/* Profile counter container type. | |

Copyright (C) 2017-2022 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 | |

struct function; | |

struct profile_count; | |

class sreal; | |

/* Quality of the profile count. Because gengtype does not support enums | |

inside of classes, this is in global namespace. */ | |

enum profile_quality { | |

/* Uninitialized value. */ | |

UNINITIALIZED_PROFILE, | |

/* Profile is based on static branch prediction heuristics and may | |

or may not match reality. It is local to function and cannot be compared | |

inter-procedurally. Never used by probabilities (they are always local). | |

*/ | |

GUESSED_LOCAL, | |

/* Profile was read by feedback and was 0, we used local heuristics to guess | |

better. This is the case of functions not run in profile feedback. | |

Never used by probabilities. */ | |

GUESSED_GLOBAL0, | |

/* Same as GUESSED_GLOBAL0 but global count is adjusted 0. */ | |

GUESSED_GLOBAL0_ADJUSTED, | |

/* Profile is based on static branch prediction heuristics. It may or may | |

not reflect the reality but it can be compared interprocedurally | |

(for example, we inlined function w/o profile feedback into function | |

with feedback and propagated from that). | |

Never used by probabilities. */ | |

GUESSED, | |

/* Profile was determined by autofdo. */ | |

AFDO, | |

/* Profile was originally based on feedback but it was adjusted | |

by code duplicating optimization. It may not precisely reflect the | |

particular code path. */ | |

ADJUSTED, | |

/* Profile was read from profile feedback or determined by accurate static | |

method. */ | |

PRECISE | |

}; | |

extern const char *profile_quality_as_string (enum profile_quality); | |

extern bool parse_profile_quality (const char *value, | |

profile_quality *quality); | |

/* 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_PROFILE is used for probabilities | |

that has not been determined yet (for example because 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 probability) | |

- 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 = 29; | |

/* 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 : 29; | |

enum profile_quality m_quality : 3; | |

friend struct profile_count; | |

public: | |

profile_probability (): m_val (uninitialized_probability), | |

m_quality (GUESSED) | |

{} | |

profile_probability (uint32_t val, profile_quality quality): | |

m_val (val), m_quality (quality) | |

{} | |

/* Named probabilities. */ | |

static profile_probability never () | |

{ | |

profile_probability ret; | |

ret.m_val = 0; | |

ret.m_quality = PRECISE; | |

return ret; | |

} | |

static profile_probability guessed_never () | |

{ | |

profile_probability ret; | |

ret.m_val = 0; | |

ret.m_quality = GUESSED; | |

return ret; | |

} | |

static profile_probability very_unlikely () | |

{ | |

/* Be consistent with PROB_VERY_UNLIKELY in predict.h. */ | |

profile_probability r = guessed_always () / 2000; | |

r.m_val--; | |

return r; | |

} | |

static profile_probability unlikely () | |

{ | |

/* Be consistent with PROB_VERY_LIKELY in predict.h. */ | |

profile_probability r = guessed_always () / 5; | |

r.m_val--; | |

return r; | |

} | |

static profile_probability even () | |

{ | |

return guessed_always () / 2; | |

} | |

static profile_probability very_likely () | |

{ | |

return always () - very_unlikely (); | |

} | |

static profile_probability likely () | |

{ | |

return always () - unlikely (); | |

} | |

static profile_probability guessed_always () | |

{ | |

profile_probability ret; | |

ret.m_val = max_probability; | |

ret.m_quality = GUESSED; | |

return ret; | |

} | |

static profile_probability always () | |

{ | |

profile_probability ret; | |

ret.m_val = max_probability; | |

ret.m_quality = 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 = 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 >= 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 = GUESSED; | |

return ret; | |

} | |

/* Return THIS with quality set to ADJUSTED. */ | |

profile_probability adjusted () const | |

{ | |

profile_probability ret = *this; | |

if (!initialized_p ()) | |

return *this; | |

ret.m_quality = ADJUSTED; | |

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) / 8; | |

ret.m_quality = (enum profile_quality)(v & 7); | |

return ret; | |

} | |

int to_reg_br_prob_note () const | |

{ | |

gcc_checking_assert (initialized_p ()); | |

int ret = m_val * 8 + m_quality; | |

gcc_checking_assert (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 = 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 == never ()) | |

