[all-commits] [llvm/llvm-project] 6aebf0: Specify branch probabilities for callbr dests

[Bill Wendling via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 6aebf0ee56e52afad3887b4230d7ed1beaf0bede
      https://github.com/llvm/llvm-project/commit/6aebf0ee56e52afad3887b4230d7ed1beaf0bede
  Author: Bill Wendling <isanbard at gmail.com>
  Date:   2020-03-11 (Wed, 11 Mar 2020)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
    M llvm/test/CodeGen/AArch64/callbr-asm-label.ll
    M llvm/test/CodeGen/AArch64/callbr-asm-obj-file.ll
    M llvm/test/CodeGen/X86/callbr-asm-branch-folding.ll
    M llvm/test/CodeGen/X86/callbr-asm.ll

  Log Message:
  -----------
  Specify branch probabilities for callbr dests

Summary:
callbr's indirect branches aren't expected to be taken, so reduce their
probabilities to 0 while increasing the default destination to 1. This
allows some code improvements through block placement.

Reviewers: nickdesaulniers

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72656