Alex Bradbury via llvm-dev
2021-Aug-02 17:00 UTC
[llvm-dev] LLVM Weekly - #396, August 2nd 2021
LLVM Weekly - #396, August 2nd 2021 ================================== If you prefer, you can read a HTML version of this email at <http://llvmweekly.org/issue/396>. Welcome to the three hundred and ninety-sixth issue of LLVM Weekly, a weekly newsletter (published every Monday) covering developments in LLVM, Clang, and related projects. LLVM Weekly is brought to you by [Alex Bradbury](https://www.linkedin.com/in/alex-bradbury/). Subscribe to future issues at <http://llvmweekly.org> and pass it on to anyone else you think may be interested. Please send any tips or feedback to <asb at asbradbury.org>, or @llvmweekly or @asbradbury on Twitter. ## News and articles from around the web LLVM 13.0.0 [has branched](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151956.html) and the first release candidate is [expected today](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151983.html). ## On the mailing lists * Jeremy Morse is [seeking testers](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151965.html) for the new variable location tracking solution that has been added to LLVM, but is off by default. * Luke Kenneth Casson Leighton posted an RFC on a proposed [vector/SIMD ISA context abstraction](https://lists.llvm.org/pipermail/llvm-dev/2021-July/152008.html). * Ben Gamari wrote to llvm-dev about a proposed change to the GHC calling convention, [querying if this may cause an issue for LLVM](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151995.html). * Michał Górny [shared](https://lists.llvm.org/pipermail/lldb-dev/2021-July/016975.html) that Mortiz Systems has been contracted to enable KGDB compatibility in LLDB and so will be working on improving compatibility between LDB and the gdbserver protocol as part of this. * Thomas Goodfellow [asked for advice](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151945.html) on building compiler-rt for RISC-V and received answers from [Fāng-ruì Sòng](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151950.html) and [Luís Marques](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151962.html). * Teresa Johnson provided [input from an ThinLTO perspective](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151948.html) on function specialization. * Geoffrey Martin-Noble shared that [pre-merge checks have been set up for the Bazel build of LLVM](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151982.html). ## LLVM commits * A jump-threading optimisation was added for deterministic finite automata was added. One well-known input where this optimisation may be triggered is the `core_state_transition` function of coremark. [02077da](https://reviews.llvm.org/rG02077da7e7a8). * Graph reordering in the SLP vectorizer has been improved. [e408d1d](https://reviews.llvm.org/rGe408d1dfab42). * AArch64 GlobalISel will no longer optimise away redundant branches at `-O0`, in order to improve the debuggability of emitted code. [c5d84d2](https://reviews.llvm.org/rGc5d84d2eb35c). * The CallPenalty for the inliner is now configurable. [46c0366](https://reviews.llvm.org/rG46c03668774c). * Support for the arch14 SystemZ architecture was added to the SystemZ backend. [8cd8120](https://reviews.llvm.org/rG8cd8120a7b5d). * Emscripten exception handling now works with Emscripten SjLJ (setjmp/longjmp). [c285a11](https://reviews.llvm.org/rGc285a11efdb0). * Initial code was added to generate assembly files on z/OS. [a8cfa4b](https://reviews.llvm.org/rGa8cfa4b9bda3). * `LLVM_ATTRIBUTE_NORETURN` has been replaced with `[[noreturn]]` in the LLVM codebase. [6da3d8b](https://reviews.llvm.org/rG6da3d8b19c32). * A new feature was introduced in AArch64 for Scalable Matrix Extension (SME) streaming mode. [3a349d2](https://reviews.llvm.org/rG3a349d22692c). ## Clang commits * `#pragma include_instead` was introduced, which can be used by system headers to indicate to a tool that the file including