From bb19e24a485e9ef43bcca3fbe9757da83f70c3a0 Mon Sep 17 00:00:00 2001
From: Erlang/OTP <otp@erlang.org>
Date: Tue, 19 Jun 2018 08:24:54 +0200
Subject: Prepare release
---
lib/compiler/doc/src/notes.xml | 220 +++++++++++++++++++++++++++++++++++++++++
lib/compiler/vsn.mk | 2 +-
2 files changed, 221 insertions(+), 1 deletion(-)
(limited to 'lib/compiler')
diff --git a/lib/compiler/doc/src/notes.xml b/lib/compiler/doc/src/notes.xml
index ee69f73890..997a506181 100644
--- a/lib/compiler/doc/src/notes.xml
+++ b/lib/compiler/doc/src/notes.xml
@@ -32,6 +32,226 @@
<p>This document describes the changes made to the Compiler
application.</p>
+<section><title>Compiler 7.2</title>
+
+ <section><title>Fixed Bugs and Malfunctions</title>
+ <list>
+ <item>
+ <p>Fixed an error in an optimization pass that caused
+ impossible tuple matching.</p>
+ <p>
+ Own Id: OTP-14855 Aux Id: ERL-549 </p>
+ </item>
+ <item>
+ <p>The exception thrown when a list comprehension was
+ given a non-list term was not always correct.</p>
+ <p>
+ Own Id: OTP-14992 Aux Id: ERL-572 </p>
+ </item>
+ <item>
+ <p>The compiler could produce incorrect code in rare
+ circumstances when the <c>[{inline,F/A}]</c> option was
+ used.</p>
+ <p>
+ Own Id: OTP-15115 Aux Id: PR-1831 </p>
+ </item>
+ </list>
+ </section>
+
+
+ <section><title>Improvements and New Features</title>
+ <list>
+ <item>
+ <p>Changed the default behaviour of <c>.erlang</c>
+ loading: <c>.erlang</c> is no longer loaded from the
+ current directory. <c>c:erlangrc(PathList)</c> can be
+ used to search and load an <c>.erlang</c> file from user
+ specified directories.</p> <p><c>escript</c>,
+ <c>erlc</c>, <c>dialyzer</c> and <c>typer</c> no longer
+ load an <c>.erlang</c> at all.</p>
+ <p>
+ *** POTENTIAL INCOMPATIBILITY ***</p>
+ <p>
+ Own Id: OTP-14439</p>
+ </item>
+ <item>
+ <p>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: <c>Var = dict:new(),
+ Var:size()</c>. This "feature" frequently caused
+ confusion, especially when such call failed. The
+ stacktrace would point out functions that don't exist in
+ the source code.</p>
+ <p>For legacy code that need to use parameterized modules
+ or tuple calls for some other reason, there is a new
+ compiler option called <c>tuple_calls</c>. When this
+ option is given, the compiler will generate extra code
+ that emulates the old behavior for calls where the module
+ is a variable.</p>
+ <p>
+ *** POTENTIAL INCOMPATIBILITY ***</p>
+ <p>
+ Own Id: OTP-14497</p>
+ </item>
+ <item>
+ <p>In code such as <c>example({ok, Val}) -> {ok,
+ Val}.</c> a tuple would be built. The compiler will now
+ automatically rewrite the code to
+ <c>example({ok,Val}=Tuple) -> Tuple.</c> which will
+ reduce code size, execution time, and remove GC
+ pressure.</p>
+ <p>
+ Own Id: OTP-14505</p>
+ </item>
+ <item>
+ <p>The optimization of <c>case</c> expression where only
+ one of the case arms can execute successfully has been
+ improved.</p>
+ <p>
+ Own Id: OTP-14525</p>
+ </item>
+ <item>
+ <p>Some uses of binary matching has been slightly
+ improved, eliminating unnecessary register shuffling.</p>
+ <p>
+ Own Id: OTP-14594 Aux Id: ERL-444 </p>
+ </item>
+ <item>
+ <p>There is a new <c>{compile_info,Info}</c> option for
+ the compiler that allows BEAM-based languages such as
+ Elixir and LFE to add their own compiler versions.</p>
+ <p>
+ Own Id: OTP-14615 Aux Id: PR-1558 </p>
+ </item>
+ <item>
+ <p>Loaded BEAM code in a 64-bit system requires less
