[RISCV] Add additional opcodes to RISCVDAGToDAGISel::hasAllNBitUsers

This adds opcodes that are handled in the RISCVOptWInstrs version but
not the SDag version.

Author: asb

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -3606,11 +3606,15 @@ bool RISCVDAGToDAGISel::hasAllNBitUsers(SDNode *Node, unsigned Bits,
       if (Use.getOperandNo() == 1 && Bits >= Log2_32(Subtarget->getXLen()))
         break;
       return false;
-    case RISCV::SLLI:
+    case RISCV::SLLI: {
       // SLLI only uses the lower (XLen - ShAmt) bits.
-      if (Bits >= Subtarget->getXLen() - User->getConstantOperandVal(1))
+      uint64_t ShAmt = User->getConstantOperandVal(1);
+      if (Bits >= Subtarget->getXLen() - ShAmt)
+        break;
+      if (hasAllNBitUsers(User, Bits + ShAmt, Depth + 1))
         break;
       return false;
+    }
     case RISCV::ANDI:
       if (Bits >= (unsigned)llvm::bit_width(User->getConstantOperandVal(1)))
         break;
@@ -3621,20 +3625,39 @@ bool RISCVDAGToDAGISel::hasAllNBitUsers(SDNode *Node, unsigned Bits,
         break;
       [[fallthrough]];
     }
+    case RISCV::COPY:
+    case RISCV::PHI:
+    case RISCV::ADD:
+    case RISCV::ADDI:
     case RISCV::AND:
+    case RISCV::MUL:
     case RISCV::OR:
+    case RISCV::SUB:
     case RISCV::XOR:
     case RISCV::XORI:
     case RISCV::ANDN:
+    case RISCV::BREV8:
+    case RISCV::CLMUL:
+    case RISCV::ORC_B:
     case RISCV::ORN:
     case RISCV::XNOR:
     case RISCV::SH1ADD:
     case RISCV::SH2ADD:
     case RISCV::SH3ADD:
+    case RISCV::BSETI:
+    case RISCV::BCLRI:
+    case RISCV::BINVI:
     RecCheck:
       if (hasAllNBitUsers(User, Bits, Depth + 1))
         break;
       return false;
+    case RISCV::CZERO_EQZ:
+    case RISCV::CZERO_NEZ:
+      if (Use.getOperandNo() != 0)
+        return false;
+      if (hasAllNBitUsers(User, Bits, Depth + 1))
+        break;
+      return false;
     case RISCV::SRLI: {
       unsigned ShAmt = User->getConstantOperandVal(1);
       // If we are shifting right by less than Bits, and users don't demand any
@@ -3670,6 +3693,10 @@ bool RISCVDAGToDAGISel::hasAllNBitUsers(SDNode *Node, unsigned Bits,
       if (Use.getOperandNo() == 0 && Bits >= 32)
         break;
       return false;
+    case RISCV::BEXTI:
+      if (User->getConstantOperandVal(1) >= Bits)
+        return false;
+      break;
     case RISCV::SB:
       if (Use.getOperandNo() == 0 && Bits >= 8)
         break;