923cbdc322
* unroll.c: Include predict.h. (unroll_loop): Drop prediction notes on preconditioning. * predict.def (PRED_LOOP_PRECONDITIONG, PRED_LOOP_CONDITION): New; add comments on the others. * Makefile.in: (unroll.o): Add dependancy on predict.h. * loop.c (strength_reduce): Fix branch prediction. * stmt.c (emit_case_nodes): Optimize test whether index is in given interval. * predict.c (estimate_probability): Do not bail out early when note is present. (combine_predictions_for_insn): Fix note removal code. From-SVN: r43441
83 lines
3.2 KiB
Modula-2
83 lines
3.2 KiB
Modula-2
/* This file contains the definitions and documentation for the
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builtins used in the GNU compiler.
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Copyright (C) 2001 Free Software Foundation, Inc.
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This file is part of GNU CC.
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GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU CC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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/* Before including this file, you should define a macro:
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DEF_PREDICTOR (ENUM, NAME, HITRATE)
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This macro will be called once for each predictor. The ENUM will
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be of type `enum predictor', and will enumerate all supported
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predictors. The order of DEF_PREDICTOR calls is important, as
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in the first match combining heuristics, the predictor appearing
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first in this file will win.
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NAME is used in the debugging output to determine predictor type.
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HITRATE is the probability that edge predicted by predictor as taken
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will be really taken (so it should be always above
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REG_BR_PROB_BASE / 2). */
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/* An combined heuristics using probability determined by first
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matching heuristics from this list. */
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DEF_PREDICTOR (PRED_FIRST_MATCH, "first match", PROB_ALWAYS)
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/* Mark unconditional jump as taken. */
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DEF_PREDICTOR (PRED_UNCONDITIONAL, "unconditional jump", PROB_ALWAYS)
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/* Use number of loop iterations determined by loop unroller to set
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probability. */
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DEF_PREDICTOR (PRED_LOOP_ITERATIONS, "loop iterations", PROB_ALWAYS)
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/* Hints dropped by user via __builtin_expect feature. */
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DEF_PREDICTOR (PRED_BUILTIN_EXPECT, "__builtin_expect", PROB_VERY_LIKELY)
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/* Branch to basic block containing call marked by noreturn attribute. */
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DEF_PREDICTOR (PRED_NORETURN, "noreturn call", PROB_ALWAYS)
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/* Loopback edge is taken. */
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DEF_PREDICTOR (PRED_LOOP_BRANCH, "loop branch", PROB_VERY_LIKELY)
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/* Edge causing loop to terminate is probably not taken. */
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DEF_PREDICTOR (PRED_LOOP_EXIT, "loop exit", PROB_LIKELY)
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/* Condition emitted by preconditiong code to ensure that variable
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setting number of iterations is greater than initial value of iterator. */
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DEF_PREDICTOR (PRED_LOOP_CONDITION, "loop condition", PROB_VERY_LIKELY)
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/* Preconditioning makes linear list of branches. */
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DEF_PREDICTOR (PRED_LOOP_PRECONDITIONING, "loop preconditioning", PROB_VERY_LIKELY)
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/* Copied condition for the first iteration of loop is probably true. */
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DEF_PREDICTOR (PRED_LOOP_HEADER, "loop header", PROB_LIKELY)
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/* Pointers are usually not NULL. */
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DEF_PREDICTOR (PRED_POINTER, "pointer", PROB_LIKELY)
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/* NE is probable, EQ not etc... */
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DEF_PREDICTOR (PRED_OPCODE, "opcode", PROB_LIKELY)
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/* Branch guarding call is probably taken. */
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DEF_PREDICTOR (PRED_CALL, "call", PROB_LIKELY)
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/* Branch causing function to terminate is probably not taken. */
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DEF_PREDICTOR (PRED_ERROR_RETURN, "error return", PROB_LIKELY)
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