Our Type class has a semantic and representational dimension.
Much code in src/ast, Crankshaft and Turbofan is based on it.
Going forward in Turbofan we'd like to remove representational information
entirely. To that end, new type AstType has been created to preserve
existing behavior for the benefit of Crankshaft and the AST.

BUG=

Review-Url: https://codereview.chromium.org/2302283002
Cr-Commit-Position: refs/heads/master@{#39135}

We (mis)used Type::Class to track stable field maps in the past. But
that always more or less unsupport and wrong for various reasons, mostly
because the class types do not really present static information and
thus it is possible to violate fundamental assumptions of the type
system (i.e. intersecting class types and other types produces
"interesting" results).

Now it is possible to finally nuke the class types completely and thus
simplify (and ideally correctify) the type system further.

Note to performance sheriff: We do expect to see some performance
regressions from this change. This is because we do not yet have a sane
replacement mechanism to track known field maps and utilize them during
LoadElimination. This will be accomplished in a follow up CL.

BUG=v8:5270,v8:5267
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2293343002
Cr-Commit-Position: refs/heads/master@{#39031}

This removes the representation axis from the type of {Load/StoreField}
operators representing a property load/store. The representation would
be narrowed to {None} which causes problems for all places where we use
the type to reason about the value representation. Instead we should
fully switch to {MachineRepresentation}. This is just a stop-gap fix.

R=jarin@chromium.org
BUG=chromium:636716

Review-Url: https://codereview.chromium.org/2255533003
Cr-Commit-Position: refs/heads/master@{#38678}

Separate ConvertTaggedHoleToUndefined and CheckTaggedHole into two
separate operators, where the former is pure and just turns into
trivial control flow in the EffectControlLinearizer.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2236443004
Cr-Commit-Position: refs/heads/master@{#38559}

Move all the typing rules for unary and binary number operations to the
OperationTyper and use them for both the regular Typer as well as the
retyper that runs as part of SimplifiedLowering.

R=epertoso@chromium.org

Review-Url: https://codereview.chromium.org/2202883005
Cr-Commit-Position: refs/heads/master@{#38283}

Infer a more precise type even in case where NaN and/or -0 is a possible
outcome of the operation, and use this more precise type to improve code
generation for the modulus itself by trying harder to stick to Word32
operations instead of going to Float64, and also optimize the pattern
where we compare the output of x % y to some non-zero integer constant
K, in which case we can truncate the output of x % y to Word32 if the
type of x % y is Signed32/Unsigned32 \/ NaN \/ MinusZero, as NaN and
MinusZero will both be truncated to zero, which cannot match the non
zero constant K.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2202413002
Cr-Commit-Position: refs/heads/master@{#38267}

These simplified operators are used to perform the hole checks when
loading elements from a holey array. Depending on the CheckHoleMode,
they either return the hole as undefined or some NaN, or deoptimize
if the value is the hole or the hole NaN.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2066223002
Cr-Commit-Position: refs/heads/master@{#37001}

Now that we have the PlainPrimitiveToNumber operator(s), we can unify
all the places where we expect a number, but can also safely handle any
plain-primitive (via ToNumber truncation).

Drive-by-fix: Also handle Math.min consistently with Math.max.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2064953004
Cr-Commit-Position: refs/heads/master@{#36984}

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2024853002
Cr-Commit-Position: refs/heads/master@{#36627}

Since both null and undefined are also marked as undetectable now, we
can just test that bit instead of having the CompareNilIC try to collect
feedback to speed up the general case (without the undetectable bit
being used).

Drive-by-fix: Update the type system to match the new handling of
undetectable in the runtime.

R=danno@chromium.org

Committed: https://crrev.com/666aec0348c8793e61c8633dee7ad29a514239ba
Cr-Commit-Position: refs/heads/master@{#34237}

Review URL: https://codereview.chromium.org/1722193002

Cr-Commit-Position: refs/heads/master@{#34344}

Revert of [compiler] Drop the CompareNilIC. (patchset #4 id:60001 of https://codereview.chromium.org/1722193002/ )

Reason for revert:
Speculative revert in attempt to fix #2 crasher on canary.

Original issue's description:
> [compiler] Drop the CompareNilIC.
>
> Since both null and undefined are also marked as undetectable now, we
> can just test that bit instead of having the CompareNilIC try to collect
> feedback to speed up the general case (without the undetectable bit
> being used).
>
> Drive-by-fix: Update the type system to match the new handling of
> undetectable in the runtime.
>
> R=danno@chromium.org
>
> Committed: https://crrev.com/666aec0348c8793e61c8633dee7ad29a514239ba
> Cr-Commit-Position: refs/heads/master@{#34237}

TBR=danno@chromium.org,verwaest@chromium.org,bmeurer@chromium.org
LOG=y
BUG=chromium:589897
NOTRY=true

Review URL: https://codereview.chromium.org/1743433002

Cr-Commit-Position: refs/heads/master@{#34308}

Since both null and undefined are also marked as undetectable now, we
can just test that bit instead of having the CompareNilIC try to collect
feedback to speed up the general case (without the undetectable bit
being used).

