Traverses the current World using Rewriter infrastructure while staying in the same world. More...

#include <mim/phase.h>

Inheritance diagram for mim::Analysis:

Public Member Functions
Construction & Destruction
	Analysis (World &world, std::string name)
	Analysis (World &world, flags_t annex)
virtual void	reset ()
	Clears the rewriter map and resets Phase::todo() for the next fixed-point iteration.
Getters
bool	is_bootstrapping () const
	< Disambiguates the Phase/Rewriter double base; for an Analysis both denote the same World.
World &	world ()
Sparse Fixed-Point Iteration
bool	is_sparse () const
	Does the current round only re-drain last round's dirty mutables?
void	make_dense ()
	Forces whole-World rounds unconditionally.
size_t	version () const
	Bumped on every observable lattice change; snapshot it around a code region to detect changes.
Public Member Functions inherited from mim::Phase
	Phase (World &world, std::string name)
	Phase (World &world, flags_t annex)
virtual	~Phase ()=default
virtual std::unique_ptr< Phase >	recreate ()
	Creates a new instance; needed by a fixed-point PhaseMan.
virtual void	apply (const App *)
	Invoked if your Phase has additional args.
virtual void	apply (Phase &)
	Dito, but invoked by Phase::recreate.
virtual bool	redirects () const
	If true, Phase::create uses take_resolved().
virtual std::unique_ptr< Phase >	take_resolved ()
	The Phase to use instead; nullptr means elide.
World &	world ()
Driver &	driver ()
Log &	log () const
std::string_view	name () const
flags_t	annex () const
const Vector< std::string > &	args ()
	Command-line arguments passed to this Phase's plugin via -X <plugin>:<arg>.
bool	todo () const
void	invalidate (bool todo=true)
	Signals that another round of fixed-point iteration is required, either as part of.
virtual void	run ()
	Entry point and generates some debug output; invokes Phase::start.
void	profile_count (std::string_view key, uint64_t n=1)
	Adds `n` to the custom Profiler counter `key` of the current run; no-op unless profiling is enabled.
Public Member Functions inherited from mim::Rewriter
template<class D = Def>
D *	curr_mut () const
	Rewriter (std::unique_ptr< World > &&ptr)
	Rewriter (World &world)
virtual	~Rewriter ()
void	reset (std::unique_ptr< World > &&ptr)
void	reset ()
World &	world ()
virtual void	push ()
virtual void	pop ()
virtual const Def *	map (const Def old_def, const Def new_def)
const Def *	map (const Def *old_def, Defs new_defs)
const Def *	map (Defs old_defs, const Def *new_def)
const Def *	map (Defs old_defs, Defs new_defs)
virtual const Def *	lookup (const Def *old_def)
	Lookup old_def by searching in reverse through the stack of maps.
virtual const Def *	rewrite (const Def *)
virtual const Def *	rewrite_imm (const Def *)
virtual const Def *	rewrite_stub (Def , Def )
virtual DefVec	rewrite (Defs)
virtual const Def *	rewrite_imm_Seq (const Seq *seq)
virtual const Def *	rewrite_mut_Seq (Seq *seq)

Protected Member Functions
Rewrite
virtual void	prepare ()
	Run before the main analysis.
virtual void	finalize ()
	Run after the main analysis - only in full rounds, so it always sees the complete abstract World.
void	start () override
	Actual entry.
virtual void	rewrite_annex (flags_t, Sym, const Def *)
virtual void	rewrite_external (Def *)
const Def *	rewrite_imm_Proxy (const Proxy *proxy) override
	By default: ignore Proxys.
Def *	rewrite_mut (Def *) override
	Schedules `mut` for a breadth-first visit of its dependencies and records mut -> mut.
Protected Member Functions inherited from mim::Rewriter
auto	enter (Def *new_mut)
	Updates curr_mut() to `new_mut` and restores it at the end of the scope.

lattice
const auto &	lattice () const
	The whole map; used e.g. to diff two fixed-point runs.
const Def *	lattice (const Def *def) const
bool	is_top (const Def *def) const
bool	lattice_force (const Def concr, const Def abstr)
	Non-monotone write of concr ↦ abstr into lattice() and map().
bool	lattice (const Def concr, const Def abstr)
	Writes concr ↦ abstr into lattice() and map().
bool	pin (const Def *def)
	Monotonically forces `def` to ⊤ (keep as is).
void	taint (Def *mut)
	Additionally schedules `mut` for the next sparse round.

