This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: Patch ping...
- From: "Richard Guenther" <richard dot guenther at gmail dot com>
- To: "Jan Hubicka" <hubicka at ucw dot cz>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Fri, 29 Aug 2008 14:52:36 +0200
- Subject: Re: Patch ping...
- References: <20080405162606.GA22594@atrey.karlin.mff.cuni.cz> <84fc9c000804050953o429fde26jb3938827ff9dc5a@mail.gmail.com> <20080828203249.GH15545@atrey.karlin.mff.cuni.cz>
On Thu, Aug 28, 2008 at 10:32 PM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> On Sat, Apr 5, 2008 at 6:26 PM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> > Hi,
>> > I would like to ping the BRANCH_COST patch
>> > http://gcc.gnu.org/ml/gcc/2008-03/msg00137.html
>> >
>> > I hope to proceed with updating GCC to optimize cold blocks in same way
>> > as -Os and explicitely marked hot functions in -Os code for speed.
>> > For this I need to populate RTL cost interfaces with the profile info
>> > and teach expansion about it.
>> > This is taking quite some years now, I realize it might not be clear
>> > what I am precisely shooting for, so I will also add wiki page.
>>
>> I think the patch makes sense (BRANCH_COST is special anyway compared to
>> other isns cost), but I'd like to see the bigger picture as well here. In
>> particular, BRANCH_COST (hot, predictable), why isn't that simply
>> BRANCH_COST (optimize_size_p, predictable) matching what I possibly
>> expect for the other cost interface (insn_cost (optimize_size_p, rtx)).
>
> Hi,
> with the optimize_*_for_speed_p predicates, this patch becomes cleaner
> now. I would also like to update other costs similar way so we can
> avoid the current way we switch optimize_size global variable.
>
> Bootstrapped/regtested i686-linux, OK?
It looks ok, but I think that PARAM_PREDICTABLE_BRANCH_OUTCOME
should be a target macro and not a param.
Ok with that change, but please wait 24h to let others comment.
Thanks,
Richard.
> * optabs.c (expand_abs_nojump): Update BRANCH_COST call.
> * fold-cost.c (LOGICAL_OP_NON_SHORT_CIRCUIT, fold_truthop): Likewise.
> * dojump.c (do_jump): Likewise.
> * ifcvt.c (MAX_CONDITIONAL_EXECUTE): Likewise.
> (note-if_info): Add BRANCH_COST.
> (noce_try_store_flag_constants, noce_try_addcc, noce_try_store_flag_mask,
> noce_try_cmove_arith, noce_try_cmove_arith, noce_try_cmove_arith,
> noce_find_if_block, find_if_case_1, find_if_case_2): Use compuated
> branch cost.
> * expr.h (BRANCH_COST): Update default.
> * predict.c (predictable_edge_p): New function.
> * expmed.c (expand_smod_pow2, expand_sdiv_pow2, emit_store_flag):
> Update BRANCH_COST call.
> * basic-block.h (predictable_edge_p): Declare.
> * config/alpha/alpha.h (BRANCH_COST): Update.
> * config/frv/frv.h (BRANCH_COST): Update.
> * config/s390/s390.h (BRANCH_COST): Update.
> * config/spu/spu.h (BRANCH_COST): Update.
> * config/sparc/sparc.h (BRANCH_COST): Update.
> * config/m32r/m32r.h (BRANCH_COST): Update.
> * config/i386/i386.h (BRANCH_COST): Update.
> * config/i386/i386.c (ix86_expand_int_movcc): Update use of BRANCH_COST.
> * config/sh/sh.h (BRANCH_COST): Update.
> * config/pdp11/pdp11.h (BRANCH_COST): Update.
> * config/avr/avr.h (BRANCH_COST): Update.
> * config/crx/crx.h (BRANCH_COST): Update.
> * config/xtensa/xtensa.h (BRANCH_COST): Update.
> * config/stormy16/stormy16.h (BRANCH_COST): Update.
> * config/m68hc11/m68hc11.h (BRANCH_COST): Update.
> * config/iq2000/iq2000.h (BRANCH_COST): Update.
> * config/ia64/ia64.h (BRANCH_COST): Update.
> * config/rs6000/rs6000.h (BRANCH_COST): Update.
> * config/arc/arc.h (BRANCH_COST): Update.
> * config/score/score.h (BRANCH_COST): Update.
> * config/arm/arm.h (BRANCH_COST): Update.
> * config/pa/pa.h (BRANCH_COST): Update.
> * config/mips/mips.h (BRANCH_COST): Update.
> * config/vax/vax.h (BRANCH_COST): Update.
> * config/h8300/h8300.h (BRANCH_COST): Update.
> * params.def (PARAM_PREDICTABLE_BRANCH_OUTCOME): New.
> * doc/invoke.texi (predictable-branch-cost-outcome): Document.
> * doc/tm.texi (BRANCH_COST): Update.
> Index: doc/tm.texi
> ===================================================================
> *** doc/tm.texi (revision 139737)
> --- doc/tm.texi (working copy)
> *************** value to the result of that function. T
> *** 5874,5882 ****
> are the same as to this macro.
> @end defmac
>
> ! @defmac BRANCH_COST
> ! A C expression for the cost of a branch instruction. A value of 1 is
> ! the default; other values are interpreted relative to that.
> @end defmac
>
> Here are additional macros which do not specify precise relative costs,
> --- 5874,5887 ----
> are the same as to this macro.
> @end defmac
>
> ! @defmac BRANCH_COST (@var{speed_p}, @var{predictable_p})
> ! A C expression for the cost of a branch instruction. A value of 1 is the
> ! default; other values are interpreted relative to that. Parameter @var{speed_p}
> ! is true when the branch in question should be optimized for speed. When
> ! it is false, @code{BRANCH_COST} should be returning value optimal for code size
> ! rather then performance considerations. @var{predictable_p} is true for well
> ! predictable branches. On many architectures the @code{BRANCH_COST} can be
> ! reduced then.
> @end defmac
>
> Here are additional macros which do not specify precise relative costs,
> Index: doc/invoke.texi
> ===================================================================
> *** doc/invoke.texi (revision 139737)
> --- doc/invoke.texi (working copy)
> *************** to the hottest structure frequency in th
> *** 6905,6910 ****
> --- 6905,6914 ----
> parameter, then structure reorganization is not applied to this structure.
> The default is 10.
>
> + @item predictable-branch-cost-outcome
> + When branch is predicted to be taken with probability lower than this threshold
> + (in percent), then it is considered well predictable. The default is 10.
> +
> @item max-crossjump-edges
> The maximum number of incoming edges to consider for crossjumping.
> The algorithm used by @option{-fcrossjumping} is @math{O(N^2)} in
> Index: optabs.c
> ===================================================================
> *** optabs.c (revision 139737)
> --- optabs.c (working copy)
> *************** expand_abs_nojump (enum machine_mode mod
> *** 3443,3449 ****
> value of X as (((signed) x >> (W-1)) ^ x) - ((signed) x >> (W-1)),
> where W is the width of MODE. */
>
> ! if (GET_MODE_CLASS (mode) == MODE_INT && BRANCH_COST >= 2)
> {
> rtx extended = expand_shift (RSHIFT_EXPR, mode, op0,
> size_int (GET_MODE_BITSIZE (mode) - 1),
> --- 3443,3451 ----
> value of X as (((signed) x >> (W-1)) ^ x) - ((signed) x >> (W-1)),
> where W is the width of MODE. */
>
> ! if (GET_MODE_CLASS (mode) == MODE_INT
> ! && BRANCH_COST (optimize_insn_for_speed_p (),
> ! false) >= 2)
> {
> rtx extended = expand_shift (RSHIFT_EXPR, mode, op0,
> size_int (GET_MODE_BITSIZE (mode) - 1),
> Index: fold-const.c
> ===================================================================
> *** fold-const.c (revision 139737)
> --- fold-const.c (working copy)
> *************** fold_cond_expr_with_comparison (tree typ
> *** 5109,5115 ****
>
>
> #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
> ! #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
> #endif
>
> /* EXP is some logical combination of boolean tests. See if we can
> --- 5109,5117 ----
>
>
> #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
> ! #define LOGICAL_OP_NON_SHORT_CIRCUIT \
> ! (BRANCH_COST (!cfun || optimize_function_for_speed_p (cfun), \
> ! false) >= 2)
> #endif
>
> /* EXP is some logical combination of boolean tests. See if we can
> *************** fold_truthop (enum tree_code code, tree
> *** 5357,5363 ****
> that can be merged. Avoid doing this if the RHS is a floating-point
> comparison since those can trap. */
>
> ! if (BRANCH_COST >= 2
> && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
> && simple_operand_p (rl_arg)
> && simple_operand_p (rr_arg))
> --- 5359,5366 ----
> that can be merged. Avoid doing this if the RHS is a floating-point
> comparison since those can trap. */
>
> ! if (BRANCH_COST (!cfun || optimize_function_for_speed_p (cfun),
> ! false) >= 2
> && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
> && simple_operand_p (rl_arg)
> && simple_operand_p (rr_arg))
> Index: dojump.c
> ===================================================================
> *** dojump.c (revision 139737)
> --- dojump.c (working copy)
> *************** do_jump (tree exp, rtx if_false_label, r
> *** 510,516 ****
> /* High branch cost, expand as the bitwise AND of the conditions.
> Do the same if the RHS has side effects, because we're effectively
> turning a TRUTH_AND_EXPR into a TRUTH_ANDIF_EXPR. */
> ! if (BRANCH_COST >= 4 || TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1)))
> goto normal;
>
> case TRUTH_ANDIF_EXPR:
> --- 510,518 ----
> /* High branch cost, expand as the bitwise AND of the conditions.
> Do the same if the RHS has side effects, because we're effectively
> turning a TRUTH_AND_EXPR into a TRUTH_ANDIF_EXPR. */
> ! if (BRANCH_COST (optimize_insn_for_speed_p (),
> ! false) >= 4
> ! || TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1)))
> goto normal;
>
> case TRUTH_ANDIF_EXPR:
> *************** do_jump (tree exp, rtx if_false_label, r
> *** 531,537 ****
> /* High branch cost, expand as the bitwise OR of the conditions.
> Do the same if the RHS has side effects, because we're effectively
> turning a TRUTH_OR_EXPR into a TRUTH_ORIF_EXPR. */
> ! if (BRANCH_COST >= 4 || TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1)))
> goto normal;
>
> case TRUTH_ORIF_EXPR:
> --- 533,540 ----
> /* High branch cost, expand as the bitwise OR of the conditions.
