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rtl.texi (simple_return): Document.

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* doc/rtl.texi (simple_return): Document.
	(parallel, PATTERN): Here too.
	* doc/md.texi (return): Mention it's allowed to expand to simple_return
	in some cases.
	(simple_return): Document standard pattern.
	* gengenrtl.c (special_rtx): SIMPLE_RETURN is special.
	* final.c (final_scan_insn): Use ANY_RETURN_P on body.
	* reorg.c (function_return_label, function_simple_return_label):
	New static variables, replacing...
	(end_of_function_label): ... this.
	(simplejump_or_return_p): New static function.
	(optimize_skip, steal_delay_list_from_fallthrough,
	fill_slots_from_thread): Use it.
	(relax_delay_slots): Likewise.  Use ANY_RETURN_P on body.
	(rare_destination, follow_jumps): Use ANY_RETURN_P on body.
	(find_end_label): Take a new arg which is one of the two return
	rtxs.  Depending on which, set either function_return_label or
	function_simple_return_label.  All callers changed.
	(make_return_insns): Make both kinds.
	(dbr_schedule): Adjust for two kinds of end labels.
	* function.c (emit_return_into_block): Set JUMP_LABEL properly.
	* genemit.c (gen_exp): Handle SIMPLE_RETURN.
	(gen_expand, gen_split): Use ANY_RETURN_P.
	* df-scan.c (df_uses_record): Handle SIMPLE_RETURN.
	* rtl.def (SIMPLE_RETURN): New code.
	* ifcvt.c (find_if_case_1): Be more careful about
	redirecting jumps to the EXIT_BLOCK.
	* jump.c (condjump_p, condjump_in_parallel_p, any_condjump_p,
	returnjump_p_1): Handle SIMPLE_RETURNs.
	* print-rtl.c (print_rtx): Likewise.
	* rtl.c (copy_rtx): Likewise.
	* bt-load.c (compute_defs_uses_and_gen): Use ANY_RETURN_P.
	* combine.c (simplify_set): Likewise.
	* resource.c (find_dead_or_set_registers, mark_set_resources):
	Likewise.
	* emit-rtl.c (verify_rtx_sharing, classify_insn, copy_insn_1,
	copy_rtx_if_shared_1, mark_used_flags): Handle SIMPLE_RETURNs.
	(init_emit_regs): Initialize simple_return_rtx.
	* cfglayout.c (fixup_reorder_chain): Pass a JUMP_LABEL to
	force_nonfallthru_and_redirect.
	* rtl.h (ANY_RETURN_P): Allow SIMPLE_RETURN.
	(GR_SIMPLE_RETURN): New enum value.
	(simple_return_rtx): New macro.
	* basic-block.h (force_nonfallthru_and_redirect): Adjust
	declaration.
	* cfgrtl.c (force_nonfallthru_and_redirect): Take a new jump_label
	argument.  All callers changed.  Be careful about what kinds of
	returnjumps to generate.
	* config/i386/3i86.c (ix86_pad_returns, ix86_count_insn_bb,
	ix86_pad_short_function): Likewise.
	* config/arm/arm.c (arm_final_prescan_insn): Handle both kinds
	of return.
	* config/mips/mips.md (any_return): New code_iterator.
	(optab): Add cases for return and simple_return.
	(return): Expand to a simple_return.
	(simple_return): New pattern.
	(*<optab>, *<optab>_internal for any_return): New patterns.
	(return_internal): Remove.
	* config/mips/mips.c (mips_expand_epilogue): Make the last insn
	a simple_return_internal.

From-SVN: r178135
This commit is contained in:
Bernd Schmidt 2011-08-27 17:38:58 +00:00 • committed by Bernd Schmidt
parent 3b0eee5d58
commit 268987713c
27 changed files with 402 additions and 197 deletions
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63
gcc/ChangeLog
View file

@ -1,3 +1,66 @@
2011-08-27 Bernd Schmidt <bernds@codesourcery.com>
* doc/rtl.texi (simple_return): Document.
(parallel, PATTERN): Here too.
* doc/md.texi (return): Mention it's allowed to expand to simple_return
in some cases.
(simple_return): Document standard pattern.
* gengenrtl.c (special_rtx): SIMPLE_RETURN is special.
* final.c (final_scan_insn): Use ANY_RETURN_P on body.
* reorg.c (function_return_label, function_simple_return_label):
New static variables, replacing...
(end_of_function_label): ... this.
(simplejump_or_return_p): New static function.
(optimize_skip, steal_delay_list_from_fallthrough,
fill_slots_from_thread): Use it.
(relax_delay_slots): Likewise. Use ANY_RETURN_P on body.
(rare_destination, follow_jumps): Use ANY_RETURN_P on body.
(find_end_label): Take a new arg which is one of the two return
rtxs. Depending on which, set either function_return_label or
function_simple_return_label. All callers changed.
(make_return_insns): Make both kinds.
(dbr_schedule): Adjust for two kinds of end labels.
* function.c (emit_return_into_block): Set JUMP_LABEL properly.
* genemit.c (gen_exp): Handle SIMPLE_RETURN.
(gen_expand, gen_split): Use ANY_RETURN_P.
* df-scan.c (df_uses_record): Handle SIMPLE_RETURN.
* rtl.def (SIMPLE_RETURN): New code.
* ifcvt.c (find_if_case_1): Be more careful about
redirecting jumps to the EXIT_BLOCK.
* jump.c (condjump_p, condjump_in_parallel_p, any_condjump_p,
returnjump_p_1): Handle SIMPLE_RETURNs.
* print-rtl.c (print_rtx): Likewise.
* rtl.c (copy_rtx): Likewise.
* bt-load.c (compute_defs_uses_and_gen): Use ANY_RETURN_P.
* combine.c (simplify_set): Likewise.
* resource.c (find_dead_or_set_registers, mark_set_resources):
Likewise.
* emit-rtl.c (verify_rtx_sharing, classify_insn, copy_insn_1,
copy_rtx_if_shared_1, mark_used_flags): Handle SIMPLE_RETURNs.
(init_emit_regs): Initialize simple_return_rtx.
* cfglayout.c (fixup_reorder_chain): Pass a JUMP_LABEL to
force_nonfallthru_and_redirect.
* rtl.h (ANY_RETURN_P): Allow SIMPLE_RETURN.
(GR_SIMPLE_RETURN): New enum value.
(simple_return_rtx): New macro.
* basic-block.h (force_nonfallthru_and_redirect): Adjust
declaration.
* cfgrtl.c (force_nonfallthru_and_redirect): Take a new jump_label
argument. All callers changed. Be careful about what kinds of
returnjumps to generate.
* config/i386/3i86.c (ix86_pad_returns, ix86_count_insn_bb,
ix86_pad_short_function): Likewise.
* config/arm/arm.c (arm_final_prescan_insn): Handle both kinds
of return.
* config/mips/mips.md (any_return): New code_iterator.
(optab): Add cases for return and simple_return.
(return): Expand to a simple_return.
(simple_return): New pattern.
(*<optab>, *<optab>_internal for any_return): New patterns.
(return_internal): Remove.
* config/mips/mips.c (mips_expand_epilogue): Make the last insn
a simple_return_internal.
2011-08-27 Uros Bizjak <ubizjak@gmail.com>
* config/i386/sse.md (*absneg<mode>2): Fix split condition.

