Mercurial > hg > CbC > CbC_gcc
diff gcc/profile-count.h @ 111:04ced10e8804
gcc 7
author | kono |
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date | Fri, 27 Oct 2017 22:46:09 +0900 |
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children | 84e7813d76e9 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gcc/profile-count.h Fri Oct 27 22:46:09 2017 +0900 @@ -0,0 +1,884 @@ +/* Profile counter container type. + Copyright (C) 2017 Free Software Foundation, Inc. + Contributed by Jan Hubicka + +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/>. */ + +#ifndef GCC_PROFILE_COUNT_H +#define GCC_PROFILE_COUNT_H + +/* Quality of the profile count. Because gengtype does not support enums + inside of classes, this is in global namespace. */ +enum profile_quality { + /* Profile is based on static branch prediction heuristics. It may or may + not reflect the reality. */ + profile_guessed = 0, + /* Profile was determined by autofdo. */ + profile_afdo = 1, + /* Profile was originally based on feedback but it was adjusted + by code duplicating optimization. It may not precisely reflect the + particular code path. */ + profile_adjusted = 2, + /* Profile was read from profile feedback or determined by accurate static + method. */ + profile_precise = 3 +}; + +/* The base value for branch probability notes and edge probabilities. */ +#define REG_BR_PROB_BASE 10000 + +#define RDIV(X,Y) (((X) + (Y) / 2) / (Y)) + +bool slow_safe_scale_64bit (uint64_t a, uint64_t b, uint64_t c, uint64_t *res); + +/* Compute RES=(a*b + c/2)/c capping and return false if overflow happened. */ + +inline bool +safe_scale_64bit (uint64_t a, uint64_t b, uint64_t c, uint64_t *res) +{ +#if (GCC_VERSION >= 5000) + uint64_t tmp; + if (!__builtin_mul_overflow (a, b, &tmp) + && !__builtin_add_overflow (tmp, c/2, &tmp)) + { + *res = tmp / c; + return true; + } + if (c == 1) + { + *res = (uint64_t) -1; + return false; + } +#else + if (a < ((uint64_t)1 << 31) + && b < ((uint64_t)1 << 31) + && c < ((uint64_t)1 << 31)) + { + *res = (a * b + (c / 2)) / c; + return true; + } +#endif + return slow_safe_scale_64bit (a, b, c, res); +} + +/* Data type to hold probabilities. It implements fixed point arithmetics + with capping so probability is always in range [0,1] and scaling requiring + values greater than 1 needs to be represented otherwise. + + In addition to actual value the quality of profile is tracked and propagated + through all operations. Special value UNINITIALIZED is used for probabilities + that has not been determined yet (for example bacause of + -fno-guess-branch-probability) + + Typically probabilities are derived from profile feedback (via + probability_in_gcov_type), autoFDO or guessed statically and then propagated + thorough the compilation. + + Named probabilities are available: + - never (0 probability) + - guessed_never + - very_unlikely (1/2000 probability) + - unlikely (1/5 probablity) + - even (1/2 probability) + - likely (4/5 probability) + - very_likely (1999/2000 probability) + - guessed_always + - always + + Named probabilities except for never/always are assumed to be statically + guessed and thus not necessarily accurate. The difference between never + and guessed_never is that the first one should be used only in case that + well behaving program will very likely not execute the "never" path. + For example if the path is going to abort () call or it exception handling. + + Always and guessed_always probabilities are symmetric. + + For legacy code we support conversion to/from REG_BR_PROB_BASE based fixpoint + integer arithmetics. Once the code is converted to branch probabilities, + these conversions will probably go away because they are lossy. +*/ + +class GTY((user)) profile_probability +{ + static const int n_bits = 30; + /* We can technically use ((uint32_t) 1 << (n_bits - 1)) - 2 but that + will lead to harder multiplication sequences. */ + static const uint32_t max_probability = (uint32_t) 1 << (n_bits - 2); + static const uint32_t uninitialized_probability + = ((uint32_t) 1 << (n_bits - 1)) - 1; + + uint32_t m_val : 30; + enum profile_quality m_quality : 2; + + friend class profile_count; +public: + + /* Named probabilities. */ + static profile_probability never () + { + profile_probability ret; + ret.m_val = 0; + ret.m_quality = profile_precise; + return ret; + } + static profile_probability guessed_never () + { + profile_probability ret; + ret.m_val = 