Drive-by-fix: Update the type system to match the new handling of
undetectable in the runtime.

R=danno@chromium.org

Review URL: https://codereview.chromium.org/1722193002

Cr-Commit-Position: refs/heads/master@{#34237}

Adds kSimd128 to MachineRepresentation.
Adds a Simd128Register concept that's platform independent.
Adds UntaggedSimd128 to types.h.

LOG=N
BUG=v8:4124

Review URL: https://codereview.chromium.org/1693963004

Cr-Commit-Position: refs/heads/master@{#34089}

Review URL: https://codereview.chromium.org/1700923002

Cr-Commit-Position: refs/heads/master@{#34026}

This CL removes the Config templatization from the types. It is not
necessary anymore, after the HeapTypes have been removed.

The CL also changes the type hierarchy - the specific type kinds are
not inner classes of the Type class and they do not inherit from Type.
This is partly because it seems impossible to make this work without
templates. Instead, a new TypeBase class is introduced and all the
structural (i.e., non-bitset) types inherit from it.

The bitset type still requires the bit-munging hack and some nasty
reinterpret-casts to pretend bitsets are of type Type*. Additionally,
there is now the same hack for TypeBase - all pointers to the sub-types
of TypeBase are reinterpret-casted to Type*. This is to keep the type
constructors in inline method definitions (although it is unclear how
much that actually buys us).

In future, we would like to move to a model where we encapsulate Type*
into a class (or possibly use Type where we used to use Type*). This
would loosen the coupling between bitset size and pointer size, and
eventually we would be able to have more bits.

TBR=bradnelson@chromium.org

Review URL: https://codereview.chromium.org/1655833002

Cr-Commit-Position: refs/heads/master@{#33656}

Field types can contain at most one map, so we can just use IsClass().

Review URL: https://codereview.chromium.org/1633213003

Cr-Commit-Position: refs/heads/master@{#33533}

This replace HeapType with a dedicated class that implements just what we need for field type tracking. In the next CL, I plan to remove FieldType::Iterator because FieldType can iterate over at most one map.

The ultimate plan is to get rid of templates in types.(h|cc) and remove type-inl.h.

TBR=rossberg@chromium.org

Review URL: https://codereview.chromium.org/1636013002

Cr-Commit-Position: refs/heads/master@{#33521}

Cleanup %ForInPrepare runtime entry, and unify common logic with
%ForInEnumerate (renamed from %GetPropertyNamesFast). Also introduce
a TupleType to properly type JSForInPrepare and its projections w/o
special hacks in the Typer. And fix %ForInNext and JSForInNext to be
consistent with fullcodegen again (after the proxy refactorings last
quarter).

R=jarin@chromium.org
BUG=v8:3650
LOG=n

Review URL: https://codereview.chromium.org/1631583002

Cr-Commit-Position: refs/heads/master@{#33487}

Avoid write barriers when storing values in the root set, and use
cheaper write barriers for storing maps or tagged pointers. Also
improve the generated code for write barriers, utilizing the out
of line code mechanism that is available to TurboFan backends,
which moves the unlikely case out of the hot path.

R=jarin@chromium.org, mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1414183006

Cr-Commit-Position: refs/heads/master@{#31914}

This inserts a new bit set type Function, which is used to represent
JSFunctions, and uses that type in typed lowering to optimize calls
to use the CallFunction builtin directly. Also allows for better typing
of the typeof operator, which can infern "function" for JSFunctions
properly.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1410343016

Cr-Commit-Position: refs/heads/master@{#31827}

We don't need to distinguish between signed and unsigned integral
representations in the big boy type system. It actually even hurts
in some cases. The representation is only about the way the values
are mapped to bits in memory/registers, but the interpretation of
the bits is specified by the semantic dimension.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1416953006

Cr-Commit-Position: refs/heads/master@{#31771}

This enables linter checking for "readability/namespace" violations
during presubmit and instead marks the few known exceptions that we
allow explicitly.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1371083003

Cr-Commit-Position: refs/heads/master@{#31019}

R=jarin
BUG=

Review URL: https://codereview.chromium.org/1343933002

Cr-Commit-Position: refs/heads/master@{#30790}

R=jarin
BUG=

Review URL: https://codereview.chromium.org/1340023003

Cr-Commit-Position: refs/heads/master@{#30728}

Also clarify some comments.

