[all-commits] [llvm/llvm-project] 186155: [InstCombine] Signed saturation patterns

[David Green via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 186155b89c2d2a2f62337081e3ca15f676c9434b
      https://github.com/llvm/llvm-project/commit/186155b89c2d2a2f62337081e3ca15f676c9434b
  Author: David Green <david.green at arm.com>
  Date:   2019-10-22 (Tue, 22 Oct 2019)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineInternal.h
    M llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
    M llvm/test/Transforms/InstCombine/sadd_sat.ll

  Log Message:
  -----------
  [InstCombine] Signed saturation patterns

This adds an instcombine matcher for code that attempts to perform signed
saturating arithmetic by casting to a higher type. Unsigned cases are already
matched, this adds extra matches for the more complex signed cases, which
involves matching the min(max(add a b)) nodes with proper extends to ensure
legality.

Differential Revision: https://reviews.llvm.org/D68651

llvm-svn: 375505