Date: Wed, 15 Aug 2012 19:34:23 +0000 Subject: Vendor import of llvm trunk r161861: http://llvm.org/svn/llvm-project/llvm/trunk@161861 --- docs/ReleaseNotes.html | 347 +++++++++++++++---------------------------------- 1 file changed, 103 insertions(+), 244 deletions(-) (limited to 'docs/ReleaseNotes.html') diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html index 71f2ceabaaa4..85448a5f3a47 100644 --- a/docs/ReleaseNotes.html +++ b/docs/ReleaseNotes.html @@ -4,11 +4,11 @@ - LLVM 3.1 Release Notes + LLVM 3.2 Release Notes -

LLVM 3.1 Release Notes

LLVM 3.2 Release Notes

Introduction

Sub-project Status Update

External Projects Using LLVM 3.1

External Projects Using LLVM 3.2

What's New in LLVM?

Installation Instructions

Known Problems

@@ -29,6 +29,12 @@

Written by the LLVM Team

These are in-progress notes for the upcoming LLVM 3.2 +release.
+You may prefer the +LLVM 3.1 +Release Notes.

Introduction @@ -38,11 +44,11 @@

This document contains the release notes for the LLVM Compiler - Infrastructure, release 3.1. Here we describe the status of LLVM, including + Infrastructure, release 3.2. Here we describe the status of LLVM, including major improvements from the previous release, improvements in various - subprojects of LLVM, and some of the current users of the code. - All LLVM releases may be downloaded from - the LLVM releases web site.
+ subprojects of LLVM, and some of the current users of the code. All LLVM + releases may be downloaded from the LLVM + releases web site.

For more information about LLVM, including information about the latest release, please check out the main LLVM web @@ -66,10 +72,10 @@
-
The LLVM 3.1 distribution currently consists of code from the core LLVM - repository (which roughly includes the LLVM optimizers, code generators and - supporting tools), and the Clang repository. In addition to this code, the - LLVM Project includes other sub-projects that are in development. Here we +
The LLVM 3.2 distribution currently consists of code from the core LLVM + repository, which roughly includes the LLVM optimizers, code generators and + supporting tools, and the Clang repository. In addition to this code, the + LLVM Project includes other sub-projects that are in development. Here we include updates on these subprojects.
@@ -88,20 +94,13 @@ production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86 (32- and 64-bit), and for Darwin/ARM targets.
-
In the LLVM 3.1 time-frame, the Clang team has made many improvements. +
In the LLVM 3.2 time-frame, the Clang team has made many improvements. Highlights include:

-
Greatly expanded C++11 - support including lambdas, initializer lists, constexpr, user-defined - literals, and atomics.
-
A new tooling - library to ease building of clang-based standalone tools.
-
Extended support for - literals in - Objective C.
+
...

-
For more details about the changes to Clang since the 3.0 release, see the +
For more details about the changes to Clang since the 3.1 release, see the Clang release notes.
@@ -127,23 +126,10 @@ Linux and OpenBSD platforms. It fully supports Ada, C, C++ and Fortran. It has partial support for Go, Java, Obj-C and Obj-C++.
-
The 3.1 release has the following notable changes:
+
The 3.2 release has the following notable changes:

-
Partial support for gcc-4.7. Ada support is poor, but other languages work - fairly well.
- -
Support for ARM processors. Some essential gcc headers that are needed to - build DragonEgg for ARM are not installed by gcc. To work around this, - copy the missing headers from the gcc source tree.
- -
Better optimization for Fortran by exploiting the fact that Fortran scalar - arguments have 'restrict' semantics.
- -
Better optimization for all languages by passing information about type - aliasing and type ranges to the LLVM optimizers.
- -
A regression test-suite was added.
+
...

@@ -160,13 +146,15 @@ target-specific hooks required by code generation and other runtime components. For example, when compiling for a 32-bit target, converting a double to a 64-bit unsigned integer is compiled into a runtime call to the - "fixunsdfdi" function. The compiler-rt library provides highly optimized - implementations of this and other low-level routines (some are 3x faster than - the equivalent libgcc routines).
+ `fixunsdfdi` function. The compiler-rt library provides highly + optimized implementations of this and other low-level routines (some are 3x + faster than the equivalent libgcc routines).
-
As of 3.1, compiler-rt includes the helper functions for atomic operations, - allowing atomic operations on arbitrary-sized quantities to work. These - functions follow the specification defined by gcc and are used by clang.
+
The 3.2 release has the following notable changes:
+ +
+
...
+

