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diff --git a/debian/NEWS.gcc b/debian/NEWS.gcc new file mode 100644 index 0000000..8f37a3a --- /dev/null +++ b/debian/NEWS.gcc @@ -0,0 +1,452 @@ + +GCC 13 Release Series +Changes, New Features, and Fixes + +This page is a "brief" summary of some of the huge number of improvements in +GCC 13. You may also want to check out our Porting_to_GCC_13 page and the full +GCC_documentation. + +Caveats + + * OpenMP offloading to Intel MIC has been removed. + * The support for the cr16-elf, tilegx*-linux, tilepro*-linux, hppa[12]*-*- + hpux10*, hppa[12]*-*-hpux11* and m32c-rtems configurations has been + removed. + * Support for Solaris 11.3 (*-*-solaris2.11.3) has been declared obsolete. + The next release of GCC will have corresponding code permanently removed. + Details can be found in the announcement. + * Support for emitting the STABS debugging format (including the -gstabs + and -gxcoff options) has been removed. (This means the dbx debugger is no + longer supported, either.) + * Legacy debug info compression option -gz=zlib-gnu was removed and the + option is ignored right now. + * -Warray-bounds=2 will no longer issue warnings for out of bounds accesses + to trailing struct members of one-element array type anymore. Instead it + diagnoses accesses to trailing arrays according to -fstrict-flex-arrays. + * -fanalyzer is still only suitable for analyzing C code. In particular, + using it on C++ is unlikely to give meaningful output. + * In the arm port, support for the iWMMXt extensions, enabled through - + mcpu=iwmmxt, has been deprecated and will be removed in a future release. + This includes support for the iWMMXt_built-in_functions. + +General Improvements + + * OpenMP + o Reverse offload is now supported with AMD GCN and nvptx devices. + Additionally, the requires handling has been improved and all + clauses are now accepted. If a requirement cannot be fulfilled for + an accessible device, this device is excluded from the list of + available devices. This may imply that the only device left is the + host (the initial device). In particular, unified_address and + unified_shared_memory are unsupported by all non-host devices. + o OpenMP 5.0: Fortran now supports some non-rectangular loop nests; + for C/C++, the support was added in GCC 11. + o The following OpenMP 5.1 features have been added: the + omp_all_memory reserved locator, the inoutset modifier to the + depend clause, the nowait clause for the taskwait directive and the + omp_target_is_accessible, omp_target_memcpy_async, + omp_target_memcpy_rect_async and omp_get_mapped_ptr API routines. + The assume and assumes directives, the begin/end declare target + syntax in C/C++ and device-specific ICV settings with environment + variables are now supported. + o Initial support for OpenMP 5.2 features has been added: + firstprivate and allocate clauses on the scope construct; the + OpenMP 5.2 syntax of the linear clause; new enum/constants + omp_initial_device and omp_invalid_device; and optionally omitting + the map-type in target enter/exit data. The enter clause (as alias + for to) has been added to the declare target directive. Also added + have been the omp_in_explicit_task routine and the doacross clause + as alias for depend with source/sink modifier. + o The _ALL suffix to the device-scope environment variables added in + Technical Report (TR11) is already handled. + o For user defined allocators requesting high bandwidth or large + capacity memspaces or interleaved partitioning, the memkind library + is used, if available at run time. + * AddressSanitizer defaults to detect_stack_use_after_return=1 on GNU/Linux + targets. For compatibility, it can be disabled with env + ASAN_OPTIONS=detect_stack_use_after_return=0. + * New debug info compression option value -gz=zstd has been added. + * Link-time optimization improvements: + o LTO supports the newly added jobserver of GNU make jobserver that + uses named pipes (--jobserver-style=fifo) by default. + o If make's jobserver is active, parallel LTO WPA streaming + communicates with it and thus avoids system overcommitting. + * -Ofast, -ffast-math and -funsafe-math-optimizations will no longer add + startup code to alter the floating-point environment when producing a + shared object with -shared. + * GCC can now emit its diagnostics using SARIF. This is a JSON-based format + suited for capturing the results of static analysis tools (like GCC's - + fanalyzer), but it can also be used to capture other GCC warnings and + errors in a machine-readable format. Specifically, the -fdiagnostics- + format= option has been extended to support these new values: + o -fdiagnostics-format=sarif-stderr + o -fdiagnostics-format=sarif-file + o -fdiagnostics-format=json-stderr, a synonym for the existing - + fdiagnostics-format=json + o -fdiagnostics-format=json-file + where the json-prefixed variants refer to GCC's own JSON diagnostic + format. + +New Languages and Language specific improvements + +Ada + + * Traceback support added in RTEMS for the PPC ELF and ARM architectures. + * Support for versions older than VxWorks 7 has been removed. + * General improvements to the contracts in the standard libraries. + * Addition of GNAT.Binary_Search. + * Further additions and fixes for the Ada 2022 specification. + * The Pragma SPARK_Mode=>Auto is now accepted. Contract analysis has been + further improved. + * Documentation improvements. + +C family + + * New warnings: + o -Wxor-used-as-pow warns about uses of ^, the exclusive or operator, + where it appears the user meant exponentiation (PR90885) + * Three new function attributes for documenting int arguments that are file + descriptors: + o __attribute__((fd_arg(N))) + o __attribute__((fd_arg_read(N))) + o __attribute__((fd_arg_write(N))) + These are used by -fanalyzer to detect misuses of file descriptors. + * A new statement attribute for C++23 P1774R8 Portable assumptions support + also in C or older C++: __attribute__((assume(EXPR))); + * GCC can now control when to treat the trailing array of a structure as a + flexible array member for the purpose of accessing the elements of such + an array. By default, all trailing arrays in aggregates are treated as + flexible array members. Use the new command-line option -fstrict-flex- + arrays to control which array members are treated as flexible arrays. + +C + + * Several C23 features have been implemented: + o N3042, Introduce the nullptr constant + o N2963, Enhanced Enumerations (fixed underlying types) + o N2975, Relax requirements for variadic parameter lists + o N3007, Type inference for object definitions (auto) + o N3018, The constexpr specifier for object definitions + o N3038, Introduce storage-class specifiers for compound literals + o typeof (previously supported as an extension) and typeof_unqual + o New keywords alignas, alignof, bool, false, static_assert, + thread_local, true + o N2764, The noreturn attribute + o Support for empty initializer braces + o __STDC_VERSION_*_H__ header version macros + o Removal of ATOMIC_VAR_INIT + o unreachable macro in <stddef.h> + o Removal of trigraphs + o Removal of unprototyped functions + o printf and scanf format checking with -Wformat for %wN and %wfN + format length modifiers + o N2836, Identifier Syntax using Unicode Standard Annex 31 + * In addition to those C23 features, existing features adopted in C23 have + been adjusted to follow C23 requirements and are not diagnosed with - + std=c2x -Wpedantic. + * New warnings: + o -Wenum-int-mismatch warns about mismatches between an enumerated + type and an integer type (PR105131) + +C++ + + * Excess precision support (which has been available in C since GCC 4.5) + has been implemented for C++ as well. It is enabled by default in strict + standard modes like -std=c++17, where it defaults to -fexcess- + precision=standard, while in GNU standard modes like -std=gnu++20 it + defaults to -fexcess-precision=fast. The option mainly affects IA-32/x86- + 64 using x87 math and in some cases on Motorola 68000, where float and + double expressions are evaluated in long double precision and S/390, + System z, IBM z Systems where float expressions are evaluated in double + precision. Also, on several architectures where std::float16_t or std:: + bfloat16_t types are supported those are evaluated