-Noteworthy changes in GCC for 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.
+
+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.
+
+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 useable 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 (effects 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.
+
+ 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.
+
+ 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
---------------------------------------
projects / gcc.git / commitdiff