[Hexagon] Handle subregisters in areMemAccessesTriviallyDisjoint

llvm-svn: 308502

1 files changed, 32 insertions, 15 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
index f8d7db0af5a..370af950942 100644
--- a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
@@ -1677,9 +1677,6 @@ DFAPacketizer *HexagonInstrInfo::CreateTargetScheduleState(
 // Currently AA considers the addresses in these instructions to be aliasing.
 bool HexagonInstrInfo::areMemAccessesTriviallyDisjoint(
     MachineInstr &MIa, MachineInstr &MIb, AliasAnalysis *AA) const {
-  int OffsetA = 0, OffsetB = 0;
-  unsigned SizeA = 0, SizeB = 0;
-
   if (MIa.hasUnmodeledSideEffects() || MIb.hasUnmodeledSideEffects() ||
       MIa.hasOrderedMemoryRef() || MIb.hasOrderedMemoryRef())
     return false;
@@ -1689,27 +1686,47 @@ bool HexagonInstrInfo::areMemAccessesTriviallyDisjoint(
   if (MIa.mayLoad() && !isMemOp(MIa) && MIb.mayLoad() && !isMemOp(MIb))
     return true;
 
-  // Get base, offset, and access size in MIa.
-  unsigned BaseRegA = getBaseAndOffset(MIa, OffsetA, SizeA);
-  if (!BaseRegA || !SizeA)
+  // Get the base register in MIa.
+  unsigned BasePosA, OffsetPosA;
+  if (!getBaseAndOffsetPosition(MIa, BasePosA, OffsetPosA))
     return false;
+  const MachineOperand &BaseA = MIa.getOperand(BasePosA);
+  unsigned BaseRegA = BaseA.getReg();
+  unsigned BaseSubA = BaseA.getSubReg();
 
-  // Get base, offset, and access size in MIb.
-  unsigned BaseRegB = getBaseAndOffset(MIb, OffsetB, SizeB);
-  if (!BaseRegB || !SizeB)
+  // Get the base register in MIb.
+  unsigned BasePosB, OffsetPosB;
+  if (!getBaseAndOffsetPosition(MIb, BasePosB, OffsetPosB))
     return false;
+  const MachineOperand &BaseB = MIb.getOperand(BasePosB);
+  unsigned BaseRegB = BaseB.getReg();
+  unsigned BaseSubB = BaseB.getSubReg();
 
-  if (BaseRegA != BaseRegB)
+  if (BaseRegA != BaseRegB || BaseSubA != BaseSubB)
     return false;
 
+  // Get the access sizes.
+  unsigned SizeA = (1u << (getMemAccessSize(MIa) - 1));
+  unsigned SizeB = (1u << (getMemAccessSize(MIb) - 1));
+
+  // Get the offsets. Handle immediates only for now.
+  const MachineOperand &OffA = MIa.getOperand(OffsetPosA);
+  const MachineOperand &OffB = MIb.getOperand(OffsetPosB);
+  if (!MIa.getOperand(OffsetPosA).isImm() ||
+      !MIb.getOperand(OffsetPosB).isImm())
+    return false;
+  int OffsetA = OffA.getImm();
+  int OffsetB = OffB.getImm();
+
   // This is a mem access with the same base register and known offsets from it.
   // Reason about it.
   if (OffsetA > OffsetB) {
-    uint64_t offDiff = (uint64_t)((int64_t)OffsetA - (int64_t)OffsetB);
-    return (SizeB <= offDiff);
-  } else if (OffsetA < OffsetB) {
-    uint64_t offDiff = (uint64_t)((int64_t)OffsetB - (int64_t)OffsetA);
-    return (SizeA <= offDiff);
+    uint64_t OffDiff = (uint64_t)((int64_t)OffsetA - (int64_t)OffsetB);
+    return SizeB <= OffDiff;
+  }
+  if (OffsetA < OffsetB) {
+    uint64_t OffDiff = (uint64_t)((int64_t)OffsetB - (int64_t)OffsetA);
+    return SizeA <= OffDiff;
   }
 
   return false;