in float precision. - + fexcess-precision=fast restores previous behavior. + * Several C++23 features have been implemented: + o P2324R1, Labels at the end of compound statements (PR103539) + o P2255R2, A type trait to detect reference binding to temporary + (PR104477) + o P2327R1, De-deprecating volatile compound operations + o P2437R1, Support for #warning (PR106646) + o P2290R3, Delimited escape sequences (PR106645) + o P2071R2, Named universal character escapes (PR106648) + o P2513R3, char8_t Compatibility and Portability Fix (PR106656) + o P1169R4, static operator() (PR106651) + o P2266R3, Simpler implicit move (PR101165) + o P2468R2, The Equality Operator You Are Looking For (PR106644) + o P2362R3, Remove non-encodable + wide character literals and multicharacter wide character literals + (PR106647) + o P2448R2, Relaxing some constexpr restrictions (PR106649) + o P1467R9, Extended floating-point types and standard names + (PR106652) + o P1774R8, Portable assumptions (PR106654) + o P2295R6, Support for UTF-8 as a portable source file encoding + (PR106655) + o P2589R1, static operator[] (PR107684) + * New warnings: + o -Wself-move warns when a value is moved to itself with std::move + (PR81159) + o -Wdangling-reference warns when a reference is bound to a temporary + whose lifetime has ended (PR106393) + * The -Wpessimizing-move and -Wredundant-move warnings have been extended + to warn in more contexts. + * The -nostdlib++ option has been added, to enable linking with g++ without + implicitly linking in the C++ standard library. + +Runtime Library (libstdc++) + + * Improved experimental support for C++20, including: + o <format> header and std::format. + o std::chrono::utc_clock and other clocks, time zones, and std:: + format support in the <chrono> header. + * Improved experimental support for C++23, including: + o Additions to the <ranges> header: views::zip, views::zip_transform, + views::adjacent, views::adjacent_transform views::pairwise, views:: + slide, views::chunk, views::chunk_by, views::repeat, views:: + chunk_by, views::cartesian_product, views::as_rvalue, views:: + enumerate, views::as_const. + o Additions to the <algorithm> header: ranges::contains, ranges:: + contains_subrange, ranges::iota, ranges::find_last, ranges:: + find_last_if, ranges::find_last_if_not, ranges::fold_left, ranges:: + fold_left_first, ranges::fold_right, ranges::fold_right_last, + ranges::fold_left_with_iter, ranges::fold_left_first_with_iter. + o Monadic operations for std::expected. + o Constexpr std::bitset, std::to_chars and std::from_chars. + o Library support for extended floating-point types. + * Support for the <experimental/scope> header from v3 of the Library + Fundamentals Technical Specification. + * Support for the <experimental/synchronized_value> header from v2 of the + Concurrency Technical Specification. + +Fortran + + * Finalization is now fully supported. + +Go + * GCC 13, like GCC 12, provides a complete implementation of the Go 1.18 + user packages. + * Although Go 1.18 includes support for generic programming, that support + is not yet available in GCC. + +Modula-2 + * Support for the language Modula-2 has been added. This includes support + for the ISO/IEC 10514-1, PIM2, PIM3, PIM4 dialects together with a + complete set of ISO/IEC 10514-1 and PIM libraries. + * The <* noreturn *> attribute is supported with the -Wreturn-type option. + +New Targets and Target Specific Improvements + +AArch64 + + * The AArch64 target now supports Decimal Floating-point in the BID format + through the libbid library. + * A number of new CPUs are supported through the -mcpu and -mtune options + (GCC identifiers in parentheses). + o Ampere-1A (ampere1a). + o Arm Cortex-A715 (cortex-a715). + o Arm Cortex-X1C (cortex-x1c). + o Arm Cortex-X3 (cortex-x3). + o Arm Neoverse V2 (neoverse-v2). + * Support has been added for the armv9.1-a, armv9.2-a and armv9.3- + a arguments to the -march= option. + * The FEAT_LRCPC feature is now supported by generating the LDAPR + instructions for C and C++ atomic loads with an acquire memory model. + This is enabled when compiling with the +rcpc extension to -march or a + CPU target