-Noteworthy changes in GCC for EGCS.
+Noteworthy changes in GCC after EGCS 1.1.
+-----------------------------------------
-The -specs=file switch allows you to override default specs used in invoking
-programs like cc1, as, etc.
+Target specific NEWS
-Options -Wall and -Wimplicit now cause GCC to warn about implicit int
-in declarations (e.g. `register i;'), since the C Standard committee
-has decided to disallow this in the next revision of the standard.
+ RS6000/PowerPC: -mcpu=401 was added as an alias for -mcpu=403. -mcpu=e603e
+ was added to do -mcpu=603e and -msoft-float.
-The following new targets are supported:
+ MCore: Port of gcc to Motorola's MCore 210 and 340 contributed.
+
+Noteworthy changes in GCC for EGCS 1.1.
+---------------------------------------
- Solaris 2.5 running on UltraSPARC's.
- The sparclet cpu (a.out file format).
- Solaris 2.51 running on PowerPC's.
- Linux running on PowerPC's.
- Embedded target m32r-elf.
- Embedded target arc-elf.
- IRIX 6.2 running on MIPS.
+The compiler now implements global common subexpression elimination (gcse) as
+well as global constant/copy propagation. (link to gcse page).
-New features for the Hitachi H8/300(H).
+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)
- -malign-300
- -ms
+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 (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.
+
+ 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
+---------------------------------------
+
+Numerous bugs have been fixed and some minor performance
+improvements (compilation speed) have been made.
+
+Noteworthy changes in GCC version 2.8.0
+---------------------------------------
+
+A major change in this release is the addition of a framework for
+exception handling, currently used by C++. Many internal changes and
+optimization improvements have been made. These increase the
+maintainability and portability of GCC. GCC now uses autoconf to
+compute many host parameters.
-The -ms switch generates code for the Hitachi H8/S processor.
+The following lists changes that add new features or targets.
+
+See cp/NEWS for new features of C++ in this release.
+
+New tools and features:
+
+ The Dwarf 2 debugging information format is supported on ELF systems, and
+ is the default for -ggdb where available. It can also be used for C++.
+ The Dwarf version 1 debugging format is also permitted for C++, but
+ does not work well.
+
+ gcov.c is provided for test coverage analysis and branch profiling
+ analysis is also supported; see -fprofile-arcs, -ftest-coverage,
+ and -fbranch-probabilities.
+
+ Support for the Checker memory checking tool.
+
+ New switch, -fstack-check, to check for stack overflow on systems that
+ don't have such built into their ABI.
+
+ New switches, -Wundef and -Wno-undef to warn if an undefined identifier
+ is evaluated in an #if directive.
+
+ Options -Wall and -Wimplicit now cause GCC to warn about implicit int
+ in declarations (e.g. `register i;'), since the C Standard committee
+ has decided to disallow this in the next revision of the standard;
+ -Wimplicit-function-declarations and -Wimplicit-int are subsets of
+ this.
+
+ Option -Wsign-compare causes GCC to warn about comparison of signed and
+ unsigned values.
+
+ Add -dI option of cccp for cxref.
+
+New features in configuration, installation and specs file handling:
+
+ New option --enable-c-cpplib to configure script.
+
+ You can use --with-cpu on the configure command to specify the default
+ CPU that GCC should generate code for.
+
+ The -specs=file switch allows you to override default specs used in
+ invoking programs like cc1, as, etc.
+
+ Allow including one specs file from another and renaming a specs
+ variable.
+
+ You can now relocate all GCC files with a single environment variable
+ or a registry entry under Windows 95 and Windows NT.
+
+Changes in Objective-C:
+
+ The Objective-C Runtime Library has been made thread-safe.
+
+ The Objective-C Runtime Library contains an interface for creating
+ mutexes, condition mutexes, and threads; it requires a back-end
+ implementation for the specific platform and/or thread package.
+ Currently supported are DEC/OSF1, IRIX, Mach, OS/2, POSIX, PCThreads,
+ Solaris, and Windows32. The --enable-threads parameter can be used
+ when configuring GCC to enable and select a thread back-end.
+
+ Objective-C is now configured as separate front-end language to GCC,
+ making it more convenient to conditionally build it.
+
+ The internal structures of the Objective-C Runtime Library have
+ changed sufficiently to warrant a new version number; now version 8.
+ Programs compiled with an older version must be recompiled.