return *this; | |

if (*this == never ()) | |

return other; | |

if (!initialized_p () || !other.initialized_p ()) | |

return 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 == never ()) | |

return *this; | |

if (*this == never ()) | |

{ | |

*this = other; | |

return *this; | |

} | |

if (!initialized_p () || !other.initialized_p ()) | |

return *this = 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 == never () | |

|| other == never ()) | |

return *this; | |

if (!initialized_p () || !other.initialized_p ()) | |

return 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 == never () | |

|| other == never ()) | |

return *this; | |

if (!initialized_p () || !other.initialized_p ()) | |

return *this = 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 == never () | |

|| other == never ()) | |

return never (); | |

if (!initialized_p () || !other.initialized_p ()) | |

return uninitialized (); | |

profile_probability ret; | |

ret.m_val = RDIV ((uint64_t)m_val * other.m_val, max_probability); | |

ret.m_quality = MIN (MIN (m_quality, other.m_quality), ADJUSTED); | |

return ret; | |

} | |

profile_probability &operator*= (const profile_probability &other) | |

{ | |

if (*this == never () | |

|| other == never ()) | |

return *this = never (); | |

if (!initialized_p () || !other.initialized_p ()) | |

return *this = uninitialized (); | |

else | |

{ | |

m_val = RDIV ((uint64_t)m_val * other.m_val, max_probability); | |

m_quality = MIN (MIN (m_quality, other.m_quality), ADJUSTED); | |

} | |

return *this; | |

} | |

profile_probability operator/ (const profile_probability &other) const | |

{ | |

if (*this == never ()) | |

return never (); | |

if (!initialized_p () || !other.initialized_p ()) | |

return uninitialized (); | |

profile_probability ret; | |

/* If we get probability above 1, mark it as unreliable and return 1. */ | |

if (m_val >= other.m_val) | |

{ | |

ret.m_val = max_probability; | |

ret.m_quality = MIN (MIN (m_quality, other.m_quality), | |

GUESSED); | |

return ret; | |

} | |

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 (MIN (m_quality, other.m_quality), ADJUSTED); | |

return ret; | |

} | |

profile_probability &operator/= (const profile_probability &other) | |

{ | |

if (*this == never ()) | |

return *this = never (); | |

if (!initialized_p () || !other.initialized_p ()) | |

return *this = uninitialized (); | |

else | |

{ | |

/* If we get probability above 1, mark it as unreliable | |

and return 1. */ | |

if (m_val > other.m_val) | |

{ | |

m_val = max_probability; | |

m_quality = MIN (MIN (m_quality, other.m_quality), | |

GUESSED); | |

return *this; | |

} | |

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 (MIN (m_quality, other.m_quality), ADJUSTED); | |

