[all-commits] [llvm/llvm-project] cf2b4d: [MLIR][SPIRVToLLVM] Implemented shift conversion p...

[George Mitenkov via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: cf2b4d5cb64cb0100473fca533edb51c2e6db6bf
      https://github.com/llvm/llvm-project/commit/cf2b4d5cb64cb0100473fca533edb51c2e6db6bf
  Author: George Mitenkov <georgemitenk0v at gmail.com>
  Date:   2020-06-12 (Fri, 12 Jun 2020)

  Changed paths:
    M mlir/lib/Conversion/SPIRVToLLVM/ConvertSPIRVToLLVM.cpp
    A mlir/test/Conversion/SPIRVToLLVM/shifts-to-llvm.mlir

  Log Message:
  -----------
  [MLIR][SPIRVToLLVM] Implemented shift conversion pattern

This patch has shift ops conversion implementation. In SPIR-V dialect,
`Shift` and `Base` may have different bit width. On the contrary,
in LLVM dialect both `Base` and `Shift` have to be of the same bit width.
This leads to the following cases:
- if `Base` has the same bit width as `Shift`, the conversion is
  straightforward.
- if `Base` has a greater bit width than `Shift`, shift is sign/zero
  extended first. Then the extended value is passed to the shift.
- otherwise the conversion is considered to be illegal.

Differential Revision: https://reviews.llvm.org/D81546