+
+ The Objective-C Runtime Library can be built as a DLL on Windows 95
+ and Windows NT systems.
+
+ The Objective-C Runtime Library implements +load.
+
+The following new targets are supported (see also list under each
+individual CPU below):
+
+ Embedded target m32r-elf.
+ Embedded Hitachi Super-H using ELF.
+ RTEMS real-time system on various CPU targets.
+ ARC processor.
+ NEC V850 processor.
+ Matsushita MN10200 processor.
+ Matsushita MN10300 processor.
+ Sparc and PowerPC running on VxWorks.
+ Support both glibc versions 1 and 2 on Linux-based GNU systems.
+
+New features for DEC Alpha systems:
+
+ Allow detailed specification of IEEE fp support:
+ -mieee, -mieee-with-inexact, and -mieee-conformant
+ -mfp-trap-mode=xxx, -mfp-round-mode=xxx, -mtrap-precision=xxx
+ -mcpu=xxx for CPU selection
+ Support scheduling parameters for EV5.
+ Add support for BWX, CIX, and MAX instruction set extensions.
+ Support Linux-based GNU systems.
+ Support VMS.
+
+Additional supported processors and systems for MIPS targets:
+
+ MIPS4 instruction set.
+ R4100, R4300 and R5000 processors.
+ N32 and N64 ABI.
+ IRIX 6.2.
+ SNI SINIX.
+
+New features for Intel x86 family:
+
+ Add scheduling parameters for Pentium and Pentium Pro.
+ Support stabs on Solaris-x86.
+ Intel x86 processors running the SCO OpenServer 5 family.
+ Intel x86 processors running DG/UX.
+ Intel x86 using Cygwin32 or Mingw32 on Windows 95 and Windows NT.
+
+New features for Motorola 68k family:
+
+ Support for 68060 processor.
+ More consistent switches to specify processor.
+ Motorola 68k family running AUX.
+ 68040 running pSOS, ELF object files, DBX debugging.
+ Coldfire variant of Motorola m68k family.
+
+New features for the HP PA RISC:
+
+ -mspace and -mno-space
+ -mlong-load-store and -mno-long-load-store
+ -mbig-switch -mno-big-switch
+
+ GCC on the PA requires either gas-2.7 or the HP assembler; for best
+ results using GAS is highly recommended. GAS is required for -g and
+ exception handling support.
New features for SPARC-based systems:
+ The ultrasparc cpu.
+ The sparclet cpu, supporting only a.out file format.
+ Sparc running SunOS 4 with the GNU assembler.
+ Sparc running the Linux-based GNU system.
+ Embedded Sparc processors running the ELF object file format.
-mcpu=xxx
-mtune=xxx
-malign-loops=xxx
-malign-functions=xxx
-mimpure-text and -mno-impure-text
-New features for all rs6000 and PowerPC systems:
+ Options -mno-v8 and -mno-sparclite are no longer supported on SPARC
+ targets. Options -mcypress, -mv8, -msupersparc, -msparclite, -mf930,
+ and -mf934 are deprecated and will be deleted in GCC 2.9. Use
+ -mcpu=xxx instead.
- -mcpu=604e
- -mcpu=801
- -mcpu=823
- -mtune=xxx
- -mupdate
- -mno-update
- -mfused-madd
- -mno-fused-madd
+New features for rs6000 and PowerPC systems:
-New features for PowerPC-based systems running either System V, Linux, Solaris,
-or embedded systems:
+ Solaris 2.51 running on PowerPC's.
+ The Linux-based GNU system running on PowerPC's.
+ -mcpu=604e,602,603e,620,801,823,mpc505,821,860,power2
+ -mtune=xxx
+ -mrelocatable-lib, -mno-relocatable-lib
+ -msim, -mmve, -memb
+ -mupdate, -mno-update
+ -mfused-madd, -mno-fused-madd
-mregnames
-meabi
- -mcall-linux
- -mcall-solaris
- -mcall-sysv-eabi
- -mcall-sysv-noeabi
- -msdata
- -msdata=none
- -msdata=default
- -msdata=sysv
- -msdata=eabi
- -memb
- -msim
- -mmvme
- -myellowknife
- -mads
- wchar_t is now of type long, not unsigned short as per ABI.
+ -mcall-linux, -mcall-solaris, -mcall-sysv-eabi, -mcall-sysv-noeabi
+ -msdata, -msdata=none, -msdata=default, -msdata=sysv, -msdata=eabi
+ -memb, -msim, -mmvme
+ -myellowknife, -mads
+ wchar_t is now of type long as per the ABI, not unsigned short.