> Do the same if the RHS has side effects, because we're effectively
> turning a TRUTH_OR_EXPR into a TRUTH_ORIF_EXPR. */
> ! if (BRANCH_COST (optimize_insn_for_speed_p (), false)>= 4
> ! || TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1)))
> goto normal;
>
> case TRUTH_ORIF_EXPR:
> Index: ifcvt.c
> ===================================================================
> *** ifcvt.c (revision 139737)
> --- ifcvt.c (working copy)
> ***************
> *** 67,73 ****
> #endif
>
> #ifndef MAX_CONDITIONAL_EXECUTE
> ! #define MAX_CONDITIONAL_EXECUTE (BRANCH_COST + 1)
> #endif
>
> #define IFCVT_MULTIPLE_DUMPS 1
> --- 67,75 ----
> #endif
>
> #ifndef MAX_CONDITIONAL_EXECUTE
> ! #define MAX_CONDITIONAL_EXECUTE \
> ! (BRANCH_COST (optimize_function_for_speed_p (cfun), false) \
> ! + 1)
> #endif
>
> #define IFCVT_MULTIPLE_DUMPS 1
> *************** struct noce_if_info
> *** 626,631 ****
> --- 628,636 ----
> from TEST_BB. For the noce transformations, we allow the symmetric
> form as well. */
> bool then_else_reversed;
> +
> + /* Estimated cost of the particular branch instruction. */
> + int branch_cost;
> };
>
> static rtx noce_emit_store_flag (struct noce_if_info *, rtx, int, int);
> *************** noce_try_store_flag_constants (struct no
> *** 963,982 ****
> normalize = 0;
> else if (ifalse == 0 && exact_log2 (itrue) >= 0
> && (STORE_FLAG_VALUE == 1
> ! || BRANCH_COST >= 2))
> normalize = 1;
> else if (itrue == 0 && exact_log2 (ifalse) >= 0 && can_reverse
> ! && (STORE_FLAG_VALUE == 1 || BRANCH_COST >= 2))
> normalize = 1, reversep = 1;
> else if (itrue == -1
> && (STORE_FLAG_VALUE == -1
> ! || BRANCH_COST >= 2))
> normalize = -1;
> else if (ifalse == -1 && can_reverse
> ! && (STORE_FLAG_VALUE == -1 || BRANCH_COST >= 2))
> normalize = -1, reversep = 1;
> ! else if ((BRANCH_COST >= 2 && STORE_FLAG_VALUE == -1)
> ! || BRANCH_COST >= 3)
> normalize = -1;
> else
> return FALSE;
> --- 968,987 ----
> normalize = 0;
> else if (ifalse == 0 && exact_log2 (itrue) >= 0
> && (STORE_FLAG_VALUE == 1
> ! || if_info->branch_cost >= 2))
> normalize = 1;
> else if (itrue == 0 && exact_log2 (ifalse) >= 0 && can_reverse
> ! && (STORE_FLAG_VALUE == 1 || if_info->branch_cost >= 2))
> normalize = 1, reversep = 1;
> else if (itrue == -1
> && (STORE_FLAG_VALUE == -1
> ! || if_info->branch_cost >= 2))
> normalize = -1;
> else if (ifalse == -1 && can_reverse
> ! && (STORE_FLAG_VALUE == -1 || if_info->branch_cost >= 2))
> normalize = -1, reversep = 1;
> ! else if ((if_info->branch_cost >= 2 && STORE_FLAG_VALUE == -1)
> ! || if_info->branch_cost >= 3)
> normalize = -1;
> else
> return FALSE;
> *************** noce_try_addcc (struct noce_if_info *if_
> *** 1107,1113 ****
>
> /* If that fails, construct conditional increment or decrement using
> setcc. */
> ! if (BRANCH_COST >= 2
> && (XEXP (if_info->a, 1) == const1_rtx
> || XEXP (if_info->a, 1) == constm1_rtx))
> {
> --- 1112,1118 ----
>
> /* If that fails, construct conditional increment or decrement using
> setcc. */
> ! if (if_info->branch_cost >= 2
> && (XEXP (if_info->a, 1) == const1_rtx
> || XEXP (if_info->a, 1) == constm1_rtx))
> {
> *************** noce_try_store_flag_mask (struct noce_if
> *** 1158,1164 ****
> int reversep;
>
> reversep = 0;
> ! if ((BRANCH_COST >= 2
> || STORE_FLAG_VALUE == -1)
> && ((if_info->a == const0_rtx
> && rtx_equal_p (if_info->b, if_info->x))
> --- 1163,1169 ----
> int reversep;
>
> reversep = 0;
> ! if ((if_info->branch_cost >= 2
> || STORE_FLAG_VALUE == -1)
> && ((if_info->a == const0_rtx
> && rtx_equal_p (if_info->b, if_info->x))
> *************** noce_try_cmove_arith (struct noce_if_inf
> *** 1317,1323 ****
> /* ??? FIXME: Magic number 5. */
> if (cse_not_expected
> && MEM_P (a) && MEM_P (b)
> ! && BRANCH_COST >= 5)
> {
> a = XEXP (a, 0);
> b = XEXP (b, 0);
> --- 1322,1328 ----
> /* ??? FIXME: Magic number 5. */
> if (cse_not_expected
> && MEM_P (a) && MEM_P (b)
> ! && if_info->branch_cost >= 5)
> {
> a = XEXP (a, 0);
> b = XEXP (b, 0);
> *************** noce_try_cmove_arith (struct noce_if_inf
> *** 1347,1353 ****
> if (insn_a)
> {
> insn_cost = insn_rtx_cost (PATTERN (insn_a));
> ! if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (BRANCH_COST))
> return FALSE;
> }
> else
> --- 1352,1358 ----
> if (insn_a)
> {
> insn_cost = insn_rtx_cost (PATTERN (insn_a));
> ! if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (if_info->branch_cost))
> return FALSE;
> }
> else
> *************** noce_try_cmove_arith (struct noce_if_inf
> *** 1356,1362 ****
> if (insn_b)
> {
> insn_cost += insn_rtx_cost (PATTERN (insn_b));
> ! if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (BRANCH_COST))
> return FALSE;
> }
>
> --- 1361,1367 ----
> if (insn_b)
> {
> insn_cost += insn_rtx_cost (PATTERN (insn_b));
> ! if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (if_info->branch_cost))
> return FALSE;
> }
>
> *************** noce_find_if_block (basic_block test_bb,
> *** 2831,2836 ****
> --- 2836,2843 ----
> if_info.cond_earliest = cond_earliest;
> if_info.jump = jump;
> if_info.then_else_reversed = then_else_reversed;
> + if_info.branch_cost = BRANCH_COST (optimize_bb_for_speed_p (test_bb),
> + predictable_edge_p (then_edge));
>
> /* Do the real work. */
>
> *************** find_if_case_1 (basic_block test_bb, edg
> *** 3597,3603 ****
> test_bb->index, then_bb->index);
>
> /* THEN is small. */
> ! if (! cheap_bb_rtx_cost_p (then_bb, COSTS_N_INSNS (BRANCH_COST)))
> return FALSE;
>
> /* Registers set are dead, or are predicable. */
> --- 3604,3612 ----
> test_bb->index, then_bb->index);
>
> /* THEN is small. */
> ! if (! cheap_bb_rtx_cost_p (then_bb,
> ! COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (then_edge->src),
> ! predictable_edge_p (then_edge)))))
> return FALSE;
>
> /* Registers set are dead, or are predicable. */
> *************** find_if_case_2 (basic_block test_bb, edg
> *** 3711,3717 ****
> test_bb->index, else_bb->index);
>
> /* ELSE is small. */
> ! if (! cheap_bb_rtx_cost_p (else_bb, COSTS_N_INSNS (BRANCH_COST)))
> return FALSE;
>
> /* Registers set are dead, or are predicable. */
> --- 3720,3728 ----
> test_bb->index, else_bb->index);
>
> /* ELSE is small. */
> ! if (! cheap_bb_rtx_cost_p (else_bb,
> ! COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (else_edge->src),
> ! predictable_edge_p (else_edge)))))
> return FALSE;
>
> /* Registers set are dead, or are predicable. */
> Index: expr.h
> ===================================================================
> *** expr.h (revision 139737)
> --- expr.h (working copy)
> *************** along with GCC; see the file COPYING3.