2
gcc/basic-block.h
View file

@ -804,7 +804,7 @@ extern rtx block_label (basic_block);
extern bool purge_all_dead_edges (void);
extern bool purge_dead_edges (basic_block);
extern bool fixup_abnormal_edges (void);
extern basic_block force_nonfallthru_and_redirect (edge, basic_block);
extern basic_block force_nonfallthru_and_redirect (edge, basic_block, rtx);
/* In cfgbuild.c. */
extern void find_many_sub_basic_blocks (sbitmap);

2
gcc/bt-load.c
View file

@ -558,7 +558,7 @@ compute_defs_uses_and_gen (fibheap_t all_btr_defs, btr_def *def_array,
/* Check for sibcall. */
if (GET_CODE (pat) == PARALLEL)
for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
if (GET_CODE (XVECEXP (pat, 0, i)) == RETURN)
if (ANY_RETURN_P (XVECEXP (pat, 0, i)))
{
COMPL_HARD_REG_SET (call_saved,
call_used_reg_set);

4
gcc/cfglayout.c
View file

@ -767,6 +767,7 @@ fixup_reorder_chain (void)
{
edge e_fall, e_taken, e;
rtx bb_end_insn;
rtx ret_label = NULL_RTX;
basic_block nb, src_bb;
edge_iterator ei;
@ -786,6 +787,7 @@ fixup_reorder_chain (void)
bb_end_insn = BB_END (bb);
if (JUMP_P (bb_end_insn))
{
ret_label = JUMP_LABEL (bb_end_insn);
if (any_condjump_p (bb_end_insn))
{
/* This might happen if the conditional jump has side
@ -899,7 +901,7 @@ fixup_reorder_chain (void)
Note force_nonfallthru can delete E_FALL and thus we have to
save E_FALL->src prior to the call to force_nonfallthru. */
src_bb = e_fall->src;
nb = force_nonfallthru_and_redirect (e_fall, e_fall->dest);
nb = force_nonfallthru_and_redirect (e_fall, e_fall->dest, ret_label);
if (nb)
{
nb->il.rtl->visited = 1;

30
gcc/cfgrtl.c
View file

@ -1117,10 +1117,13 @@ rtl_redirect_edge_and_branch (edge e, basic_block target)
}
/* Like force_nonfallthru below, but additionally performs redirection
Used by redirect_edge_and_branch_force. */
Used by redirect_edge_and_branch_force. JUMP_LABEL is used only
when redirecting to the EXIT_BLOCK, it is either ret_rtx or
simple_return_rtx, indicating which kind of returnjump to create.
It should be NULL otherwise. */
basic_block
force_nonfallthru_and_redirect (edge e, basic_block target)
force_nonfallthru_and_redirect (edge e, basic_block target, rtx jump_label)
{
basic_block jump_block, new_bb = NULL, src = e->src;
rtx note;
@ -1252,12 +1255,25 @@ force_nonfallthru_and_redirect (edge e, basic_block target)
e->flags &= ~EDGE_FALLTHRU;
if (target == EXIT_BLOCK_PTR)
{
if (jump_label == ret_rtx)
{
#ifdef HAVE_return
emit_jump_insn_after_setloc (gen_return (), BB_END (jump_block), loc);
JUMP_LABEL (BB_END (jump_block)) = ret_rtx;
emit_jump_insn_after_setloc (gen_return (), BB_END (jump_block), loc);
#else
gcc_unreachable ();
gcc_unreachable ();
#endif
}
else
{
gcc_assert (jump_label == simple_return_rtx);
#ifdef HAVE_simple_return
emit_jump_insn_after_setloc (gen_simple_return (),
BB_END (jump_block), loc);
#else
gcc_unreachable ();
#endif
}
JUMP_LABEL (BB_END (jump_block)) = jump_label;
}
else
{
@ -1284,7 +1300,7 @@ force_nonfallthru_and_redirect (edge e, basic_block target)
static basic_block
rtl_force_nonfallthru (edge e)
{
return force_nonfallthru_and_redirect (e, e->dest);
return force_nonfallthru_and_redirect (e, e->dest, NULL_RTX);
}
/* Redirect edge even at the expense of creating new jump insn or
@ -1301,7 +1317,7 @@ rtl_redirect_edge_and_branch_force (edge e, basic_block target)
/* In case the edge redirection failed, try to force it to be non-fallthru
and redirect newly created simplejump. */
df_set_bb_dirty (e->src);
return force_nonfallthru_and_redirect (e, target);
return force_nonfallthru_and_redirect (e, target, NULL_RTX);
}
/* The given edge should potentially be a fallthru edge. If that is in

2
gcc/combine.c
View file

@ -6303,7 +6303,7 @@ simplify_set (rtx x)
rtx *cc_use;
/* (set (pc) (return)) gets written as (return). */
if (GET_CODE (dest) == PC && GET_CODE (src) == RETURN)
if (GET_CODE (dest) == PC && ANY_RETURN_P (src))
return src;
/* Now that we know for sure which bits of SRC we are using, see if we can

19
gcc/config/arm/arm.c
View file

@ -17836,6 +17836,7 @@ arm_final_prescan_insn (rtx insn)
/* If we start with a return insn, we only succeed if we find another one. */
int seeking_return = 0;
enum rtx_code return_code = UNKNOWN;
/* START_INSN will hold the insn from where we start looking. This is the
first insn after the following code_label if REVERSE is true. */
@ -17874,7 +17875,7 @@ arm_final_prescan_insn (rtx insn)
else
return;
}
else if (GET_CODE (body) == RETURN)
else if (ANY_RETURN_P (body))
{
start_insn = next_nonnote_insn (start_insn);
if (GET_CODE (start_insn) == BARRIER)
@ -17885,6 +17886,7 @@ arm_final_prescan_insn (rtx insn)
{
reverse = TRUE;
seeking_return = 1;
return_code = GET_CODE (body);
}
else
return;
@ -17925,11 +17927,15 @@ arm_final_prescan_insn (rtx insn)
label = XEXP (XEXP (SET_SRC (body), 2), 0);
then_not_else = FALSE;
}
else if (GET_CODE (XEXP (SET_SRC (body), 1)) == RETURN)
seeking_return = 1;
else if (GET_CODE (XEXP (SET_SRC (body), 2)) == RETURN)
else if (ANY_RETURN_P (XEXP (SET_SRC (body), 1)))
{
seeking_return = 1;
return_code = GET_CODE (XEXP (SET_SRC (body), 1));
}
else if (ANY_RETURN_P (XEXP (SET_SRC (body), 2)))
{
seeking_return = 1;
return_code = GET_CODE (XEXP (SET_SRC (body), 2));
then_not_else = FALSE;
}
else
@ -18026,12 +18032,11 @@ arm_final_prescan_insn (rtx insn)
}
/* Fail if a conditional return is undesirable (e.g. on a
StrongARM), but still allow this if optimizing for size. */
else if (GET_CODE (scanbody) == RETURN
else if (GET_CODE (scanbody) == return_code
&& !use_return_insn (TRUE, NULL)
&& !optimize_size)
fail = TRUE;
else if (GET_CODE (scanbody) == RETURN
&& seeking_return)
else if (GET_CODE (scanbody) == return_code)
{
arm_ccfsm_state = 2;
succeed = TRUE;

