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 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. Allow --with-cpu on configure command to specify a default CPU. 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-jumps=xxx -malign-functions=xxx -mimpure-text and -mno-impure-text 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 rs6000 and PowerPC 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 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. New features for the Hitachi H8/300(H): -malign-300 -ms (for the Hitachi H8/S processor) -mint32 New features for the ARM: -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. New feature for Solaris systems: GCC installation no longer makes a copy of system include files, thus insulating GCC better from updates to the operating system.
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