> *** 36,42 ****
>
> /* The default branch cost is 1. */
> #ifndef BRANCH_COST
> ! #define BRANCH_COST 1
> #endif
>
> /* This is the 4th arg to `expand_expr'.
> --- 36,42 ----
>
> /* The default branch cost is 1. */
> #ifndef BRANCH_COST
> ! #define BRANCH_COST(speed_p, predictable_p) 1
> #endif
>
> /* This is the 4th arg to `expand_expr'.
> Index: predict.c
> ===================================================================
> *** predict.c (revision 139737)
> --- predict.c (working copy)
> *************** optimize_insn_for_speed_p (void)
> *** 245,250 ****
> --- 245,267 ----
> return !optimize_insn_for_size_p ();
> }
>
> + /* Return true when edge E is likely to be well predictable by branch
> + predictor. */
> +
> + bool
> + predictable_edge_p (edge e)
> + {
> + if (profile_status == PROFILE_ABSENT)
> + return false;
> + if ((e->probability
> + <= PARAM_VALUE (PARAM_PREDICTABLE_BRANCH_OUTCOME) * REG_BR_PROB_BASE / 100)
> + || (REG_BR_PROB_BASE - e->probability
> + <= PARAM_VALUE (PARAM_PREDICTABLE_BRANCH_OUTCOME) * REG_BR_PROB_BASE / 100))
> + return true;
> + return false;
> + }
> +
> +
> /* Set RTL expansion for BB profile. */
>
> void
> Index: expmed.c
> ===================================================================
> *** expmed.c (revision 139737)
> --- expmed.c (working copy)
> *************** expand_smod_pow2 (enum machine_mode mode
> *** 3492,3498 ****
> result = gen_reg_rtx (mode);
>
> /* Avoid conditional branches when they're expensive. */
> ! if (BRANCH_COST >= 2
> && optimize_insn_for_speed_p ())
> {
> rtx signmask = emit_store_flag (result, LT, op0, const0_rtx,
> --- 3492,3498 ----
> result = gen_reg_rtx (mode);
>
> /* Avoid conditional branches when they're expensive. */
> ! if (BRANCH_COST (optimize_insn_for_speed_p (), false) >= 2
> && optimize_insn_for_speed_p ())
> {
> rtx signmask = emit_store_flag (result, LT, op0, const0_rtx,
> *************** expand_sdiv_pow2 (enum machine_mode mode
> *** 3592,3598 ****
> logd = floor_log2 (d);
> shift = build_int_cst (NULL_TREE, logd);
>
> ! if (d == 2 && BRANCH_COST >= 1)
> {
> temp = gen_reg_rtx (mode);
> temp = emit_store_flag (temp, LT, op0, const0_rtx, mode, 0, 1);
> --- 3592,3600 ----
> logd = floor_log2 (d);
> shift = build_int_cst (NULL_TREE, logd);
>
> ! if (d == 2
> ! && BRANCH_COST (optimize_insn_for_speed_p (),
> ! false) >= 1)
> {
> temp = gen_reg_rtx (mode);
> temp = emit_store_flag (temp, LT, op0, const0_rtx, mode, 0, 1);
> *************** expand_sdiv_pow2 (enum machine_mode mode
> *** 3602,3608 ****
> }
>
> #ifdef HAVE_conditional_move
> ! if (BRANCH_COST >= 2)
> {
> rtx temp2;
>
> --- 3604,3611 ----
> }
>
> #ifdef HAVE_conditional_move
> ! if (BRANCH_COST (optimize_insn_for_speed_p (), false)
> ! >= 2)
> {
> rtx temp2;
>
> *************** expand_sdiv_pow2 (enum machine_mode mode
> *** 3631,3637 ****
> }
> #endif
>
> ! if (BRANCH_COST >= 2)
> {
> int ushift = GET_MODE_BITSIZE (mode) - logd;
>
> --- 3634,3641 ----
> }
> #endif
>
> ! if (BRANCH_COST (optimize_insn_for_speed_p (),
> ! false) >= 2)
> {
> int ushift = GET_MODE_BITSIZE (mode) - logd;
>
> *************** emit_store_flag (rtx target, enum rtx_co
> *** 5345,5351 ****
> comparison with zero. Don't do any of these cases if branches are
> very cheap. */
>
> ! if (BRANCH_COST > 0
> && GET_MODE_CLASS (mode) == MODE_INT && (code == EQ || code == NE)
> && op1 != const0_rtx)
> {
> --- 5349,5356 ----
> comparison with zero. Don't do any of these cases if branches are
> very cheap. */
>
> ! if (BRANCH_COST (optimize_insn_for_speed_p (),
> ! false) > 0
> && GET_MODE_CLASS (mode) == MODE_INT && (code == EQ || code == NE)
> && op1 != const0_rtx)
> {
> *************** emit_store_flag (rtx target, enum rtx_co
> *** 5368,5377 ****
> do LE and GT if branches are expensive since they are expensive on
> 2-operand machines. */
>
> ! if (BRANCH_COST == 0
> || GET_MODE_CLASS (mode) != MODE_INT || op1 != const0_rtx
> || (code != EQ && code != NE
> ! && (BRANCH_COST <= 1 || (code != LE && code != GT))))
> return 0;
>
> /* See what we need to return. We can only return a 1, -1, or the
> --- 5373,5384 ----
> do LE and GT if branches are expensive since they are expensive on
> 2-operand machines. */
>
> ! if (BRANCH_COST (optimize_insn_for_speed_p (),
> ! false) == 0
> || GET_MODE_CLASS (mode) != MODE_INT || op1 != const0_rtx
> || (code != EQ && code != NE
> ! && (BRANCH_COST (optimize_insn_for_speed_p (),
> ! false) <= 1 || (code != LE && code != GT))))
> return 0;
>
> /* See what we need to return. We can only return a 1, -1, or the
> *************** emit_store_flag (rtx target, enum rtx_co
> *** 5467,5473 ****
> that "or", which is an extra insn, so we only handle EQ if branches
> are expensive. */
>
> ! if (tem == 0 && (code == NE || BRANCH_COST > 1))
> {
> if (rtx_equal_p (subtarget, op0))
> subtarget = 0;
> --- 5474,5483 ----
> that "or", which is an extra insn, so we only handle EQ if branches
> are expensive. */
>
> ! if (tem == 0
> ! && (code == NE
