[llvm] AMDGPU: Scratch instructions are trivially disjoint from SMEM and buffer instructions (PR #65287)

[Matt Arsenault via llvm-commits]

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@@ -3425,19 +3425,30 @@ bool SIInstrInfo::areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
     if (isMUBUF(MIb) || isMTBUF(MIb))
       return checkInstOffsetsDoNotOverlap(MIa, MIb);
 
-    return !isFLAT(MIb) && !isSMRD(MIb);
+    if (isFLAT(MIb))
+      return isFLATScratch(MIb);
+
+    return !isSMRD(MIb);
   }
 
   if (isSMRD(MIa)) {
     if (isSMRD(MIb))
       return checkInstOffsetsDoNotOverlap(MIa, MIb);
 
-    return !isFLAT(MIb) && !isMUBUF(MIb) && !isMTBUF(MIb);
+    if (isFLAT(MIb))
+      return isFLATScratch(MIb);
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arsenm wrote:

This looks backwards? 

https://github.com/llvm/llvm-project/pull/65287