@@ -183,6 +171,12 @@ expression parsing (particularly for C++) and uses the LLVM JIT for target support.
+
The 3.2 release has the following notable changes:
+ +
+
...
+
+ @@ -196,15 +190,10 @@ licensed under the MIT and UIUC license, allowing it to be used more permissively.
-
Within the LLVM 3.1 time-frame there were the following highlights:
+
Within the LLVM 3.2 time-frame there were the following highlights:

-
The `<atomic>` header is now passing all tests, when - compiling with clang and linking against the support code from - compiler-rt.
-
FreeBSD now includes libc++ as part of the base system.
-
libc++ has been ported to Solaris and, in combination with libcxxrt and - clang, is working with a large body of existing code.
+
...

@@ -220,8 +209,11 @@ of a Java Virtual Machine (Java VM or JVM) that uses LLVM for static and just-in-time compilation.
-
In the LLVM 3.1 time-frame, VMKit has had significant improvements on both - runtime and startup performance.
+
The 3.2 release has the following notable changes:
+ +
+
...
+
@@ -239,16 +231,10 @@ Work in the area of automatic SIMD and accelerator code generation was started.
-
Within the LLVM 3.1 time-frame there were the following highlights:
+
Within the LLVM 3.2 time-frame there were the following highlights:

-
Polly became an official LLVM project
-
Polly can be loaded directly into clang (enabled by '-O3 -mllvm -polly')
-
An automatic scheduling optimizer (derived - from Pluto) was - integrated. It performs loop transformations to optimize for data-locality - and parallelism. The transformations include, but are not limited to - interchange, fusion, fission, skewing and tiling.
+
...

@@ -257,15 +243,15 @@

- External Open Source Projects Using LLVM 3.1 + External Open Source Projects Using LLVM 3.2

An exciting aspect of LLVM is that it is used as an enabling technology for - a lot of other language and tools projects. This section lists some of the - projects that have already been updated to work with LLVM 3.1.

+ a lot of other language and tools projects. This section lists some of the + projects that have already been updated to work with LLVM 3.2.

Crack

@@ -409,14 +395,14 @@

- What's New in LLVM 3.1? + What's New in LLVM 3.2?

This release includes a huge number of bug fixes, performance tweaks and - minor improvements. Some of the major improvements and new features are + minor improvements. Some of the major improvements and new features are listed in this section.

@@ -426,13 +412,13 @@

- @@ -443,17 +429,10 @@ llvm/lib/Archive - replace with lib object? --> -

LLVM 3.1 includes several major changes and big features:

LLVM 3.2 includes several major changes and big features:

AddressSanitizer, - a fast memory error detector.
MachineInstr Bundles, - Support to model instruction bundling / packing.
ARM Integrated Assembler, - A full featured assembler and direct-to-object support for ARM.
Basic Block Placement - Probability driven basic block placement.
...

@@ -470,19 +449,9 @@ expose new optimization opportunities:

A new type representing 16 bit half floating point values has - been added.
IR now supports vectors of pointers, including vector GEPs.
Module flags have been introduced. They convey information about the - module as a whole to LLVM subsystems. This is currently used to encode - Objective C ABI information.
Loads can now have range metadata attached to them to describe the - possible values being loaded.
The llvm.ctlz and llvm.cttz intrinsics now have an - additional argument which indicates whether the behavior of the intrinsic - is undefined on a zero input. This can be used to generate more efficient - code on platforms that only have instructions which don't return the type - size when counting bits in 0.
Thread local variables may have a specified TLS model. See the + Language Reference Manual.
...

@@ -494,22 +463,11 @@

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

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

The loop unroll pass now is able to unroll loops with run-time trip counts. - This feature is turned off by default, and is enabled with the - -unroll-runtime flag.
A new basic-block autovectorization pass is available. Pass - -vectorize to run this pass along with some associated - post-vectorization cleanup passes. For more information, see the EuroLLVM - 2012 slides: - Autovectorization with LLVM.
Inline cost heuristics have been completely overhauled and now closely - model constant propagation through call sites, disregard trivially dead - code costs, and can model C++ STL iterator patterns.
...

@@ -524,14 +482,12 @@

The LLVM Machine Code (aka MC) subsystem was created to solve a number of problems in the realm of assembly, disassembly, object file format handling, and a number of other related areas that CPU instruction-set level tools work - in. For more information, please see - the Intro - to the LLVM MC Project Blog Post.