> ! || BRANCH_COST (optimize_insn_for_speed_p (),
> ! false) > 1))
> {
> if (rtx_equal_p (subtarget, op0))
> subtarget = 0;
> Index: basic-block.h
> ===================================================================
> *** basic-block.h (revision 139737)
> --- basic-block.h (working copy)
> *************** extern void guess_outgoing_edge_probabil
> *** 848,853 ****
> --- 848,854 ----
> extern void remove_predictions_associated_with_edge (edge);
> extern bool edge_probability_reliable_p (const_edge);
> extern bool br_prob_note_reliable_p (const_rtx);
> + extern bool predictable_edge_p (edge);
>
> /* In cfg.c */
> extern void dump_regset (regset, FILE *);
> Index: config/alpha/alpha.h
> ===================================================================
> *** config/alpha/alpha.h (revision 139737)
> --- config/alpha/alpha.h (working copy)
> *************** extern int alpha_memory_latency;
> *** 640,646 ****
> #define MEMORY_MOVE_COST(MODE,CLASS,IN) (2*alpha_memory_latency)
>
> /* Provide the cost of a branch. Exact meaning under development. */
> ! #define BRANCH_COST 5
>
> /* Stack layout; function entry, exit and calling. */
>
> --- 640,646 ----
> #define MEMORY_MOVE_COST(MODE,CLASS,IN) (2*alpha_memory_latency)
>
> /* Provide the cost of a branch. Exact meaning under development. */
> ! #define BRANCH_COST(speed_p, predictable_p) 5
>
> /* Stack layout; function entry, exit and calling. */
>
> Index: config/frv/frv.h
> ===================================================================
> *** config/frv/frv.h (revision 139737)
> --- config/frv/frv.h (working copy)
> *************** do { \
> *** 2193,2199 ****
>
> /* A C expression for the cost of a branch instruction. A value of 1 is the
> default; other values are interpreted relative to that. */
> ! #define BRANCH_COST frv_branch_cost_int
>
> /* Define this macro as a C expression which is nonzero if accessing less than
> a word of memory (i.e. a `char' or a `short') is no faster than accessing a
> --- 2193,2199 ----
>
> /* A C expression for the cost of a branch instruction. A value of 1 is the
> default; other values are interpreted relative to that. */
> ! #define BRANCH_COST(speed_p, predictable_p) frv_branch_cost_int
>
> /* Define this macro as a C expression which is nonzero if accessing less than
> a word of memory (i.e. a `char' or a `short') is no faster than accessing a
> Index: config/s390/s390.h
> ===================================================================
> *** config/s390/s390.h (revision 139737)
> --- config/s390/s390.h (working copy)
> *************** extern struct rtx_def *s390_compare_op0,
> *** 828,834 ****
>
> /* A C expression for the cost of a branch instruction. A value of 1
> is the default; other values are interpreted relative to that. */
> ! #define BRANCH_COST 1
>
> /* Nonzero if access to memory by bytes is slow and undesirable. */
> #define SLOW_BYTE_ACCESS 1
> --- 828,834 ----
>
> /* A C expression for the cost of a branch instruction. A value of 1
> is the default; other values are interpreted relative to that. */
> ! #define BRANCH_COST(speed_p, predictable_p) 1
>
> /* Nonzero if access to memory by bytes is slow and undesirable. */
> #define SLOW_BYTE_ACCESS 1
> Index: config/spu/spu.h
> ===================================================================
> *** config/spu/spu.h (revision 139737)
> --- config/spu/spu.h (working copy)
> *************** targetm.resolve_overloaded_builtin = spu
> *** 434,440 ****
>
> /* Costs */
>
> ! #define BRANCH_COST spu_branch_cost
>
> #define SLOW_BYTE_ACCESS 0
>
> --- 434,440 ----
>
> /* Costs */
>
> ! #define BRANCH_COST(speed_p, predictable_p) spu_branch_cost
>
> #define SLOW_BYTE_ACCESS 0
>
> Index: config/sparc/sparc.h
> ===================================================================
> *** config/sparc/sparc.h (revision 139737)
> --- config/sparc/sparc.h (working copy)
> *************** do {
> *** 2196,2202 ****
> On Niagara-2, a not-taken branch costs 1 cycle whereas a taken
> branch costs 6 cycles. */
>
> ! #define BRANCH_COST \
> ((sparc_cpu == PROCESSOR_V9 \
> || sparc_cpu == PROCESSOR_ULTRASPARC) \
> ? 7 \
> --- 2196,2202 ----
> On Niagara-2, a not-taken branch costs 1 cycle whereas a taken
> branch costs 6 cycles. */
>
> ! #define BRANCH_COST (speed_p, predictable_p) \
> ((sparc_cpu == PROCESSOR_V9 \
> || sparc_cpu == PROCESSOR_ULTRASPARC) \
> ? 7 \
> Index: config/m32r/m32r.h
> ===================================================================
> *** config/m32r/m32r.h (revision 139737)
> --- config/m32r/m32r.h (working copy)
> *************** L2: .word STATIC
> *** 1224,1230 ****
> /* A value of 2 here causes GCC to avoid using branches in comparisons like
> while (a < N && a). Branches aren't that expensive on the M32R so
> we define this as 1. Defining it as 2 had a heavy hit in fp-bit.c. */
> ! #define BRANCH_COST ((TARGET_BRANCH_COST) ? 2 : 1)
>
> /* Nonzero if access to memory by bytes is slow and undesirable.