0; + ret.m_quality = profile_guessed; + return ret; + } + static profile_probability very_unlikely () + { + /* Be consistent with PROB_VERY_UNLIKELY in predict.h. */ + profile_probability r + = profile_probability::always ().apply_scale (1, 2000); + r.m_val--; + return r; + } + static profile_probability unlikely () + { + /* Be consistent with PROB_VERY_LIKELY in predict.h. */ + profile_probability r + = profile_probability::always ().apply_scale (1, 5); + r.m_val--; + return r; + } + static profile_probability even () + { + return profile_probability::always ().apply_scale (1, 2); + } + static profile_probability very_likely () + { + return profile_probability::always () - very_unlikely (); + } + static profile_probability likely () + { + return profile_probability::always () - unlikely (); + } + static profile_probability guessed_always () + { + profile_probability ret; + ret.m_val = max_probability; + ret.m_quality = profile_guessed; + return ret; + } + static profile_probability always () + { + profile_probability ret; + ret.m_val = max_probability; + ret.m_quality = profile_precise; + return ret; + } + /* Probabilities which has not been initialized. Either because + initialization did not happen yet or because profile is unknown. */ + static profile_probability uninitialized () + { + profile_probability c; + c.m_val = uninitialized_probability; + c.m_quality = profile_guessed; + return c; + } + + + /* Return true if value has been initialized. */ + bool initialized_p () const + { + return m_val != uninitialized_probability; + } + /* Return true if value can be trusted. */ + bool reliable_p () const + { + return m_quality >= profile_adjusted; + } + + /* Conversion from and to REG_BR_PROB_BASE integer fixpoint arithmetics. + this is mostly to support legacy code and should go away. */ + static profile_probability from_reg_br_prob_base (int v) + { + profile_probability ret; + gcc_checking_assert (v >= 0 && v <= REG_BR_PROB_BASE); + ret.m_val = RDIV (v * (uint64_t) max_probability, REG_BR_PROB_BASE); + ret.m_quality = profile_guessed; + return ret; + } + int to_reg_br_prob_base () const + { + gcc_checking_assert (initialized_p ()); + return RDIV (m_val * (uint64_t) REG_BR_PROB_BASE, max_probability); + } + + /* Conversion to and from RTL representation of profile probabilities. */ + static profile_probability from_reg_br_prob_note (int v) + { + profile_probability ret; + ret.m_val = ((unsigned int)v) / 4; + ret.m_quality = (enum profile_quality)(v & 3); + return ret; + } + int to_reg_br_prob_note () const + { + gcc_checking_assert (initialized_p ()); + int ret = m_val * 4 + m_quality; + gcc_checking_assert (profile_probability::from_reg_br_prob_note (ret) + == *this); + return ret; + } + + /* Return VAL1/VAL2. */ + static profile_probability probability_in_gcov_type + (gcov_type val1, gcov_type val2) + { + profile_probability ret; + gcc_checking_assert (val1 >= 0 && val2 > 0); + if (val1 > val2) + ret.m_val = max_probability; + else + { + uint64_t tmp; + safe_scale_64bit (val1, max_probability, val2, &tmp); + gcc_checking_assert (tmp <= max_probability); + ret.m_val = tmp; + } + ret.m_quality = profile_precise; + return ret; + } + + /* Basic operations. */ + bool operator== (const profile_probability &other) const + { + return m_val == other.m_val && m_quality == other.m_quality; + } + profile_probability operator+ (const profile_probability &other) const + { + if (other == profile_probability::never ()) + return *this; + if (*this == profile_probability::never ()) + return other; + if (!initialized_p () || !other.initialized_p ()) + return profile_probability::uninitialized (); + + profile_probability ret; + ret.m_val = MIN ((uint32_t)(m_val + other.m_val), max_probability); + ret.m_quality = MIN (m_quality, other.m_quality); + return ret; + } + profile_probability &operator+= (const profile_probability &other) + { + if (other == profile_probability::never ()) + return *this; + if (*this == profile_probability::never ()) + { + *this = other; + return *this; + } + if (!initialized_p () || !other.initialized_p ()) + return *this = profile_probability::uninitialized (); + else + { + m_val = MIN ((uint32_t)(m_val + other.m_val), max_probability); + m_quality = MIN (m_quality, other.m_quality); + } + return *this; + } + profile_probability operator- (const profile_probability &other) const + { + if (*this == profile_probability::never () + || other == profile_probability::never ()) + return *this; + if (!initialized_p () || !other.initialized_p ()) + return profile_probability::uninitialized (); + profile_probability ret; + ret.m_val = m_val >= other.m_val ? m_val - other.m_val : 0; + ret.m_quality = MIN (m_quality, other.m_quality); + return ret; + } + profile_probability &operator-= (const profile_probability &other) + { + if (*this == profile_probability::never () + || other == profile_probability::never ()) + return *this; + if (!initialized_p () || !other.initialized_p ()) + return *this = profile_probability::uninitialized (); + else + { + m_val = m_val >= other.m_val ? m_val - other.m_val : 0; + m_quality = MIN (m_quality, other.m_quality); + } + return *this; + } + profile_probability operator* (const profile_probability &other) const + { + if (*this == profile_probability::never () + || other == profile_probability::never ()) + return profile_probability::never (); + if (!initialized_p () || !other.initialized_p ()) + return profile_probability::uninitialized (); + profile_probability ret; + ret.m_val = RDIV ((uint64_t)m_val * other.m_val, max_probability); + ret.m_quality = MIN (m_quality, other.m_quality); + return ret; + } + profile_probability &operator*= (const profile_probability &other) + { + if (*this == profile_probability::never () + || other == profile_probability::never ()) + return *this = profile_probability::never (); + if (!initialized_p () || !other.initialized_p ()) + return *this = profile_probability::uninitialized (); + else + { + m_val = RDIV ((uint64_t)m_val * other.m_val, max_probability); + m_quality = MIN (m_quality, other.m_quality); + } + return *this; + } + profile_probability operator/ (const profile_probability &other) const + { + if (*this == profile_probability::never ()) + return profile_probability::never (); + if (!initialized_p () || !other.initialized_p ()) + return profile_probability::uninitialized (); + profile_probability ret; + if (m_val >= other.m_val) + ret.m_val = max_probability; + else if (!m_val) + ret.m_val = 0; + else + { + gcc_checking_assert (other.m_val); + ret.m_val = MIN (RDIV ((uint64_t)m_val * max_probability, + other.m_val), + max_probability); + } + ret.m_quality = MIN (m_quality, other.m_quality); + return ret; + } + profile_probability &operator/= (const profile_probability &other) + { + if (*this == profile_probability::never ()) + return *this = profile_probability::never (); + if (!initialized_p () || !other.initialized_p ()) + return *this = profile_probability::uninitialized (); + else + { + if (m_val > other.m_val) + m_val = max_probability; + else if (!m_val) + ; + else + { + gcc_checking_assert (other.m_val); + m_val = MIN (RDIV ((uint64_t)m_val * max_probability, + other.m_val), + max_probability); + } + m_quality = MIN (m_quality, other.m_quality); + } + return *this; + } + + gcov_type apply (gcov_type val) const + { + if (*this == profile_probability::uninitialized ()) + return val / 2; + return RDIV (val * m_val, max_probability); + } + + /* Return 1-*THIS. */ + profile_probability invert () const + { + return profile_probability::always() - *this; + } + + /* Return THIS with quality dropped to GUESSED. */ + profile_probability guessed () const + { + profile_probability ret = *this; + ret.m_quality = profile_guessed; + return ret; + } + + /* Return THIS with quality dropped to AFDO. */ + profile_probability afdo () const + { + profile_probability ret = *this; + ret.m_quality = profile_afdo; + return ret; + } + + profile_probability combine_with_freq (int freq1, profile_probability other, + int freq2) const + { + profile_probability ret; + + if (*this == profile_probability::uninitialized () + || other == profile_probability::uninitialized ()) + return profile_probability::uninitialized (); + + gcc_checking_assert (freq1 >= 0 && freq2 >= 0); + if (!freq1 && !freq2) + { + ret.m_val = (m_val + other.m_val) / 2; + } + else + ret.m_val = RDIV (m_val * (uint64_t) freq1 + + other.m_val * (uint64_t) freq2, freq1 + freq2); + ret.m_quality = MIN (m_quality, other.m_quality); + return ret; + } + + /* Return *THIS * NUM / DEN. */ + profile_probability apply_scale (int64_t num, int64_t den) const + { + if (*this == profile_probability::never ()) + return *this; + if (!initialized_p ()) + return profile_probability::uninitialized (); + profile_probability ret; + uint64_t tmp; + safe_scale_64bit (m_val, num, den, &tmp); + ret.m_val = MIN (tmp, max_probability); + ret.m_quality = MIN (m_quality, profile_adjusted); + return ret; + } + + /* Return true when the probability of edge is reliable. + + The profile guessing code is good at predicting branch outcome (ie. + taken/not taken), that is predicted right slightly over 75% of time. + It is however notoriously poor on predicting the probability itself. + In general the profile appear a lot flatter (with probabilities closer + to 50%) than the reality so it is bad idea to use it to drive optimization + such as those disabling dynamic branch prediction for well predictable + branches. + + There are two exceptions - edges leading to noreturn edges and edges + predicted by number of iterations heuristics are predicted well. This macro + should be able to distinguish those, but at the moment it simply check for + noreturn heuristic that is only one giving probability over 99% or bellow + 1%. In future we might want to propagate reliability information across the + CFG if we find this information useful on multiple places. */ + + bool probably_reliable_p () const + { + if (m_quality >= profile_adjusted) + return true; + if (!initialized_p ()) + return false; + return m_val < max_probability / 100 + || m_val > max_probability - max_probability / 100; + } + + /* Return false if profile_probability is bogus. */ + bool verify () const + { + if (m_val == uninitialized_probability) + return m_quality == profile_guessed; + else + return m_val <= max_probability; + } + + /* Comparsions are three-state and conservative. False is returned if + the inequality can not be decided. */ + bool operator< (const profile_probability &other) const + { + return initialized_p () && other.initialized_p () && m_val < other.m_val; + } + bool operator> (const profile_probability &other) const + { + return initialized_p () && other.initialized_p () && m_val > other.m_val; + } + + bool operator<= (const profile_probability &other) const + { + return initialized_p () && other.initialized_p () && m_val <= other.m_val; + } + bool operator>= (const profile_probability &other) const + { + return initialized_p () && other.initialized_p () && m_val >= other.m_val; + } + + /* Output THIS to F. */ + void dump (FILE *f) const; + + /* Print THIS to stderr. */ + void debug () const; + + /* Return true if THIS is known to differ significantly from OTHER. */ + bool differs_from_p (profile_probability other) const; + /* Return if difference is greater than 50%. */ + bool differs_lot_from_p (profile_probability other) const; + + /* LTO streaming support. */ + static profile_probability stream_in (struct lto_input_block *); + void stream_out (struct output_block *); + void stream_out (struct lto_output_stream *); +}; + +/* Main data type to hold profile counters in GCC. In most cases profile + counts originate from profile feedback. They are 64bit integers + representing number of executions during the train run. + As the profile is maintained during the compilation, many adjustments are + made. Not all transformations can be made precisely, most importantly + when code is being duplicated. It also may happen that part of CFG has + profile counts known while other do not - for example when LTO optimizing + partly profiled program or when profile was lost due to COMDAT merging. + + For this reason profile_count tracks more information than + just unsigned integer and it is also ready for profile mismatches. + The API of this data type represent operations that are natural + on profile counts - sum, difference and operation with scales and + probabilities. All operations are safe by never getting negative counts + and they do end up in uninitialized scale if any of the parameters is + uninitialized. + + All comparsions that are three state and handling of probabilities. Thus + a < b is not equal to !