anton-afanasyev marked 3 inline comments as done.
anton-afanasyev added inline comments.
================
Comment at: cfe/trunk/lib/CodeGen/BackendUtil.cpp:1426-1431
EmitAssemblyHelper AsmHelper(Diags, HeaderOpts, CGOpts, TOpts, LOpts, M);
if (CGOpts.ExperimentalNewPassManager)
AsmHelper.EmitAssemblyWithNewPassManager(Action, std::move(OS));
else
AsmHelper.EmitAssembly(Action, std::move(OS));
----------------
lebedev.ri wrote:
> anton-afanasyev wrote:
> > lebedev.ri wrote:
> > > anton-afanasyev wrote:
> > > > anton-afanasyev wrote:
> > > > > lebedev.ri wrote:
> > > > > > This isn't covered by any timer; if you look in `BackendUtil.cpp`,
> > > > > > `EmitAssemblyHelper` actually has `CodeGenerationTime("codegen",
> > > > > > "Code Generation Time")` timer.
> > > > > Thanks, I'm to add it.
> > > > Hmm, I've figured out this isn't needed: such new timer mostly
> > > > coincides with "Backend" timer (above). Legacy `Timer
> > > > CodeGenerationTime(...)` is bad example of doing right timing.
> > > "Mostly coincides" may not be the best way to approach fine-grained
> > > timings, i think? :)
> > >
> > > I have noticed this because when i looked at the produced time flame
> > > graph,
> > > there's large section in the end that is covered only by `"Backend"`
> > > timer,
> > > but nothing else. Now, i'm not going to say whether or not that extra
> > > section
> > > should or should not be within `"Backend"` timer, but it certainly should
> > > *also*
> > > be within `"codegen"` timer. Or is there no codegen time spent there?
> > > {F10062322}
> > > {F10062316}
> > "Mostly coincides" here means "identical" I believe, the difference is
> > auxiliary stuff.
> > Please look at `clang::EmitBackendOutput()`, `"Backend"` timer is outer for
> > `"codegen"` one.
> Then we are talking about different things using the same name.
> There are two distinct codegen steps:
> 1. clang AST -> LLVM IR codegen
> (after that, all the opt passes run)
> 2. LLVM IR -> final assembly. This happens after all the opt middle-end
> passes.
>
> Those are *different* codegen's.
Yes, and step 1 is named as "CodeGen Function" whereas step 2 is named just
"Backend".
Repository:
rL LLVM
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D58675/new/
https://reviews.llvm.org/D58675
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