> For RISC chips, it means that access to memory by bytes is no
> --- 1224,1230 ----
> /* A value of 2 here causes GCC to avoid using branches in comparisons like
> while (a < N && a). Branches aren't that expensive on the M32R so
> we define this as 1. Defining it as 2 had a heavy hit in fp-bit.c. */
> ! #define BRANCH_COST(speed_p, predictable_p) ((TARGET_BRANCH_COST) ? 2 : 1)
>
> /* Nonzero if access to memory by bytes is slow and undesirable.
> For RISC chips, it means that access to memory by bytes is no
> Index: config/i386/i386.h
> ===================================================================
> *** config/i386/i386.h (revision 139737)
> --- config/i386/i386.h (working copy)
> *************** do { \
> *** 1975,1981 ****
> /* A C expression for the cost of a branch instruction. A value of 1
> is the default; other values are interpreted relative to that. */
>
> ! #define BRANCH_COST ix86_branch_cost
>
> /* Define this macro as a C expression which is nonzero if accessing
> less than a word of memory (i.e. a `char' or a `short') is no
> --- 1975,1982 ----
> /* A C expression for the cost of a branch instruction. A value of 1
> is the default; other values are interpreted relative to that. */
>
> ! #define BRANCH_COST(speed_p, predictable_p) \
> ! (!(speed_p) ? 2 : (predictable_p) ? 0 : ix86_branch_cost)
>
> /* Define this macro as a C expression which is nonzero if accessing
> less than a word of memory (i.e. a `char' or a `short') is no
> Index: config/i386/i386.c
> ===================================================================
> *** config/i386/i386.c (revision 139737)
> --- config/i386/i386.c (working copy)
> *************** ix86_expand_int_movcc (rtx operands[])
> *** 14636,14642 ****
> */
>
> if ((!TARGET_CMOVE || (mode == QImode && TARGET_PARTIAL_REG_STALL))
> ! && BRANCH_COST >= 2)
> {
> if (cf == 0)
> {
> --- 14636,14643 ----
> */
>
> if ((!TARGET_CMOVE || (mode == QImode && TARGET_PARTIAL_REG_STALL))
> ! && BRANCH_COST (optimize_insn_for_speed_p (),
> ! false) >= 2)
> {
> if (cf == 0)
> {
> *************** ix86_expand_int_movcc (rtx operands[])
> *** 14721,14727 ****
> optab op;
> rtx var, orig_out, out, tmp;
>
> ! if (BRANCH_COST <= 2)
> return 0; /* FAIL */
>
> /* If one of the two operands is an interesting constant, load a
> --- 14722,14728 ----
> optab op;
> rtx var, orig_out, out, tmp;
>
> ! if (BRANCH_COST (optimize_insn_for_speed_p (), false) <= 2)
> return 0; /* FAIL */
>
> /* If one of the two operands is an interesting constant, load a
> Index: config/sh/sh.h
> ===================================================================
> *** config/sh/sh.h (revision 139737)
> --- config/sh/sh.h (working copy)
> *************** struct sh_args {
> *** 2847,2853 ****
> The SH1 does not have delay slots, hence we get a pipeline stall
> at every branch. The SH4 is superscalar, so the single delay slot
> is not sufficient to keep both pipelines filled. */
> ! #define BRANCH_COST (TARGET_SH5 ? 1 : ! TARGET_SH2 || TARGET_HARD_SH4 ? 2 : 1)
>
> /* Assembler output control. */
>
> --- 2847,2854 ----
> The SH1 does not have delay slots, hence we get a pipeline stall
> at every branch. The SH4 is superscalar, so the single delay slot
> is not sufficient to keep both pipelines filled. */
> ! #define BRANCH_COST(speed_p, predictable_p) \
> ! (TARGET_SH5 ? 1 : ! TARGET_SH2 || TARGET_HARD_SH4 ? 2 : 1)
>
> /* Assembler output control. */
>
> Index: config/pdp11/pdp11.h
> ===================================================================
> *** config/pdp11/pdp11.h (revision 139737)
> --- config/pdp11/pdp11.h (working copy)
> *************** JMP FUNCTION 0x0058 0x0000 <- FUNCTION
> *** 1057,1063 ****
> /* there is no point in avoiding branches on a pdp,
> since branches are really cheap - I just want to find out
> how much difference the BRANCH_COST macro makes in code */
> ! #define BRANCH_COST (TARGET_BRANCH_CHEAP ? 0 : 1)
>
>
> #define COMPARE_FLAG_MODE HImode
> --- 1057,1063 ----
> /* there is no point in avoiding branches on a pdp,
> since branches are really cheap - I just want to find out
> how much difference the BRANCH_COST macro makes in code */
> ! #define BRANCH_COST(speed_p, predictable_p) (TARGET_BRANCH_CHEAP ? 0 : 1)
>
>
> #define COMPARE_FLAG_MODE HImode
> Index: config/avr/avr.h
> ===================================================================
> *** config/avr/avr.h (revision 139737)
> --- config/avr/avr.h (working copy)
> *************** do { \
> *** 511,517 ****
> (MODE)==SImode ? 8 : \
> (MODE)==SFmode ? 8 : 16)
>
> ! #define BRANCH_COST 0
>
> #define SLOW_BYTE_ACCESS 0
>
> --- 511,517 ----
> (MODE)==SImode ? 8 : \
> (MODE)==SFmode ? 8 : 16)
>
> ! #define BRANCH_COST(speed_p, predictable_p) 0
>
> #define SLOW_BYTE_ACCESS 0
>
> Index: config/crx/crx.h
> ===================================================================
> *** config/crx/crx.h (revision 139737)
> --- config/crx/crx.h (working copy)
> *************** struct cumulative_args
> *** 420,426 ****
> /* Moving to processor register flushes pipeline - thus asymmetric */
> #define REGISTER_MOVE_COST(MODE, FROM, TO) ((TO != GENERAL_REGS) ? 8 : 2)
> /* Assume best case (branch predicted) */
> ! #define BRANCH_COST 2
>
> #define SLOW_BYTE_ACCESS 1
>
> --- 420,426 ----
> /* Moving to processor register flushes pipeline - thus asymmetric */
> #define REGISTER_MOVE_COST(MODE, FROM, TO) ((TO != GENERAL_REGS) ? 8 : 2)
> /* Assume best case (branch predicted) */
> ! #define BRANCH_COST(speed_p, predictable_p) 2
>
> #define SLOW_BYTE_ACCESS 1
>
> Index: config/xtensa/xtensa.h
> ===================================================================
> *** config/xtensa/xtensa.h (revision 139737)
> --- config/xtensa/xtensa.h (working copy)
> *************** typedef struct xtensa_args
> *** 882,888 ****
>
> #define MEMORY_MOVE_COST(MODE, CLASS, IN) 4
>
> ! #define BRANCH_COST 3
>
> /* How to refer to registers in assembler output.