6
gcc/config/i386/i386.c
View file

@ -30585,7 +30585,7 @@ ix86_pad_returns (void)
rtx prev;
bool replace = false;
if (!JUMP_P (ret) || GET_CODE (PATTERN (ret)) != RETURN
if (!JUMP_P (ret) || !ANY_RETURN_P (PATTERN (ret))
|| optimize_bb_for_size_p (bb))
continue;
for (prev = PREV_INSN (ret); prev; prev = PREV_INSN (prev))
@ -30636,7 +30636,7 @@ ix86_count_insn_bb (basic_block bb)
{
/* Only happen in exit blocks. */
if (JUMP_P (insn)
&& GET_CODE (PATTERN (insn)) == RETURN)
&& ANY_RETURN_P (PATTERN (insn)))
break;
if (NONDEBUG_INSN_P (insn)
@ -30709,7 +30709,7 @@ ix86_pad_short_function (void)
FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
{
rtx ret = BB_END (e->src);
if (JUMP_P (ret) && GET_CODE (PATTERN (ret)) == RETURN)
if (JUMP_P (ret) && ANY_RETURN_P (PATTERN (ret)))
{
int insn_count = ix86_count_insn (e->src);

3
gcc/config/mips/mips.c
View file

@ -10453,7 +10453,8 @@ mips_expand_epilogue (bool sibcall_p)
regno = GP_REG_FIRST + 7;
else
regno = RETURN_ADDR_REGNUM;
emit_jump_insn (gen_return_internal (gen_rtx_REG (Pmode, regno)));
emit_jump_insn (gen_simple_return_internal (gen_rtx_REG (Pmode,
regno)));
}
}

23
gcc/config/mips/mips.md
View file

@ -777,6 +777,8 @@
(define_code_iterator any_lt [lt ltu])
(define_code_iterator any_le [le leu])
(define_code_iterator any_return [return simple_return])
;; <u> expands to an empty string when doing a signed operation and
;; "u" when doing an unsigned operation.
(define_code_attr u [(sign_extend "") (zero_extend "u")
@ -798,7 +800,9 @@
(xor "xor")
(and "and")
(plus "add")
(minus "sub")])
(minus "sub")
(return "return")
(simple_return "simple_return")])
;; <insn> expands to the name of the insn that implements a particular code.
(define_code_attr insn [(ashift "sll")
@ -5713,21 +5717,26 @@
;; allows jump optimizations to work better.
(define_expand "return"
[(return)]
[(simple_return)]
"mips_can_use_return_insn ()"
{ mips_expand_before_return (); })
(define_insn "*return"
[(return)]
"mips_can_use_return_insn ()"
(define_expand "simple_return"
[(simple_return)]
""
{ mips_expand_before_return (); })
(define_insn "*<optab>"
[(any_return)]
""
"%*j\t$31%/"
[(set_attr "type" "jump")
(set_attr "mode" "none")])
;; Normal return.
(define_insn "return_internal"
[(return)
(define_insn "<optab>_internal"
[(any_return)
(use (match_operand 0 "pmode_register_operand" ""))]
""
"%*j\t%0%/"

1
gcc/df-scan.c
View file

@ -3181,6 +3181,7 @@ df_uses_record (struct df_collection_rec *collection_rec,
}
case RETURN:
case SIMPLE_RETURN:
break;
case ASM_OPERANDS:

14
gcc/doc/md.texi
View file

@ -4992,6 +4992,20 @@ some class of functions only requires one instruction to implement a
return. Normally, the applicable functions are those which do not need
to save any registers or allocate stack space.
It is valid for this pattern to expand to an instruction using
@code{simple_return} if no epilogue is required.
@cindex @code{simple_return} instruction pattern
@item @samp{simple_return}
Subroutine return instruction. This instruction pattern name should be
defined only if a single instruction can do all the work of returning
from a function on a path where no epilogue is required. This pattern
is very similar to the @code{return} instruction pattern, but it is emitted
only by the shrink-wrapping optimization on paths where the function
prologue has not been executed, and a function return should occur without
any of the effects of the epilogue. Additional uses may be introduced on
paths where both the prologue and the epilogue have executed.
@findex reload_completed
@findex leaf_function_p
For such machines, the condition specified in this pattern should only

27
gcc/doc/rtl.texi
View file

@ -2915,6 +2915,13 @@ placed in @code{pc} to return to the caller.
Note that an insn pattern of @code{(return)} is logically equivalent to
@code{(set (pc) (return))}, but the latter form is never used.
@findex simple_return
@item (simple_return)
Like @code{(return)}, but truly represents only a function return, while
@code{(return)} may represent an insn that also performs other functions
of the function epilogue. Like @code{(return)}, this may also occur in
conditional jumps.
@findex call
@item (call @var{function} @var{nargs})
Represents a function call. @var{function} is a @code{mem} expression
@ -3044,7 +3051,7 @@ Represents several side effects performed in parallel. The square
brackets stand for a vector; the operand of @code{parallel} is a
vector of expressions. @var{x0}, @var{x1} and so on are individual
side effect expressions---expressions of code @code{set}, @code{call},
@code{return}, @code{clobber} or @code{use}.
@code{return}, @code{simple_return}, @code{clobber} or @code{use}.
``In parallel'' means that first all the values used in the individual
side-effects are computed, and second all the actual side-effects are
@ -3683,14 +3690,16 @@ and @code{call_insn} insns:
@table @code
@findex PATTERN
@item PATTERN (@var{i})
An expression for the side effect performed by this insn. This must be
one of the following codes: @code{set}, @code{call}, @code{use},
@code{clobber}, @code{return}, @code{asm_input}, @code{asm_output},
@code{addr_vec}, @code{addr_diff_vec}, @code{trap_if}, @code{unspec},
@code{unspec_volatile}, @code{parallel}, @code{cond_exec}, or @code{sequence}. If it is a @code{parallel},
each element of the @code{parallel} must be one these codes, except that
@code{parallel} expressions cannot be nested and @code{addr_vec} and
@code{addr_diff_vec} are not permitted inside a @code{parallel} expression.
An expression for the side effect performed by this insn. This must
be one of the following codes: @code{set}, @code{call}, @code{use},
@code{clobber}, @code{return}, @code{simple_return}, @code{asm_input},
@code{asm_output}, @code{addr_vec}, @code{addr_diff_vec},
@code{trap_if}, @code{unspec}, @code{unspec_volatile},
@code{parallel}, @code{cond_exec}, or @code{sequence}. If it is a
@code{parallel}, each element of the @code{parallel} must be one these
codes, except that @code{parallel} expressions cannot be nested and
@code{addr_vec} and @code{addr_diff_vec} are not permitted inside a
@code{parallel} expression.
@findex INSN_CODE
@item INSN_CODE (@var{i})

