diff options
Diffstat (limited to 'lib/hipe/doc/src')
| -rw-r--r-- | lib/hipe/doc/src/hipe_app.xml | 35 | ||||
| -rw-r--r-- | lib/hipe/doc/src/notes.xml | 39 |
2 files changed, 74 insertions, 0 deletions
diff --git a/lib/hipe/doc/src/hipe_app.xml b/lib/hipe/doc/src/hipe_app.xml index aaeb06193d..fc42ecd97d 100644 --- a/lib/hipe/doc/src/hipe_app.xml +++ b/lib/hipe/doc/src/hipe_app.xml @@ -99,6 +99,41 @@ each mode.</p> </item> + <tag>Optimization for <c>receive</c> with unique references</tag> + <item> + <p> + The BEAM compiler can do an optimization when a receive + statement is only waiting for messages containing a reference + created before the receive. All messages that existed in the + queue when the reference was created will be bypassed, as they + cannot possibly contain the reference. HiPE currently has an + optimization similar this, but it is not guaranteed to + bypass all messages. In the worst case scenario it, cannot + bypass any messages at all. + </p> + <p> + An example of this is when <c>gen_server:call()</c> waits for + the reply message. + </p> + </item> + + </taglist> + </section> + <section> + <title>Stability Issues</title> + <taglist> + <tag>Not yielding in <c>receive</c> statements</tag> + <item> + <p>HiPE will not yield in <c>receive</c> statements where + appropriate. If a process have lots of signals in its signal + queue and execute a HiPE compiled <c>receive</c> statement, + the scheduler thread performing the execution may be stuck + in the <c>receive</c> statement for a very long time. This + can in turn cause various severe issues such as for example + prevent the runtime system from being able to release + memory. + </p> + </item> </taglist> </section> <section> diff --git a/lib/hipe/doc/src/notes.xml b/lib/hipe/doc/src/notes.xml index bad0c254ce..c190a89260 100644 --- a/lib/hipe/doc/src/notes.xml +++ b/lib/hipe/doc/src/notes.xml @@ -31,6 +31,45 @@ </header> <p>This document describes the changes made to HiPE.</p> +<section><title>Hipe 3.17.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Fix HiPE bug for binary constructs like + <c><<X/utf8>></c> which could in rare cases + cause faulty results or VM crash.</p> + <p> + This fix affects both the <c>hipe</c> compiler and + <c>erts</c> runtime in an <em>incompatible</em> way. Old + hipe compiled files need to be recompiled to load and run + properly as native.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14850 Aux Id: PR-1664 </p> + </item> + <item> + <p>The BEAM compiler chooses not to perform tailcall + optimisations for some calls in tail position, for + example to some built-in functions. However, when the + ErLLVM HiPE backend is used, LLVM may choose to perform + tailcall optimisation on these calls, breaking the + expected semantics.</p> + <p>To preserve the precise semantics exhibited by BEAM, + the 'notail' marker, present in LLVM since version 3.8, + is added to call instructions that BEAM has not turned + into tail calls, which inhibits LLVM from performing + tail-call optimisation in turn.</p> + <p> + Own Id: OTP-14886</p> + </item> + </list> + </section> + +</section> + <section><title>Hipe 3.17</title> <section><title>Fixed Bugs and Malfunctions</title> |