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Diffstat (limited to 'lib/gcc/arm-none-eabi/13.2.1/plugin/include/predict.def')
| -rw-r--r-- | lib/gcc/arm-none-eabi/13.2.1/plugin/include/predict.def | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/lib/gcc/arm-none-eabi/13.2.1/plugin/include/predict.def b/lib/gcc/arm-none-eabi/13.2.1/plugin/include/predict.def new file mode 100644 index 0000000..1f391a0 --- /dev/null +++ b/lib/gcc/arm-none-eabi/13.2.1/plugin/include/predict.def @@ -0,0 +1,238 @@ +/* Definitions for the branch prediction routines in the GNU compiler. + Copyright (C) 2001-2023 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +/* Before including this file, you should define a macro: + + DEF_PREDICTOR (ENUM, NAME, HITRATE) + + This macro will be called once for each predictor. The ENUM will + be of type `enum br_predictor', and will enumerate all supported + predictors. The order of DEF_PREDICTOR calls is important, as + in the first match combining heuristics, the predictor appearing + first in this file will win. + + NAME is used in the debugging output to determine predictor type. + + HITRATE is the probability that edge predicted by predictor as taken + will be really taken (so it should be always above + REG_BR_PROB_BASE / 2). */ + + +/* A value used as final outcome of all heuristics. */ +DEF_PREDICTOR (PRED_COMBINED, "combined", PROB_ALWAYS, 0) + +/* An outcome estimated by Dempster-Shaffer theory. */ +DEF_PREDICTOR (PRED_DS_THEORY, "DS theory", PROB_ALWAYS, 0) + +/* A combined heuristics using probability determined by first + matching heuristics from this list. */ +DEF_PREDICTOR (PRED_FIRST_MATCH, "first match", PROB_ALWAYS, 0) + +/* Heuristic applying when no heuristic below applies. */ +DEF_PREDICTOR (PRED_NO_PREDICTION, "no prediction", PROB_ALWAYS, 0) + +/* Mark unconditional jump as taken. */ +DEF_PREDICTOR (PRED_UNCONDITIONAL, "unconditional jump", PROB_ALWAYS, + PRED_FLAG_FIRST_MATCH) + +/* Return value of malloc function is almost always non-null. */ +DEF_PREDICTOR (PRED_MALLOC_NONNULL, "malloc returned non-NULL", \ + PROB_VERY_LIKELY, PRED_FLAG_FIRST_MATCH) + +/* Use number of loop iterations determined by # of iterations + analysis to set probability. We don't want to use Dempster-Shaffer + theory here, as the predictions is exact. */ +DEF_PREDICTOR (PRED_LOOP_ITERATIONS, "loop iterations", PROB_UNINITIALIZED, + PRED_FLAG_FIRST_MATCH) + +/* Assume that any given atomic operation has low contention, + and thus the compare-and-swap operation succeeds. */ +DEF_PREDICTOR (PRED_COMPARE_AND_SWAP, "compare and swap", PROB_VERY_LIKELY, + PRED_FLAG_FIRST_MATCH) + +/* Hints dropped by user via __builtin_expect feature. Note: the + probability of PROB_VERY_LIKELY is now overwritten by param + builtin_expect_probability with a default value of HITRATE(90). + Refer to param.def for details. */ +DEF_PREDICTOR (PRED_BUILTIN_EXPECT, "__builtin_expect", PROB_VERY_LIKELY, + PRED_FLAG_FIRST_MATCH) + +/* Hints provided by user via __builtin_expect_with_probability. */ +DEF_PREDICTOR (PRED_BUILTIN_EXPECT_WITH_PROBABILITY, + "__builtin_expect_with_probability", PROB_UNINITIALIZED, + PRED_FLAG_FIRST_MATCH) + +/* Branches to hot labels are likely. */ +DEF_PREDICTOR (PRED_HOT_LABEL, "hot label", HITRATE (90), + PRED_FLAG_FIRST_MATCH) + +/* Branches to cold labels are extremely unlikely. */ +DEF_PREDICTOR (PRED_COLD_LABEL, "cold label", HITRATE (90), + PRED_FLAG_FIRST_MATCH) + +/* Use number of loop iterations guessed by the contents of the loop. */ +DEF_PREDICTOR (PRED_LOOP_ITERATIONS_GUESSED, "guessed loop iterations", + PROB_UNINITIALIZED, PRED_FLAG_FIRST_MATCH) + +/* Use number of loop iterations guessed by the contents of the loop. */ +DEF_PREDICTOR (PRED_LOOP_ITERATIONS_MAX, "guessed loop iterations", + PROB_UNINITIALIZED, PRED_FLAG_FIRST_MATCH) + +/* Branch containing goto is probably not taken. */ +DEF_PREDICTOR (PRED_CONTINUE, "continue", HITRATE (67), 0) + +/* Branch to basic block containing call marked by noreturn attribute. */ +DEF_PREDICTOR (PRED_NORETURN, "noreturn call", PROB_VERY_LIKELY, + PRED_FLAG_FIRST_MATCH) + +/* Branch to basic block containing call marked by cold function attribute. */ +DEF_PREDICTOR (PRED_COLD_FUNCTION, "cold function call", PROB_VERY_LIKELY, + PRED_FLAG_FIRST_MATCH) + +/* Edge causing loop to terminate is probably not taken. */ +DEF_PREDICTOR (PRED_LOOP_EXIT, "loop exit", HITRATE (89), + PRED_FLAG_FIRST_MATCH) + +/* Same as LOOP_EXIT but for loops containing recursive call. */ +DEF_PREDICTOR (PRED_LOOP_EXIT_WITH_RECURSION, "loop exit with recursion", + HITRATE (78), PRED_FLAG_FIRST_MATCH) + +/* Edge causing loop to terminate by computing value used by later + conditional. */ +DEF_PREDICTOR (PRED_LOOP_EXTRA_EXIT, "extra loop exit", HITRATE (67), + PRED_FLAG_FIRST_MATCH) + +/* Pointers are usually not NULL. */ +DEF_PREDICTOR (PRED_POINTER, "pointer", HITRATE (70), 0) +DEF_PREDICTOR (PRED_TREE_POINTER, "pointer (on trees)", HITRATE (70), 0) + +/* NE is probable, EQ not etc... */ +DEF_PREDICTOR (PRED_OPCODE_POSITIVE, "opcode values positive", HITRATE (59), 0) +DEF_PREDICTOR (PRED_OPCODE_NONEQUAL, "opcode values nonequal", HITRATE (66), 0) +DEF_PREDICTOR (PRED_FPOPCODE, "fp_opcode", HITRATE (90), 0) +DEF_PREDICTOR (PRED_TREE_OPCODE_POSITIVE, "opcode values positive (on trees)", + HITRATE (59), 0) +DEF_PREDICTOR (PRED_TREE_OPCODE_NONEQUAL, "opcode values nonequal (on trees)", + HITRATE (66), 0) +DEF_PREDICTOR (PRED_TREE_FPOPCODE, "fp_opcode (on trees)", HITRATE (90), 0) + +/* Branch guarding call is probably taken. */ +DEF_PREDICTOR (PRED_CALL, "call", HITRATE (67), 0) + +/* Call predictors are for now ignored, lets leave the predictor + to measure its benefit. */ +DEF_PREDICTOR (PRED_INDIR_CALL, "indirect call", PROB_EVEN, 0) +DEF_PREDICTOR (PRED_POLYMORPHIC_CALL, "polymorphic call", PROB_EVEN, 0) +DEF_PREDICTOR (PRED_RECURSIVE_CALL, "recursive call", PROB_EVEN, 0) + +/* Branch causing function to terminate is probably not taken. */ +DEF_PREDICTOR (PRED_TREE_EARLY_RETURN, "early return (on trees)", HITRATE (66), + 0) + +/* Branch containing goto is probably not taken. */ +DEF_PREDICTOR (PRED_GOTO, "goto", HITRATE (66), 0) + +/* Branch ending with return constant is probably not taken. */ +DEF_PREDICTOR (PRED_CONST_RETURN, "const return", HITRATE (65), 0) + +/* Branch ending with return negative constant is probably not taken. */ +DEF_PREDICTOR (PRED_NEGATIVE_RETURN, "negative return", HITRATE (98), 0) + +/* Branch ending with return; is probably not taken */ +DEF_PREDICTOR (PRED_NULL_RETURN, "null return", HITRATE (71), 