Mercurial > hg > graal-jvmci-8
diff graal/Compiler/bin/com/sun/c1x/doc/performance.txt @ 2507:9ec15d6914ca
Pull over of compiler from maxine repository.
author | Thomas Wuerthinger <thomas@wuerthinger.net> |
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date | Wed, 27 Apr 2011 11:43:22 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/Compiler/bin/com/sun/c1x/doc/performance.txt Wed Apr 27 11:43:22 2011 +0200 @@ -0,0 +1,85 @@ +Issues that can be addressed for improving performance in C1X +---------------------------------------------------------------- + +- indicates not done +* indicates done + +Backend: + - better handling of constants, especially immediates + - (non XIR) checkcast, instanceof: use nullity + - (non XIR) checkcast, instanceof: emit fastpath direct compare + - use LEA instruction on x86 + - recognize pointer arithmetic addressing modes + - recognize multiply by 3, 5, 9 and emit lea rk, [rs, rs*2], etc + - Maxine XIR: make direct runtime calls instead of through global stub + - Maxine XIR: implement inline allocation + - Maxine XIR: implement biased locking fastpath + - Maxine XIR: faster subtype checks for classes, leaves + - Maxine XIR: make use of XirSite nullity, range check information + - better handling of tableswitch bytecode + - better handling of two operand LIR form + - Make the following bytecode implementations inline: + - f2i f2l f2d d2i d2l d2f (SSE2) + * lrem ldiv (64 bit) + - fneg dneg + - Make the following bytecode implementations global stubs: + - frem drem + - Global stubs: use EAX for return value as normal instead of [rsp - 16] + - Emit direct call to runtime for new instance, monitorenter, monitorexit + + * XIR: expose nullity, range checkness across XIR interface + - XIR: make use of CSE'd array length + - XIR: generate special if-instanceof XIR variant with label parameters + - Optimize special cases of bytecodes: + - (MIN_INT / -1) in IDIV,IREM + - (MIN_LONG / -1) in LDIV,LREM + - (-infinity, Nan, +infinity) in F2I, F2L, D2I, D2L + + +Frontend: + - Remove redundant null check branches in NullCheckEliminator + - XIR: implement HIR -> HIR xir translation + - Refactor exception edges to allow removal, optimization + - Implement typecast elimination + - Implement constant propagation + - Implement GVN of memory loads / stores + - Implement memory reordering + - Implement loop invariant code motion + - Optimize endianness conversions and endian-writes + (e.g. (x >> 24 & 0xff) | (....)) and a[0] = x >> 24 ... + - Finish loop peeling + - Implement loop unrolling + - Allow value numbering of constant loads + - Finish loop peeling + - Guarded and multiple inlining + - Maxine: speculative leaf class and leaf method assumption + - Maxine: adjust static / dynamic inlining heuristics + (e.g. static: trivial methods only in cold spots) + - Aggressive optimization of array copy + +Compilation speed: + - Make special iterators for LIROperand input, temp, output + - Add analysisInfo field to Value and use in NullCheckEliminator + - Remove RiConstantPool, cpi from unresolved HIR instructions (move to RiField, RiMethod) + - Use BlockList instead of ArrayList<Block> where appropriate + - Use FrameState instead of ValueStack + - Remove exceptionHandlers, make DebugInfo hold FrameState, CiCodePos, + exception flags and exception handlers + - Clean up and simplify LIRInstruction constructor + - Create fewer LIRAddresses + - Simplify LIRGenerator logic (forcing of loading, etc) + - LIROperand: split into virtual register table? + - Cleanup assembler and remove dead code, useless assertions + - Chain assembler byte buffers and only assemble at the end + - Pick optimal initial assembler byte buffer size + - Pick good initial sizes for LinearScan data structures + - Remove unnecessary uses of ArrayList and replace with arrays or other list + - Use iteration over ArrayList instead of explicit loop + - Revisit manual editing / removal of items from ArrayList + - Remove non-XIR backend + - Pre-assemble XIR for backend + + * Initialize compilation-unique instruction id's lazily with thread local compilation + * Remove dead LIROpcodes + * Remove dead code in LIRGenerator, X86LIRGenerator, LIRAssembler, X86LIRAssembler + (remove commented out code)