-p/-pg support
-mcpu=403 now implies -mstrict-align.
+ Implement System V profiling.
+
+ Aix 4.1 GCC targets now default to -mcpu=common so that programs
+ compiled can be moved between rs6000 and powerpc based systems. A
+ consequence of this is that -static won't work, and that some programs
+ may be slightly slower.
+
+ You can select the default value to use for -mcpu=xxx on rs6000 and
+ powerpc targets by using the --with-cpu=xxx option when configuring the
+ compiler. In addition, a new options, -mtune=xxx was added that
+ selects the machine to schedule for but does not select the
+ architecture level.
+
+ Directory names used for storing the multilib libraries on System V
+ and embedded PowerPC systems have been shortened to work with commands
+ like tar that have fixed limits on pathname size.
-Options -mno-v8 and -mno-sparclite are no longer supported on SPARC
-targets. Options -mcypress, -mv8, -msupersparc, -msparclite, -mf930,
-and -mf934 are deprecated and will be deleted in GCC 2.9.
-Use -mcpu=xxx instead.
+New features for the Hitachi H8/300(H):
-GCC on the PA requires either gas-2.7 or the HP assembler; for best
-results using GAS is highly recommended. GAS is required for -g
-and exception handling support.
+ -malign-300
+ -ms (for the Hitachi H8/S processor)
+ -mint32
-Aix 4.1 GCC targets now default to -mcpu=common so that programs compiled can
-be moved between rs6000 and powerpc based systems. A consequence of this is
-that -static won't work, and that some programs may be slightly slower.
+New features for the ARM:
-You can select the default value to use for -mcpu=xxx on rs6000 and powerpc
-targets by using the --with-cpu=xxx option when confiuring the compiler. In
-addition, a new options, -mtune=xxx was added that selects the machine to
-schedule for but does not select the architecture level.
+ -march=xxx, -mtune=xxx, -mcpu=xxx
+ Support interworking with Thumb code.
+ ARM processor with a.out object format, COFF, or AOF assembler.
+ ARM on "semi-hosted" platform.
+ ARM running NetBSD.
+ ARM running the Linux-based GNU system.
-Directory names used for storing the multilib libraries on System V and
-embedded PowerPC systems have been shortened to work with commands like tar
-that have fixed limits on pathname size.
+New feature for Solaris systems:
-The DWARF 2 debugging information format is supported on ELF systems, and
-is the default for -ggdb where available.
+ GCC installation no longer makes a copy of system include files,
+ thus insulating GCC better from updates to the operating system.
-Noteworthy changes in GCC version 2.7.2:
+\f
+Noteworthy changes in GCC version 2.7.2
+---------------------------------------
A few bugs have been fixed (most notably the generation of an
invalid assembler opcode on some RS/6000 systems).
-Noteworthy changes in GCC version 2.7.1:
+Noteworthy changes in GCC version 2.7.1
+---------------------------------------
This release fixes numerous bugs (mostly minor) in GCC 2.7.0, but
also contains a few new features, mostly related to specific targets.
calling sequence without function descriptors. To compile code for that older
calling sequence, either configure the compiler for powerpc-*-eabiaix or use
the -mcall-aix switch when compiling and linking.
-
-Noteworthy changes in GCC version 2.7.0:
+\f
+Noteworthy changes in GCC version 2.7.0
+---------------------------------------
GCC now works better on systems that use ".obj" and ".exe" instead of
".o" and no extension. This involved changes to the driver program,
GNU on x86 (instead of treating it like MACH)
NetBSD on Sparc and Motorola 68k
AIX 4.1 on RS/6000 and PowerPC systems
- Sequent DYNUX/ptx 1.x and 2.x.
+ Sequent DYNIX/ptx 1.x and 2.x.
Both COFF and ELF configurations on AViiON without using /bin/gcc
Windows/NT on x86 architecture; preliminary
AT&T DSP1610 digital signal processor chips
* GCC now supports `long double' meaningfully on the Sparc (128-bit
floating point) and on the 386 (96-bit floating point). The Sparc
-support is enabled on on Solaris 2.x because earlier system versions
+support is enabled on Solaris 2.x because earlier system versions
(SunOS 4) have bugs in the emulation.
* All targets now have assertions for cpu, machine and system. So you
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