#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))
#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;
+
+/* We save the value of in_system_header here when pushing the first
+ function on the cfun stack, and we restore it from here when
+ popping the last function. */
+
+static bool saved_in_system_header;
+
+/* Push the current cfun onto the stack, and set cfun to new_cfun. */
+
+void
+push_cfun (struct function *new_cfun)
+{
+ if (cfun == NULL)
+ saved_in_system_header = in_system_header;
+ VEC_safe_push (function_p, heap, cfun_stack, cfun);
+ if (new_cfun)
+ in_system_header = DECL_IN_SYSTEM_HEADER (new_cfun->decl);
+ set_cfun (new_cfun);
+}
+
+/* Pop cfun from the stack. */
+
+void
+pop_cfun (void)
+{
+ struct function *new_cfun = VEC_pop (function_p, cfun_stack);
+ in_system_header = ((new_cfun == NULL) ? saved_in_system_header
+ : DECL_IN_SYSTEM_HEADER (new_cfun->decl));
+ set_cfun (new_cfun);
+}
/* 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)
+{
+ if (cfun == NULL)
+ saved_in_system_header = in_system_header;
+ VEC_safe_push (function_p, heap, cfun_stack, cfun);
+ if (fndecl)
+ in_system_header = DECL_IN_SYSTEM_HEADER (fndecl);
+ 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
}
}
- /* 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 ();
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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