init_dummy_function_start ();
+ allocate_struct_function (NULL);
p = cfun;
p->outer = outer_function_chain;
lang_hooks.function.enter_nested (p);
- cfun = 0;
+ set_cfun (NULL);
}
void
{
struct function *p = outer_function_chain;
- cfun = p;
+ set_cfun (p);
outer_function_chain = p->outer;
current_function_decl = p->decl;
EXP may be a type node or an expression (whose type is tested). */
int
-aggregate_value_p (tree exp, tree fntype)
+aggregate_value_p (const_tree exp, const_tree fntype)
{
int i, regno, nregs;
rtx reg;
- tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
+ const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
/* DECL node associated with FNTYPE when relevant, which we might need to
check for by-invisible-reference returns, typically for CALL_EXPR input
EXPressions. */
- tree fndecl = NULL_TREE;
+ const_tree fndecl = NULL_TREE;
if (fntype)
switch (TREE_CODE (fntype))
should live on the local stack. */
bool
-use_register_for_decl (tree decl)
+use_register_for_decl (const_tree decl)
{
/* Honor volatile. */
if (TREE_SIDE_EFFECTS (decl))
#endif
)
{
- rtx reg = gen_rtx_REG (mode, REGNO (entry_parm));
+ rtx reg;
+
+ /* We are really truncating a word_mode value containing
+ SIZE bytes into a value of mode MODE. If such an
+ operation requires no actual instructions, we can refer
+ to the value directly in mode MODE, otherwise we must
+ start with the register in word_mode and explicitly
+ convert it. */
+ if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
+ reg = gen_rtx_REG (mode, REGNO (entry_parm));
+ else
+ {
+ reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
+ reg = convert_to_mode (mode, copy_to_reg (reg), 1);
+ }
emit_move_insn (change_address (mem, mode, 0), reg);
}
return NULL_TREE;
}
\f
+/* Keep track of whether we're in a dummy function context. If we are,
+ we don't want to invoke the set_current_function hook, because we'll
+ get into trouble if the hook calls target_reinit () recursively or
+ when the initial initialization is not yet complete. */
+
+static bool in_dummy_function;
+
+/* Invoke the target hook when setting cfun. */
+
+static void
+invoke_set_current_function_hook (tree fndecl)
+{
+ if (!in_dummy_function)
+ targetm.set_current_function (fndecl);
+}
+
+/* cfun should never be set directly; use this function. */
+
+void
+set_cfun (struct function *new_cfun)
+{
+ if (cfun != new_cfun)
+ {
+ cfun = new_cfun;
+ invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
+ }
+}
+
+/* Keep track of the cfun stack. */
+
+typedef struct function *function_p;
+
+DEF_VEC_P(function_p);
+DEF_VEC_ALLOC_P(function_p,heap);
+
+/* Initialized with NOGC, making this poisonous to the garbage collector. */
+
+static VEC(function_p,heap) *cfun_stack;
+
+/* Push the current cfun onto the stack, and set cfun to new_cfun. */
+
+void
+push_cfun (struct function *new_cfun)
+{
+ VEC_safe_push (function_p, heap, cfun_stack, cfun);
+ set_cfun (new_cfun);
+}
+
+/* Pop cfun from the stack. */
+
+void
+pop_cfun (void)
+{
+ set_cfun (VEC_pop (function_p, cfun_stack));
+}
/* Return value of funcdef and increase it. */
int
}
/* Allocate a function structure for FNDECL and set its contents
- to the defaults. */
+ to the defaults. Set cfun to the newly-allocated object.
+ Some of the helper functions invoked during initialization assume
+ that cfun has already been set. Therefore, assign the new object
+ directly into cfun and invoke the back end hook explicitly at the
+ very end, rather than initializing a temporary and calling set_cfun
+ on it.
