mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-02-14 02:33:53 +00:00
rough pass moving stuff into relevant sections, still much
editing to do. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101987 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
parent
b136f09deb
commit
b7c85b49a4
@ -60,10 +60,6 @@ main LLVM web page, this document applies to the <i>next</i> release, not the
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current one. To see the release notes for a specific release, please see the
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<a href="http://llvm.org/releases/">releases page</a>.</p>
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<p>FIXME: llvm.org moved to new server, mention new logo, Ted and Doug new code
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owners, web page in llvm-www repos.</p>
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</div>
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@ -79,14 +75,9 @@ Almost dead code.
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<!-- Features that need text if they're finished for 2.7:
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gcc plugin.
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strong phi elim
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variable debug info for optimized code
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postalloc scheduler: anti dependence breaking, hazard recognizer?
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metadata
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llvm.dbg.value: variable debug info for optimized code
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loop dependence analysis
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ELF Writer? How stable?
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<li>PostRA scheduler improvements, ARM adoption (David Goodwin).</li>
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-->
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<!-- for announcement email:
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@ -216,7 +207,8 @@ libgcc routines).</p>
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<p>
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All of the code in the compiler-rt project is available under the standard LLVM
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License, a "BSD-style" license.</p>
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License, a "BSD-style" license. New in LLVM 2.7: compiler_rt now
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supports ARM targets.</p>
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</div>
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@ -381,6 +373,24 @@ minor improvements. Some of the major improvements and new features are listed
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in this section.
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</p>
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<p>In addition to changes to the code, between LLVM 2.6 and 2.7, a number of
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organization changes have happened:
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</p>
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<ul>
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<li>LLVM has a new <a href="http://llvm.org/Logo.html">official Logo</a>!</li>
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<li><a href="http://llvm.org">llvm.org</a> is now hosted on a new (and much
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faster) server. It is still hosted as the University of Illinois.</li>
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<li>Ted Kremenek and Doug Gregor have stepped forward as <a
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href="http://llvm.org/docs/DeveloperPolicy.html#owners">Code Owners</a> of the
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Clang static analyzer and the Clang Frontend, respectively.</li>
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<li>The LLVM web pages are now checked into the SVN server, in the "www",
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"www-pubs" and "www-releases" SVN modules. Previously they were hidden in a
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largely inaccessible old CVS server.</p>
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</ul>
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</div>
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<!--=========================================================================-->
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@ -393,87 +403,25 @@ in this section.
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<p>LLVM 2.7 includes several major new capabilities:</p>
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<ul>
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<li>...</li>
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<li>New MicroBlaze backend. http://en.wikipedia.org/wiki/MicroBlaze</li>
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<li>Extensible metadata solid.</li>
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<li>Debug info improvements: using metadata instead of llvm.dbg global variables.
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This brings several enhancements including improved compile times.</li>
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<li>Indirect branch + address of label (blog post), particularly useful for
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interpreters.</li>
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<li>New instruction selector.</li>
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</ul>
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Extensible metadata solid.
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Debug info improvements: using metadata instead of llvm.dbg global variables.
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This brings several enhancements including improved compile times.
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New instruction selector.
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GHC Haskell ABI/ calling conv support.
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Pre-Alpha support for unions in IR.
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New InlineHint and StackAlignment function attributes
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Code generator MC'ized except for debug info and EH.
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New SCEV AA pass: -scev-aa
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Inliner reuses arrays allocas when inlining multiple callers to reduce stack usage.
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MC encoding and disassembler apis.
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Optimal Edge Profiling?
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Instcombine is now a library, has its own IRBuilder to simplify itself.
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New llvm/Support/Regex.h API. FileCheck now does regex's
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Many subtle pointer invalidation bugs in Callgraph have been fixed and it now uses asserting value handles.
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MC Disassembler (with blog post), MCInstPrinter. Many X86 backend and AsmPrinter simplifications
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Various tools like llc and opt now read either .ll or .bc files as input.
