llvm/llvm-project

[DAG] SDPatternMatch - add m_BinOp/m_c_BinOp variants driven by TLI.isBinOp/isCommutativeBinOp

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#84,940 opened on Mar 12, 2024

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good first issuellvm:SelectionDAG

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Description

As noticed on #84759 - we should be able to allow folds to generally match any binary ops that are recognized by the TLI.isBinOp/isCommutativeBinOp callbacks, allowing us to match target binops in generic dag combines.

CC @mshockwave

Contributor guide

Research direction
Inspect the TLI.isBinOp and isCommutativeBinOp callbacks in the target lowering, and then add corresponding m BinOp/m c BinOp pattern matching functions in SDPatternMatch.h. Follow the pattern of existing operators like m Add, m Sub etc.
Tech stack
cpp
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
3-5 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Mostly clear
Prerequisites
C++LLVMGit
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40