+*/
void
allocate_struct_function (tree fndecl)
if (init_machine_status)
cfun->machine = (*init_machine_status) ();
- if (fndecl == NULL)
- return;
-
- DECL_STRUCT_FUNCTION (fndecl) = cfun;
- cfun->decl = fndecl;
-
- result = DECL_RESULT (fndecl);
- if (aggregate_value_p (result, fndecl))
+ if (fndecl != NULL)
{
+ DECL_STRUCT_FUNCTION (fndecl) = cfun;
+ cfun->decl = fndecl;
+
+ result = DECL_RESULT (fndecl);
+ if (aggregate_value_p (result, fndecl))
+ {
#ifdef PCC_STATIC_STRUCT_RETURN
- current_function_returns_pcc_struct = 1;
+ current_function_returns_pcc_struct = 1;
#endif
- current_function_returns_struct = 1;
+ current_function_returns_struct = 1;
+ }
+
+ current_function_stdarg
+ = (fntype
+ && TYPE_ARG_TYPES (fntype) != 0
+ && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
+ != void_type_node));
+
+ /* Assume all registers in stdarg functions need to be saved. */
+ cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
+ cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
}
- current_function_returns_pointer = POINTER_TYPE_P (TREE_TYPE (result));
+ invoke_set_current_function_hook (fndecl);
+}
- current_function_stdarg
- = (fntype
- && TYPE_ARG_TYPES (fntype) != 0
- && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
- != void_type_node));
+/* This is like allocate_struct_function, but pushes a new cfun for FNDECL
+ instead of just setting it. */
- /* Assume all registers in stdarg functions need to be saved. */
- cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
- cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
+void
+push_struct_function (tree fndecl)
+{
+ VEC_safe_push (function_p, heap, cfun_stack, cfun);
+ allocate_struct_function (fndecl);
}
/* Reset cfun, and other non-struct-function variables to defaults as
appropriate for emitting rtl at the start of a function. */
static void
-prepare_function_start (tree fndecl)
+prepare_function_start (void)
{
- if (fndecl && DECL_STRUCT_FUNCTION (fndecl))
- cfun = DECL_STRUCT_FUNCTION (fndecl);
- else
- allocate_struct_function (fndecl);
init_emit ();
init_varasm_status (cfun);
init_expr ();
/* Initialize the rtl expansion mechanism so that we can do simple things
like generate sequences. This is used to provide a context during global
- initialization of some passes. */
+ initialization of some passes. You must call expand_dummy_function_end
+ to exit this context. */
+
void
init_dummy_function_start (void)
{
- prepare_function_start (NULL);
+ gcc_assert (!in_dummy_function);
+ in_dummy_function = true;
+ push_struct_function (NULL_TREE);
+ prepare_function_start ();
}
/* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
void
init_function_start (tree subr)
{
- prepare_function_start (subr);
+ if (subr && DECL_STRUCT_FUNCTION (subr))
+ set_cfun (DECL_STRUCT_FUNCTION (subr));
+ else
+ allocate_struct_function (subr);
+ prepare_function_start ();
/* Warn if this value is an aggregate type,
regardless of which calling convention we are using for it. */
void
expand_dummy_function_end (void)
{
+ gcc_assert (in_dummy_function);
+
/* End any sequences that failed to be closed due to syntax errors. */
while (in_sequence_p ())
end_sequence ();
free_after_parsing (cfun);
free_after_compilation (cfun);
- cfun = 0;
+ pop_cfun ();
+ in_dummy_function = false;
}
/* Call DOIT for each hard register used as a return value from
for (decl = DECL_ARGUMENTS (fn);
decl; decl = TREE_CHAIN (decl))
if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
- && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl))
+ && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
+ && !TREE_NO_WARNING (decl))
warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
}
}
}
- /* Possibly warn about unused parameters.
- When frontend does unit-at-a-time, the warning is already
- issued at finalization time. */
- if (warn_unused_parameter
- && !lang_hooks.callgraph.expand_function)
- do_warn_unused_parameter (current_function_decl);
-
/* End any sequences that failed to be closed due to syntax errors. */
while (in_sequence_p ())
end_sequence ();
/* @@@ This is a kludge. We want to ensure that instructions that
may trap are not moved into the epilogue by scheduling, because
- we don't always emit unwind information for the epilogue.