Additional Inherited Members
Static Public Member Functions inherited from mim::Phase
static std::unique_ptr< Phase >	create (const Flags2Phases &phases, const Def *def)
template<class A, class P>
static void	hook (Flags2Phases &phases)
template<class P, class... Args>
static void	run (Args &&... args)
	Runs a single Phase.
Protected Attributes inherited from mim::Phase
std::string	name_
Protected Attributes inherited from mim::Rewriter
std::deque< Def2Def >	old2news_

Detailed Description

Traverses the current World using Rewriter infrastructure while staying in the same world.

It recursively rewrites

all World::annexes() (during which Analysis::is_bootstrapping() is true), and then
all World::externals() (during which it is false).

Analysis provides a reusable lattice() mapping old Defs to abstract values, represented as ordinary MimIR Defs.

Fixed-point iteration is sparse by default: whenever a lattice write changes observable information, the mutable currently being drained is recorded as dirty. The next round then re-drains only those dirty mutables - plus everything reachable from them - instead of walking the whole World. At the start of such a round, the accumulated lattice() is replayed into the rewriter map, so a dirty mutable's body sees the substitutions its (non-revisited) producers installed in earlier rounds. Since dirt tracks writers - not readers - a sparse round may miss affected mutables; hence, once sparse rounds quiesce, one final full round certifies the fixed point.

Note

You can override

See also: Analysis; SSA without Dominance for how an Analysis substitutes Def::nests for the classical SSA dominance check.

Definition at line 149 of file phase.h.

Constructor & Destructor Documentation

◆ Analysis() [1/2]

mim::Analysis::Analysis	(	World &	world,
		std::string	name )

inline

Definition at line 153 of file phase.h.

References mim::Phase::name(), mim::Phase::Phase(), mim::Rewriter::Rewriter(), and world().

Referenced by mim::plug::gpu::phase::MemChecks::MemChecks().

◆ Analysis() [2/2]

mim::Analysis::Analysis	(	World &	world,
		flags_t	annex )

inline

Definition at line 156 of file phase.h.

References mim::Phase::annex(), mim::Phase::Phase(), mim::Rewriter::Rewriter(), and world().

Member Function Documentation

◆ finalize()

virtual void mim::Analysis::finalize ( )

inlineprotectedvirtual

Run after the main analysis - only in full rounds, so it always sees the complete abstract World.

Definition at line 256 of file phase.h.

Referenced by start().

◆ is_bootstrapping()

bool mim::Analysis::is_bootstrapping ( ) const

inline

< Disambiguates the Phase/Rewriter double base; for an Analysis both denote the same World.

Definition at line 171 of file phase.h.

◆ is_sparse()

bool mim::Analysis::is_sparse ( ) const

inline

Does the current round only re-drain last round's dirty mutables?

Definition at line 176 of file phase.h.

◆ is_top()

bool mim::Analysis::is_top ( const Def * def ) const

inline

Returns: whether def is pinned to ⊤ (def ↦ def).

Definition at line 197 of file phase.h.

◆ lattice() [1/3]

const auto & mim::Analysis::lattice ( ) const

inline

The whole map; used e.g. to diff two fixed-point runs.

Definition at line 188 of file phase.h.

Referenced by pin().

◆ lattice() [2/3]

bool mim::Analysis::lattice	(	const Def *	concr,
		const Def *	abstr )

inlineprotected

Writes concr ↦ abstr into lattice() and map().

invalidate()s - and thereby triggers another fixed-point round - iff this changes observable information: an existing entry was overwritten, or a fresh fact other than ⊤ was inserted. Freshly inserting ⊤ (concr ↦ concr) stays silent, as it is indistinguishable from absent for consumers. Every change also touch()es curr_mut() - the seed set of the next sparse round.

Returns: true iff this changed observable information - i.e. iff it invalidate()d.

Definition at line 229 of file phase.h.

References mim::Rewriter::map().

◆ lattice() [3/3]

const Def * mim::Analysis::lattice ( const Def * def ) const

inline

Returns: the abstract value recorded for def, or nullptr if unknown.

Definition at line 191 of file phase.h.

◆ lattice_force()

bool mim::Analysis::lattice_force	(	const Def *	concr,
		const Def *	abstr )

inlineprotected

Non-monotone write of concr ↦ abstr into lattice() and map().

This is the escape hatch for analyses that must overwrite an earlier round's value (descending from ⊤ is fine). invalidate()s iff the stored value changed; an absent entry counts as changed - even for ⊤ - since a non-monotone lattice's consumers may well distinguish ⊥ from ⊤. Every change also touch()es curr_mut() - the seed set of the next sparse round.

