[all-commits] [llvm/llvm-project] ea9228: [SystemZ] Implement ISD::BITCAST for fp128 -> i128.

[Jonas Paulsson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: ea92283449f9b132531ef152625e3e799395e449
      https://github.com/llvm/llvm-project/commit/ea92283449f9b132531ef152625e3e799395e449
  Author: Jonas Paulsson <paulsson at linux.vnet.ibm.com>
  Date:   2021-09-24 (Fri, 24 Sep 2021)

  Changed paths:
    M llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
    A llvm/test/CodeGen/SystemZ/fp-conv-19.ll

  Log Message:
  -----------
  [SystemZ] Implement ISD::BITCAST for fp128 -> i128.

The type legalizer has by default no method of doing this bitcast other than
storing and reloading the value from stack.

This patch implements a custom lowering of this operation using extractions
of subregs (z13 and earlier using FP128 register pairs), or of vector
elements (with 'vector enhancements 1' using VR128 FP registers).

Review: Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D110346