+ in. For more information, please see the + Intro + to the LLVM MC Project Blog Post.

The integrated assembler can optionally emit debug information when - assembling a .s file. It can be enabled by passing the - -g option to llvm-mc.
...

@@ -556,21 +512,7 @@ make it run faster:

TableGen can now synthesize register classes that are only needed to - represent combinations of constraints from instructions and sub-registers. - The synthetic register classes inherit most of their properties form their - closest user-defined super-class.
MachineRegisterInfo now allows the reserved registers to be - frozen when register allocation starts. Target hooks should use the - MRI->canReserveReg(FramePtr) method to avoid accidentally - disabling frame pointer elimination during register allocation.
A new kind of MachineOperand provides a compact - representation of large clobber lists on call instructions. The register - mask operand references a bit mask of preserved registers. Everything else - is clobbered.
The DWARF debug info writer gained support for emitting data for the - name accelerator tables - DWARF extension. It is used by LLDB to speed up name lookup.
...

We added new TableGen infrastructure to support bundling for @@ -587,11 +529,14 @@

Basic Block Placement

A probability based block placement and code layout algorithm was added to -LLVM's code generator. This layout pass supports probabilities derived from -static heuristics as well as source code annotations such as -__builtin_expect.

+ LLVM's code generator. This layout pass supports probabilities derived from + static heuristics as well as source code annotations such as + __builtin_expect.

@@ -604,14 +549,7 @@ static heuristics as well as source code annotations such as

New features and major changes in the X86 target include:

Greatly improved support for AVX2.
Lots of bug fixes and improvements for AVX1.
Support for the FMA4 and XOP instruction set extensions.
Call instructions use the new register mask operands for faster compile - times and better support for different calling conventions. The old WINCALL - instructions are no longer needed.
DW2 Exception Handling is enabled on Cygwin and MinGW.
Support for implicit TLS model used with MSVC runtime.
...

@@ -626,65 +564,45 @@ static heuristics as well as source code annotations such as

New features of the ARM target include:

The constant island pass now supports basic block and constant pool entry - alignments greater than 4 bytes.
On Darwin, the ARM target now has a full-featured integrated assembler. -
...

+ +

ARM Integrated Assembler

The ARM target now includes a full featured macro assembler, including -direct-to-object module support for clang. The assembler is currently enabled -by default for Darwin only pending testing and any additional necessary -platform specific support for Linux.

+ direct-to-object module support for clang. The assembler is currently enabled + by default for Darwin only pending testing and any additional necessary + platform specific support for Linux.

Full support is included for Thumb1, Thumb2 and ARM modes, along with -subtarget and CPU specific extensions for VFP2, VFP3 and NEON.

+ subtarget and CPU specific extensions for VFP2, VFP3 and NEON.

The assembler is Unified Syntax only (see ARM Architecural Reference Manual -for details). While there is some, and growing, support for pre-unfied (divided) -syntax, there are still significant gaps in that support.

+ for details). While there is some, and growing, support for pre-unfied + (divided) syntax, there are still significant gaps in that support.

- -

-MIPS Target Improvements -

-New features and major changes in the MIPS target include:

- -

MIPS32 little-endian direct object code emission is functional.
MIPS64 little-endian code generation is largely functional for N64 ABI in assembly printing mode with the exception of handling of long double (f128) type.
Support for new instructions has been added, which includes swap-bytes - instructions (WSBH and DSBH), floating point multiply-add/subtract and - negative multiply-add/subtract instructions, and floating - point load/store instructions with reg+reg addressing (LWXC1, etc.)
Various fixes to improve performance have been implemented.
Post-RA scheduling is now enabled at -O3.
Support for soft-float code generation has been added.
clang driver's support for MIPS 64-bits targets.
Support for MIPS floating point ABI option in clang driver.

-PTX Target Improvements +MIPS Target Improvements

An outstanding conditional inversion bug was fixed in this release.

New features and major changes in the MIPS target include:

NOTE: LLVM 3.1 marks the last release of the PTX back-end, in its - current form. The back-end is currently being replaced by the NVPTX - back-end, currently in SVN ToT.

@@ -696,7 +614,7 @@ New features and major changes in the MIPS target include:

Support for Qualcomm's Hexagon VLIW processor has been added.
...

@@ -709,25 +627,11 @@ New features and major changes in the MIPS target include:

If you're already an LLVM user or developer with out-of-tree changes based on - LLVM 3.1, this section lists some "gotchas" that you may run into upgrading + LLVM 3.2, this section lists some "gotchas" that you may run into upgrading from the previous release.

