HomePhabricator

Add !annotation metadata and remarks pass.

Authored by fhahn on Nov 13 2020, 1:46 AM.

Description

Add !annotation metadata and remarks pass.

This patch adds a new !annotation metadata kind which can be used to
attach annotation strings to instructions.

It also adds a new pass that emits summary remarks per function with the
counts for each annotation kind.

The intended uses cases for this new metadata is annotating
'interesting' instructions and the remarks should provide additional
insight into transformations applied to a program.

To motivate this, consider these specific questions we would like to get answered:

  • How many stores added for automatic variable initialization remain after optimizations? Where are they?
  • How many runtime checks inserted by a frontend could be eliminated? Where are the ones that did not get eliminated?

Discussed on llvm-dev as part of 'RFC: Combining Annotation Metadata and Remarks'
(http://lists.llvm.org/pipermail/llvm-dev/2020-November/146393.html)

Reviewed By: thegameg, jdoerfert

Differential Revision: https://reviews.llvm.org/D91188

Details

Committed
fhahnNov 13 2020, 5:24 AM
Reviewer
thegameg
Differential Revision
D91188: Add !annotation metadata and remarks pass.
Parents
rG7ad6c8414ce2: [clang] Fix an assertion crash in delayed access check.
Branches
Unknown
Tags
Unknown