0) + +/* Branches to compare induction variable to a loop bound is + extremely likely. */ +DEF_PREDICTOR (PRED_LOOP_IV_COMPARE_GUESS, "guess loop iv compare", + HITRATE (64), 0) + +/* Use number of loop iterations determined by # of iterations analysis + to set probability of branches that compares IV to loop bound variable. */ +DEF_PREDICTOR (PRED_LOOP_IV_COMPARE, "loop iv compare", PROB_UNINITIALIZED, + PRED_FLAG_FIRST_MATCH) + +/* In the following code + for (loop1) + if (cond) + for (loop2) + body; + guess that cond is unlikely. */ +DEF_PREDICTOR (PRED_LOOP_GUARD, "loop guard", HITRATE (73), 0) + +/* Same but for loops containing recursion. */ +DEF_PREDICTOR (PRED_LOOP_GUARD_WITH_RECURSION, "loop guard with recursion", + HITRATE (85), 0) + +/* The following predictors are used in Fortran. */ + +/* Branch leading to an integer overflow are extremely unlikely. */ +DEF_PREDICTOR (PRED_FORTRAN_OVERFLOW, "Fortran overflow", PROB_ALWAYS, + PRED_FLAG_FIRST_MATCH) + +/* Branch leading to a failure status are unlikely. This can occur for out + of memory. This predictor only occurs when the user explicitly asked + for a return status. By default, the code aborts, + which is handled via PRED_NORETURN. */ +DEF_PREDICTOR (PRED_FORTRAN_FAIL_ALLOC, "Fortran fail alloc", + PROB_VERY_LIKELY, 0) + +/* Predictor is used for an allocation of an already allocated memory or + deallocating an already deallocated allocatable. */ +DEF_PREDICTOR (PRED_FORTRAN_REALLOC, "Fortran repeated allocation/deallocation", + PROB_LIKELY, 0) + +/* Branch leading to an I/O failure status are unlikely. This predictor is + used for I/O failures such as for invalid unit numbers. This predictor + only occurs when the user explicitly asked for a return status. By default, + the code aborts, which is handled via PRED_NORETURN. */ +DEF_PREDICTOR (PRED_FORTRAN_FAIL_IO, "Fortran fail IO", HITRATE (85), 0) + +/* Branch leading to a run-time warning message which is printed only once + are unlikely. The print-warning branch itself can be likely or unlikely. */ +DEF_PREDICTOR (PRED_FORTRAN_WARN_ONCE, "Fortran warn once", HITRATE (75), 0) + +/* Branch belonging to a zero-sized array. */ +DEF_PREDICTOR (PRED_FORTRAN_SIZE_ZERO, "Fortran zero-sized array", \ + HITRATE (99), 0) + +/* Branch belonging to an invalid bound index, in a context where it is + standard conform and well defined but rather pointless and, hence, rather + unlikely to occur. */ +DEF_PREDICTOR (PRED_FORTRAN_INVALID_BOUND, "Fortran invalid bound", \ + HITRATE (90), 0) + +/* Branch belonging to the handling of absent optional arguments. This + predictor is used when an optional dummy argument, associated with an + absent argument, is passed on as actual argument to another procedure, + which in turn has an optional argument. */ +DEF_PREDICTOR (PRED_FORTRAN_ABSENT_DUMMY, "Fortran absent dummy", \ + HITRATE (60), 0) + +/* Fortran DO statement generates a pre-header guard: + empty = (step > 0 ? to < from : to > from), which can be predicted + to be very likely. */ +DEF_PREDICTOR (PRED_FORTRAN_LOOP_PREHEADER, "Fortran loop preheader", \ + HITRATE (99), 0) + +/* Fortran assumed size arrays can be non-contiguous, so they need + to be repacked. */ + +DEF_PREDICTOR (PRED_FORTRAN_CONTIGUOUS, "Fortran contiguous", \ + HITRATE (75), 0) + |