R=jarin@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1328193003

Cr-Commit-Position: refs/heads/master@{#30708}

BUG=

Review URL: https://codereview.chromium.org/1312893010

Cr-Commit-Position: refs/heads/master@{#30559}

Unbounded is defined in terms of None any Any,
which don't require an explicit zone.
Switching Unbounded to be the same.

BUG= None
TEST= trybots
R= titzer@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1322003002

Cr-Commit-Position: refs/heads/master@{#30482}

- Introduce a proper bit for SIMD primitive values.
- Introduce constructors for individual SIMD types. These are currently just classes, which seems good enough for now, given that we always have exactly one global map per SIMD type.

The only problem with using class types for SIMD is that a SIMD constant won't be a subtype of its specific type, only of the general SIMD type. But until we actually introduce SIMD constants into the compiler that shouldn't matter.

R=jarin@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1303863002

Cr-Commit-Position: refs/heads/master@{#30294}

This CL us a pure refactoring that makes an empty compilation unit
including just "foo.h" but not "foo-inl.h" compile without warnings or
errors. This is needed to further reduce the header dependency tangle.

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/1290743005

Cr-Commit-Position: refs/heads/master@{#30158}

This is a precursor to using specialized LoadIC and StoreIC stubs for
global variable access. It also removes the need to keep track of the
global object in the type system, hence freeing up one bit.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1205473004

Cr-Commit-Position: refs/heads/master@{#29231}

This change does the following:

  a.) Remove unused fields from the Typer.
  b.) Move some interesting unions to types.h.
  c.) Reduce Typer constructor overhead.
  d.) Avoid heap allocation in the Typer.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1199903002

Cr-Commit-Position: refs/heads/master@{#29178}

The TryLowerDirectJSCall method tried to lower to a direct JavaScript
function call depending on the type of the receiver, but only if the
target is a cosntant JSFunction. Since this depends on types and is not
required for correctness, it shouldn't be part of generic lowering
anyway. So this functionality was moved to typed lowering instead, and
we use proper types for the target instead.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1182193005

Cr-Commit-Position: refs/heads/master@{#29028}

enum defaults to signed on win, and kTagged has 1<<31 causing
warning.

Full errors:

d:\src\cr3\src\v8\src\types.cc(1259): error C2220: warning treated as error - no 'object' file generated
d:\src\cr3\src\v8\src\types.cc(1241): note: while compiling class template member function 'void v8::internal::TypeImpl<v8::internal::ZoneTypeConfig>::BitsetType::Print(std::ostream &,v8::internal::TypeImpl<v8::internal::ZoneTypeConfig>::bitset)'
d:\src\cr3\src\v8\src\types.cc(1283): note: see reference to function template instantiation 'void v8::internal::TypeImpl<v8::internal::ZoneTypeConfig>::BitsetType::Print(std::ostream &,v8::internal::TypeImpl<v8::internal::ZoneTypeConfig>::bitset)' being compiled
d:\src\cr3\src\v8\src\types.cc(1355): note: see reference to class template instantiation 'v8::internal::TypeImpl<v8::internal::ZoneTypeConfig>::BitsetType' being compiled
d:\src\cr3\src\v8\src\types.cc(1259): warning C4838: conversion from 'int' to 'const v8::internal::TypeImpl<v8::internal::ZoneTypeConfig>::bitset' requires a narrowing conversion
d:\src\cr3\src\v8\src\types.cc(1259): note: to simplify migration, consider the temporary use of /Wv:18 flag with the version of the compiler with which you used to build without warnings
d:\src\cr3\src\v8\src\types.cc(323): warning C4838: conversion from '' to 'v8::internal::TypeImpl<v8::internal::ZoneTypeConfig>::bitset' requires a narrowing conversion
d:\src\cr3\src\v8\src\types.cc(323): note: to simplify migration, consider the temporary use of /Wv:18 flag with the version of the compiler with which you used to build without warnings
d:\src\cr3\src\v8\src\types.cc(315): note: while compiling class template static data member 'const v8::internal::TypeImpl<v8::internal::ZoneTypeConfig>::BitsetType::Boundary v8::internal::TypeImpl<v8::internal::ZoneTypeConfig>::BitsetType::BoundariesArray[]'
d:\src\cr3\src\v8\src\types.cc(1259): warning C4838: conversion from 'int' to 'const v8::internal::TypeImpl<v8::internal::HeapTypeConfig>::bitset' requires a narrowing conversion
d:\src\cr3\src\v8\src\types.cc(1259): note: to simplify migration, consider the temporary use of /Wv:18 flag with the version of the compiler with which you used to build without warnings
d:\src\cr3\src\v8\src\types.cc(1241): note: while compiling class template member function 'void v8::internal::TypeImpl<v8::internal::HeapTypeConfig>::BitsetType::Print(std::ostream &,v8::internal::TypeImpl<v8::internal::HeapTypeConfig>::bitset)'
d:\src\cr3\src\v8\src\types.cc(1283): note: see reference to function template instantiation 'void v8::internal::TypeImpl<v8::internal::HeapTypeConfig>::BitsetType::Print(std::ostream &,v8::internal::TypeImpl<v8::internal::HeapTypeConfig>::bitset)' being compiled
d:\src\cr3\src\v8\src\types.cc(1359): note: see reference to class template instantiation 'v8::internal::TypeImpl<v8::internal::HeapTypeConfig>::BitsetType' being compiled
d:\src\cr3\src\v8\src\types.cc(323): warning C4838: conversion from '' to 'v8::internal::TypeImpl<v8::internal::HeapTypeConfig>::bitset' requires a narrowing conversion
d:\src\cr3\src\v8\src\types.cc(323): note: to simplify migration, consider the temporary use of /Wv:18 flag with the version of the compiler with which you used to build without warnings
d:\src\cr3\src\v8\src\types.cc(315): note: while compiling class template static data member 'const v8::internal::TypeImpl<v8::internal::HeapTypeConfig>::BitsetType::Boundary v8::internal::TypeImpl<v8::internal::HeapTypeConfig>::BitsetType::BoundariesArray[]'

