[llvm-branch-commits] [llvm] c540ce9 - [AMDGPU] pin lit test divergent-unswitch.ll to the old pass manager

[Sameer Sahasrabuddhe via llvm-branch-commits]

Author: Sameer Sahasrabuddhe
Date: 2021-01-20T22:02:09+05:30
New Revision: c540ce9900ff99566b4951186e2f070b3b36cdbe

URL: https://github.com/llvm/llvm-project/commit/c540ce9900ff99566b4951186e2f070b3b36cdbe
DIFF: https://github.com/llvm/llvm-project/commit/c540ce9900ff99566b4951186e2f070b3b36cdbe.diff

LOG: [AMDGPU] pin lit test divergent-unswitch.ll to the old pass manager

The loop-unswitch transform should not be performed on a loop whose
condition is divergent. For this to happen correctly, divergence
analysis must be available. The existing divergence analysis has not
been ported to the new pass manager yet. As a result, loop unswitching
on the new pass manager is currently unsafe on targets that care about
divergence.

This test is temporarily disabled to unblock work on the new pass
manager. The issue is now tracked in bug 48819.

Reviewed By: foad

Differential Revision: https://reviews.llvm.org/D95051

Added: 
    

Modified: 
    llvm/test/Transforms/LoopUnswitch/AMDGPU/divergent-unswitch.ll

Removed: 
    


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diff  --git a/llvm/test/Transforms/LoopUnswitch/AMDGPU/divergent-unswitch.ll b/llvm/test/Transforms/LoopUnswitch/AMDGPU/divergent-unswitch.ll
index 1f106bd894a8..873a7653973d 100644
--- a/llvm/test/Transforms/LoopUnswitch/AMDGPU/divergent-unswitch.ll
+++ b/llvm/test/Transforms/LoopUnswitch/AMDGPU/divergent-unswitch.ll
@@ -1,4 +1,7 @@
-; RUN: opt -mtriple=amdgcn-- -O3 -S %s | FileCheck %s
+; RUN: opt -mtriple=amdgcn-- -O3 -S -enable-new-pm=0 %s | FileCheck %s
+
+; This fails with the new pass manager:
+; https://bugs.llvm.org/show_bug.cgi?id=48819
 
 ; Check that loop unswitch happened and condition hoisted out of the loop.
 ; Condition is uniform so all targets should perform unswitching.