> This sequence is indexed by compiler's hard-register-number (see above). */
> --- 882,888 ----
>
> #define MEMORY_MOVE_COST(MODE, CLASS, IN) 4
>
> ! #define BRANCH_COST(speed_p, predictable_p) 3
>
> /* How to refer to registers in assembler output.
> This sequence is indexed by compiler's hard-register-number (see above). */
> Index: config/stormy16/stormy16.h
> ===================================================================
> *** config/stormy16/stormy16.h (revision 139737)
> --- config/stormy16/stormy16.h (working copy)
> *************** do { \
> *** 587,593 ****
>
> #define MEMORY_MOVE_COST(M,C,I) (5 + memory_move_secondary_cost (M, C, I))
>
> ! #define BRANCH_COST 5
>
> #define SLOW_BYTE_ACCESS 0
>
> --- 587,593 ----
>
> #define MEMORY_MOVE_COST(M,C,I) (5 + memory_move_secondary_cost (M, C, I))
>
> ! #define BRANCH_COST(speed_p, predictable_p) 5
>
> #define SLOW_BYTE_ACCESS 0
>
> Index: config/m68hc11/m68hc11.h
> ===================================================================
> *** config/m68hc11/m68hc11.h (revision 139737)
> --- config/m68hc11/m68hc11.h (working copy)
> *************** extern unsigned char m68hc11_reg_valid_f
> *** 1266,1272 ****
>
> Pretend branches are cheap because GCC generates sub-optimal code
> for the default value. */
> ! #define BRANCH_COST 0
>
> /* Nonzero if access to memory by bytes is slow and undesirable. */
> #define SLOW_BYTE_ACCESS 0
> --- 1266,1272 ----
>
> Pretend branches are cheap because GCC generates sub-optimal code
> for the default value. */
> ! #define BRANCH_COST(speed_p, predictable_p) 0
>
> /* Nonzero if access to memory by bytes is slow and undesirable. */
> #define SLOW_BYTE_ACCESS 0
> Index: config/iq2000/iq2000.h
> ===================================================================
> *** config/iq2000/iq2000.h (revision 139737)
> --- config/iq2000/iq2000.h (working copy)
> *************** typedef struct iq2000_args
> *** 624,630 ****
> #define MEMORY_MOVE_COST(MODE,CLASS,TO_P) \
> (TO_P ? 2 : 16)
>
> ! #define BRANCH_COST 2
>
> #define SLOW_BYTE_ACCESS 1
>
> --- 624,630 ----
> #define MEMORY_MOVE_COST(MODE,CLASS,TO_P) \
> (TO_P ? 2 : 16)
>
> ! #define BRANCH_COST(speed_p, predictable_p) 2
>
> #define SLOW_BYTE_ACCESS 1
>
> Index: config/ia64/ia64.h
> ===================================================================
> *** config/ia64/ia64.h (revision 139737)
> --- config/ia64/ia64.h (working copy)
> *************** do { \
> *** 1384,1390 ****
> many additional insn groups we run into, vs how good the dynamic
> branch predictor is. */
>
> ! #define BRANCH_COST 6
>
> /* Define this macro as a C expression which is nonzero if accessing less than
> a word of memory (i.e. a `char' or a `short') is no faster than accessing a
> --- 1384,1390 ----
> many additional insn groups we run into, vs how good the dynamic
> branch predictor is. */
>
> ! #define BRANCH_COST(speed_p, predictable_p) 6
>
> /* Define this macro as a C expression which is nonzero if accessing less than
> a word of memory (i.e. a `char' or a `short') is no faster than accessing a
> Index: config/rs6000/rs6000.h
> ===================================================================
> *** config/rs6000/rs6000.h (revision 139737)
> --- config/rs6000/rs6000.h (working copy)
> *************** extern enum rs6000_nop_insertion rs6000_
> *** 967,973 ****
> Set this to 3 on the RS/6000 since that is roughly the average cost of an
> unscheduled conditional branch. */
>
> ! #define BRANCH_COST 3
>
> /* Override BRANCH_COST heuristic which empirically produces worse
> performance for removing short circuiting from the logical ops. */
> --- 967,973 ----
> Set this to 3 on the RS/6000 since that is roughly the average cost of an
> unscheduled conditional branch. */
>
> ! #define BRANCH_COST(speed_p, predictable_p) 3
>
> /* Override BRANCH_COST heuristic which empirically produces worse
> performance for removing short circuiting from the logical ops. */
> Index: config/arc/arc.h
> ===================================================================
> *** config/arc/arc.h (revision 139737)
> --- config/arc/arc.h (working copy)
> *************** arc_select_cc_mode (OP, X, Y)
> *** 824,830 ****
> /* The cost of a branch insn. */
> /* ??? What's the right value here? Branches are certainly more
> expensive than reg->reg moves. */
> ! #define BRANCH_COST 2
>
> /* Nonzero if access to memory by bytes is slow and undesirable.