} | |

return *this; | |

} | |

/* Split *THIS (ORIG) probability into 2 probabilities, such that | |

the returned one (FIRST) is *THIS * CPROB and *THIS is | |

adjusted (SECOND) so that FIRST + FIRST.invert () * SECOND | |

== ORIG. This is useful e.g. when splitting a conditional | |

branch like: | |

if (cond) | |

goto lab; // ORIG probability | |

into | |

if (cond1) | |

goto lab; // FIRST = ORIG * CPROB probability | |

if (cond2) | |

goto lab; // SECOND probability | |

such that the overall probability of jumping to lab remains | |

the same. CPROB gives the relative probability between the | |

branches. */ | |

profile_probability split (const profile_probability &cprob) | |

{ | |

profile_probability ret = *this * cprob; | |

/* The following is equivalent to: | |

*this = cprob.invert () * *this / ret.invert (); | |

Avoid scaling when overall outcome is supposed to be always. | |

Without knowing that one is inverse of other, the result would be | |

conservative. */ | |

if (!(*this == always ())) | |

*this = (*this - ret) / ret.invert (); | |

return ret; | |

} | |

gcov_type apply (gcov_type val) const | |

{ | |

if (*this == uninitialized ()) | |

return val / 2; | |

return RDIV (val * m_val, max_probability); | |

} | |

/* Return 1-*THIS. */ | |

profile_probability invert () const | |

{ | |

return always() - *this; | |

} | |

/* Return THIS with quality dropped to GUESSED. */ | |

profile_probability guessed () const | |

{ | |

profile_probability ret = *this; | |

ret.m_quality = GUESSED; | |

return ret; | |

} | |

/* Return THIS with quality dropped to AFDO. */ | |

profile_probability afdo () const | |

{ | |

profile_probability ret = *this; | |

ret.m_quality = AFDO; | |

return ret; | |

} | |

/* Return *THIS * NUM / DEN. */ | |

profile_probability apply_scale (int64_t num, int64_t den) const | |

{ | |

if (*this == never ()) | |

return *this; | |

if (!initialized_p ()) | |

return 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, ADJUSTED); | |

return ret; | |

} | |

/* Return true when the probability of edge is reliable. | |

The profile guessing code is good at predicting branch outcome (i.e. | |

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 >= 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 | |

{ | |

gcc_checking_assert (m_quality != UNINITIALIZED_PROFILE); | |

if (m_val == uninitialized_probability) | |

return m_quality == GUESSED; | |

else if (m_quality < GUESSED) | |

return false; | |

return m_val <= max_probability; | |

} | |

/* Comparisons are three-state and conservative. False is returned if | |

the inequality cannot 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; | |

} | |

profile_probability operator* (int64_t num) const | |

{ | |

return apply_scale (num, 1); | |

} | |

profile_probability operator*= (int64_t num) | |

{ | |

*this = apply_scale (num, 1); | |

return *this; | |

} | |

profile_probability operator/ (int64_t den) const | |

{ | |

return apply_scale (1, den); | |

} | |

profile_probability operator/= (int64_t den) | |

{ | |

*this = apply_scale (1, den); | |

return *this; | |

} | |

/* Get the value of the count. */ | |

uint32_t value () const { return m_val; } | |

/* Get the quality of the count. */ | |

enum profile_quality quality () const { return m_quality; } | |

/* Output THIS to F. */ | |

void dump (FILE *f) const; | |

/* Output THIS to BUFFER. */ | |

void dump (char *buffer) 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; | |

/* COUNT1 times event happens with *THIS probability, COUNT2 times OTHER | |

happens with COUNT2 probability. Return probability that either *THIS or | |

OTHER happens. */ | |

profile_probability combine_with_count (profile_count count1, | |

profile_probability other, | |

profile_count count2) const; | |

/* Return probability as sreal. */ | |

sreal to_sreal () const; | |

/* LTO streaming support. */ | |

static profile_probability stream_in (class 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. Profile counts originate | |

either from profile feedback, static profile estimation or both. We do not | |

perform whole program profile propagation and thus profile estimation | |

counters are often local to function, while counters from profile feedback | |

(or special cases of profile estimation) can be used inter-procedurally. | |

There are 3 basic types | |

1) local counters which are result of intra-procedural static profile | |

estimation. | |

2) ipa counters which are result of profile feedback or special case | |

of static profile estimation (such as in function main). | |

3) counters which counts as 0 inter-procedurally (because given function | |

was never run in train feedback) but they hold local static profile | |

estimate. | |

Counters of type 1 and 3 cannot be mixed with counters of different type | |

within operation (because whole function should use one type of counter) | |

with exception that global zero mix in most operations where outcome is | |

well defined. | |

To take local counter and use it inter-procedurally use ipa member function | |

which strips information irrelevant at the inter-procedural level. | |

Counters are 61bit integers representing number of executions during the | |

train run or normalized frequency within the function. | |

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 comparisons 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. | |

