[CodeGen][NFC] Make `TII::getMemOpBaseImmOfs` return a base operand

Currently, instructions doing memory accesses through a base operand that is
not a register can not be analyzed using `TII::getMemOpBaseRegImmOfs`.

This means that functions such as `TII::shouldClusterMemOps` will bail
out on instructions using an FI as a base instead of a register.

The goal of this patch is to refactor all this to return a base
operand instead of a base register.

Then in a separate patch, I will add FI support to the mem op clustering
in the MachineScheduler.

Differential Revision: https://reviews.llvm.org/D54846

llvm-svn: 347746

1 files changed, 18 insertions, 16 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
index a3c160d01f8..ff3865b831a 100644
--- a/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp
@@ -2894,14 +2894,15 @@ bool HexagonInstrInfo::addLatencyToSchedule(const MachineInstr &MI1,
 }
 
 /// Get the base register and byte offset of a load/store instr.
-bool HexagonInstrInfo::getMemOpBaseRegImmOfs(MachineInstr &LdSt,
-      unsigned &BaseReg, int64_t &Offset, const TargetRegisterInfo *TRI)
-      const {
+bool HexagonInstrInfo::getMemOperandWithOffset(
+    MachineInstr &LdSt, MachineOperand *&BaseOp, int64_t &Offset,
+    const TargetRegisterInfo *TRI) const {
   unsigned AccessSize = 0;
-  int OffsetVal = 0;
-  BaseReg = getBaseAndOffset(LdSt, OffsetVal, AccessSize);
-  Offset = OffsetVal;
-  return BaseReg != 0;
+  BaseOp = getBaseAndOffset(LdSt, Offset, AccessSize);
+  assert(!BaseOp || BaseOp->isReg() &&
+                        "getMemOperandWithOffset only supports base "
+                        "operands of type register.");
+  return BaseOp != nullptr;
 }
 
 /// Can these instructions execute at the same time in a bundle.
@@ -3108,21 +3109,22 @@ unsigned HexagonInstrInfo::getAddrMode(const MachineInstr &MI) const {
 
 // Returns the base register in a memory access (load/store). The offset is
 // returned in Offset and the access size is returned in AccessSize.
-// If the base register has a subregister or the offset field does not contain
-// an immediate value, return 0.
-unsigned HexagonInstrInfo::getBaseAndOffset(const MachineInstr &MI,
-      int &Offset, unsigned &AccessSize) const {
+// If the base operand has a subregister or the offset field does not contain
+// an immediate value, return nullptr.
+MachineOperand *HexagonInstrInfo::getBaseAndOffset(const MachineInstr &MI,
+                                                   int64_t &Offset,
+                                                   unsigned &AccessSize) const {
   // Return if it is not a base+offset type instruction or a MemOp.
   if (getAddrMode(MI) != HexagonII::BaseImmOffset &&
       getAddrMode(MI) != HexagonII::BaseLongOffset &&
       !isMemOp(MI) && !isPostIncrement(MI))
-    return 0;
+    return nullptr;
 
   AccessSize = getMemAccessSize(MI);
 
   unsigned BasePos = 0, OffsetPos = 0;
   if (!getBaseAndOffsetPosition(MI, BasePos, OffsetPos))
-    return 0;
+    return nullptr;
 
   // Post increment updates its EA after the mem access,
   // so we need to treat its offset as zero.
@@ -3131,14 +3133,14 @@ unsigned HexagonInstrInfo::getBaseAndOffset(const MachineInstr &MI,
   } else {
     const MachineOperand &OffsetOp = MI.getOperand(OffsetPos);
     if (!OffsetOp.isImm())
-      return 0;
+      return nullptr;
     Offset = OffsetOp.getImm();
   }
 
   const MachineOperand &BaseOp = MI.getOperand(BasePos);
   if (BaseOp.getSubReg() != 0)
-    return 0;
-  return BaseOp.getReg();
+    return nullptr;
+  return &const_cast<MachineOperand&>(BaseOp);
 }
 
 /// Return the position of the base and offset operands for this instruction.