this pragma shouldn't be directly included by user code. [e8a64e5](https://reviews.llvm.org/rGe8a64e549126). * `#pragma clang deprecated` was added in order to enable deprecation of preprocessor macros. [26c695b](https://reviews.llvm.org/rG26c695b78930). * Clang option `-ffp-model=precise` now enables `-ffp-contract=on`. [48ad446a](https://reviews.llvm.org/rG48ad446a0fb2). * Support was added for the `-ffp-eval-method` command-line option. [66ddac2](https://reviews.llvm.org/rG66ddac22e2a7). ## Other project commits * A new on-by-default libc++ CMake option was added to disable the usage of incomplete headers which aren't guaranteed to be ABI stable. [71909de](https://reviews.llvm.org/rG71909de37495). * The Hierarchical Trace Representation (HTR) format for large traces (e.g. processor traces from Intel PT) was introduced to LLDB. [aad17c5](https://reviews.llvm.org/rGaad17c55a811). * A prototype of a new OpenMP GPU device runtime library was introduced. [67ab875](https://reviews.llvm.org/rG67ab875ff578). * Initial Objective-C and Swift support was added to the ORC runtime's MachOPlatform. [cdcc354](https://reviews.llvm.org/rGcdcc35476833). * The migration of Flang's tests to GTest has been completed. [65436e6](https://reviews.llvm.org/rG65436e6ba127). * A new `-Bsymbolic-non-weak-functions` option was added to the LLD ELF linker. [b06426d](https://reviews.llvm.org/rGb06426da764a). * LLDB gained a new option to write memory tags (when Arm's Memory Tagging Extension is supported). [6a7a2ee](https://reviews.llvm.org/rG6a7a2ee8161d). * MLIR's Python build support was reworked. [310c949](https://reviews.llvm.org/rG310c9496d809). * The llvm-omp-device-info tool was added. [313c523](https://reviews.llvm.org/rG313c5239959b).
Alex Bradbury via llvm-dev
2021-Aug-02 17:36 UTC
[llvm-dev] LLVM Weekly - #396, August 2nd 2021
On Mon, 2 Aug 2021 at 18:00, Alex Bradbury <asb at asbradbury.org> wrote:> > LLVM Weekly - #396, August 2nd 2021 > ==================================> > If you prefer, you can read a HTML version of this email at > <http://llvmweekly.org/issue/396>. > > Welcome to the three hundred and ninety-sixth issue of LLVM Weekly, a weekly > newsletter (published every Monday) covering developments in LLVM, Clang, and > related projects. LLVM Weekly is brought to you by [Alex > Bradbury](https://www.linkedin.com/in/alex-bradbury/). Subscribe to future > issues at <http://llvmweekly.org> and pass it on to anyone else you think may > be interested. Please send any tips or feedback to <asb at asbradbury.org>, or > @llvmweekly or @asbradbury on Twitter. > > > ## News and articles from around the web > > LLVM 13.0.0 [has > branched](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151956.html) and > the first release candidate is [expected > today](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151983.html). > > > ## On the mailing lists > > * Jeremy Morse is [seeking > testers](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151965.html) > for the new variable location tracking solution that has been added to LLVM, > but is off by default. > > * Luke Kenneth Casson Leighton posted an RFC on a proposed [vector/SIMD ISA > context > abstraction](https://lists.llvm.org/pipermail/llvm-dev/2021-July/152008.html). > > * Ben Gamari wrote to llvm-dev about a proposed change to the GHC calling > convention, [querying if this may cause an issue for > LLVM](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151995.html). > > * Michał Górny > [shared](https://lists.llvm.org/pipermail/lldb-dev/2021-July/016975.html) > that Mortiz Systems has been contracted to enable KGDB compatibility in LLDB > and so will be working on improving compatibility between LDB and the > gdbserver protocol as part of this. > > * Thomas Goodfellow [asked for > advice](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151945.html) on > building compiler-rt for RISC-V and received answers from [Fāng-ruì > Sòng](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151950.html) and > [Luís > Marques](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151962.html). > > * Teresa Johnson provided [input from an ThinLTO > perspective](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151948.html) > on function specialization. > > * Geoffrey Martin-Noble shared that [pre-merge checks have been set up for the > Bazel build of > LLVM](https://lists.llvm.org/pipermail/llvm-dev/2021-July/151982.html). > > > ## LLVM commits > > * A jump-threading optimisation was added for deterministic finite automata > was added. One well-known input where this optimisation may be triggered is > the `core_state_transition` function of coremark. > [02077da](https://reviews.llvm.org/rG02077da7e7a8). > > * Graph reordering in the SLP vectorizer has been improved. > [e408d1d](https://reviews.llvm.org/rGe408d1dfab42). > > * AArch64 GlobalISel will no longer optimise away redundant branches at `-O0`, > in order to improve the debuggability of emitted code. > [c5d84d2](https://reviews.llvm.org/rGc5d84d2eb35c). > > * The CallPenalty for the inliner is now configurable. > [46c0366](https://reviews.llvm.org/rG46c03668774c). > > * Support for the arch14 SystemZ architecture was added to the SystemZ > backend. [8cd8120](https://reviews.llvm.org/rG8cd8120a7b5d). > > * Emscripten exception handling now works with Emscripten SjLJ > (setjmp/longjmp). [c285a11](https://reviews.llvm.org/rGc285a11efdb0). > > * Initial code was added to generate assembly files on z/OS. > [a8cfa4b](https://reviews.llvm.org/rGa8cfa4b9bda3). > > * `LLVM_ATTRIBUTE_NORETURN` has been replaced with `[[noreturn]]` in the LLVM > codebase. [6da3d8b](https://reviews.llvm.org/rG6da3d8b19c32). > > * A new feature was introduced in AArch64 for Scalable Matrix Extension (SME) > streaming mode. [3a349d2](https://reviews.llvm.org/rG3a349d22692c). > > > ## Clang commits > > * `#pragma include_instead` was introduced, which can be used by system > headers to indicate to a tool that the file including this pragma shouldn't > be directly included by user code. > [e8a64e5](https://reviews.llvm.org/rGe8a64e549126). > > * `#pragma clang deprecated` was added in order to enable deprecation of > preprocessor macros. [26c695b](https://reviews.llvm.org/rG26c695b78930). > > * Clang option `-ffp-model=precise` now enables `-ffp-contract=on`. > [48ad446a](https://reviews.llvm.org/rG48ad446a0fb2). > > * Support was added for the `-ffp-eval-method` command-line option. > [66ddac2](https://reviews.llvm.org/rG66ddac22e2a7). > > > ## Other project commits > > * A new on-by-default libc++ CMake option was added to disable the usage of > incomplete headers which aren't guaranteed to be ABI stable. > [71909de](https://reviews.llvm.org/rG71909de37495).A slight correction - I'd got the wrong end of the stick from reading the commit message on this one. You have to opt-in to disable incomplete headers.> * The Hierarchical Trace Representation (HTR) format for large traces (e.g. > processor traces from Intel PT) was introduced to LLDB. > [aad17c5](https://reviews.llvm.org/rGaad17c55a811). > > * A prototype of a new OpenMP GPU device runtime library was introduced. > [67ab875](https://reviews.llvm.org/rG67ab875ff578). > > * Initial Objective-C and Swift support was added to the ORC runtime's > MachOPlatform. [cdcc354](https://reviews.llvm.org/rGcdcc35476833). > > * The migration of Flang's tests to GTest has been completed. > [65436e6](https://reviews.llvm.org/rG65436e6ba127). > > * A new `-Bsymbolic-non-weak-functions` option was added to the LLD ELF > linker. [b06426d](https://reviews.llvm.org/rGb06426da764a). > > * LLDB gained a new option to write memory tags (when Arm's Memory Tagging > Extension is supported). [6a7a2ee](https://reviews.llvm.org/rG6a7a2ee8161d). > > * MLIR's Python build support was reworked. > [310c949](https://reviews.llvm.org/rG310c9496d809). > > * The llvm-omp-device-info tool was added. > [313c523](https://reviews.llvm.org/rG313c5239959b).