7
gcc/emit-rtl.c
View file

@ -2518,6 +2518,7 @@ verify_rtx_sharing (rtx orig, rtx insn)
case PC:
case CC0:
case RETURN:
case SIMPLE_RETURN:
case SCRATCH:
return;
/* SCRATCH must be shared because they represent distinct values. */
@ -2725,6 +2726,7 @@ repeat:
case PC:
case CC0:
case RETURN:
case SIMPLE_RETURN:
case SCRATCH:
/* SCRATCH must be shared because they represent distinct values. */
return;
@ -2845,6 +2847,7 @@ repeat:
case PC:
case CC0:
case RETURN:
case SIMPLE_RETURN:
return;
case DEBUG_INSN:
@ -5008,7 +5011,7 @@ classify_insn (rtx x)
return CODE_LABEL;
if (GET_CODE (x) == CALL)
return CALL_INSN;
if (GET_CODE (x) == RETURN)
if (ANY_RETURN_P (x))
return JUMP_INSN;
if (GET_CODE (x) == SET)
{
@ -5264,6 +5267,7 @@ copy_insn_1 (rtx orig)
case PC:
case CC0:
case RETURN:
case SIMPLE_RETURN:
return orig;
case CLOBBER:
if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER)
@ -5521,6 +5525,7 @@ init_emit_regs (void)
/* Assign register numbers to the globally defined register rtx. */
pc_rtx = gen_rtx_fmt_ (PC, VOIDmode);
ret_rtx = gen_rtx_fmt_ (RETURN, VOIDmode);
simple_return_rtx = gen_rtx_fmt_ (SIMPLE_RETURN, VOIDmode);
cc0_rtx = gen_rtx_fmt_ (CC0, VOIDmode);
stack_pointer_rtx = gen_raw_REG (Pmode, STACK_POINTER_REGNUM);
frame_pointer_rtx = gen_raw_REG (Pmode, FRAME_POINTER_REGNUM);

2
gcc/final.c
View file

@ -2492,7 +2492,7 @@ final_scan_insn (rtx insn, FILE *file, int optimize_p ATTRIBUTE_UNUSED,
delete_insn (insn);
break;
}
else if (GET_CODE (SET_SRC (body)) == RETURN)
else if (ANY_RETURN_P (SET_SRC (body)))
/* Replace (set (pc) (return)) with (return). */
PATTERN (insn) = body = SET_SRC (body);

6
gcc/function.c
View file

@ -5306,7 +5306,11 @@ static void
emit_return_into_block (basic_block bb)
{
rtx jump = emit_jump_insn_after (gen_return (), BB_END (bb));
JUMP_LABEL (jump) = ret_rtx;
rtx pat = PATTERN (jump);
if (GET_CODE (pat) == PARALLEL)
pat = XVECEXP (pat, 0, 0);
gcc_assert (ANY_RETURN_P (pat));
JUMP_LABEL (jump) = pat;
}
#endif /* HAVE_return */

9
gcc/genemit.c
View file

@ -169,6 +169,9 @@ gen_exp (rtx x, enum rtx_code subroutine_type, char *used)
case RETURN:
printf ("ret_rtx");
return;
case SIMPLE_RETURN:
printf ("simple_return_rtx");
return;
case CLOBBER:
if (REG_P (XEXP (x, 0)))
{
@ -489,8 +492,8 @@ gen_expand (rtx expand)
|| (GET_CODE (next) == PARALLEL
&& ((GET_CODE (XVECEXP (next, 0, 0)) == SET
&& GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
|| GET_CODE (XVECEXP (next, 0, 0)) == RETURN))
|| GET_CODE (next) == RETURN)
|| ANY_RETURN_P (XVECEXP (next, 0, 0))))
|| ANY_RETURN_P (next))
printf (" emit_jump_insn (");
else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
|| GET_CODE (next) == CALL
@ -607,7 +610,7 @@ gen_split (rtx split)
|| (GET_CODE (next) == PARALLEL
&& GET_CODE (XVECEXP (next, 0, 0)) == SET
&& GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
|| GET_CODE (next) == RETURN)
|| ANY_RETURN_P (next))
printf (" emit_jump_insn (");
else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
|| GET_CODE (next) == CALL

1
gcc/gengenrtl.c
View file

@ -131,6 +131,7 @@ special_rtx (int idx)
|| strcmp (defs[idx].enumname, "PC") == 0
|| strcmp (defs[idx].enumname, "CC0") == 0
|| strcmp (defs[idx].enumname, "RETURN") == 0
|| strcmp (defs[idx].enumname, "SIMPLE_RETURN") == 0
|| strcmp (defs[idx].enumname, "CONST_VECTOR") == 0);
}

11
gcc/ifcvt.c
View file

@ -3796,6 +3796,7 @@ find_if_case_1 (basic_block test_bb, edge then_edge, edge else_edge)
basic_block then_bb = then_edge->dest;
basic_block else_bb = else_edge->dest;
basic_block new_bb;
rtx else_target = NULL_RTX;
int then_bb_index;
/* If we are partitioning hot/cold basic blocks, we don't want to
@ -3845,6 +3846,13 @@ find_if_case_1 (basic_block test_bb, edge then_edge, edge else_edge)
predictable_edge_p (then_edge)))))
return FALSE;
if (else_bb == EXIT_BLOCK_PTR)
{
rtx jump = BB_END (else_edge->src);
gcc_assert (JUMP_P (jump));
else_target = JUMP_LABEL (jump);
}
/* Registers set are dead, or are predicable. */
if (! dead_or_predicable (test_bb, then_bb, else_bb,
single_succ_edge (then_bb), 1))
@ -3864,6 +3872,9 @@ find_if_case_1 (basic_block test_bb, edge then_edge, edge else_edge)
redirect_edge_succ (FALLTHRU_EDGE (test_bb), else_bb);
new_bb = 0;
}
else if (else_bb == EXIT_BLOCK_PTR)
new_bb = force_nonfallthru_and_redirect (FALLTHRU_EDGE (test_bb),
else_bb, else_target);
else
new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb),
else_bb);

17
gcc/jump.c
View file

@ -29,7 +29,8 @@ along with GCC; see the file COPYING3. If not see
JUMP_LABEL internal field. With this we can detect labels that
become unused because of the deletion of all the jumps that
formerly used them. The JUMP_LABEL info is sometimes looked
at by later passes.
at by later passes. For return insns, it contains either a
RETURN or a SIMPLE_RETURN rtx.
The subroutines redirect_jump and invert_jump are used
from other passes as well. */
@ -775,10 +776,10 @@ condjump_p (const_rtx insn)
return (GET_CODE (x) == IF_THEN_ELSE
&& ((GET_CODE (XEXP (x, 2)) == PC
&& (GET_CODE (XEXP (x, 1)) == LABEL_REF
|| GET_CODE (XEXP (x, 1)) == RETURN))
|| ANY_RETURN_P (XEXP (x, 1))))
|| (GET_CODE (XEXP (x, 1)) == PC
&& (GET_CODE (XEXP (x, 2)) == LABEL_REF
|| GET_CODE (XEXP (x, 2)) == RETURN))));
|| ANY_RETURN_P (XEXP (x, 2))))));
}
/* Return nonzero if INSN is a (possibly) conditional jump inside a
@ -807,11 +808,11 @@ condjump_in_parallel_p (const_rtx insn)
return 0;
if (XEXP (SET_SRC (x), 2) == pc_rtx
&& (GET_CODE (XEXP (SET_SRC (x), 1)) == LABEL_REF
|| GET_CODE (XEXP (SET_SRC (x), 1)) == RETURN))
|| ANY_RETURN_P (XEXP (SET_SRC (x), 1))))
return 1;
if (XEXP (SET_SRC (x), 1) == pc_rtx
&& (GET_CODE (XEXP (SET_SRC (x), 2)) == LABEL_REF
|| GET_CODE (XEXP (SET_SRC (x), 2)) == RETURN))
|| ANY_RETURN_P (XEXP (SET_SRC (x), 2))))
return 1;
return 0;
}
@ -873,8 +874,9 @@ any_condjump_p (const_rtx insn)
a = GET_CODE (XEXP (SET_SRC (x), 1));
b = GET_CODE (XEXP (SET_SRC (x), 2));
return ((b == PC && (a == LABEL_REF || a == RETURN))
|| (a == PC && (b == LABEL_REF || b == RETURN)));
return ((b == PC && (a == LABEL_REF || a == RETURN || a == SIMPLE_RETURN))
|| (a == PC
&& (b == LABEL_REF || b == RETURN || b == SIMPLE_RETURN)));
}
/* Return the label of a conditional jump. */
@ -911,6 +913,7 @@ returnjump_p_1 (rtx *loc, void *data ATTRIBUTE_UNUSED)
switch (GET_CODE (x))
{
case RETURN:
case SIMPLE_RETURN:
case EH_RETURN:
return true;