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Malloc and free instructions got removed, along with LowerAllocations pass.
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compiler-rt support for ARM.
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completely llvm-gcc NEON support.
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Can transcode from GAS to intel syntax with "llvm-mc foo.s -output-asm-variant=1"
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JIT debug information with GDB 7.0
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New CodeGen Level CSE
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CMake can now run tests, what other improvements?
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ARM/Thumb using reg scavenging for stack object address materialization (PEI).
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New SSAUpdater and MachineSSAUpdater classes for unstructured ssa updating,
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changed jump threading, GVN, etc to use it which simplified them and speed
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them up.
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Combiner-AA improvements, why not on by default?
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Pre-regalloc tail duplication
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x86 sibcall / tailcall optimization in CCC mode.
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New LSR with "full strength reduction" mode. Description?
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Codegen level OptimizeExtsPass pass, takes advantage of x86 subregs.
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Better code size analysis in loop unswitch, inliner code split out to a new
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CodeMetrics class for reuse.
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The ARM backend now has good support for ARMv4 backend (tested on StrongARM
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hardware), previously only supported ARMv4T and newer.
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Half-float support in APFloat
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Indirect branch + address of label (blog post), particularly useful for interpreters.
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Many changes to the pass ordering for improved optimization effectiveness.
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BasicAA improved to be less dependent on "type safe" pointers, it can now look
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through bitcasts more aggressively.
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GVN PHI Translation improvements. blog post: http://blog.llvm.org/2009/12/advanced-topics-in-redundant-load.html
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llvm.objectsize.
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MachineSSAUpdater.h
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PostRA scheduler for X86?
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llvm.dbg.value, not being used by default though, more in 2.8. Many improvements to debug info
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Support for the GCC option -fno-schedule-insns
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non-temporal load/store
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libllvm2.7.so?? configure with --enable-shared
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dbgs() and -debug-buffer-size=N
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New MicroBlaze backend. http://en.wikipedia.org/wiki/MicroBlaze
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XMM subreg modeling for extraction of the low element.
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MC encoding and disassembler apis.
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MC Disassembler (with blog post), MCInstPrinter. Many X86 backend and AsmPrinter simplifications
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Can transcode from GAS to intel syntax with "llvm-mc foo.s -output-asm-variant=1"
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Opt now works conservatively if no target data is set (is this fully working?)
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Target data now has notion of 'native' integer data types which optimizations can use.
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ARM backend generates instructions in unified assembly syntax.
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New Analysis/InstructionSimplify.h interface for simplifying instructions that don't exist.
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Jump threading is now much more aggressive at simplifying correlated
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conditionals and threading blocks with otherwise complex logic. CondProp pass
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removed (functionality merged into jump threading).
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X86 and XCore supports returning arbitrary return values, returning too many values is
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supported by returning through a hidden pointer.
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verbose-asm now produces information about spill slots and loop nests
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Defaults to RTTI off (smaller code size!), packagers should build with make REQUIRE_RTTI=1.
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AndersAA got removed
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PredSimplify, LoopVR, GVNPRE, RSProfiling (random sampling profiling) got removed.
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LLVM command line tools now overwrite their output, before they would only do this with -f.
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DOUT removed, use DEBUG(errs() instead.
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Much stuff converted to use raw_ostream instead of std::ostream.
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TargetAsmInfo renamed to MCAsmInfo
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llvm/ADT/iterator.h gone.
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</div>
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@ -487,7 +435,13 @@ llvm/ADT/iterator.h gone.
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expose new optimization opportunities:</p>
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<ul>
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<li>...</li>
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<li>New InlineHint and StackAlignment function attributes
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Half-float support in APFloat
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llvm.objectsize.
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New llvm/Support/Regex.h API. FileCheck now does regex's
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Pre-Alpha support for unions in IR.
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dbgs() and -debug-buffer-size=N
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</li>
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</ul>
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</div>
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@ -505,11 +459,29 @@ release includes a few major enhancements and additions to the optimizers:</p>
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<ul>
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<li>...</li>
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Inliner reuses arrays allocas when inlining multiple callers to reduce stack usage.
