# LLVM Weekly - #77, Jun 22nd 2015

DevFeed: [LLVM Weekly - #77, Jun 22nd 2015](<https://devfeed.tech/articles/llvm-weekly-77-jun-22nd-2015-42980.md>)

Original publisher: [Read original article](<https://blog.llvm.org/2015/06/llvm-weekly-77-jun-22nd-2015.html>)

Author: Alex Bradbury

Published: 2015-06-22T04:52:00Z

Content type: news

Language: en

Sources: [The LLVM Project Blog](<https://devfeed.tech/sources/the-llvm-project-blog.md>)

Topics: [LLVM](<https://devfeed.tech/topics/llvm.md>), [clang](<https://devfeed.tech/topics/clang.md>), [Compiler](<https://devfeed.tech/topics/compiler.md>), [WebAssembly](<https://devfeed.tech/topics/web-assembly.md>), [build times](<https://devfeed.tech/topics/build-times.md>), [RISC-V](<https://devfeed.tech/topics/riscv.md>)

Tags: [build-times](<https://devfeed.tech/tags/build-times.md>), [clang](<https://devfeed.tech/tags/clang.md>), [compiler](<https://devfeed.tech/tags/compiler.md>), [llvm](<https://devfeed.tech/tags/llvm.md>), [llvmweekly](<https://devfeed.tech/tags/llvmweekly.md>), [risc-v](<https://devfeed.tech/tags/risc-v.md>), [webassembly](<https://devfeed.tech/tags/webassembly.md>)

## AI overview

The seventy-seventh LLVM Weekly covers WebAssembly as a new browser-vendor collaboration and compilation target, approaches for improving Clang build times, LLVM backend proposals for WebAssembly and SPIR-V, profile-guided optimization work, and recent LLVM commits.

## Source excerpt

Welcome to the seventy-seventh 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 http://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. I'll be in California next week for the second RISC-V workshop. Me and my colleague Wei will both be giving talks about recent lowRISC progress. Say hi if you're going to be there. I might have some spare time towards the end of the week too if anyone wants to meet up. The canonical home for this issue can be found here at llvmweekly.org. News and articles from around the web WebAssembly has been announced. It is a new collaboration between browser vendors to define a new binary executable format that can be used as a compilation target. A good summary is available here on the emscripten mailing list. Tilmann Scheller has written up a pair of blog posts about improving build times of Clang. He steps through a wide range of generic approaches (using Ninja, ccache, the gold linker, LTO+PGO in the host compiler etc etc) and some specific to Clang/LLVM. The Cambridge LLVM Social will be taking place on Wed 24th June, 7.30pm at the Blue. On the mailing lists Dan Gohman has posted an RFC for the inclusion of a WebAssembly backend in LLVM. It seems like everyone is in favour of the proposed approach. Yaxun Li has posted a revised RFC on adding a SPIR-V target to LLVM. There still seems to be some push-back on the proposed approach. Chandler Carruth makes an argument that SPIR-V should make use of the existing SelectionDAG legalization layer. Igor Laevsky is seeking more feedback on adding an attribute to mark that a function only accesses memory through its arguments. Philip Reames point out in the thread that this isn't a new concept to LLVM, except right now such