而对于PGO来说,损失10%的边执行次数未尝不可接受。 Clang其实还有另一套coverage机制,在2014年开发:-fprofile-instr-generate -fcoverage-mapping。 clangCodeGen实现了-fprofile-instr-generate,既用于Clang的PGO instrumentation,也用于coverage。 假如你用llvm-cov导出coverage信息,可以发现它有非常精确的列号和覆盖区间...
Submit CLs in toolchain/llvm_android and toolchain/llvm-project together. Examples are in aosp/1515350 and aosp/1515697. Step 2. Update profdata It is to speed up compile time for the new compiler. The profdata is generated in go/ab/aosp-master-plus-llvm, target Clang-PGO. An example is...
"extracted from PGO related analysis."));+static cl::opt<bool> EmitJumpTableSizesSection(+"emit-jump-table-sizes-section",+cl::desc("Emit a section containing jump table addresses and sizes"),+cl::Hidden, cl::init(false));+STATISTIC(EmittedInsts, "Number of machine instrs printed"); ...
像谷歌这样的公司早已在其移动设备上的内核构建中使用 Clang LTO 并取得了不错的效果:大约 3 年前开始, Android 内核不仅由 Clang 构建,而且还利用了链接式优化。微软也探索过使用 LTO + PGO 来给 Linux 内核提升性能。除了性能之外,Clang LTO 还允许启用 CFI 以获得更高的安全性。 令人兴奋的是,Linus Torvald...
linux-pgo,mac-pgo,win32-pgo,win64-pgo > Cq-Include-Trybots: luci.chromium.try:linux-cast-x64-rel > Cq-Include-Trybots: chromium/try:android-rust-arm32-rel > Cq-Include-Trybots: chromium/try:android-rust-arm64-dbg > Cq-Include-Trybots: chromium/try:android-rust-arm64-rel > Cq-...
Flags |= static_cast<uint32_t>(CompileSym3Flags::PGO); } using ArchType = llvm::Triple::ArchType; ArchType Arch = Triple(MMI->getModule()->getTargetTriple()).getArch(); ArchType Arch = MMI->getModule()->getTargetTriple().getArch(); if (Asm->TM.Options.Hotpatch || Arch == ...
I'm apologise for the long delay in investigating this. This seems to be a bug in ld.bfd which may have been fixed inhttps://sourceware.org/bugzilla/show_bug.cgi?id=24857. To verify, runreadelf -aWon the problematic shared library. In my repro, thesh_infofor.dynsymis 3 whereas the...
linux-pgo,mac-pgo,win32-pgo,win64-pgo Cq-Include-Trybots: luci.chromium.try:linux-cast-x64-rel Cq-Include-Trybots: chromium/try:android-rust-arm32-rel Cq-Include-Trybots: chromium/try:android-rust-arm64-dbg Cq-Include-Trybots: chromium/try:android-rust-arm64-rel Cq-Include-Trybots: ...
9363071 .github bolt clang-tools-extra clang cmake compiler-rt cross-project-tests flang libc libclc libcxx libcxxabi libunwind lld COFF Common ELF Arch AArch64ErrataFix.cpp AArch64ErrataFix.h ARMErrataFix.cpp ARMErrataFix.h CMakeLists.txt ...