that supports this feature. + * The FEAT_CSSC feature from the 2022 Arm Architecture extensions is + supported through the +cssc extension option. When enabled, scalar + operations like integer minimum, maximum, absolute value, count trailing + zeroes (__builtin_ctz), population count (__builtin_popcount) can be + implemented in a single instruction. + * The FEAT_LSE2 feature is now supported through libatomic and provides + lockless 16-byte atomics on systems that implement it. + +AMD Radeon (GCN) + + * Support for the Instinct MI200 series devices (gfx90a) has been added. + * SIMD vectorization support has been improved; this and stack-handling + changes require newlib 4.3.0 (or newer). + +arm + * A number of new CPUs are supported through the -mcpu and -mtune options + (GCC identifiers in parentheses). + o STAR-MC1 (star-mc1). + o Arm Cortex-X1C (cortex-x1c). + o Arm Cortex-M85 (cortex-m85). + * Support has been added for the M-profile PACBTI extension that can help + harden the generated code against return-oriented and jump-oriented + attacks. It can be enabled through the -mbranch-protection= option. + +IA-32/x86-64 + * For both C and C++ the __bf16 type is supported on x86 systems with SSE2 + and above enabled. + * Use real __bf16 type for AVX512BF16 intrinsics. Previously we use + __bfloat16 which is typedef of short. Now we introduced real __bf16 type + to x86 psABI. Users need to adjust their AVX512BF16-related source code + when upgrading GCC12 to GCC13. + * New ISA extension support for Intel AVX-IFMA was added. AVX-IFMA + intrinsics are available via the -mavxifma compiler switch. + * New ISA extension support for Intel AVX-VNNI-INT8 was added. AVX-VNNI- + INT8 intrinsics are available via the -mavxvnniint8 compiler switch. + * New ISA extension support for Intel AVX-NE-CONVERT was added. AVX-NE- + CONVERT intrinsics are available via the -mavxneconvert compiler switch. + * New ISA extension support for Intel CMPccXADD was added. CMPccXADD + intrinsics are available via the -mcmpccxadd compiler switch. + * New ISA extension support for Intel AMX-FP16 was added. AMX-FP16 + intrinsics are available via the -mamx-fp16 compiler switch. + * New ISA extension support for Intel PREFETCHI was added. PREFETCHI + intrinsics are available via the -mprefetchi compiler switch. + * New ISA extension support for Intel RAO-INT was added. RAO-INT intrinsics + are available via the -mraoint compiler switch. + * New ISA extension support for Intel AMX-COMPLEX was added. AMX-COMPLEX + intrinsics are available via the -mamx-complex compiler switch. + * GCC now supports the Intel CPU named Raptor Lake through - + march=raptorlake. Raptor Lake is based on Alder Lake. + * GCC now supports the Intel CPU named Meteor Lake through - + march=meteorlake. Meteor Lake is based on Alder Lake. + * GCC now supports the Intel CPU named Sierra Forest through - + march=sierraforest. The switch enables the AVX-IFMA, AVX-VNNI-INT8, AVX- + NE-CONVERT and CMPccXADD ISA extensions. + * GCC now supports the Intel CPU named Grand Ridge through - + march=grandridge. The switch enables the AVX-IFMA, AVX-VNNI-INT8, AVX-NE- + CONVERT, CMPccXADD and RAO-INT ISA extensions. + * GCC now supports the Intel CPU named Emerald Rapids through - + march=emeraldrapids. Emerald Rapids is based on Sapphire Rapids. + * GCC now supports the Intel CPU named Granite Rapids through - + march=graniterapids. The switch enables the AMX-FP16, PREFETCHI and AMX- + COMPLEX ISA extensions. + * GCC now supports AMD CPUs based on the znver4 core via -march=znver4. The + switch makes GCC consider using 512 bit vectors when auto-vectorizing. + +LoongArch + + * New features + o The new command-line option -mexplicit-relocs decides whether to + use the assembler relocation operator when dealing with symbolic + addresses. It is enabled by default if a compatible assembler + (binutils 2.40 or later) is present at GCC build time. + o The new command-line option -mdirect-extern-access can be used to + prevent accessing external symbols through GOT. + o The new variable attribute model has been added. + * Built-in functions + o The rint and copysign mathematical builtins (and