(a >= b). + + The following pre-defined counts are available: + + profile_count::zero () for code that is known to execute zero times at + runtime (this can be detected statically i.e. for paths leading to + abort (); + profile_count::one () for code that is known to execute once (such as + main () function + profile_count::uninitialized () for unknown execution count. + + */ + +class GTY(()) profile_count +{ + /* Use 62bit to hold basic block counters. Should be at least + 64bit. Although a counter cannot be negative, we use a signed + type to hold various extra stages. */ + + static const int n_bits = 62; + static const uint64_t max_count = ((uint64_t) 1 << n_bits) - 2; + static const uint64_t uninitialized_count = ((uint64_t) 1 << n_bits) - 1; + + uint64_t m_val : n_bits; + enum profile_quality m_quality : 2; +public: + + /* Used for counters which are expected to be never executed. */ + static profile_count zero () + { + return from_gcov_type (0); + } + static profile_count guessed_zero () + { + profile_count c; + c.m_val = 0; + c.m_quality = profile_guessed; + return c; + } + static profile_count one () + { + return from_gcov_type (1); + } + /* Value of counters which has not been initialized. Either because + initialization did not happen yet or because profile is unknown. */ + static profile_count uninitialized () + { + profile_count c; + c.m_val = uninitialized_count; + c.m_quality = profile_guessed; + return c; + } + + /* The profiling runtime uses gcov_type, which is usually 64bit integer. + Conversions back and forth are used to read the coverage and get it + into internal representation. */ + static profile_count from_gcov_type (gcov_type v) + { + profile_count ret; + gcc_checking_assert (v >= 0 && (uint64_t) v <= max_count); + ret.m_val = v; + ret.m_quality = profile_precise; + return ret; + } + + /* Conversion to gcov_type is lossy. */ + gcov_type to_gcov_type () const + { + gcc_checking_assert (initialized_p ()); + return m_val; + } + + /* Return true if value has been initialized. */ + bool initialized_p () const + { + return m_val != uninitialized_count; + } + /* Return true if value can be trusted. */ + bool reliable_p () const + { + return m_quality >= profile_adjusted; + } + + /* When merging basic blocks, the two different profile counts are unified. + Return true if this can be done without losing info about profile. + The only case we care about here is when first BB contains something + that makes it terminate in a way not visible in CFG. */ + bool ok_for_merging (profile_count other) const + { + if (m_quality < profile_adjusted + || other.m_quality < profile_adjusted) + return true; + return !(other < *this); + } + + /* When merging two BBs with different counts, pick common count that looks + most representative. */ + profile_count merge (profile_count other) const + { + if (*this == other || !other.initialized_p () + || m_quality > other.m_quality) + return *this; + if (other.m_quality > m_quality + || other > *this) + return other; + return *this; + } + + /* Basic operations. */ + bool operator== (const profile_count &other) const + { + return m_val == other.m_val && m_quality == other.m_quality; + } + profile_count operator+ (const profile_count &other) const + { + if (other == profile_count::zero ()) + return *this; + if (*this == profile_count::zero ()) + return other; + if (!initialized_p () || !other.initialized_p ()) + return profile_count::uninitialized (); + + profile_count ret; + ret.m_val = m_val + other.m_val; + ret.m_quality = MIN (m_quality, other.m_quality); + return ret; + } + profile_count &operator+= (const profile_count &other) + { + if (other == profile_count::zero ()) + return *this; + if (*this == profile_count::zero ()) + { + *this = other; + return *this; + } + if (!initialized_p () || !other.initialized_p ()) + return *this = profile_count::uninitialized (); + else + { + m_val += other.m_val; + m_quality = MIN (m_quality, other.m_quality); + } + return *this; + } + profile_count operator- (const profile_count &other) const + { + if (*this == profile_count::zero () || other == profile_count::zero ()) + return *this; + if (!initialized_p () || !other.initialized_p ()) + return profile_count::uninitialized (); + profile_count ret; + ret.m_val = m_val >= other.m_val ? m_val - other.m_val : 0; + ret.m_quality = MIN (m_quality, other.m_quality); + return ret; + } + profile_count &operator-= (const profile_count &other) + { + if (*this == profile_count::zero () || other == profile_count::zero ()) + return *this; + if (!initialized_p () || !other.initialized_p ()) + return *this = profile_count::uninitialized (); + else + { + m_val = m_val >= other.m_val ? m_val - other.m_val: 0; + m_quality = MIN (m_quality, other.m_quality); + } + return *this; + } + + /* Return false if profile_count is bogus. */ + bool verify () const + { + return m_val != uninitialized_count || m_quality == profile_guessed; + } + + /* Comparsions are three-state and conservative. False is returned if + the inequality can not be decided. */ + bool operator< (const