2
gcc/print-rtl.c
View file

@ -328,6 +328,8 @@ print_rtx (const_rtx in_rtx)
fprintf (outfile, "\n%s%*s -> ", print_rtx_head, indent * 2, "");
if (GET_CODE (JUMP_LABEL (in_rtx)) == RETURN)
fprintf (outfile, "return");
else if (GET_CODE (JUMP_LABEL (in_rtx)) == SIMPLE_RETURN)
fprintf (outfile, "simple_return");
else
fprintf (outfile, "%d", INSN_UID (JUMP_LABEL (in_rtx)));
}

327
gcc/reorg.c
View file

@ -161,8 +161,11 @@ static rtx *unfilled_firstobj;
#define unfilled_slots_next \
((rtx *) obstack_next_free (&unfilled_slots_obstack))
/* Points to the label before the end of the function. */
static rtx end_of_function_label;
/* Points to the label before the end of the function, or before a
return insn. */
static rtx function_return_label;
/* Likewise for a simple_return. */
static rtx function_simple_return_label;
/* Mapping between INSN_UID's and position in the code since INSN_UID's do
not always monotonically increase. */
@ -175,7 +178,7 @@ static int stop_search_p (rtx, int);
static int resource_conflicts_p (struct resources *, struct resources *);
static int insn_references_resource_p (rtx, struct resources *, bool);
static int insn_sets_resource_p (rtx, struct resources *, bool);
static rtx find_end_label (void);
static rtx find_end_label (rtx);
static rtx emit_delay_sequence (rtx, rtx, int);
static rtx add_to_delay_list (rtx, rtx);
static rtx delete_from_delay_slot (rtx);
@ -231,6 +234,15 @@ first_active_target_insn (rtx insn)
return next_active_insn (insn);
}
/* Return true iff INSN is a simplejump, or any kind of return insn. */
static bool
simplejump_or_return_p (rtx insn)
{
return (JUMP_P (insn)
&& (simplejump_p (insn) || ANY_RETURN_P (PATTERN (insn))));
}
/* Return TRUE if this insn should stop the search for insn to fill delay
slots. LABELS_P indicates that labels should terminate the search.
In all cases, jumps terminate the search. */
@ -346,23 +358,34 @@ insn_sets_resource_p (rtx insn, struct resources *res,
??? There may be a problem with the current implementation. Suppose
we start with a bare RETURN insn and call find_end_label. It may set
end_of_function_label just before the RETURN. Suppose the machinery
function_return_label just before the RETURN. Suppose the machinery
is able to fill the delay slot of the RETURN insn afterwards. Then
end_of_function_label is no longer valid according to the property
function_return_label is no longer valid according to the property
described above and find_end_label will still return it unmodified.
Note that this is probably mitigated by the following observation:
once end_of_function_label is made, it is very likely the target of
once function_return_label is made, it is very likely the target of
a jump, so filling the delay slot of the RETURN will be much more
difficult. */
difficult.
KIND is either simple_return_rtx or ret_rtx, indicating which type of
return we're looking for. */
static rtx
find_end_label (void)
find_end_label (rtx kind)
{
rtx insn;
rtx *plabel;
if (kind == ret_rtx)
plabel = &function_return_label;
else
{
gcc_assert (kind == simple_return_rtx);
plabel = &function_simple_return_label;
}
/* If we found one previously, return it. */
if (end_of_function_label)
return end_of_function_label;
if (*plabel)
return *plabel;
/* Otherwise, see if there is a label at the end of the function. If there
is, it must be that RETURN insns aren't needed, so that is our return
@ -377,44 +400,45 @@ find_end_label (void)
/* When a target threads its epilogue we might already have a
suitable return insn. If so put a label before it for the
end_of_function_label. */
function_return_label. */
if (BARRIER_P (insn)
&& JUMP_P (PREV_INSN (insn))
&& GET_CODE (PATTERN (PREV_INSN (insn))) == RETURN)
&& PATTERN (PREV_INSN (insn)) == kind)
{
rtx temp = PREV_INSN (PREV_INSN (insn));
end_of_function_label = gen_label_rtx ();
LABEL_NUSES (end_of_function_label) = 0;
rtx label = gen_label_rtx ();
LABEL_NUSES (label) = 0;
/* Put the label before an USE insns that may precede the RETURN insn. */
/* Put the label before any USE insns that may precede the RETURN
insn. */
while (GET_CODE (temp) == USE)
temp = PREV_INSN (temp);
emit_label_after (end_of_function_label, temp);
emit_label_after (label, temp);
*plabel = label;
}
else if (LABEL_P (insn))
end_of_function_label = insn;
*plabel = insn;
else
{
end_of_function_label = gen_label_rtx ();
LABEL_NUSES (end_of_function_label) = 0;
rtx label = gen_label_rtx ();
LABEL_NUSES (label) = 0;
/* If the basic block reorder pass moves the return insn to
some other place try to locate it again and put our
end_of_function_label there. */
while (insn && ! (JUMP_P (insn)
&& (GET_CODE (PATTERN (insn)) == RETURN)))
function_return_label there. */
while (insn && ! (JUMP_P (insn) && (PATTERN (insn) == kind)))
insn = PREV_INSN (insn);
if (insn)
{
insn = PREV_INSN (insn);
/* Put the label before an USE insns that may proceed the
/* Put the label before any USE insns that may precede the
RETURN insn. */
while (GET_CODE (insn) == USE)
insn = PREV_INSN (insn);
emit_label_after (end_of_function_label, insn);
emit_label_after (label, insn);
}
else
{
@ -424,19 +448,16 @@ find_end_label (void)
&& ! HAVE_return
#endif
)
{
/* The RETURN insn has its delay slot filled so we cannot
emit the label just before it. Since we already have
an epilogue and cannot emit a new RETURN, we cannot
emit the label at all. */
end_of_function_label = NULL_RTX;
return end_of_function_label;
}
/* The RETURN insn has its delay slot filled so we cannot
emit the label just before it. Since we already have
an epilogue and cannot emit a new RETURN, we cannot
emit the label at all. */
return NULL_RTX;
#endif /* HAVE_epilogue */
/* Otherwise, make a new label and emit a RETURN and BARRIER,
if needed. */
emit_label (end_of_function_label);
emit_label (label);
#ifdef HAVE_return
/* We don't bother trying to create a return insn if the
epilogue has filled delay-slots; we would have to try and
@ -455,13 +476,14 @@ find_end_label (void)
}
#endif
}
*plabel = label;
}
/* Show one additional use for this label so it won't go away until
we are done. */
++LABEL_NUSES (end_of_function_label);
++LABEL_NUSES (*plabel);
return end_of_function_label;
return *plabel;
}
/* Put INSN and LIST together in a SEQUENCE rtx of LENGTH, and replace
@ -809,10 +831,8 @@ optimize_skip (rtx insn)
if ((next_trial == next_active_insn (JUMP_LABEL (insn))
&& ! (next_trial == 0 && crtl->epilogue_delay_list != 0))
|| (next_trial != 0
&& JUMP_P (next_trial)
&& JUMP_LABEL (insn) == JUMP_LABEL (next_trial)
&& (simplejump_p (next_trial)
|| GET_CODE (PATTERN (next_trial)) == RETURN)))
&& simplejump_or_return_p (next_trial)
&& JUMP_LABEL (insn) == JUMP_LABEL (next_trial)))
{
if (eligible_for_annul_false (insn, 0, trial, flags))
{
@ -831,13 +851,11 @@ optimize_skip (rtx insn)
branch, thread our jump to the target of that branch. Don't
change this into a RETURN here, because it may not accept what
we have in the delay slot. We'll fix this up later. */
if (next_trial && JUMP_P (next_trial)
&& (simplejump_p (next_trial)
|| GET_CODE (PATTERN (next_trial)) == RETURN))