Returns: true iff this changed the entry - i.e. iff it invalidate()d.

Definition at line 213 of file phase.h.

References mim::Rewriter::map().

◆ make_dense()

void mim::Analysis::make_dense ( )

inline

Forces whole-World rounds unconditionally.

Definition at line 179 of file phase.h.

◆ pin()

bool mim::Analysis::pin ( const Def * def )

inlineprotected

Monotonically forces def to ⊤ (keep as is).

Returns: true iff this changed observable information - i.e. iff it invalidate()d.

Definition at line 244 of file phase.h.

References lattice().

◆ prepare()

virtual void mim::Analysis::prepare ( )

inlineprotectedvirtual

Run before the main analysis.

Definition at line 254 of file phase.h.

Referenced by start().

◆ reset()

void mim::Analysis::reset ( )

virtual

Clears the rewriter map and resets Phase::todo() for the next fixed-point iteration.

lattice() is preserved across iterations so that abstract values accumulated in earlier rounds remain available - this is what makes fixed-point convergence possible. The dirty set survives as well; start() consumes it to decide whether the round can be sparse.

See also: RWPhase::analyze

Definition at line 51 of file phase.cpp.

References mim::Rewriter::old2news_, and mim::Rewriter::push().

◆ rewrite_annex()

void mim::Analysis::rewrite_annex	(	flags_t	,
		Sym	,
		const Def *	def )

protectedvirtual

Definition at line 101 of file phase.cpp.

References mim::Rewriter::rewrite().

Referenced by start().

◆ rewrite_external()

void mim::Analysis::rewrite_external ( Def * mut )

protectedvirtual

Reimplemented in mim::plug::gpu::phase::MemChecks.

Definition at line 102 of file phase.cpp.

References mim::Rewriter::rewrite().

Referenced by mim::plug::gpu::phase::MemChecks::rewrite_external(), and start().

◆ rewrite_imm_Proxy()

const Def * mim::Analysis::rewrite_imm_Proxy ( const Proxy * proxy )

inlineoverrideprotected

By default: ignore Proxys.

Definition at line 260 of file phase.h.

◆ rewrite_mut()

Def * mim::Analysis::rewrite_mut ( Def * mut )

overrideprotectedvirtual

Schedules mut for a breadth-first visit of its dependencies and records mut -> mut.

Mutables are enqueued instead of recursed into; Analysis::drain then walks them in BFS order. The mut -> mut entry doubles as the per-round "already scheduled" marker (Rewriter::old2news_ is cleared by reset()), so each mutable's deps are visited at most once per fixed-point round.

Reimplemented from mim::Rewriter.

Definition at line 104 of file phase.cpp.

References mim::Rewriter::lookup(), and mim::Rewriter::map().

◆ start()

void mim::Analysis::start ( )

overrideprotectedvirtual

Actual entry.

Implements mim::Phase.

Definition at line 58 of file phase.cpp.

References finalize(), mim::Phase::invalidate(), mim::Rewriter::map(), prepare(), mim::Phase::profile_count(), mim::Rewriter::rewrite(), rewrite_annex(), rewrite_external(), mim::Phase::todo(), VLOG, and world().

◆ taint()

void mim::Analysis::taint ( Def * mut )

inlineprotected

Additionally schedules mut for the next sparse round.

Use this when a lattice change must re-visit other mutables than curr_mut() - e.g. all call sites of a Lam whose var's abstract value changed.

Definition at line 249 of file phase.h.

◆ version()

size_t mim::Analysis::version ( ) const

inline

Bumped on every observable lattice change; snapshot it around a code region to detect changes.

Definition at line 181 of file phase.h.

◆ world()

World & mim::Phase::world ( )

inline

Definition at line 77 of file phase.h.

Referenced by Analysis(), Analysis(), mim::plug::gpu::phase::MemChecks::MemChecks(), and start().

The documentation for this class was generated from the following files:

include/mim/phase.h
src/mim/phase.cpp

Public Member Functions

Protected Member Functions

lattice

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Analysis() [1/2]

◆ Analysis() [2/2]

Member Function Documentation

◆ finalize()

◆ is_bootstrapping()

◆ is_sparse()

◆ is_top()

◆ lattice() [1/3]

◆ lattice() [2/3]

◆ lattice() [3/3]

◆ lattice_force()

◆ make_dense()

◆ pin()

◆ prepare()

◆ reset()

◆ rewrite_annex()

◆ rewrite_external()

◆ rewrite_imm_Proxy()

◆ rewrite_mut()

◆ start()

◆ taint()

◆ version()

◆ world()