*/ | |

struct GTY(()) profile_count | |

{ | |

public: | |

/* 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 = 61; | |

static const uint64_t max_count = ((uint64_t) 1 << n_bits) - 2; | |

private: | |

static const uint64_t uninitialized_count = ((uint64_t) 1 << n_bits) - 1; | |

#if defined (__arm__) && (__GNUC__ >= 6 && __GNUC__ <= 8) | |

/* Work-around for PR88469. A bug in the gcc-6/7/8 PCS layout code | |

incorrectly detects the alignment of a structure where the only | |

64-bit aligned object is a bit-field. We force the alignment of | |

the entire field to mitigate this. */ | |

#define UINT64_BIT_FIELD_ALIGN __attribute__ ((aligned(8))) | |

#else | |

#define UINT64_BIT_FIELD_ALIGN | |

#endif | |

uint64_t UINT64_BIT_FIELD_ALIGN m_val : n_bits; | |

#undef UINT64_BIT_FIELD_ALIGN | |

enum profile_quality m_quality : 3; | |

public: | |

/* Return true if both values can meaningfully appear in single function | |

body. We have either all counters in function local or global, otherwise | |

operations between them are not really defined well. */ | |

bool compatible_p (const profile_count other) const | |

{ | |

if (!initialized_p () || !other.initialized_p ()) | |

return true; | |

if (*this == zero () | |

|| other == zero ()) | |

return true; | |

/* Do not allow nonzero global profile together with local guesses | |

that are globally0. */ | |

if (ipa ().nonzero_p () | |

&& !(other.ipa () == other)) | |

return false; | |

if (other.ipa ().nonzero_p () | |

&& !(ipa () == *this)) | |

return false; | |

return ipa_p () == other.ipa_p (); | |

} | |

/* Used for counters which are expected to be never executed. */ | |

static profile_count zero () | |

{ | |

return from_gcov_type (0); | |

} | |

static profile_count adjusted_zero () | |

{ | |

profile_count c; | |

c.m_val = 0; | |

c.m_quality = ADJUSTED; | |

return c; | |

} | |

static profile_count guessed_zero () | |

{ | |

profile_count c; | |

c.m_val = 0; | |

c.m_quality = 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 = GUESSED_LOCAL; | |

return c; | |

} | |

/* 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 >= ADJUSTED; | |

} | |

/* Return true if value can be operated inter-procedurally. */ | |

bool ipa_p () const | |

{ | |

return !initialized_p () || m_quality >= GUESSED_GLOBAL0; | |

} | |

/* Return true if quality of profile is precise. */ | |

bool precise_p () const | |

{ | |

return m_quality == PRECISE; | |

} | |

/* Get the value of the count. */ | |

uint64_t value () const { return m_val; } | |

/* Get the quality of the count. */ | |

enum profile_quality quality () const { return m_quality; } | |

/* 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 < ADJUSTED | |

|| other.m_quality < 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 == zero ()) | |

return *this; | |

if (*this == zero ()) | |

return other; | |

if (!initialized_p () || !other.initialized_p ()) | |

return uninitialized (); | |

profile_count ret; | |

gcc_checking_assert (compatible_p (other)); | |

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 == zero ()) | |

return *this; | |

if (*this == zero ()) | |

{ | |

*this = other; | |

return *this; | |

} | |

if (!initialized_p () || !other.initialized_p ()) | |

return *this = uninitialized (); | |

else | |

{ | |

gcc_checking_assert (compatible_p (other)); | |

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 == zero () || other == zero ()) | |

return *this; | |

if (!initialized_p () || !other.initialized_p ()) | |

return uninitialized (); | |

gcc_checking_assert (compatible_p (other)); | |

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 == zero () || other == zero ()) | |