> For RISC chips, it means that access to memory by bytes is no
> --- 824,830 ----
> /* The cost of a branch insn. */
> /* ??? What's the right value here? Branches are certainly more
> expensive than reg->reg moves. */
> ! #define BRANCH_COST(speed_p, predictable_p) 2
>
> /* Nonzero if access to memory by bytes is slow and undesirable.
> For RISC chips, it means that access to memory by bytes is no
> Index: config/score/score.h
> ===================================================================
> *** config/score/score.h (revision 139737)
> --- config/score/score.h (working copy)
> *************** typedef struct score_args
> *** 793,799 ****
> (4 + memory_move_secondary_cost ((MODE), (CLASS), (TO_P)))
>
> /* Try to generate sequences that don't involve branches. */
> ! #define BRANCH_COST 2
>
> /* Nonzero if access to memory by bytes is slow and undesirable. */
> #define SLOW_BYTE_ACCESS 1
> --- 793,799 ----
> (4 + memory_move_secondary_cost ((MODE), (CLASS), (TO_P)))
>
> /* Try to generate sequences that don't involve branches. */
> ! #define BRANCH_COST(speed_p, predictable_p) 2
>
> /* Nonzero if access to memory by bytes is slow and undesirable. */
> #define SLOW_BYTE_ACCESS 1
> Index: config/arm/arm.h
> ===================================================================
> *** config/arm/arm.h (revision 139737)
> --- config/arm/arm.h (working copy)
> *************** do { \
> *** 2297,2303 ****
>
> /* Try to generate sequences that don't involve branches, we can then use
> conditional instructions */
> ! #define BRANCH_COST \
> (TARGET_32BIT ? 4 : (optimize > 0 ? 2 : 0))
>
> /* Position Independent Code. */
> --- 2297,2303 ----
>
> /* Try to generate sequences that don't involve branches, we can then use
> conditional instructions */
> ! #define BRANCH_COST(speed_p, predictable_p) \
> (TARGET_32BIT ? 4 : (optimize > 0 ? 2 : 0))
>
> /* Position Independent Code. */
> Index: config/pa/pa.h
> ===================================================================
> *** config/pa/pa.h (revision 139737)
> --- config/pa/pa.h (working copy)
> *************** do { \
> *** 1570,1576 ****
> : 2)
>
> /* Adjust the cost of branches. */
> ! #define BRANCH_COST (pa_cpu == PROCESSOR_8000 ? 2 : 1)
>
> /* Handling the special cases is going to get too complicated for a macro,
> just call `pa_adjust_insn_length' to do the real work. */
> --- 1570,1576 ----
> : 2)
>
> /* Adjust the cost of branches. */
> ! #define BRANCH_COST(speed_p, predictable_p) (pa_cpu == PROCESSOR_8000 ? 2 : 1)
>
> /* Handling the special cases is going to get too complicated for a macro,
> just call `pa_adjust_insn_length' to do the real work. */
> Index: config/mips/mips.h
> ===================================================================
> *** config/mips/mips.h (revision 139737)
> --- config/mips/mips.h (working copy)
> *************** typedef struct mips_args {
> *** 2551,2557 ****
> /* A C expression for the cost of a branch instruction. A value of
> 1 is the default; other values are interpreted relative to that. */
>
> ! #define BRANCH_COST mips_branch_cost
> #define LOGICAL_OP_NON_SHORT_CIRCUIT 0
>
> /* If defined, modifies the length assigned to instruction INSN as a
> --- 2551,2557 ----
> /* A C expression for the cost of a branch instruction. A value of
> 1 is the default; other values are interpreted relative to that. */
>
> ! #define BRANCH_COST(speed_p, predictable_p) mips_branch_cost
> #define LOGICAL_OP_NON_SHORT_CIRCUIT 0
>
> /* If defined, modifies the length assigned to instruction INSN as a
> Index: config/vax/vax.h
> ===================================================================
> *** config/vax/vax.h (revision 139737)
> --- config/vax/vax.h (working copy)
> *************** enum reg_class { NO_REGS, ALL_REGS, LIM_
> *** 648,654 ****
> Branches are extremely cheap on the VAX while the shift insns often
> used to replace branches can be expensive. */
>
> ! #define BRANCH_COST 0
>
> /* Tell final.c how to eliminate redundant test instructions. */
>
> --- 648,654 ----
> Branches are extremely cheap on the VAX while the shift insns often
> used to replace branches can be expensive. */
>
> ! #define BRANCH_COST(speed_p, predictable_p) 0
>
> /* Tell final.c how to eliminate redundant test instructions. */
>
> Index: config/h8300/h8300.h
> ===================================================================
> *** config/h8300/h8300.h (revision 139737)
> --- config/h8300/h8300.h (working copy)
> *************** struct cum_arg
> *** 1004,1010 ****
> #define DELAY_SLOT_LENGTH(JUMP) \
> (NEXT_INSN (PREV_INSN (JUMP)) == JUMP ? 0 : 2)
>
> ! #define BRANCH_COST 0
>
> /* Tell final.c how to eliminate redundant test instructions. */
>
> --- 1004,1010 ----
> #define DELAY_SLOT_LENGTH(JUMP) \
> (NEXT_INSN (PREV_INSN (JUMP)) == JUMP ? 0 : 2)
>
> ! #define BRANCH_COST(speed_p, predictable_p) 0
>
> /* Tell final.c how to eliminate redundant test instructions. */
>
> Index: params.def
> ===================================================================
> *** params.def (revision 139737)
> --- params.def (working copy)
> *************** DEFPARAM (PARAM_STRUCT_REORG_COLD_STRUCT
> *** 78,83 ****
> --- 78,90 ----
> "The threshold ratio between current and hottest structure counts",
> 10, 0, 100)
>
> + /* When branch is predicted to be taken with probability lower than this
> + threshold (in percent), then it is considered well predictable. */
> + DEFPARAM (PARAM_PREDICTABLE_BRANCH_OUTCOME,
> + "predictable-branch-outcome",
> + "Maximal esitmated outcome of branch considered predictable",
> + 2, 0, 50)
> +
> /* The single function inlining limit. This is the maximum size
> of a function counted in internal gcc instructions (not in
> real machine instructions) that is eligible for inlining
>