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Optimal Edge Profiling?
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Instcombine is now a library, has its own IRBuilder to simplify itself.
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Better code size analysis in loop unswitch, inliner code split out to a new
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CodeMetrics class for reuse.
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Many changes to the pass ordering for improved optimization effectiveness.
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BasicAA improved to be less dependent on "type safe" pointers, it can now look
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through bitcasts more aggressively.
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GVN PHI Translation improvements. blog post: http://blog.llvm.org/2009/12/advanced-topics-in-redundant-load.html
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New SCEV AA pass: -scev-aa
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Target data now has notion of 'native' integer data types which optimizations can use.
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Opt now works conservatively if no target data is set (is this fully working?)
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New Analysis/InstructionSimplify.h interface for simplifying instructions that don't exist.
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Jump threading is now much more aggressive at simplifying correlated
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conditionals and threading blocks with otherwise complex logic. CondProp pass
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removed (functionality merged into jump threading).
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New SSAUpdater and MachineSSAUpdater classes for unstructured ssa updating,
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changed jump threading, GVN, etc to use it which simplified them and speed
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them up.
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</ul>
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<p>Also, -anders-aa was removed</p>
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</div>
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@ -521,15 +493,21 @@ release includes a few major enhancements and additions to the optimizers:</p>
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<div class="doc_text">
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<ul>
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<li>The JIT now supports generating debug information, which is compatible with
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the new GDB 7.0 (and later) interfaces for registering debug info for
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dynamically generated code.</li>
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<li>The JIT now <a
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href="http://llvm.org/viewvc/llvm-project?view=rev&revision=85295">defaults
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to compiling eagerly</a> to avoid a race condition in the lazy JIT.
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Clients that still want the lazy JIT can switch it on by calling
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<tt>ExecutionEngine::DisableLazyCompilation(false)</tt>.</li>
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<li>It is now possible to create more than one JIT instance in the same process.
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These JITs can generate machine code in parallel,
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although <a href="http://llvm.org/docs/ProgrammersManual.html#jitthreading">you
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still have to obey the other threading restrictions</a>.</li>
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</ul>
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</div>
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@ -547,6 +525,23 @@ it run faster:</p>
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<ul>
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Code generator MC'ized except for debug info and EH.
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New CodeGen Level CSE
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Combiner-AA improvements, why not on by default?
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Pre-regalloc tail duplication
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New LSR with "full strength reduction" mode. Description?
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Codegen level OptimizeExtsPass pass, takes advantage of x86 subregs.
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Support for the GCC option -fno-schedule-insns
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non-temporal load/store
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MachineSSAUpdater.h
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X86 and XCore supports returning arbitrary return values, returning too many values is
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supported by returning through a hidden pointer.
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verbose-asm now produces information about spill slots and loop nests
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GHC Haskell ABI / calling conv support.