return *this; | |

if (!initialized_p () || !other.initialized_p ()) | |

return *this = uninitialized (); | |

else | |

{ | |

gcc_checking_assert (compatible_p (other)); | |

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 | |

{ | |

gcc_checking_assert (m_quality != UNINITIALIZED_PROFILE); | |

return m_val != uninitialized_count || m_quality == GUESSED_LOCAL; | |

} | |

/* Comparisons are three-state and conservative. False is returned if | |

the inequality cannot be decided. */ | |

bool operator< (const profile_count &other) const | |

{ | |

if (!initialized_p () || !other.initialized_p ()) | |

return false; | |

if (*this == zero ()) | |

return !(other == zero ()); | |

if (other == zero ()) | |

return false; | |

gcc_checking_assert (compatible_p (other)); | |

return m_val < other.m_val; | |

} | |

bool operator> (const profile_count &other) const | |

{ | |

if (!initialized_p () || !other.initialized_p ()) | |

return false; | |

if (*this == zero ()) | |

return false; | |

if (other == zero ()) | |

return !(*this == zero ()); | |

gcc_checking_assert (compatible_p (other)); | |

return initialized_p () && other.initialized_p () && m_val > other.m_val; | |

} | |

bool operator< (const gcov_type other) const | |

{ | |

gcc_checking_assert (ipa_p ()); | |

gcc_checking_assert (other >= 0); | |

return ipa ().initialized_p () && ipa ().m_val < (uint64_t) other; | |

} | |

bool operator> (const gcov_type other) const | |

{ | |

gcc_checking_assert (ipa_p ()); | |

gcc_checking_assert (other >= 0); | |

return ipa ().initialized_p () && ipa ().m_val > (uint64_t) other; | |

} | |

bool operator<= (const profile_count &other) const | |

{ | |

if (!initialized_p () || !other.initialized_p ()) | |

return false; | |

if (*this == zero ()) | |

return true; | |

if (other == zero ()) | |

return (*this == zero ()); | |

gcc_checking_assert (compatible_p (other)); | |

return m_val <= other.m_val; | |

} | |

bool operator>= (const profile_count &other) const | |

{ | |

if (!initialized_p () || !other.initialized_p ()) | |

return false; | |

if (other == zero ()) | |

return true; | |

if (*this == zero ()) | |

return (other == zero ()); | |

gcc_checking_assert (compatible_p (other)); | |

return m_val >= other.m_val; | |

} | |

bool operator<= (const gcov_type other) const | |

{ | |

gcc_checking_assert (ipa_p ()); | |

gcc_checking_assert (other >= 0); | |

return ipa ().initialized_p () && ipa ().m_val <= (uint64_t) other; | |

} | |

bool operator>= (const gcov_type other) const | |

{ | |

gcc_checking_assert (ipa_p ()); | |

gcc_checking_assert (other >= 0); | |

return ipa ().initialized_p () && ipa ().m_val >= (uint64_t) other; | |

} | |

profile_count operator* (int64_t num) const | |

{ | |

return apply_scale (num, 1); | |

} | |

profile_count operator*= (int64_t num) | |

{ | |

*this = apply_scale (num, 1); | |

return *this; | |

} | |

profile_count operator/ (int64_t den) const | |

{ | |

return apply_scale (1, den); | |

} | |

profile_count operator/= (int64_t den) | |

{ | |

*this = apply_scale (1, den); | |

return *this; | |

} | |

/* Return true when value is not zero and can be used for scaling. | |

This is different from *this > 0 because that requires counter to | |

be IPA. */ | |

bool nonzero_p () const | |

{ | |

return initialized_p () && m_val != 0; | |

} | |

/* Make counter forcibly nonzero. */ | |

profile_count force_nonzero () const | |

{ | |

if (!initialized_p ()) | |

return *this; | |

profile_count ret = *this; | |

if (ret.m_val == 0) | |

{ | |

ret.m_val = 1; | |

ret.m_quality = MIN (m_quality, ADJUSTED); | |

} | |

return ret; | |

} | |

profile_count max (profile_count other) const | |

{ | |

profile_count val = *this; | |

/* Always prefer nonzero IPA counts over local counts. */ | |

if (ipa ().nonzero_p () || other.ipa ().nonzero_p ()) | |

{ | |

val = ipa (); | |

other = other.ipa (); | |

} | |

if (!initialized_p ()) | |

return other; | |

if (!other.initialized_p ()) | |

return *this; | |

if (*this == zero ()) | |

return other; | |

if (other == zero ()) | |

return *this; | |

gcc_checking_assert (compatible_p (other)); | |

if (val.m_val < other.m_val || (m_val == other.m_val | |

&& val.m_quality < other.m_quality)) | |

return other; | |

return *this; | |

} | |

/* 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 uninitialized (); | |

profile_count ret; | |

ret.m_val = RDIV (m_val * prob, REG_BR_PROB_BASE); | |

ret.m_quality = MIN (m_quality, ADJUSTED); | |

return ret; | |

} | |

/* Scale counter according to PROB. */ | |

profile_count apply_probability (profile_probability prob) const | |

{ | |

if (*this == zero ()) | |

return *this; | |

if (prob == profile_probability::never ()) | |

return zero (); | |

if (!initialized_p ()) | |

return 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 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, ADJUSTED); | |

return ret; | |

} | |

profile_count apply_scale (profile_count num, profile_count den) const | |

{ | |

if (*this == zero ()) | |

return *this; | |

if (num == zero ()) | |

return num; | |

if (!initialized_p () || !num.initialized_p () || !den.initialized_p ()) | |

return uninitialized (); | |

if (num == den) | |

return *this; | |

gcc_checking_assert (den.m_val); | |

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 (MIN (MIN (m_quality, ADJUSTED), | |

