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Diffstat (limited to 'gcc/ONEWS')
| -rw-r--r-- | gcc/ONEWS | 98 |
1 files changed, 7 insertions, 91 deletions
diff --git a/gcc/ONEWS b/gcc/ONEWS index 4d4b54b65c1..f4b358102ee 100644 --- a/gcc/ONEWS +++ b/gcc/ONEWS @@ -1,112 +1,28 @@ This file contains information about GCC releases up to GCC 2.8.1, and -some information about EGCS releases. For more details of changes in -EGCS releases, and details of changes in GCC 2.95 and more recent -releases, see the release notes on the GCC web site and the file NEWS -which contains the most relevant parts of those release notes in text -form. +a tiny bit of information on EGCS. -Noteworthy changes in GCC for EGCS 1.1. ---------------------------------------- - -The compiler now implements global common subexpression elimination (gcse) as -well as global constant/copy propagation. (link to gcse page). - -More major improvements have been made to the alias analysis code. A new -option to allow front-ends to provide alias information to the optimizers -has also been added (-fstrict-aliasing). -fstrict-aliasing is off by default -now, but will be enabled by default in the future. (link to alias page) - -Major changes continue in the exception handling support. This release -includes some changes to reduce static overhead for exception handling. It -also includes some major changes to the setjmp/longjmp based EH mechanism to -make it less pessimistic. And finally, major infrastructure improvements -to the dwarf2 EH mechanism have been made to make our EH support extensible. - -We have fixed the infamous security problems with temporary files. - -The "regmove" optimization pass has been nearly completely rewritten. It now -uses much more information about the target to determine profitability of -transformations. +For details of changes in EGCS releases and GCC 2.95 and later releases, +see the release notes on the GCC web site or the file NEWS which contains +the most relevant parts of those release notes in text form. -The compiler now recomputes register usage information immediately before -register allocation. Previously such information was only not kept up to -date after instruction combination which led to poor register allocation -choices by our priority based register allocator. - -The register reloading phase of the compiler has been improved to better -optimize spill code. This primarily helps targets which generate lots of -spills (like the x86 ports and many register poor embedded ports). - -A few changes in the heuristics used by the register allocator and scheduler -have been made which can significantly improve performance for certain -applications. - -The compiler's branch shortening algorithms have been significantly improved -to work better on targets which align jump targets. +Changes in GCC for EGCS (that are not listed in the web release notes) +--------------------------------------------------------------------- The compiler now supports the "ADDRESSOF" optimization which can significantly reduce the overhead for certain inline calls (and inline calls in general). -The compiler now supports a code size optimization switch (-Os). When enabled -the compiler will prefer optimizations which improve code size over those -which improve code speed. - -The compiler has been improved to completely eliminate library calls which -compute constant values. This is particularly useful on machines which -do not have integer mul/div or floating point support on-chip. - -GCC now supports a "--help" option to print detailed help information. - -cpplib has been greatly improved. It is probably usable for some sites now -(major missing feature is trigraphs). - -Memory footprint for the compiler has been significantly reduced for certain -pathalogical cases. - -Build time improvements for targets which support lots of sched parameters -(alpha and mips primarily). - Compile time for certain programs using large constant initializers has been improved (affects glibc significantly). -Plus an incredible number of infrastructure changes, warning fixes, bugfixes -and local optimizations. - Various improvements have been made to better support cross compilations. They are still not easy, but they are improving. -Target specific NEWS - - Sparc: Now includes V8 plus and V9 support, lots of tuning for Ultrasparcs - and uses the Haifa scheduler by default. - - Alpha: EV6 tuned, optimized expansion of memcpy/bzero. - - x86: Data in the static store is aligned per Intel recommendations. Jump - targets are aligned per Intel recommendations. Improved epilogue - sequences for Pentium chips. Backend improvements which should help - register allocation on all x86 variants. Support for PPro conditional - move instructions has been fixed and enabled. Random changes - throughout the port to make generated code more Pentium friendly. - Improved support for 64bit integer operations. - Unixware 7, a System V Release 5 target is now supported. - SCO OpenServer targets can support GAS. See gcc/INSTALL for details. - - RS6000/PowerPC: Includes AIX4.3 support as well as PowerPC64 support. - Haifa instruction scheduling is enabled by default now. - - MIPS: Multiply/Multiply-Add support has been largely rewritten to generate - more efficient code. Includes mips16 support. - - M68K: Various micro-optimizations and Coldfire fixes. +Target-specific changes: M32r: Major improvements to this port. Arm: Includes Thumb and super interworking support. -EGCS includes all gcc2 changes up to and including the June 9, 1998 snapshot. - - Noteworthy changes in GCC version 2.8.1 --------------------------------------- |