their float + variants) are now implemented as inline LoongArch intrinsics. + o The lrint, logb, scalbln, scalbn and ldexp mathematical builtins + (and their float variants) are now implemented as inline LoongArch + intrinsics when using -fno-math-errno. + o The lceil and lfloor mathematical builtins (and their float + variants) are now implemented as inline LoongArch intrinsics when + using -ffp-int-builtin-inexact. + * Subprojects Support + o libvtv now supports LoongArch. + o libitm now supports LoongArch. + o Address sanitizers other than HWASan and TSan are now supported on + LoongArch. + +NVPTX + + * The default value for the -march option can be now changed when building + GCC using the --with-arch= configure option. GCC's target libraries are + then build both with sm_30 and the specified target architecture. If not + specified, GCC defaults to sm_30. + +RISC-V + + * Support for vector intrinsics as specified in version_0.11_of_the_RISC- + V_vector_intrinsic_specification, thanks Ju-Zhe Zhong from RiVAI for + contributing most of implementation. + * Support for the following standard extensions has been added: + o Zawrs + o Zbkb + o Zbkc + o Zbkx + o Zdinx + o Zfinx + o Zfh + o Zfhmin + o Zhinx + o Zhinxmin + o Zicbom + o Zicbop + o Zicboz + o Zknd + o Zkne + o Zksed + o Zksh + o Zmmul + * Support for the following vendor extensions has been added: + o XTheadBa + o XTheadBb + o XTheadBs + o XTheadCmo + o XTheadCondMov + o XTheadFMemIdx + o XTheadFmv + o XTheadInt + o XTheadMac + o XTheadMemIdx + o XTheadMemPair + o XTheadSync + * The following new CPUs are supported through the -mcpu option (GCC + identifiers in parentheses). + o T-Head's XuanTie C906 (thead-c906). + * Improves the multi-lib selection mechanism for the bare-metal toolchain + (riscv*-elf*). GCC will now automatically select the best-fit multi-lib + candidate instead of requiring all possible reuse rules to be listed at + build time. + +Operating Systems + +Improvements to Static Analyzer + + * The analyzer has gained 20 new warnings: + o -Wanalyzer-allocation-size + o -Wanalyzer-deref-before-check + o -Wanalyzer-exposure-through-uninit-copy + o Seven new warnings relating to misuse of file descriptors: + # -Wanalyzer-fd-access-mode-mismatch + # -Wanalyzer-fd-double-close + # -Wanalyzer-fd-leak + # -Wanalyzer-fd-phase-mismatch (e.g. calling accept on a socket + before calling listen on it) + # -Wanalyzer-fd-type-mismatch (e.g. using a stream socket + operation on a datagram socket) + # -Wanalyzer-fd-use-after-close + # -Wanalyzer-fd-use-without-check + along with special-casing handling of the behavior of open, close, + creat, dup, dup2, dup3, pipe, pipe2, read, and write. + o -Wanalyzer-imprecise-fp-arithmetic + o -Wanalyzer-infinite-recursion + o -Wanalyzer-jump-through-null + o -Wanalyzer-out-of-bounds + o -Wanalyzer-putenv-of-auto-var + o -Wanalyzer-tainted-assertion + o Four new warnings for misuses of <stdarg.h>: + # -Wanalyzer-va-list-leak for complaining about missing va_end + after a va_start or va_copy + # -Wanalyzer-va-list-use-after-va-end for complaining about + va_arg or va_copy used on a va_list that's had va_end called + on it + # -Wanalyzer-va-arg-type-mismatch for type-checking of va_arg + usage in interprocedural execution paths against the types of + the parameters that were actually passed to the variadic call + # -Wanalyzer-va-list-exhausted for complaining in + interprocedural execution paths if va_arg is used too many + times on a va_list + along with numerous other improvements. + +Improvements for plugin authors + * GCC diagnostics can now be associated_with_rules such as from coding + standards documents, or specifications. Such rules have a code name and + can have a URL, which GCC can print in text form or capture in its SARIF + output when emitting diagnostics. + +Other significant improvements + +GCC 13.1 + +This is the list_of_problem_reports_(PRs) from GCC's bug tracking system that +are known to be fixed in the 13.1 release. This list might not be complete +(that is, it is possible that some PRs that have been fixed are not listed +here). +https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=13.0 |