LLVM's build system now requires a python 2 interpreter to be present at - build time. A perl interpreter is no longer required.
The C backend has been removed. It had numerous problems, to the point of - not being able to compile any nontrivial program.
The Alpha, Blackfin and SystemZ targets have been removed due to lack of - maintenance.
LLVM 3.1 removes support for reading LLVM 2.9 bitcode files. Going - forward, we aim for all future versions of LLVM to read bitcode files and - .ll files produced by LLVM 3.0 and later.
The unwind instruction is now gone. With the introduction of the - new exception handling system in LLVM 3.0, the unwind instruction - became obsolete.
LLVM 3.0 and earlier automatically added the returns_twice fo functions - like setjmp based on the name. This functionality was removed in 3.1. - This affects Clang users, if -ffreestanding is used.
...

@@ -743,40 +647,7 @@ New features and major changes in the MIPS target include:

LLVM API changes are:

Target specific options have been moved from global variables to members - on the new TargetOptions class, which is local to each - TargetMachine. As a consequence, the associated flags will - no longer be accepted by clang -mllvm. This includes: -
- llvm::PrintMachineCode
- llvm::NoFramePointerElim
- llvm::NoFramePointerElimNonLeaf
- llvm::DisableFramePointerElim(const MachineFunction &)
- llvm::LessPreciseFPMADOption
- llvm::LessPrecideFPMAD()
- llvm::NoExcessFPPrecision
- llvm::UnsafeFPMath
- llvm::NoInfsFPMath
- llvm::NoNaNsFPMath
- llvm::HonorSignDependentRoundingFPMathOption
- llvm::HonorSignDependentRoundingFPMath()
- llvm::UseSoftFloat
- llvm::FloatABIType
- llvm::NoZerosInBSS
- llvm::JITExceptionHandling
- llvm::JITEmitDebugInfo
- llvm::JITEmitDebugInfoToDisk
- llvm::GuaranteedTailCallOpt
- llvm::StackAlignmentOverride
- llvm::RealignStack
- llvm::DisableJumpTables
- llvm::EnableFastISel
- llvm::getTrapFunctionName()
- llvm::EnableSegmentedStacks
The MDBuilder class has been added to simplify the creation - of metadata.
...

@@ -791,13 +662,8 @@ New features and major changes in the MIPS target include:

In addition, some tools have changed in this release. Some of the changes are:

llvm-stress is a command line tool for generating random - .ll files to fuzz different LLVM components.
The llvm-ld tool has been removed. The clang driver provides a - more reliable solution for turning a set of bitcode files into a binary. - To merge bitcode files llvm-link can be used instead.
...

@@ -811,19 +677,12 @@ New features and major changes in the MIPS target include:

Officially supported Python bindings have been added! Feature support is far -from complete. The current bindings support interfaces to:

+ from complete. The current bindings support interfaces to:

Object File Interface
Disassembler
...

Using the Object File Interface, it is possible to inspect binary object files. -Think of it as a Python version of readelf or llvm-objdump.

- -

Support for additional features is currently being developed by community -contributors. If you are interested in shaping the direction of the Python -bindings, please express your intent on IRC or the developers list.

@@ -839,11 +698,11 @@ bindings, please express your intent on IRC or the developers list.

LLVM is generally a production quality compiler, and is used by a broad range of applications and shipping in many products. That said, not every subsystem is as mature as the aggregate, particularly the more obscure - targets. If you run into a problem, please check the LLVM bug database and submit a bug if - there isn't already one or ask on the LLVMdev - list.

+ targets. If you run into a problem, please check + the LLVM bug database and submit a bug if + there isn't already one or ask on + the LLVMdev + list.

Known problem areas include:

@@ -851,7 +710,7 @@ bindings, please express your intent on IRC or the developers list.

The CellSPU, MSP430, PTX and XCore backends are experimental.

The integrated assembler, disassembler, and JIT is not supported by - several targets. If an integrated assembler is not supported, then a + several targets. If an integrated assembler is not supported, then a system assembler is required. For more details, see the Target Features Matrix.

@@ -890,7 +749,7 @@ bindings, please express your intent on IRC or the developers list.

src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"> LLVM Compiler Infrastructure
- Last modified: $Date: 2012-05-15 23:58:06 +0200 (Tue, 15 May 2012) $ + Last modified: $Date: 2012-07-13 14:44:23 +0200 (Fri, 13 Jul 2012) $ -- cgit v1.3