[RISCV] Fix more boundary cases in immediate selection for Zdinx load/store on RV32.

llvm/lib/Target/RISCV/RISCVExpandPseudoInsts.cpp

@@ -291,9 +291,6 @@ bool RISCVExpandPseudo::expandRV32ZdinxStore(MachineBasicBlock &MBB,
       .setMemRefs(MMOLo);
 
   if (MBBI->getOperand(2).isGlobal() || MBBI->getOperand(2).isCPI()) {
-    // FIXME: Zdinx RV32 can not work on unaligned scalar memory.
-    assert(!STI->enableUnalignedScalarMem());
-
     assert(MBBI->getOperand(2).getOffset() % 8 == 0);
     MBBI->getOperand(2).setOffset(MBBI->getOperand(2).getOffset() + 4);
     BuildMI(MBB, MBBI, DL, TII->get(RISCV::SW))
@@ -344,7 +341,7 @@ bool RISCVExpandPseudo::expandRV32ZdinxLoad(MachineBasicBlock &MBB,
 
   if (MBBI->getOperand(2).isGlobal() || MBBI->getOperand(2).isCPI()) {
     auto Offset = MBBI->getOperand(2).getOffset();
-    assert(MBBI->getOperand(2).getOffset() % 8 == 0);
+    assert(Offset % 8 == 0);
     MBBI->getOperand(2).setOffset(Offset + 4);
     BuildMI(MBB, MBBI, DL, TII->get(RISCV::LW), Hi)
         .addReg(MBBI->getOperand(1).getReg())

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -2522,7 +2522,8 @@ bool RISCVDAGToDAGISel::SelectFrameAddrRegImm(SDValue Addr, SDValue &Base,
 static bool selectConstantAddr(SelectionDAG *CurDAG, const SDLoc &DL,
                                const MVT VT, const RISCVSubtarget *Subtarget,
                                SDValue Addr, SDValue &Base, SDValue &Offset,
-                               bool IsPrefetch = false) {
+                               bool IsPrefetch = false,
+                               bool IsRV32Zdinx = false) {
   if (!isa<ConstantSDNode>(Addr))
     return false;
 
@@ -2536,6 +2537,8 @@ static bool selectConstantAddr(SelectionDAG *CurDAG, const SDLoc &DL,
   if (!Subtarget->is64Bit() || isInt<32>(Hi)) {
     if (IsPrefetch && (Lo12 & 0b11111) != 0)
       return false;
+    if (IsRV32Zdinx && !isInt<12>(Lo12 + 4))
+      return false;
 
     if (Hi) {
       int64_t Hi20 = (Hi >> 12) & 0xfffff;
@@ -2560,6 +2563,8 @@ static bool selectConstantAddr(SelectionDAG *CurDAG, const SDLoc &DL,
   Lo12 = Seq.back().getImm();
   if (IsPrefetch && (Lo12 & 0b11111) != 0)
     return false;
+  if (IsRV32Zdinx && !isInt<12>(Lo12 + 4))
+    return false;
 
   // Drop the last instruction.
   Seq.pop_back();
@@ -2649,20 +2654,44 @@ bool RISCVDAGToDAGISel::SelectAddrRegRegScale(SDValue Addr,
 }
 
 bool RISCVDAGToDAGISel::SelectAddrRegImm(SDValue Addr, SDValue &Base,
-                                         SDValue &Offset, bool IsINX) {
+                                         SDValue &Offset, bool IsRV32Zdinx) {
   if (SelectAddrFrameIndex(Addr, Base, Offset))
     return true;
 
   SDLoc DL(Addr);
   MVT VT = Addr.getSimpleValueType();
 
   if (Addr.getOpcode() == RISCVISD::ADD_LO) {
-    Base = Addr.getOperand(0);
-    Offset = Addr.getOperand(1);
-    return true;
+    // If this is non RV32Zdinx we can always fold.
+    if (!IsRV32Zdinx) {
+      Base = Addr.getOperand(0);
+      Offset = Addr.getOperand(1);
+      return true;
+    }
+
+    // For RV32Zdinx we need to have more than 4 byte alignment so we can add 4
+    // to the offset when we expand in RISCVExpandPseudoInsts.
+    if (auto *GA = dyn_cast<GlobalAddressSDNode>(Addr.getOperand(1))) {
+      const DataLayout &DL = CurDAG->getDataLayout();
+      Align Alignment = commonAlignment(
+          GA->getGlobal()->getPointerAlignment(DL), GA->getOffset());
+      if (Alignment > 4) {
+        Base = Addr.getOperand(0);
+        Offset = Addr.getOperand(1);
+        return true;
+      }
+    }
+    if (auto *CP = dyn_cast<ConstantPoolSDNode>(Addr.getOperand(1))) {
+      Align Alignment = commonAlignment(CP->getAlign(), CP->getOffset());
+      if (Alignment > 4) {
+        Base = Addr.getOperand(0);
+        Offset = Addr.getOperand(1);
+        return true;
+      }
+    }
   }
 