profile_count &other) const + { + return initialized_p () && other.initialized_p () && m_val < other.m_val; + } + bool operator> (const profile_count &other) const + { + return initialized_p () && other.initialized_p () && m_val > other.m_val; + } + bool operator< (const gcov_type other) const + { + gcc_checking_assert (other >= 0); + return initialized_p () && m_val < (uint64_t) other; + } + bool operator> (const gcov_type other) const + { + gcc_checking_assert (other >= 0); + return initialized_p () && m_val > (uint64_t) other; + } + + bool operator<= (const profile_count &other) const + { + return initialized_p () && other.initialized_p () && m_val <= other.m_val; + } + bool operator>= (const profile_count &other) const + { + return initialized_p () && other.initialized_p () && m_val >= other.m_val; + } + bool operator<= (const gcov_type other) const + { + gcc_checking_assert (other >= 0); + return initialized_p () && m_val <= (uint64_t) other; + } + bool operator>= (const gcov_type other) const + { + gcc_checking_assert (other >= 0); + return initialized_p () && m_val >= (uint64_t) other; + } + + /* PROB is a probability in scale 0...REG_BR_PROB_BASE. Scale counter + accordingly. */ + profile_count apply_probability (int prob) const + { + gcc_checking_assert (prob >= 0 && prob <= REG_BR_PROB_BASE); + if (m_val == 0) + return *this; + if (!initialized_p ()) + return profile_count::uninitialized (); + profile_count ret; + ret.m_val = RDIV (m_val * prob, REG_BR_PROB_BASE); + ret.m_quality = MIN (m_quality, profile_adjusted); + return ret; + } + + /* Scale counter according to PROB. */ + profile_count apply_probability (profile_probability prob) const + { + if (*this == profile_count::zero ()) + return *this; + if (prob == profile_probability::never ()) + return profile_count::zero (); + if (!initialized_p ()) + return profile_count::uninitialized (); + profile_count ret; + uint64_t tmp; + safe_scale_64bit (m_val, prob.m_val, profile_probability::max_probability, + &tmp); + ret.m_val = tmp; + ret.m_quality = MIN (m_quality, prob.m_quality); + return ret; + } + /* Return *THIS * NUM / DEN. */ + profile_count apply_scale (int64_t num, int64_t den) const + { + if (m_val == 0) + return *this; + if (!initialized_p ()) + return profile_count::uninitialized (); + profile_count ret; + uint64_t tmp; + + gcc_checking_assert (num >= 0 && den > 0); + safe_scale_64bit (m_val, num, den, &tmp); + ret.m_val = MIN (tmp, max_count); + ret.m_quality = MIN (m_quality, profile_adjusted); + return ret; + } + profile_count apply_scale (profile_count num, profile_count den) const + { + if (m_val == 0) + return *this; + if (num.m_val == 0) + return num; + if (!initialized_p () || !num.initialized_p () || !den.initialized_p ()) + return profile_count::uninitialized (); + gcc_checking_assert (den > 0); + if (num == den) + return *this; + + profile_count ret; + uint64_t val; + safe_scale_64bit (m_val, num.m_val, den.m_val, &val); + ret.m_val = MIN (val, max_count); + ret.m_quality = MIN (m_quality, profile_adjusted); + return ret; + } + + /* Return THIS with quality dropped to GUESSED. */ + profile_count guessed () const + { + profile_count ret = *this; + ret.m_quality = profile_guessed; + return ret; + } + + /* Return THIS with quality dropped to AFDO. */ + profile_count afdo () const + { + profile_count ret = *this; + ret.m_quality = profile_afdo; + return ret; + } + + /* Return probability of event with counter THIS within event with counter + OVERALL. */ + profile_probability probability_in (const profile_count overall) const + { + if (!m_val) + return profile_probability::never (); + if (!initialized_p () || !overall.initialized_p () + || !overall.m_val) + return profile_probability::uninitialized (); + profile_probability ret; + if (overall < m_val) + ret.m_val = profile_probability::max_probability; + else + ret.m_val = RDIV (m_val * profile_probability::max_probability, + overall.m_val); + ret.m_quality = MIN (m_quality, overall.m_quality); + return ret; + } + + /* Output THIS to F. */ + void dump (FILE *f) const; + + /* Print THIS to stderr. */ + void debug () const; + + /* Return true if THIS is known to differ significantly from OTHER. */ + bool differs_from_p (profile_count other) const; + + /* LTO streaming support. */ + static profile_count stream_in (struct lto_input_block *); + void stream_out (struct output_block *); + void stream_out (struct lto_output_stream *); +}; +#endif