LOG=N
R=jochen@chromium.org
BUG=440500

Review URL: https://codereview.chromium.org/1055933004

Cr-Commit-Position: refs/heads/master@{#27854}

R=rossberg@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1074133002

Cr-Commit-Position: refs/heads/master@{#27749}

BUG=
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/972543003

Cr-Commit-Position: refs/heads/master@{#26944}

R=rossberg@chromium.org
BUG=

Review URL: https://codereview.chromium.org/904863002

Cr-Commit-Position: refs/heads/master@{#26621}

BUG=
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/882063002

Cr-Commit-Position: refs/heads/master@{#26307}

This reverts commit 76193749.

BUG=

Review URL: https://codereview.chromium.org/877643002

Cr-Commit-Position: refs/heads/master@{#26301}

Revert of Steps towards unification of number bitset and range types. (patchset #4 id:60001 of https://codereview.chromium.org/837723006/)

Reason for revert:
Breaks test-types/Maybe, i.e.

out/Release/cctest --random-seed=-707413401 test-types/Maybe

started failing afterwards

Original issue's description:
> Steps towards unification of number bitset and range types.
>
> - New invariant on union types: if the union has a range then the number
>   bits in the bitset must be cleared.
>
> - Various tweaks in intersection and union to satisfy the invariant.
>
> - Exposed and used representation bits in range types (and the Limits
>   helper class).
>
> - Implemented Glb for ranges so that the Is predicate handles
>   ranges correctly.
>
> - Change typer weakening so that it does not rely on GetRange.
>   However, the code still seems to be a bit fragile.
>
> - Removed the Smi types from the type system core, instead introduced
>   Signed31, Unsigned30 and created constructors for Small(Un)Signed
>   that point to the right type for the architecture.
>
> - Punched a hole in the config to be able to get to the isolate so
>   that it is possible to allocate heap numbers for newly created
>   ranges.
>
> Patch by jarin@chromium.prg, original review here:
> https://codereview.chromium.org/795713003/
>
> TBR=jarin@chromium.org
> BUG=
>
> Committed: https://crrev.com/2764fd8d1a266a9136c987c2483492113b0c8d80
> Cr-Commit-Position: refs/heads/master@{#26197}

TBR=jkummerow@chromium.org,rossberg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/868583002

Cr-Commit-Position: refs/heads/master@{#26207}

- New invariant on union types: if the union has a range then the number
  bits in the bitset must be cleared.

- Various tweaks in intersection and union to satisfy the invariant.

- Exposed and used representation bits in range types (and the Limits
  helper class).

- Implemented Glb for ranges so that the Is predicate handles
  ranges correctly.

- Change typer weakening so that it does not rely on GetRange.
  However, the code still seems to be a bit fragile.

- Removed the Smi types from the type system core, instead introduced
  Signed31, Unsigned30 and created constructors for Small(Un)Signed
  that point to the right type for the architecture.

- Punched a hole in the config to be able to get to the isolate so
  that it is possible to allocate heap numbers for newly created
  ranges.

Patch by jarin@chromium.prg, original review here:
https://codereview.chromium.org/795713003/

TBR=jarin@chromium.org
BUG=

Review URL: https://codereview.chromium.org/837723006

Cr-Commit-Position: refs/heads/master@{#26197}