if (next_trial && simplejump_or_return_p (next_trial))
{
rtx target_label = JUMP_LABEL (next_trial);
if (ANY_RETURN_P (target_label))
target_label = find_end_label ();
target_label = find_end_label (target_label);
if (target_label)
{
@ -951,7 +969,7 @@ rare_destination (rtx insn)
return. */
return 2;
case JUMP_INSN:
if (GET_CODE (PATTERN (insn)) == RETURN)
if (ANY_RETURN_P (PATTERN (insn)))
return 1;
else if (simplejump_p (insn)
&& jump_count++ < 10)
@ -1368,8 +1386,7 @@ steal_delay_list_from_fallthrough (rtx insn, rtx condition, rtx seq,
/* We can't do anything if SEQ's delay insn isn't an
unconditional branch. */
if (! simplejump_p (XVECEXP (seq, 0, 0))
&& GET_CODE (PATTERN (XVECEXP (seq, 0, 0))) != RETURN)
if (! simplejump_or_return_p (XVECEXP (seq, 0, 0)))
return delay_list;
for (i = 1; i < XVECLEN (seq, 0); i++)
@ -2383,7 +2400,7 @@ fill_simple_delay_slots (int non_jumps_p)
if (new_label != 0)
new_label = get_label_before (new_label);
else
new_label = find_end_label ();
new_label = find_end_label (simple_return_rtx);
if (new_label)
{
@ -2515,7 +2532,8 @@ fill_simple_delay_slots (int non_jumps_p)
/* Follow any unconditional jump at LABEL;
return the ultimate label reached by any such chain of jumps.
Return ret_rtx if the chain ultimately leads to a return instruction.
Return a suitable return rtx if the chain ultimately leads to a
return instruction.
If LABEL is not followed by a jump, return LABEL.
If the chain loops or we can't find end, return LABEL,
since that tells caller to avoid changing the insn. */
@ -2536,7 +2554,7 @@ follow_jumps (rtx label)
&& JUMP_P (insn)
&& JUMP_LABEL (insn) != NULL_RTX
&& ((any_uncondjump_p (insn) && onlyjump_p (insn))
|| GET_CODE (PATTERN (insn)) == RETURN)
|| ANY_RETURN_P (PATTERN (insn)))
&& (next = NEXT_INSN (insn))
&& BARRIER_P (next));
depth++)
@ -3003,16 +3021,14 @@ fill_slots_from_thread (rtx insn, rtx condition, rtx thread,
gcc_assert (thread_if_true);
if (new_thread && JUMP_P (new_thread)
&& (simplejump_p (new_thread)
|| GET_CODE (PATTERN (new_thread)) == RETURN)
if (new_thread && simplejump_or_return_p (new_thread)
&& redirect_with_delay_list_safe_p (insn,
JUMP_LABEL (new_thread),
delay_list))
new_thread = follow_jumps (JUMP_LABEL (new_thread));
if (ANY_RETURN_P (new_thread))
label = find_end_label ();
label = find_end_label (new_thread);
else if (LABEL_P (new_thread))
label = new_thread;
else
@ -3362,7 +3378,7 @@ relax_delay_slots (rtx first)
{
target_label = skip_consecutive_labels (follow_jumps (target_label));
if (ANY_RETURN_P (target_label))
target_label = find_end_label ();
target_label = find_end_label (target_label);
if (target_label && next_active_insn (target_label) == next
&& ! condjump_in_parallel_p (insn))
@ -3377,9 +3393,8 @@ relax_delay_slots (rtx first)
/* See if this jump conditionally branches around an unconditional
jump. If so, invert this jump and point it to the target of the
second jump. */
if (next && JUMP_P (next)
if (next && simplejump_or_return_p (next)
&& any_condjump_p (insn)
&& (simplejump_p (next) || GET_CODE (PATTERN (next)) == RETURN)
&& target_label
&& next_active_insn (target_label) == next_active_insn (next)
&& no_labels_between_p (insn, next))
@ -3421,8 +3436,7 @@ relax_delay_slots (rtx first)
Don't do this if we expect the conditional branch to be true, because
we would then be making the more common case longer. */
if (JUMP_P (insn)
&& (simplejump_p (insn) || GET_CODE (PATTERN (insn)) == RETURN)
if (simplejump_or_return_p (insn)
&& (other = prev_active_insn (insn)) != 0
&& any_condjump_p (other)
&& no_labels_between_p (other, insn)
@ -3463,10 +3477,10 @@ relax_delay_slots (rtx first)
Only do so if optimizing for size since this results in slower, but
smaller code. */
if (optimize_function_for_size_p (cfun)
&& GET_CODE (PATTERN (delay_insn)) == RETURN
&& ANY_RETURN_P (PATTERN (delay_insn))
&& next
&& JUMP_P (next)
&& GET_CODE (PATTERN (next)) == RETURN)
&& PATTERN (next) == PATTERN (delay_insn))
{
rtx after;
int i;
@ -3505,73 +3519,71 @@ relax_delay_slots (rtx first)
continue;
target_label = JUMP_LABEL (delay_insn);
if (target_label && ANY_RETURN_P (target_label))
continue;
if (!ANY_RETURN_P (target_label))
/* If this jump goes to another unconditional jump, thread it, but
don't convert a jump into a RETURN here. */
trial = skip_consecutive_labels (follow_jumps (target_label));
if (ANY_RETURN_P (trial))
trial = find_end_label (trial);
if (trial && trial != target_label
&& redirect_with_delay_slots_safe_p (delay_insn, trial, insn))
{
/* If this jump goes to another unconditional jump, thread it, but
don't convert a jump into a RETURN here. */
trial = skip_consecutive_labels (follow_jumps (target_label));
if (ANY_RETURN_P (trial))
trial = find_end_label ();
reorg_redirect_jump (delay_insn, trial);
target_label = trial;
}
if (trial && trial != target_label
&& redirect_with_delay_slots_safe_p (delay_insn, trial, insn))
/* If the first insn at TARGET_LABEL is redundant with a previous
insn, redirect the jump to the following insn and process again.
We use next_real_insn instead of next_active_insn so we
don't skip USE-markers, or we'll end up with incorrect
liveness info. */
trial = next_real_insn (target_label);
if (trial && GET_CODE (PATTERN (trial)) != SEQUENCE
&& redundant_insn (trial, insn, 0)
&& ! can_throw_internal (trial))
{
/* Figure out where to emit the special USE insn so we don't
later incorrectly compute register live/death info. */
rtx tmp = next_active_insn (trial);
if (tmp == 0)
tmp = find_end_label (simple_return_rtx);
if (tmp)
{
reorg_redirect_jump (delay_insn, trial);
target_label = trial;
/* Insert the special USE insn and update dataflow info. */
update_block (trial, tmp);
/* Now emit a label before the special USE insn, and
redirect our jump to the new label. */
target_label = get_label_before (PREV_INSN (tmp));
reorg_redirect_jump (delay_insn, target_label);
next = insn;
continue;
}
}
/* If the first insn at TARGET_LABEL is redundant with a previous
insn, redirect the jump to the following insn and process again.
We use next_real_insn instead of next_active_insn so we
don't skip USE-markers, or we'll end up with incorrect
liveness info. */
trial = next_real_insn (target_label);
if (trial && GET_CODE (PATTERN (trial)) != SEQUENCE
&& redundant_insn (trial, insn, 0)
&& ! can_throw_internal (trial))
/* Similarly, if it is an unconditional jump with one insn in its
delay list and that insn is redundant, thread the jump. */
if (trial && GET_CODE (PATTERN (trial)) == SEQUENCE
&& XVECLEN (PATTERN (trial), 0) == 2
&& JUMP_P (XVECEXP (PATTERN (trial), 0, 0))
&& simplejump_or_return_p (XVECEXP (PATTERN (trial), 0, 0))
&& redundant_insn (XVECEXP (PATTERN (trial), 0, 1), insn, 0))
{
target_label = JUMP_LABEL (XVECEXP (PATTERN (trial), 0, 0));
if (ANY_RETURN_P (target_label))
target_label = find_end_label (target_label);
if (target_label
&& redirect_with_delay_slots_safe_p (delay_insn, target_label,
insn))
{
/* Figure out where to emit the special USE insn so we don't
later incorrectly compute register live/death info. */
