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Bugfix
======
P->current (Fix observable behaviour?)
New calling convention for guard bifs (Recognize at load time).
Long branches:
timer:tc(hipe,c,[megaco_text_parser,[{timeout,infinity}]]).
{4801210531,
{error,[{problem,too_long_branch},{address,3381732},{length,-828622}]}}
Performance
===========
Better handling of multimove in regalloc.
Faster closure creation. (Can static fields be preallocated?)
Expand pseudo-ops before scheduler (SPARC)
Stack maps for SPARC + Make frames in Sparc not in RTL.
Coalesce spill locations.
Feature
=======
Stack traces from stack maps.
Cleanup
=======
Speedup renaming and other bottlenecks in the compiler.
Only calls with fail label should end basic blocks.
Remove fail-entry-points from RTL (sparc/x86).
Cleanup hipe_*_registers.erl and interface/rules with regalloc.
HiPE in bootstrap.
Cleanup and merge loaders. (Better handling of data.)
Re-examine switching code.
Extensions
==========
Design strategy for finding all processes holding a certain closure.
Design strategy for native code unloading.
mbufs: In guards -> throw away, in bifs -> trigger special GC. (fix for native.)
Unified heap + process optimization (+ PE).
Incremental GC.
Old list compiled by Thomas Lindgren (needs cleaning up)
========================================================
<h1>Experimental implementations</h1>
<h2>RTL</h2>
<UL>
<LI> Algebraiska förenklingar av uttryck (ex. reducera integer multiply,
ta bort addition med 0, etc)
<LI> Partial redundancy elimination
</UL>
<h1>Unimplemented optimizations</h1>
<H2>Erlang/Core source-level-optimizations</H2>
<UL>
<LI> "Context compilation"
<LI> CDR-kodning
<LI> List reuse
<LI> Compilation by transformation
</UL>
<H2>Icode-optimizations</H2>
<UL>
<LI> Convertion to loops from recursive programs
<LI> Dominatorer
(<a href="./thomasl/icode/dominators.erl">långsamma</a>, snabba)
</UL>
<H2>RTL-optimizations</H2>
<UL>
<LI> Common subexpression elimination
<LI> Ta bort redundanta tester globalt (ex. upprepade typtester)
<LI> Ordna om hopp (ex. byt ordning på nil/cons-tester)
<LI> Goto eliminering (= expandera uncond. jumps m. känd måltavla)
<LI> Save/restore-placering: dataflödesanalys, interaktion m. catch-frames
<LI> Loop optimeringar
<UL>
<LI> Dominatorer (se dominatorer för icode)
<LI> Unrolling
<LI> Invariant expression removal
</UL>
<LI> Partial redundancy elimination by lazy code motion
<LI> Partially dead code
</UL>
<H2>Sparc-optimizations</H2>
<UL>
<LI> Global register allocation
<UL>
<LI> <a href="./thomasl/regalloc/regalloc.erl">
Pessimistisk färgning</a>
<LI> Optimistisk färgning (kan slås på i samma fil som pessimistisk
färgning ovan).
<LI> Bättre beräkning av spillkostnader
<LI> Renaming
<LI> Callee-saves register
<LI> Live-range splitting
</UL>
<LI> Instruktionsschedulering
<UL>
<LI> Branch delay slot scheduling
<LI> Load delay slot scheduling
<LI> Spekulativa loads med lduwa
<LI> Kollapsa serier av tester med bpr
<LI> Begränsad predicated execution med movcc
</UL>
<LI> Kodlayout: statiska förutsägelser om riktning av hopp,
layout, sätta branch prediction bits i hopp, etc.
<LI> Prefetching av kod med SparcV9:s bpn.
</UL>
<H2>Other optimizations</H2>
Profile driven optimizations.
<UL>
<LI> Utplacering av räknare i CFG:er (per block, per båge)
<LI> Statiska metoder att uppskatta exekveringstid (inom och mellan proc.)
<LI> Feedback till program, annotering av CFG:er med profileringsinfo.
<LI> Kodlayout med profileringsinfo.
<LI> Skapa superblock
<LI> Skapa hyperblock
<LI> Plocka fram heta block, skapa en 'het' sub-CFG som hoppar
till den kalla huvud-CFG:n vid behov.
<LI> Optimering av het CFG, kodförflyttning från het till kall CFG.
<LI> Spawn-time specialization
</UL>
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