- However, not all machine descriptions define a blockage insn, so
- emit an ASM_INPUT to act as one. */
+ we don't always emit unwind information for the epilogue. */
if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
- emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
+ emit_insn (gen_blockage ());
/* If stack protection is enabled for this function, check the guard. */
if (cfun->stack_protect_guard)
be running after reorg, SEQUENCE rtl is possible. */
static int
-contains (rtx insn, VEC(int,heap) **vec)
+contains (const_rtx insn, VEC(int,heap) **vec)
{
int i, j;
}
int
-prologue_epilogue_contains (rtx insn)
+prologue_epilogue_contains (const_rtx insn)
{
if (contains (insn, &prologue))
return 1;
}
int
-sibcall_epilogue_contains (rtx insn)
+sibcall_epilogue_contains (const_rtx insn)
{
if (sibcall_epilogue)
return contains (insn, &sibcall_epilogue);
};
static void handle_epilogue_set (rtx, struct epi_info *);
-static void update_epilogue_consts (rtx, rtx, void *);
+static void update_epilogue_consts (rtx, const_rtx, void *);
static void emit_equiv_load (struct epi_info *);
/* Modify INSN, a list of one or more insns that is part of the epilogue, to
/* Update the tracking information for registers set to constants. */
static void
-update_epilogue_consts (rtx dest, rtx x, void *data)
+update_epilogue_consts (rtx dest, const_rtx x, void *data)
{
struct epi_info *p = (struct epi_info *) data;
rtx new;
#if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
rtx seq;
#endif
-#ifdef HAVE_prologue
- rtx prologue_end = NULL_RTX;
-#endif
#if defined (HAVE_epilogue) || defined(HAVE_return)
rtx epilogue_end = NULL_RTX;
#endif
/* Retain a map of the prologue insns. */
record_insns (seq, &prologue);
- prologue_end = emit_note (NOTE_INSN_PROLOGUE_END);
+ emit_note (NOTE_INSN_PROLOGUE_END);
+
+#ifndef PROFILE_BEFORE_PROLOGUE
+ /* Ensure that instructions are not moved into the prologue when
+ profiling is on. The call to the profiling routine can be
+ emitted within the live range of a call-clobbered register. */
+ if (current_function_profile)
+ emit_insn (gen_blockage ());
+#endif
seq = get_insns ();
end_sequence ();
epilogue_done:
if (inserted)
- commit_edge_insertions ();
+ {
+ commit_edge_insertions ();
+
+ /* The epilogue insns we inserted may cause the exit edge to no longer
+ be fallthru. */
+ FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
+ {
+ if (((e->flags & EDGE_FALLTHRU) != 0)
+ && returnjump_p (BB_END (e->src)))
+ e->flags &= ~EDGE_FALLTHRU;
+ }
+ }
#ifdef HAVE_sibcall_epilogue
/* Emit sibling epilogues before any sibling call sites. */
0, /* properties_destroyed */
TODO_verify_flow, /* todo_flags_start */
TODO_dump_func |
- TODO_df_finish |
+ TODO_df_verify |
+ TODO_df_finish | TODO_verify_rtl_sharing |
TODO_ggc_collect, /* todo_flags_finish */
'w' /* letter */
};
rtx input, output, insns;
const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
char *end;
- int match;
+ int match, j;
match = strtoul (constraint, &end, 10);
if (end == constraint)
gcc_assert (match < noutputs);
output = SET_DEST (p_sets[match]);
input = RTVEC_ELT (inputs, i);
- if (rtx_equal_p (output, input)
+ /* Only do the transformation for pseudos. */
+ if (! REG_P (output)
+ || rtx_equal_p (output, input)
|| (GET_MODE (input) != VOIDmode
&& GET_MODE (input) != GET_MODE (output)))
continue;
+ /* We can't do anything if the output is also used as input,
+ as we're going to overwrite it. */
+ for (j = 0; j < ninputs; j++)
+ if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
+ break;
+ if (j != ninputs)
+ continue;
+
start_sequence ();
- emit_move_insn (copy_rtx (output), input);
- RTVEC_ELT (inputs, i) = copy_rtx (output);
+ emit_move_insn (output, input);
insns = get_insns ();
end_sequence ();
-
emit_insn_before (insns, insn);
+
+ /* Now replace all mentions of the input with output. We can't
+ just replace the occurence in inputs[i], as the register might
+ also be used in some other input (or even in an address of an
+ output), which would mean possibly increasing the number of
+ inputs by one (namely 'output' in addition), which might pose
+ a too complicated problem for reload to solve. E.g. this situation:
+
+ asm ("" : "=r" (output), "=m" (input) : "0" (input))
+
+ Here 'input' is used in two occurrences as input (once for the
+ input operand, once for the address in the second output operand).
+ If we would replace only the occurence of the input operand (to
+ make the matching) we would be left with this:
+
+ output = input
+ asm ("" : "=r" (output), "=m" (input) : "0" (output))
+
+ Now we suddenly have two different input values (containing the same
+ value, but different pseudos) where we formerly had only one.
+ With more complicated asms this might lead to reload failures
+ which wouldn't have happen without this pass. So, iterate over
+ all operands and replace all occurrences of the register used. */
+ for (j = 0; j < noutputs; j++)
+ if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
+ && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
+ SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
+ input, output);
+ for (j = 0; j < ninputs; j++)
+ if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
+ RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
+ input, output);
+
changed = true;
}
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