From fd8e49b5bddceaae803670121b603b5eee8c5c08 Mon Sep 17 00:00:00 2001 From: Erlang/OTP Date: Fri, 25 May 2018 12:14:27 +0200 Subject: Prepare release --- lib/compiler/doc/src/notes.xml | 213 +++++++++++++++++++++++++++++++++++++++++ lib/compiler/vsn.mk | 2 +- 2 files changed, 214 insertions(+), 1 deletion(-) (limited to 'lib/compiler') diff --git a/lib/compiler/doc/src/notes.xml b/lib/compiler/doc/src/notes.xml index bc1f68337b..357a940f24 100644 --- a/lib/compiler/doc/src/notes.xml +++ b/lib/compiler/doc/src/notes.xml @@ -32,6 +32,219 @@

This document describes the changes made to the Compiler application.

+
Compiler 7.2 + +
Fixed Bugs and Malfunctions + + +

Fixed an error in an optimization pass that caused + impossible tuple matching.

+

+ Own Id: OTP-14855 Aux Id: ERL-549

+ + +

The exception thrown when a list comprehension was + given a non-list term was not always correct.

+

+ Own Id: OTP-14992 Aux Id: ERL-572

+ + +
+ + +
Improvements and New Features + + +

Changed the default behaviour of .erlang + loading: .erlang is no longer loaded from the + current directory. c:erlangrc(PathList) can be + used to search and load an .erlang file from user + specified directories.

escript, + erlc, dialyzer and typer no longer + load an .erlang at all.

+

+ *** POTENTIAL INCOMPATIBILITY ***

+

+ Own Id: OTP-14439

+ + +

Support for "tuple calls" have been removed from the + run-time system. Tuple calls was an undocumented and + unsupported feature which allowed the module argument for + an apply operation to be a tuple: Var = dict:new(), + Var:size(). This "feature" frequently caused + confusion, especially when such call failed. The + stacktrace would point out functions that don't exist in + the source code.

+

For legacy code that need to use parameterized modules + or tuple calls for some other reason, there is a new + compiler option called tuple_calls. When this + option is given, the compiler will generate extra code + that emulates the old behavior for calls where the module + is a variable.

+

+ *** POTENTIAL INCOMPATIBILITY ***

+

+ Own Id: OTP-14497

+ + +

In code such as example({ok, Val}) -> {ok, + Val}. a tuple would be built. The compiler will now + automatically rewrite the code to + example({ok,Val}=Tuple) -> Tuple. which will + reduce code size, execution time, and remove GC + pressure.

+

+ Own Id: OTP-14505

+ + +

The optimization of case expression where only + one of the case arms can execute successfully has been + improved.

+

+ Own Id: OTP-14525

+ + +

Some uses of binary matching has been slightly + improved, eliminating unnecessary register shuffling.

+

+ Own Id: OTP-14594 Aux Id: ERL-444

+ + +

There is a new {compile_info,Info} option for + the compiler that allows BEAM-based languages such as + Elixir and LFE to add their own compiler versions.

+

+ Own Id: OTP-14615 Aux Id: PR-1558

+ + +

Loaded BEAM code in a 64-bit system requires less + memory because of better packing of operands for + instructions.

+

These memory savings were achieved by major + improvements to the beam_makeops scripts used when + building the run time system and BEAM compiler. There is + also new for documentation for beam_makeops that + describes how new BEAM instructions and loader + transformations can be implemented. The documentation is + found in here in a source directory or git repository: + erts/emulator/internal_doc/beam_makeops.md. An online + version can be found here: + https://github.com/erlang/otp/blob/master/erts/emulator/internal_doc/beam_makeops.md

+

+ Own Id: OTP-14626

+ + +

Size calculations for binary constructions has been + somewhat optimized, producing smaller code.

+

+ Own Id: OTP-14654

+ + +

When the value returned from a 'catch' + expression is ignored, no stacktrace will be built if an + exception is caught. That will save time and produce less + garbage. There are also some minor optimizations of + 'try/catch' both in the compiler and + run-time system.

+

+ Own Id: OTP-14683

+ + +

There is a new syntax in 'try/catch' for + retrieving the stacktrace without calling + 'erlang:get_stacktrace/0'. See the reference + manual for a description of the new syntax. The + 'erlang:get_stacktrace/0' BIF is now + deprecated.

+

+ Own Id: OTP-14692

+ + +

The following is an internal change in the compiler, + that is not noticeable for normal use of the compiler: + The module v3_life has been removed. Its + functionality has been simplified and integrated into + v3_codegen.

+

+ Own Id: OTP-14712

+ + +

The optimization of binary matching that delays + creation of sub binaries (see the Efficiency Guide) could + be thwarted by the argument order and could be necessary + to change the argument order. The compiler has now become + smarter and can handle any argument order.

+

+ Own Id: OTP-14774

+ + +

When the compiler was faced with complex case + expressions it would unnecessarily allocate stack + elements and shuffle data between x and y registers. + Improved code generation to only allocate a stack frame + when strictly necessary.

+

+ Own Id: OTP-14808 Aux Id: ERL-514

+ + +

There is a new option 'makedep_side_effect' for + the compiler and -MMD for 'erlc' that + generates dependencies and continues to compile as + normal.

+

+ Own Id: OTP-14830

+ + +

When compiling modules with huge functions, the + compiler would generate a lot of atoms for its internal, + sometimes so many that the atom table would overflow. The + compiler has been rewritten to generate far less internal + atoms to avoid filling the atom table.

+

+ Own Id: OTP-14968 Aux Id: ERL-563

+ + +

External funs with literal values for module, name, + and arity (e.g. erlang:abs/1) are now treated as + literals. That means more efficient code that produces + less garbage on the heap.

+

+ Own Id: OTP-15003

+ + +

Two new guards BIFs operating on maps have been added: + map_get/2 and is_map_key/2. They do the + same as maps:get/2 and maps:is_key/2, + respectively, except that they are allowed to be used in + guards.

+

+ Own Id: OTP-15037 Aux Id: PR-1784, PR-1802

+ + +

A call or apply of a literal external fun will be + replaced with a direct call.

+

+ Own Id: OTP-15044 Aux Id: ERL-614

+ + +

Part of EEP-44 has been implemented.

+

There is a new predefined macro called + OTP_RELEASE which is an integer indicating the OTP + release number (its value is 21 in this + release).

+

There are new preprocessor directives + -if(Condition). and -elif(Condition).. The + if/elif supports the builtin function + defined(Symbol).

+

+ Own Id: OTP-15087 Aux Id: PR-1810

+ + +
+ +
+
Compiler 7.1.5
Fixed Bugs and Malfunctions diff --git a/lib/compiler/vsn.mk b/lib/compiler/vsn.mk index ee75ee27fd..a26cb09dff 100644 --- a/lib/compiler/vsn.mk +++ b/lib/compiler/vsn.mk @@ -1 +1 @@ -COMPILER_VSN = 7.1.5 +COMPILER_VSN = 7.2 -- cgit v1.2.3