rtx tmp = next_active_insn (trial);
if (tmp == 0)
tmp = find_end_label ();
if (tmp)
{
/* Insert the special USE insn and update dataflow info. */
update_block (trial, tmp);
/* Now emit a label before the special USE insn, and
redirect our jump to the new label. */
target_label = get_label_before (PREV_INSN (tmp));
reorg_redirect_jump (delay_insn, target_label);
next = insn;
continue;
}
}
/* Similarly, if it is an unconditional jump with one insn in its
delay list and that insn is redundant, thread the jump. */
if (trial && GET_CODE (PATTERN (trial)) == SEQUENCE
&& XVECLEN (PATTERN (trial), 0) == 2
&& JUMP_P (XVECEXP (PATTERN (trial), 0, 0))
&& (simplejump_p (XVECEXP (PATTERN (trial), 0, 0))
|| GET_CODE (PATTERN (XVECEXP (PATTERN (trial), 0, 0))) == RETURN)
&& redundant_insn (XVECEXP (PATTERN (trial), 0, 1), insn, 0))
{
target_label = JUMP_LABEL (XVECEXP (PATTERN (trial), 0, 0));
if (ANY_RETURN_P (target_label))
target_label = find_end_label ();
if (target_label
&& redirect_with_delay_slots_safe_p (delay_insn, target_label,
insn))
{
reorg_redirect_jump (delay_insn, target_label);
next = insn;
continue;
}
reorg_redirect_jump (delay_insn, target_label);
next = insn;
continue;
}
}
@ -3640,8 +3652,7 @@ relax_delay_slots (rtx first)
a RETURN here. */
if (! INSN_ANNULLED_BRANCH_P (delay_insn)
&& any_condjump_p (delay_insn)
&& next && JUMP_P (next)
&& (simplejump_p (next) || GET_CODE (PATTERN (next)) == RETURN)
&& next && simplejump_or_return_p (next)
&& next_active_insn (target_label) == next_active_insn (next)
&& no_labels_between_p (insn, next))
{
@ -3649,7 +3660,7 @@ relax_delay_slots (rtx first)
rtx old_label = JUMP_LABEL (delay_insn);
if (ANY_RETURN_P (label))
label = find_end_label ();
label = find_end_label (label);
/* find_end_label can generate a new label. Check this first. */
if (label
@ -3710,7 +3721,8 @@ static void
make_return_insns (rtx first)
{
rtx insn, jump_insn, pat;
rtx real_return_label = end_of_function_label;
rtx real_return_label = function_return_label;
rtx real_simple_return_label = function_simple_return_label;
int slots, i;
#ifdef DELAY_SLOTS_FOR_EPILOGUE
@ -3728,15 +3740,22 @@ make_return_insns (rtx first)
made for END_OF_FUNCTION_LABEL. If so, set up anything we can't change
into a RETURN to jump to it. */
for (insn = first; insn; insn = NEXT_INSN (insn))
if (JUMP_P (insn) && GET_CODE (PATTERN (insn)) == RETURN)
if (JUMP_P (insn) && ANY_RETURN_P (PATTERN (insn)))
{
real_return_label = get_label_before (insn);
rtx t = get_label_before (insn);
if (PATTERN (insn) == ret_rtx)
real_return_label = t;
else
real_simple_return_label = t;
break;
}
/* Show an extra usage of REAL_RETURN_LABEL so it won't go away if it
was equal to END_OF_FUNCTION_LABEL. */
LABEL_NUSES (real_return_label)++;
if (real_return_label)
LABEL_NUSES (real_return_label)++;
if (real_simple_return_label)
LABEL_NUSES (real_simple_return_label)++;
/* Clear the list of insns to fill so we can use it. */
obstack_free (&unfilled_slots_obstack, unfilled_firstobj);
@ -3744,13 +3763,27 @@ make_return_insns (rtx first)
for (insn = first; insn; insn = NEXT_INSN (insn))
{
int flags;
rtx kind, real_label;
/* Only look at filled JUMP_INSNs that go to the end of function
label. */
if (!NONJUMP_INSN_P (insn)
|| GET_CODE (PATTERN (insn)) != SEQUENCE
|| !JUMP_P (XVECEXP (PATTERN (insn), 0, 0))
|| JUMP_LABEL (XVECEXP (PATTERN (insn), 0, 0)) != end_of_function_label)
|| !jump_to_label_p (XVECEXP (PATTERN (insn), 0, 0)))
continue;
if (JUMP_LABEL (XVECEXP (PATTERN (insn), 0, 0)) == function_return_label)
{
kind = ret_rtx;
real_label = real_return_label;
}
else if (JUMP_LABEL (XVECEXP (PATTERN (insn), 0, 0))
== function_simple_return_label)
{
kind = simple_return_rtx;
real_label = real_simple_return_label;
}
else
continue;
pat = PATTERN (insn);
@ -3758,14 +3791,12 @@ make_return_insns (rtx first)
/* If we can't make the jump into a RETURN, try to redirect it to the best
RETURN and go on to the next insn. */
if (! reorg_redirect_jump (jump_insn, ret_rtx))
if (!reorg_redirect_jump (jump_insn, kind))
{
/* Make sure redirecting the jump will not invalidate the delay
slot insns. */
if (redirect_with_delay_slots_safe_p (jump_insn,
real_return_label,
insn))
reorg_redirect_jump (jump_insn, real_return_label);
if (redirect_with_delay_slots_safe_p (jump_insn, real_label, insn))
reorg_redirect_jump (jump_insn, real_label);
continue;
}
@ -3805,7 +3836,7 @@ make_return_insns (rtx first)
RETURN, delete the SEQUENCE and output the individual insns,
followed by the RETURN. Then set things up so we try to find
insns for its delay slots, if it needs some. */
if (GET_CODE (PATTERN (jump_insn)) == RETURN)
if (ANY_RETURN_P (PATTERN (jump_insn)))
{
rtx prev = PREV_INSN (insn);
@ -3822,13 +3853,16 @@ make_return_insns (rtx first)
else
/* It is probably more efficient to keep this with its current
delay slot as a branch to a RETURN. */
reorg_redirect_jump (jump_insn, real_return_label);
reorg_redirect_jump (jump_insn, real_label);
}
/* Now delete REAL_RETURN_LABEL if we never used it. Then try to fill any
new delay slots we have created. */
if (--LABEL_NUSES (real_return_label) == 0)
if (real_return_label != NULL_RTX && --LABEL_NUSES (real_return_label) == 0)
delete_related_insns (real_return_label);
if (real_simple_return_label != NULL_RTX
&& --LABEL_NUSES (real_simple_return_label) == 0)
delete_related_insns (real_simple_return_label);
fill_simple_delay_slots (1);
fill_simple_delay_slots (0);
@ -3842,6 +3876,7 @@ dbr_schedule (rtx first)
{
rtx insn, next, epilogue_insn = 0;
int i;
bool need_return_insns;
/* If the current function has no insns other than the prologue and
epilogue, then do not try to fill any delay slots. */
@ -3897,7 +3932,7 @@ dbr_schedule (rtx first)
init_resource_info (epilogue_insn);
/* Show we haven't computed an end-of-function label yet. */
end_of_function_label = 0;
function_return_label = function_simple_return_label = NULL_RTX;
/* Initialize the statistics for this function. */
memset (num_insns_needing_delays, 0, sizeof num_insns_needing_delays);
@ -3919,13 +3954,21 @@ dbr_schedule (rtx first)
/* If we made an end of function label, indicate that it is now
safe to delete it by undoing our prior adjustment to LABEL_NUSES.
If it is now unused, delete it. */
if (end_of_function_label && --LABEL_NUSES (end_of_function_label) == 0)
delete_related_insns (end_of_function_label);
if (function_return_label && --LABEL_NUSES (function_return_label) == 0)
delete_related_insns (function_return_label);
if (function_simple_return_label
&& --LABEL_NUSES (function_simple_return_label) == 0)
delete_related_insns (function_simple_return_label);
need_return_insns = false;
#ifdef HAVE_return
if (HAVE_return && end_of_function_label != 0)
make_return_insns (first);
need_return_insns |= HAVE_return && function_return_label != 0;
#endif
#ifdef HAVE_simple_return
need_return_insns |= HAVE_simple_return && function_simple_return_label != 0;
#endif
if (need_return_insns)
make_return_insns (first);
/* Delete any USE insns made by update_block; subsequent passes don't need
them or know how to deal with them. */

