From: Chris Lattner Date: Wed, 6 Apr 2011 00:45:11 +0000 (+0000) Subject: distribute content out to the appropriate sections X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1efe27eb797144ba4488e7b771fdd9611ee5cd0e;p=oota-llvm.git distribute content out to the appropriate sections git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128968 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html index b25f1ae1423..719346992b7 100644 --- a/docs/ReleaseNotes.html +++ b/docs/ReleaseNotes.html @@ -102,7 +102,7 @@ standards, fast compilation, and low memory use. Like LLVM, Clang provides a modular, library-based architecture that makes it suitable for creating or integrating with other development tools. Clang is considered a production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86 -(32- and 64-bit), and for darwin-arm targets.

+(32- and 64-bit), and for darwin/arm targets.

In the LLVM 2.9 time-frame, the Clang team has made many improvements in C, C++ and Objective-C support. C++ support is now generally rock solid, has @@ -293,137 +293,80 @@ in this section.

LLVM 2.9 includes several major new capabilities:

-New Nvidia PTX backend, not generally useful in 2.9 though. + -Much better debug info generated, particularly in optimized code situations. + +

+LLVM IR and Core Improvements +

-ARM Fast ISel +
+

LLVM IR has several new features for better support of new targets and that +expose new optimization opportunities:

-ELF MC support: on by default in clang. There are still known missing features - for human written assembly. + -TargetLibraryInfo - -X86 support for FS/GS relative loads and stores using address space 256/257 are - reliable now. - -ARM: New code placement pass. - -unnamed_addr + PR8927 - -PointerTracking has been removed from mainline, moved to ClamAV. - -EarlyCSE pass. -LoopInstSimplify pass. +
-- DIBuilder provides simpler interface for front ends like Clang to encode debug info in LLVM IR. - - This interface hides implementation details (e.g. DIDerivedType, existence of compile unit etc..) that any front end should not know about. - For example, DIFactory DebugFactory; - Ty = DebugFactory.CreateDerivedType(DW_TAG_volatile_type, - findRegion(TYPE_CONTEXT(type)), - StringRef(), - getOrCreateFile(main_input_filename), - 0 /*line no*/, - NodeSizeInBits(type), - NodeAlignInBits(type), - 0 /*offset */, - 0 /* flags */, - MainTy); - can be replaced by - DbgTy = DBuilder.createQualifiedType(DW_TAG_volatile_type, MainTy); -DIFactory is gone now. - -PPC: Switched to MCInstPrinter, and MCCodeEmitter. Ready to implement support - for directly writing out mach-o object files, but noone seems interested. + +

+Optimizer Improvements +

-ARM: Improved code generation for Cortex-A8 and Cortex-A9 CPUs. - -Scheduler now models operand latency and pipeline forwarding. - -Can optimize printf to iprintf when no floating point is used, for embedded - targets with smaller iprintf implementation. - -error_code + libsystem + PathV2 changes - The system_error header from C++0x was added. - * Use if (error_code ec = function()) to check for error conditions - from functions which return it. - * error_code::message returns a human readable description of the error. - - PathV1 has been deprecated in favor of PathV2 (sorry I didn't finish - this before the release). - * No Path class, use a r-value convertible to a twine instead. - * Assumes all paths are UTF-8. - -new macho-dump tool +
-Major regalloc rewrite, not on by default for 2.9 and not advised to use it. - * New basic register allocator that can be used as a safe fallback when - debugging. Enable with -regalloc=basic. - * New infrastructure for live range splitting. SplitKit can break a live - interval into smaller pieces while preserving SSA form, and SpillPlacement - can help find the best split points. This is a work in progress so the API - is changing quickly. - * The inline spiller has learned to clean up after live range splitting. It - can hoist spills out of loops, and it can eliminate redundant spills. - Rematerialization works with live range splitting. - * New greedy register allocator using live range splitting. This will be the - default register allocator in the next LLVM release, but it is not turned on - by default in 2.9. +

In addition to a large array of minor performance tweaks and bug fixes, this +release includes a few major enhancements and additions to the optimizers:

-ARM: __builtin_prefetch turns into prefetch instructions. - -MC assembler support for 3dNow! and 3DNowA instructions. + - -
- - -

-LLVM IR and Core Improvements -

- -
-

LLVM IR has several new features for better support of new targets and that -expose new optimization opportunities:

- - - -
- - -

-Optimizer Improvements -

- -
- -

In addition to a large array of minor performance tweaks and bug fixes, this -release includes a few major enhancements and additions to the optimizers:

- - -FastISel for ARM. + +
  • The pre-register-allocation (preRA) instruction scheduler models register + pressure much more accurately in some cases. This allows the adoption of more + aggressive scheduling heuristics. +
    • + + LiveDebugVariables is a new pass that keeps track of debugging information for + user variables that are kept in registers in optimized builds. + + +Scheduler now models operand latency and pipeline forwarding. + +Major regalloc rewrite, not on by default for 2.9 and not advised to use it. + * New basic register allocator that can be used as a safe fallback when + debugging. Enable with -regalloc=basic. + * New infrastructure for live range splitting. SplitKit can break a live + interval into smaller pieces while preserving SSA form, and SpillPlacement + can help find the best split points. This is a work in progress so the API + is changing quickly. + * The inline spiller has learned to clean up after live range splitting. It + can hoist spills out of loops, and it can eliminate redundant spills. + Rematerialization works with live range splitting. + * New greedy register allocator using live range splitting. This will be the + default register allocator in the next LLVM release, but it is not turned on + by default in 2.9. + + +
    @@ -583,6 +515,30 @@ FastISel for ARM.

    @@ -598,9 +554,39 @@ FastISel for ARM.

    + + +

    +Other Target Specific Improvements +

    +
    + +

    @@ -614,30 +600,78 @@ on LLVM 2.8, this section lists some "gotchas" that you may run into upgrading from the previous release.

    + last release for llvm-gcc +- DIBuilder provides simpler interface for front ends like Clang to encode debug info in LLVM IR. + - This interface hides implementation details (e.g. DIDerivedType, existence of compile unit etc..) that any front end should not know about. + For example, DIFactory DebugFactory; + Ty = DebugFactory.CreateDerivedType(DW_TAG_volatile_type, + findRegion(TYPE_CONTEXT(type)), + StringRef(), + getOrCreateFile(main_input_filename), + 0 /*line no*/, + NodeSizeInBits(type), + NodeAlignInBits(type), + 0 /*offset */, + 0 /* flags */, + MainTy); + can be replaced by + DbgTy = DBuilder.createQualifiedType(DW_TAG_volatile_type, MainTy); +DIFactory is gone now. + + -

    In addition, many APIs have changed in this release. Some of the major LLVM -API changes are:

    -

    -Development Infrastructure Changes +Internal API Changes

    -

    This section lists changes to the LLVM development infrastructure. This -mostly impacts users who actively work on LLVM or follow development on -mainline, but may also impact users who leverage the LLVM build infrastructure -or are interested in LLVM qualification.

    +

    In addition, many APIs have changed in this release. Some of the major + LLVM API changes are: