LLVM Weekly - #346, August 17th 2020

Welcome to the three hundred and forty-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. Subscribe to future issues at https://llvmweekly.org and pass it on to anyone else you think may be interested. Please send any tips or feedback to asb@asbradbury.org, or @llvmweekly or @asbradbury on Twitter.

News and articles from around the web

The submission deadline for the LLVM-HPC2020 workshop at SC20 is approaching, with proposals due by September 1.

A new talk from Nick Desaulniers provides an introduction to the architecture of LLVM.

On the mailing lists

• Carlos Enciso proposed llvm-diva for inclusion in LLVM. The Debug Information Visual Analyzer was developed at Sony to help visualise debug info at a high level. It also provides a comparison mode.

• Jeroen Dobbelaere reports that the previously discussed full restrict patches are now almost ready for review, and seeks feedback on the current plan for moving forwards.

• Discussion continued on support for zeroing caller saved regs with David Chisnall further discussing its security properties.

• David Spickett posted an RFC on supporting AArch64's tagging extension in LLDB.

• OT JIT Weekly #20 is out, with the headline item being that llvm-jitlink moved to the TargetProcessControl API for memory allocation and access.

LLVM commits

• Initial backend infrastructure was added for -mtune, represented as a "tune-cpu" function attribute. c7a0b26.

• Support was added for emitting the GNU .debug_macro extension. e2f3240.

• UpdateTestChecks was modified to match most uses of temporary named values in the IR via regular expressions. 97ce7fd.

• BranchProbabilityInfo's static heuristics for integer comparisons were improved, matching GCC's. 385c9d6.

• ORC gained a JITLink-compatible remote memory-manager. 30c4561.

• The tablegen asm matcher backend will now allow mnemonics with uppercase letters to be matched. 3cf7efe.

Clang commits

• clang-tidy's modernize-user-trailing-return-type gained support for C++20 concepts and decltype. 3450533.

• Support was added for -fno-eliminate-unused-debug-types. 4f2ad15.

• Clang will now default to using /usr/bin/ld on Solaris. f59bec7.

Other project commits

• An OpenACC MLIR dialect was introduced. 4225e7f.

• LLVM's libc gained strtok and strtok_r implementations. 667843c.

• std::visit benchmarks were added to libcxx and its implementation was optimised. c6f5137, a175a96.

• lld-macho continues development with support for dynamic linking of thread-locals, -force_load, and other features. 3c9100f, 437e6bd.

• MLIR's pattern rewrite infrastructure was documented. f7a1347.

• A libomptarget host plugin for amdgpu was added. d0b3129.