4
gcc/resource.c
View file

@ -492,7 +492,7 @@ find_dead_or_set_registers (rtx target, struct resources *res,
if (jump_count++ < 10)
{
if (any_uncondjump_p (this_jump_insn)
|| GET_CODE (PATTERN (this_jump_insn)) == RETURN)
|| ANY_RETURN_P (PATTERN (this_jump_insn)))
{
next = JUMP_LABEL (this_jump_insn);
if (ANY_RETURN_P (next))
@ -829,7 +829,7 @@ mark_set_resources (rtx x, struct resources *res, int in_dest,
static bool
return_insn_p (const_rtx insn)
{
if (JUMP_P (insn) && GET_CODE (PATTERN (insn)) == RETURN)
if (JUMP_P (insn) && ANY_RETURN_P (PATTERN (insn)))
return true;
if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)

1
gcc/rtl.c
View file

@ -256,6 +256,7 @@ copy_rtx (rtx orig)
case PC:
case CC0:
case RETURN:
case SIMPLE_RETURN:
case SCRATCH:
/* SCRATCH must be shared because they represent distinct values. */
return orig;

6
gcc/rtl.def
View file

@ -296,6 +296,12 @@ DEF_RTL_EXPR(CALL, "call", "ee", RTX_EXTRA)
DEF_RTL_EXPR(RETURN, "return", "", RTX_EXTRA)
/* Like RETURN, but truly represents only a function return, while
RETURN may represent an insn that also performs other functions
of the function epilogue. Like RETURN, this may also occur in
conditional jumps. */
DEF_RTL_EXPR(SIMPLE_RETURN, "simple_return", "", RTX_EXTRA)
/* Special for EH return from subroutine. */
DEF_RTL_EXPR(EH_RETURN, "eh_return", "", RTX_EXTRA)

7
gcc/rtl.h
View file

@ -432,8 +432,9 @@ struct GTY((variable_size)) rtvec_def {
(JUMP_P (INSN) && (GET_CODE (PATTERN (INSN)) == ADDR_VEC || \
GET_CODE (PATTERN (INSN)) == ADDR_DIFF_VEC))
/* Predicate yielding nonzero iff X is a return. */
#define ANY_RETURN_P(X) ((X) == ret_rtx)
/* Predicate yielding nonzero iff X is a return or simple_return. */
#define ANY_RETURN_P(X) \
(GET_CODE (X) == RETURN || GET_CODE (X) == SIMPLE_RETURN)
/* 1 if X is a unary operator. */
@ -2111,6 +2112,7 @@ enum global_rtl_index
GR_PC,
GR_CC0,
GR_RETURN,
GR_SIMPLE_RETURN,
GR_STACK_POINTER,
GR_FRAME_POINTER,
/* For register elimination to work properly these hard_frame_pointer_rtx,
@ -2206,6 +2208,7 @@ extern struct target_rtl *this_target_rtl;
/* Standard pieces of rtx, to be substituted directly into things. */
#define pc_rtx (global_rtl[GR_PC])
#define ret_rtx (global_rtl[GR_RETURN])
#define simple_return_rtx (global_rtl[GR_SIMPLE_RETURN])
#define cc0_rtx (global_rtl[GR_CC0])
/* All references to certain hard regs, except those created

3
gcc/sched-vis.c
View file

@ -554,6 +554,9 @@ print_pattern (char *buf, const_rtx x, int verbose)
case RETURN:
sprintf (buf, "return");
break;
case SIMPLE_RETURN:
sprintf (buf, "simple_return");
break;
case CALL:
print_exp (buf, x, verbose);
break;