https://bugs.llvm.org/show_bug.cgi?id=51827
Bug ID: 51827
Summary: Huge codegen performance regression for Windows
targets since LLVM 12, incl. latest 13-rc2
Product: new-bugs
Version: trunk
Hardware: PC
OS: Windows NT
Status: NEW
Severity: release blocker
Priority: P
Component: new bugs
Assignee: unassignedb...@nondot.org
Reporter: ki...@gmx.net
CC: htmldevelo...@gmail.com, llvm-bugs@lists.llvm.org
Created attachment 25252
--> https://bugs.llvm.org/attachment.cgi?id=25252&action=edit
xz-compressed bitcode input file
I'm seeing a codegen slowdown by about 2 orders of magnitude for the attached
.bc file (generated by LDC, the LLVM D compiler) starting with LLVM 12.0.0.
Seems to be specific to Windows/MSVC targets, and timings are back to normal
when enabling the optimizer.
Using clang from the official LLVM Windows builds from GitHub and compiling via
`clang -c template9.bc`:
* v11.0.1: ~2.4 seconds
* v12.0.1: ~246 seconds
* v13.0.0-rc2: ~227 seconds
Enabling the optimizer by adding `-O3` hints at a further little regression in
v13:
* v11.0.1: ~3.3 seconds
* v12.0.1: ~3.3 seconds
* v13.0.0-rc2: ~5.0 seconds
--
You are receiving this mail because:
You are on the CC list for the bug._______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