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Many improvements to debug info
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<li>...</li>
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</ul>
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</div>
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@ -562,34 +557,14 @@ it run faster:</p>
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<ul>
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<li>...</li>
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<li>PostRA scheduler for X86?</li>
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<li>x86 sibcall / tailcall optimization in CCC mode.</li>
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<li>X86: XMM subreg modeling for extraction of the low element.</li>
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</ul>
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</div>
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<!--=========================================================================-->
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<div class="doc_subsection">
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<a name="pic16">PIC16 Target Improvements</a>
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</div>
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<div class="doc_text">
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<p>New features of the PIC16 target include:
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</p>
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<ul>
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<li>...</li>
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</ul>
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<p>Things not yet supported:</p>
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<ul>
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<li>Variable arguments.</li>
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<li>Interrupts/programs.</li>
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</ul>
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</div>
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<!--=========================================================================-->
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<div class="doc_subsection">
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<a name="ARM">ARM Target Improvements</a>
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@ -601,7 +576,12 @@ it run faster:</p>
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<ul>
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<li>...</li>
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<li>complete llvm-gcc NEON support.</li>
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<li>ARM/Thumb using reg scavenging for stack object address materialization
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(PEI).</li>
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<li>The ARM backend now has good support for ARMv4 backend (tested on StrongARM
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hardware), previously only supported ARMv4T and newer.</li>
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<li>ARM backend generates instructions in unified assembly syntax.</li>
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</ul>
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@ -649,7 +629,13 @@ it run faster:</p>
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<p>Other miscellaneous features include:</p>
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<ul>
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<li>...</li>
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<li>LLVM command line tools now overwrite their output by default, before they
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would only do this with -f. This makes them more convenient to use, and
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behave more like standard unix tools.</li>
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<li>The opt and llc tools now autodetect whether their input is a .ll or .bc
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file, and automatically do the right thing. This means you don't need to
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explicitly use the llvm-as tool for most things.</li>
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</ul>
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</div>
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@ -667,18 +653,45 @@ on LLVM 2.6, this section lists some "gotchas" that you may run into upgrading
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from the previous release.</p>
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<ul>
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<li>
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The Andersen's alias analysis ("anders-aa") pass, the Predicate Simplifier
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("predsimplify") pass, the LoopVR pass, the GVNPRE pass, and the random sampling
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profiling ("rsprofiling") passes have all been removed. They were not being
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actively maintained and had substantial problems. If you are interested in
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these components, you are welcome to ressurect them from SVN, fix the
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correctness problems, and resubmit them to mainline.</li>
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<li>LLVM now defaults to building most libraries with RTTI turned off, providing
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a code size reduction. Packagers who are interested in building LLVM to support
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plugins that require RTTI information should build with "make REQUIRE_RTTI=1"
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and should read the new <a href="Packaging.html">Advice on Packaging LLVM</a>
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document.</li>
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<li>The LLVM interpreter now defaults to <em>not</em> using <tt>libffi</tt> even
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if you have it installed. This makes it more likely that an LLVM built on one
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system will work when copied to a similar system. To use <tt>libffi</tt>,
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configure with <tt>--enable-libffi</tt>.
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</li>
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</ul>
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configure with <tt>--enable-libffi</tt></li>.
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<li>Debug information uses a completely different representation, an LLVM 2.6
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.bc file should work with LLVM 2.7, but debug info won't come forward.</li>
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<li>The LLVM 2.6 (and earlier) "malloc" and "free" instructions got removed,
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along with LowerAllocations pass. Now you should just use a call to the
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malloc and free functions in libc. These calls are optimized as well as
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the old instructions were.</li>
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</ul>
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<p>In addition, many APIs have changed in this release. Some of the major LLVM
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||||
API changes are:</p>
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||||
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<ul>
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||||
<li>Just about everything has been converted to use raw_ostream instead of
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std::ostream.</li>
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||||
<li>llvm/ADT/iterator.h has been removed, just use <iterator>
|
||||
instead.</li>
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<li>The Streams.h file and "DOUT" got removed, use "DEBUG(errs() << ...);"
|
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instead.</li>
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||||
<li><tt>ModuleProvider</tt> has been <a
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href="http://llvm.org/viewvc/llvm-project?view=rev&revision=94686">removed</a>
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and its methods moved to <tt>Module</tt> and <tt>GlobalValue</tt>.
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@ -698,8 +711,6 @@ Clients must replace calls to
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<tt>GlobalValue::hasNotBeenReadFromBitcode</tt> with
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<tt>GlobalValue::isMaterializable</tt>.</li>
|
||||
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||||
<li>FIXME: Debug info has been totally redone. Add pointers to new APIs. Substantial caveats about compatibility of .ll and .bc files.</li>
|
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||||
<li>The <tt>llvm/Support/DataTypes.h</tt> header has moved
|
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to <tt>llvm/System/DataTypes.h</tt>.</li>
|
||||
|
||||
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||||
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Reference in New Issue
Block a user