From: Florian Hahn <flo@fhahn.com>
Date: Thu, 23 Apr 2020 19:37:26 +0000 (+0100)
Subject: [DSE,MSSA] Skip checking write clobber for DomAccess (NFC).
X-Git-Tag: llvmorg-12-init~7925
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=44ce588670d093ba4385403d007ffbf4a195d9a7;p=platform%2Fupstream%2Fllvm.git

[DSE,MSSA] Skip checking write clobber for DomAccess (NFC).

There is no need to check if the starting access for is a write clobber
and all of its uses have already been checked.
---

diff --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
index 2939a87..68ef90b 100644
--- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -1707,11 +1707,11 @@ struct DSEState {
         return None;
       }
 
-      // For the KillingDef we only have to check if it reads the memory
-      // location.
+      // For the KillingDef and DomAccess we only have to check if it reads the
+      // memory location.
       // TODO: It would probably be better to check for self-reads before
       // calling the function.
-      if (KillingDef == UseAccess)
+      if (KillingDef == UseAccess || DomAccess == UseAccess)
         continue;
 
       // Check all uses for MemoryDefs, except for defs completely overwriting