[all-commits] [llvm/llvm-project] a6492e: [IR] Value::getPointerAlignment(): handle pointer ...

[Roman Lebedev via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: a6492e22711e45f1e60416371f7b5c29be5f508e
      https://github.com/llvm/llvm-project/commit/a6492e22711e45f1e60416371f7b5c29be5f508e
  Author: Roman Lebedev <lebedev.ri at gmail.com>
  Date:   2020-01-22 (Wed, 22 Jan 2020)

  Changed paths:
    M llvm/lib/IR/Value.cpp
    M llvm/test/Transforms/Attributor/ArgumentPromotion/2008-07-02-array-indexing.ll
    M llvm/test/Transforms/Attributor/IPConstantProp/pthreads.ll
    M llvm/test/Transforms/Attributor/align.ll
    M llvm/test/Transforms/Attributor/callbacks.ll
    M llvm/test/Transforms/Attributor/nocapture-1.ll
    M llvm/test/Transforms/Attributor/nonnull.ll
    M llvm/test/Transforms/Attributor/value-simplify.ll

  Log Message:
  -----------
  [IR] Value::getPointerAlignment(): handle pointer constants

Summary:
New `@test13` in `Attributor/align.ll` is the main motivation - `null` pointer
really does not limit our alignment knowledge, in fact it is fully aligned
since it has no bits set.

Here we don't special-case `null` pointer because it is somewhat controversial
to add one more place where we enforce that `null` pointer is zero,
but instead we do the more general thing of trying to perform constant-fold
of pointer constant to an integer, and perform alignment inferrment on that.

Reviewers: jdoerfert, gchatelet, courbet, sstefan1

Reviewed By: jdoerfert

Subscribers: hiraditya, arphaman, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73131