+ memory because of better packing of operands for
+ instructions.</p>
+ <p>These memory savings were achieved by major
+ improvements to the <c>beam_makeops</c> scripts used when
+ building the run time system and BEAM compiler. There is
+ also new for documentation for <c>beam_makeops</c> 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</p>
+ <p>
+ Own Id: OTP-14626</p>
+ </item>
+ <item>
+ <p>Size calculations for binary constructions has been
+ somewhat optimized, producing smaller code.</p>
+ <p>
+ Own Id: OTP-14654</p>
+ </item>
+ <item>
+ <p>When the value returned from a '<c>catch</c>'
+ 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
+ '<c>try</c>/<c>catch</c>' both in the compiler and
+ run-time system.</p>
+ <p>
+ Own Id: OTP-14683</p>
+ </item>
+ <item>
+ <p>There is a new syntax in '<c>try/catch</c>' for
+ retrieving the stacktrace without calling
+ '<c>erlang:get_stacktrace/0</c>'. See the reference
+ manual for a description of the new syntax. The
+ '<c>erlang:get_stacktrace/0</c>' BIF is now
+ deprecated.</p>
+ <p>
+ Own Id: OTP-14692</p>
+ </item>
+ <item>
+ <p>The following is an internal change in the compiler,
+ that is not noticeable for normal use of the compiler:
+ The module <c>v3_life</c> has been removed. Its
+ functionality has been simplified and integrated into
+ <c>v3_codegen</c>.</p>
+ <p>
+ Own Id: OTP-14712</p>
+ </item>
+ <item>
+ <p>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.</p>
+ <p>
+ Own Id: OTP-14774</p>
+ </item>
+ <item>
+ <p>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.</p>
+ <p>
+ Own Id: OTP-14808 Aux Id: ERL-514 </p>
+ </item>
+ <item>
+ <p>There is a new option '<c>makedep_side_effect</c>' for
+ the compiler and <c>-MMD</c> for '<c>erlc</c>' that
+ generates dependencies and continues to compile as
+ normal.</p>
+ <p>
+ Own Id: OTP-14830</p>
+ </item>
+ <item>
+ <p>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.</p>
+ <p>
+ Own Id: OTP-14968 Aux Id: ERL-563 </p>
+ </item>
+ <item>
+ <p>External funs with literal values for module, name,
+ and arity (e.g. <c>erlang:abs/1</c>) are now treated as
+ literals. That means more efficient code that produces
+ less garbage on the heap.</p>
+ <p>
+ Own Id: OTP-15003</p>
+ </item>
+ <item>
+ <p>Two new guards BIFs operating on maps have been added:
+ <c>map_get/2</c> and <c>is_map_key/2</c>. They do the
+ same as <c>maps:get/2</c> and <c>maps:is_key/2</c>,
+ respectively, except that they are allowed to be used in
+ guards.</p>
+ <p>
+ Own Id: OTP-15037 Aux Id: PR-1784, PR-1802 </p>
+ </item>
+ <item>
+ <p>A call or apply of a literal external fun will be
+ replaced with a direct call.</p>
+ <p>
+ Own Id: OTP-15044 Aux Id: ERL-614 </p>
+ </item>
+ <item>
+ <p>Part of EEP-44 has been implemented.</p>
+ <p>There is a new predefined macro called
+ <c>OTP_RELEASE</c> which is an integer indicating the OTP
+ release number (its value is <c>21</c> in this
+ release).</p>
+ <p>There are new preprocessor directives
+ <c>-if(Condition).</c> and <c>-elif(Condition).</c>. The
+ <c>if/elif</c> supports the builtin function
+ <c>defined(Symbol)</c>.</p>
+ <p>
+ Own Id: OTP-15087 Aux Id: PR-1810 </p>
+ </item>
+ </list>
+ </section>
+
+</section>
+
<section><title>Compiler 7.1.5</title>
<section><title>Fixed Bugs and Malfunctions</title>
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
--
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