-  int64_t RV32ZdinxRange = IsINX ? 4 : 0;
+  int64_t RV32ZdinxRange = IsRV32Zdinx ? 4 : 0;
   if (CurDAG->isBaseWithConstantOffset(Addr)) {
     int64_t CVal = cast<ConstantSDNode>(Addr.getOperand(1))->getSExtValue();
     if (isInt<12>(CVal) && isInt<12>(CVal + RV32ZdinxRange)) {
@@ -2678,7 +2707,8 @@ bool RISCVDAGToDAGISel::SelectAddrRegImm(SDValue Addr, SDValue &Base,
           const DataLayout &DL = CurDAG->getDataLayout();
           Align Alignment = commonAlignment(
               GA->getGlobal()->getPointerAlignment(DL), GA->getOffset());
-          if (CVal == 0 || Alignment > CVal) {
+          if ((CVal == 0 || Alignment > CVal) &&
+              (!IsRV32Zdinx || Alignment > (CVal + 4))) {
             int64_t CombinedOffset = CVal + GA->getOffset();
             Base = Base.getOperand(0);
             Offset = CurDAG->getTargetGlobalAddress(
@@ -2705,7 +2735,7 @@ bool RISCVDAGToDAGISel::SelectAddrRegImm(SDValue Addr, SDValue &Base,
     // Handle immediates in the range [-4096,-2049] or [2048, 4094]. We can use
     // an ADDI for part of the offset and fold the rest into the load/store.
     // This mirrors the AddiPair PatFrag in RISCVInstrInfo.td.
-    if (isInt<12>(CVal / 2) && isInt<12>(CVal - CVal / 2)) {
+    if (CVal >= -4096 && CVal <= (4094 - RV32ZdinxRange)) {
       int64_t Adj = CVal < 0 ? -2048 : 2047;
       Base = SDValue(
           CurDAG->getMachineNode(
@@ -2724,7 +2754,7 @@ bool RISCVDAGToDAGISel::SelectAddrRegImm(SDValue Addr, SDValue &Base,
     // instructions.
     if (isWorthFoldingAdd(Addr) &&
         selectConstantAddr(CurDAG, DL, VT, Subtarget, Addr.getOperand(1), Base,
-                           Offset)) {
+                           Offset, /*IsPrefetch=*/false, RV32ZdinxRange)) {
       // Insert an ADD instruction with the materialized Hi52 bits.
       Base = SDValue(
           CurDAG->getMachineNode(RISCV::ADD, DL, VT, Addr.getOperand(0), Base),
@@ -2733,7 +2763,8 @@ bool RISCVDAGToDAGISel::SelectAddrRegImm(SDValue Addr, SDValue &Base,
     }
   }
 
-  if (selectConstantAddr(CurDAG, DL, VT, Subtarget, Addr, Base, Offset))
+  if (selectConstantAddr(CurDAG, DL, VT, Subtarget, Addr, Base, Offset,
+                         /*IsPrefetch=*/false, RV32ZdinxRange))
     return true;
 
   Base = Addr;
@@ -2791,7 +2822,7 @@ bool RISCVDAGToDAGISel::SelectAddrRegImmLsb00000(SDValue Addr, SDValue &Base,
     }
 
     if (selectConstantAddr(CurDAG, DL, VT, Subtarget, Addr.getOperand(1), Base,
-                           Offset, true)) {
+                           Offset, /*IsPrefetch=*/true)) {
       // Insert an ADD instruction with the materialized Hi52 bits.
       Base = SDValue(
           CurDAG->getMachineNode(RISCV::ADD, DL, VT, Addr.getOperand(0), Base),
@@ -2800,7 +2831,8 @@ bool RISCVDAGToDAGISel::SelectAddrRegImmLsb00000(SDValue Addr, SDValue &Base,
     }
   }
 
-  if (selectConstantAddr(CurDAG, DL, VT, Subtarget, Addr, Base, Offset, true))
+  if (selectConstantAddr(CurDAG, DL, VT, Subtarget, Addr, Base, Offset,
+                         /*IsPrefetch=*/true))
     return true;
 
   Base = Addr;

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h

@@ -48,8 +48,8 @@ class RISCVDAGToDAGISel : public SelectionDAGISel {
   bool SelectAddrFrameIndex(SDValue Addr, SDValue &Base, SDValue &Offset);
   bool SelectFrameAddrRegImm(SDValue Addr, SDValue &Base, SDValue &Offset);
   bool SelectAddrRegImm(SDValue Addr, SDValue &Base, SDValue &Offset,
-                        bool IsINX = false);
-  bool SelectAddrRegImmINX(SDValue Addr, SDValue &Base, SDValue &Offset) {
+                        bool IsRV32Zdinx = false);
+  bool SelectAddrRegImmRV32Zdinx(SDValue Addr, SDValue &Base, SDValue &Offset) {
     return SelectAddrRegImm(Addr, Base, Offset, true);
   }
   bool SelectAddrRegImmLsb00000(SDValue Addr, SDValue &Base, SDValue &Offset);

llvm/lib/Target/RISCV/RISCVInstrInfoD.td

@@ -25,7 +25,7 @@ def SDT_RISCVSplitF64     : SDTypeProfile<2, 1, [SDTCisVT<0, i32>,
 def RISCVBuildPairF64 : SDNode<"RISCVISD::BuildPairF64", SDT_RISCVBuildPairF64>;
 def RISCVSplitF64     : SDNode<"RISCVISD::SplitF64", SDT_RISCVSplitF64>;
 
-def AddrRegImmINX : ComplexPattern<iPTR, 2, "SelectAddrRegImmINX">;
+def AddrRegImmINX : ComplexPattern<iPTR, 2, "SelectAddrRegImmRV32Zdinx">;
 
 //===----------------------------------------------------------------------===//
 // Operand and SDNode transformation definitions.