[all-commits] [llvm/llvm-project] d384ad: [TargetLowering][DAGCombine][MSP430] Shift Amount ...

[John Lluch Zorrilla via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: d384ad6b636d4a8c55ef53d5316d008a05161b1f
      https://github.com/llvm/llvm-project/commit/d384ad6b636d4a8c55ef53d5316d008a05161b1f
  Author: joanlluch <joan.lluch at icloud.com>
  Date:   2019-11-13 (Wed, 13 Nov 2019)

  Changed paths:
    M llvm/include/llvm/CodeGen/TargetLowering.h
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
    M llvm/lib/Target/MSP430/MSP430ISelLowering.cpp
    M llvm/lib/Target/MSP430/MSP430ISelLowering.h
    M llvm/test/CodeGen/MSP430/shift-amount-threshold.ll

  Log Message:
  -----------
  [TargetLowering][DAGCombine][MSP430] Shift Amount Threshold in DAGCombine (4)

Summary:
Replaces
```
unsigned getShiftAmountThreshold(EVT VT)
```
by

```
bool shouldAvoidTransformToShift(EVT VT, unsigned amount)
```
thus giving more flexibility for targets to decide whether particular shift amounts must be considered expensive or not.

Updates the MSP430 target with a custom implementation.

This continues  D69116, D69120, D69326 and updates them, so all of them must be committed before this.

Existing tests apply, a few more have been added.

Reviewers: asl, spatel

Reviewed By: spatel

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70042