[LLVMdev] JIT compilation 2-3 times slower in latest LLVM snapshot (original) (raw)

Dibyendu Majumdar mobile at majumdar.org.uk
Sat Jul 11 05:50:37 PDT 2015

On 11 July 2015 at 13:16, Dibyendu Majumdar <mobile at majumdar.org.uk> wrote:

On 11 July 2015 at 13:14, Caldarale, Charles R <Chuck.Caldarale at unisys.com> wrote:

From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Dibyendu Majumdar Subject: [LLVMdev] JIT compilation 2-3 times slower in latest LLVM snapshot

I updated my clone of the LLVM github mirror today and I am finding that the JIT compilation is now 2-3 times slower. The last time I refreshed was maybe 2 weeks ago. Is there a known change that would explain this? Debug+Asserts build rather than Release (or Release+Asserts)? I haven't changed my build - it is a Release build. Have the settings in the Released build has changed recently?

Just to be sure I completely rebuilt LLVM (below are some snippets from the build):

C:\github\llvm\build>cmake -DCMAKE_INSTALL_PREFIX=c:\LLVM37 -DCMAKE_BUILD_TYPE=Release -DLLVM_TARGETS_TO_BUILD="X86" -G "Visual Studio 14 Win64" .. -- Target triple: x86_64-pc-win32 -- Native target architecture is X86 -- Threads enabled. -- Doxygen disabled. -- Sphinx disabled. -- Go bindings disabled. -- Could NOT find OCaml (missing: OCAMLFIND OCAML_VERSION OCAML_STDLIB_PATH) -- OCaml bindings disabled. -- Using Debug VC++ CRT: MDd -- Using Release VC++ CRT: MD -- Using MinSizeRel VC++ CRT: MD -- Using RelWithDebInfo VC++ CRT: MD -- Using Release VC++ CRT: MD -- Constructing LLVMBuild project information -- LLVMHello ignored -- Loadable modules not supported on this platform. -- Targeting X86 -- BugpointPasses ignored -- Loadable modules not supported on this platform. -- Configuring done -- Generating done -- Build files have been written to: C:/github/llvm/build

Visual Studio output:

140>Project not selected to build for this solution configuration 141>------ Skipped Build: Project: check-all, Configuration: Release x64 ------ 141>Project not selected to build for this solution configuration 142>------ Skipped Build: Project: check, Configuration: Release x64 ------ 142>Project not selected to build for this solution configuration ========== Build: 136 succeeded, 0 failed, 0 up-to-date, 6 skipped ==========

and

1>------ Build started: Project: LTO_exports, Configuration: Release x64 ------ 2>------ Build started: Project: intrinsics_gen, Configuration: Release x64 ------ 3>------ Build started: Project: LibOptionsTableGen, Configuration: Release x64 ------ 4>------ Build started: Project: X86CommonTableGen, Configuration: Release x64 ------ 5>------ Build started: Project: llvm-ranlib, Configuration: Release x64 ------ 6>------ Build started: Project: llvm-lib, Configuration: Release x64 ------ 7>------ Build started: Project: INSTALL, Configuration: Release x64 ------ 7> -- Install configuration: "Release"

Same issue.

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