num.m_quality), den.m_quality); | |

/* Be sure that ret is not local if num is global. | |

Also ensure that ret is not global0 when num is global. */ | |

if (num.ipa_p ()) | |

ret.m_quality = MAX (ret.m_quality, | |

num == num.ipa () ? GUESSED : num.m_quality); | |

return ret; | |

} | |

/* Return THIS with quality dropped to GUESSED_LOCAL. */ | |

profile_count guessed_local () const | |

{ | |

profile_count ret = *this; | |

if (!initialized_p ()) | |

return *this; | |

ret.m_quality = GUESSED_LOCAL; | |

return ret; | |

} | |

/* We know that profile is globally 0 but keep local profile if present. */ | |

profile_count global0 () const | |

{ | |

profile_count ret = *this; | |

if (!initialized_p ()) | |

return *this; | |

ret.m_quality = GUESSED_GLOBAL0; | |

return ret; | |

} | |

/* We know that profile is globally adjusted 0 but keep local profile | |

if present. */ | |

profile_count global0adjusted () const | |

{ | |

profile_count ret = *this; | |

if (!initialized_p ()) | |

return *this; | |

ret.m_quality = GUESSED_GLOBAL0_ADJUSTED; | |

return ret; | |

} | |

/* Return THIS with quality dropped to GUESSED. */ | |

profile_count guessed () const | |

{ | |

profile_count ret = *this; | |

ret.m_quality = MIN (ret.m_quality, GUESSED); | |

return ret; | |

} | |

/* Return variant of profile count which is always safe to compare | |

across functions. */ | |

profile_count ipa () const | |

{ | |

if (m_quality > GUESSED_GLOBAL0_ADJUSTED) | |

return *this; | |

if (m_quality == GUESSED_GLOBAL0) | |

return zero (); | |

if (m_quality == GUESSED_GLOBAL0_ADJUSTED) | |

return adjusted_zero (); | |

return uninitialized (); | |

} | |

/* Return THIS with quality dropped to AFDO. */ | |

profile_count afdo () const | |

{ | |

profile_count ret = *this; | |

ret.m_quality = 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 (*this == zero () | |

&& !(overall == zero ())) | |

return profile_probability::never (); | |

if (!initialized_p () || !overall.initialized_p () | |

|| !overall.m_val) | |

return profile_probability::uninitialized (); | |

if (*this == overall && m_quality == PRECISE) | |

return profile_probability::always (); | |

profile_probability ret; | |

gcc_checking_assert (compatible_p (overall)); | |

if (overall.m_val < m_val) | |

{ | |

ret.m_val = profile_probability::max_probability; | |

ret.m_quality = GUESSED; | |

return ret; | |

} | |

else | |

ret.m_val = RDIV (m_val * profile_probability::max_probability, | |

overall.m_val); | |

ret.m_quality = MIN (MAX (MIN (m_quality, overall.m_quality), | |

GUESSED), ADJUSTED); | |

return ret; | |

} | |

int to_frequency (struct function *fun) const; | |

int to_cgraph_frequency (profile_count entry_bb_count) const; | |

sreal to_sreal_scale (profile_count in, bool *known = NULL) const; | |

/* Output THIS to F. */ | |

void dump (FILE *f) const; | |

/* Output THIS to BUFFER. */ | |

void dump (char *buffer) 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; | |

/* We want to scale profile across function boundary from NUM to DEN. | |

Take care of the side case when NUM and DEN are zeros of incompatible | |

kinds. */ | |

static void adjust_for_ipa_scaling (profile_count *num, profile_count *den); | |

/* THIS is a count of bb which is known to be executed IPA times. | |

Combine this information into bb counter. This means returning IPA | |

if it is nonzero, not changing anything if IPA is uninitialized | |

and if IPA is zero, turning THIS into corresponding local profile with | |

global0. */ | |

profile_count combine_with_ipa_count (profile_count ipa); | |

/* Same as combine_with_ipa_count but inside function with count IPA2. */ | |

profile_count combine_with_ipa_count_within | |

(profile_count ipa, profile_count ipa2); | |

/* 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_quality quality = PRECISE); | |

/* LTO streaming support. */ | |

static profile_count stream_in (class lto_input_block *); | |

void stream_out (struct output_block *); | |

void stream_out (struct lto_output_stream *); | |

}; | |

#endif |