[all-commits] [llvm/llvm-project] 33e2f6: [AMDGPU][LoopUnroll] Increase BB size to analyze f...

[Daniil Fukalov via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 33e2f69a24b4ea271a83899b1a5c1af31c6a9c06
      https://github.com/llvm/llvm-project/commit/33e2f69a24b4ea271a83899b1a5c1af31c6a9c06
  Author: dfukalov <daniil.fukalov at amd.com>
  Date:   2020-08-20 (Thu, 20 Aug 2020)

  Changed paths:
    M llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
    M llvm/test/Transforms/LoopUnroll/AMDGPU/unroll-analyze-small-loops.ll

  Log Message:
  -----------
  [AMDGPU][LoopUnroll] Increase BB size to analyze for complete unroll.

The `UnrollMaxBlockToAnalyze` parameter is used at the stage when we have no
information about a loop body BB cost. In some cases, e.g. for simple loop
```
for(int i=0; i<32; ++i){
  D = Arr2[i*8 + C1];
  Arr1[i*64 + C2] += C3 * D;
  Arr1[i*64 + C2 + 2048] += C4 * D;
}

```
current default parameter value is not enough to run deeper cost analyze so the
loop is not completely unrolled.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D86248