diff options
Diffstat (limited to 'lib/hipe')
| -rw-r--r-- | lib/hipe/doc/src/hipe_app.xml | 66 | ||||
| -rw-r--r-- | lib/hipe/main/hipe.app.src | 2 | ||||
| -rw-r--r-- | lib/hipe/rtl/hipe_rtl_binary_construct.erl | 9 |
3 files changed, 74 insertions, 3 deletions
diff --git a/lib/hipe/doc/src/hipe_app.xml b/lib/hipe/doc/src/hipe_app.xml index e489d155c3..9299c6d73f 100644 --- a/lib/hipe/doc/src/hipe_app.xml +++ b/lib/hipe/doc/src/hipe_app.xml @@ -47,6 +47,72 @@ Details on HiPE compiler options are given by <c>hipe:help_options()</c>.</p> </description> <section> + <title>Feature Limitations</title> + <p> + The HiPE compiler is in general compliant with the normal BEAM compiler, + with respect to semantic behavior. There are however features in the BEAM compiler + and the runtime system that have limited or no support for HiPE compiled modules. + </p> + <taglist> + <tag>Stack traces</tag> + <item><p>Stack traces returned from <seealso marker="erts:erlang#get_stacktrace/0"> + <c>erlang:get_stacktrace/0</c></seealso> or as part of <c>'EXIT'</c> terms + can look incomplete if HiPE compiled functions are involved. Typically a stack trace + will contain only BEAM compiled functions or only HiPE compiled functions, depending + on where the exception was raised.</p> + <p>Source code line numbers in stack traces are also not supported by HiPE compiled functions.</p> + </item> + + <tag>Tracing</tag> + <item><p>Erlang call trace is not supported by HiPE. Calling + <seealso marker="erts:erlang#trace_pattern/3"><c>erlang:trace_pattern({M,F,A}, ...)</c></seealso> + does not have any effect on HiPE compiled modules.</p> + </item> + + <tag>NIFs</tag> + <item><p>Modules compiled with HiPE can not call <seealso marker="erts:erlang#load_nif-2"> + <c>erlang:load_nif/2</c></seealso> to load NIFs.</p> + </item> + + <tag>-on_load</tag> + <item><p>Modules compiled with HiPE can not use + <seealso marker="doc/reference_manual:code_loading#on_load"><c>-on_load()</c></seealso> + directives.</p> + </item> + </taglist> + + </section> + <section> + <title>Performance Limitations</title> + <p> + The HiPE compiler does in general produce faster code than the + BEAM compiler. There are however some situation when HiPE + compiled code will perform worse than BEAM code. + </p> + <taglist> + <tag>Mode switches</tag> + <item><p>Every time a process changes from executing code in a + HiPE compiled module to a BEAM compiled module (or vice versa), + it will do a mode switch. This involves a certain amount of + CPU overhead which can have a negative net impact if the + process is switching back and forth without getting enough done in + 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 <c>receive</c> statement is <em>only</em> 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 + does not implement this optimization.</p> + <p>An example of this is when + <c>gen_server:call()</c> waits for the reply message.</p> + </item> + + </taglist> + </section> + <section> <title>SEE ALSO</title> <p> <seealso marker="stdlib:c">c(3)</seealso>, diff --git a/lib/hipe/main/hipe.app.src b/lib/hipe/main/hipe.app.src index 5b2280594f..fb750dd418 100644 --- a/lib/hipe/main/hipe.app.src +++ b/lib/hipe/main/hipe.app.src @@ -236,4 +236,4 @@ {applications, [kernel,stdlib]}, {env, []}, {runtime_dependencies, ["syntax_tools-1.6.14","stdlib-3.4","kernel-5.3", - "erts-9.0","compiler-5.0"]}]}. + "erts-9.2","compiler-5.0"]}]}. diff --git a/lib/hipe/rtl/hipe_rtl_binary_construct.erl b/lib/hipe/rtl/hipe_rtl_binary_construct.erl index 52ea5db382..bc215e3abe 100644 --- a/lib/hipe/rtl/hipe_rtl_binary_construct.erl +++ b/lib/hipe/rtl/hipe_rtl_binary_construct.erl @@ -195,8 +195,13 @@ gen_rtl(BsOP, Dst, Args, TrueLblName, FalseLblName, SystemLimitLblName, ConstTab bs_validate_unicode -> [_Arg] = Args, - [hipe_rtl:mk_call([], bs_validate_unicode, Args, - TrueLblName, FalseLblName, not_remote)]; + [IsUnicode] = create_regs(1), + RetLbl = hipe_rtl:mk_new_label(), + [hipe_rtl:mk_call([IsUnicode], is_unicode, Args, + hipe_rtl:label_name(RetLbl), [], not_remote), + RetLbl, + hipe_rtl:mk_branch(IsUnicode, ne, hipe_rtl:mk_imm(0), + TrueLblName, FalseLblName, 0.99)]; bs_final -> Zero = hipe_rtl:mk_imm(0), |