We have a textual representation of contextual profiles for test scenarios, mainly. This patch moves that to YAML instead of JSON. YAML is more succinct and readable (some of the .ll tests should be illustrative). In addition, JSON is parse-able by the YAML reader.
A subsequent patch will address deserialization.
(thanks, @kazutakahirata, for showing me how to use the llvm YAML reader/writer APIs, which I incorrectly thought to be more low-level than the JSON ones!)
Add an overload of `InlineFunction` that updates the contextual profile. If there is no contextual profile, this overload is equivalent to the non-contextual profile variant.
Post-inlining, the update mainly consists of:
- making the PGO instrumentation of the callee "the caller's": the owner function (the "name" parameter of the instrumentation instructions) becomes the caller, and new index values are allocated for each of the callee's indices (this happens for both increment and callsite instrumentation instructions)
- in the contextual profile:
- each context corresponding to the caller has its counters updated to incorporate the counters inherited from the callee at the inlined callsite. Counter values are copied as-is because no scaling is required since the profile is contextual.
- the contexts of the callee (at the inlined callsite) are moved to the caller.
- the callee context at the inlined callsite is deleted.
An overload of `llvm::promoteCallWithIfThenElse` that updates the contextual profile.
High-level, this is very simple: after creating the `if... then (direct call) else (indirect call)` structure, we instrument the new callsites and BBs (the instrumentation will help with tracking for other IPO transformations, and, ultimately, to match counter values before flattening to `MD_prof`).
In more detail:
- move the callsite instrumentation of the indirect call to the `else` BB, before the indirect call
- create a new callsite instrumentation for the direct call
- create instrumentation for both the `then` and `else` BBs - we could instrument just one (MST-style) but we're not running the binary with this instrumentation, and at most this would save some space (less counters tracked). For simplicity instrumenting both at this point
- update each context belonging to the caller by updating the counters, and moving the indirect callee to the new, direct callsite ID
Issue #89287
Summary:
Updated CallPromotionUtils and impacted sites. Parameters that are
expected to be non-null, and return values that are guranteed non-null,
were replaced with CallBase references rather than pointers.
Left FIXME in places where more changes are facilitated by CallBase, but
aren't CallSites: Instruction* parameters or return values, for example,
where the contract that they are actually CallBase values.
Reviewers: davidxl, dblaikie, wmi
Reviewed By: dblaikie
Subscribers: arsenm, jvesely, nhaehnle, eraman, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77930
Summary: This fixes the crash that led to the revert of D69591.
Reviewers: davidxl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75307
Summary: It attempts to devirtualize a call on alloca through vtable loads.
Reviewers: davidxl
Subscribers: mgorny, Prazek, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71308
