[lanai] Expand findClosestSuitableAluInstr check to consider offset r…

…egister.

Previously findClosestSuitableAluInstr was only considering the base register when checking the current instruction for suitability. Expand check to consider the offset if the offset is a register.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267424 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Lanai/LanaiMemAluCombiner.cpp

@@ -347,9 +347,12 @@ MbbIterator LanaiMemAluCombiner::findClosestSuitableAluInstr(
       return First;
     }
 
-    // Usage of the base register of a form not suitable for merging
-    if (First != Last && InstrUsesReg(First, Base)) {
-      break;
+    // Usage of the base or offset register is not a form suitable for merging.
+    if (First != Last) {
+      if (InstrUsesReg(First, Base))
+        break;
+      if (Offset->isReg() && InstrUsesReg(First, Offset))
+        break;
     }
   }