diff --git a/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h b/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h
--- a/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h
+++ b/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h
@@ -111,7 +111,8 @@
 #include "RISCVGenDAGISel.inc"
 
 private:
-  void doPeepholeLoadStoreADDI();
+  bool doPeepholeLoadStoreADDI(SDNode *Node);
+  bool doPeepholeSExtW(SDNode *Node);
 };
 
 namespace RISCV {
diff --git a/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp b/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
--- a/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
@@ -108,7 +108,21 @@
 }
 
 void RISCVDAGToDAGISel::PostprocessISelDAG() {
-  doPeepholeLoadStoreADDI();
+  SelectionDAG::allnodes_iterator Position = CurDAG->allnodes_end();
+
+  bool MadeChange = false;
+  while (Position != CurDAG->allnodes_begin()) {
+    SDNode *N = &*--Position;
+    // Skip dead nodes and any non-machine opcodes.
+    if (N->use_empty() || !N->isMachineOpcode())
+      continue;
+
+    MadeChange |= doPeepholeSExtW(N);
+    MadeChange |= doPeepholeLoadStoreADDI(N);
+  }
+
+  if (MadeChange)
+    CurDAG->RemoveDeadNodes();
 }
 
 static SDNode *selectImm(SelectionDAG *CurDAG, const SDLoc &DL, int64_t Imm,
@@ -1682,113 +1696,162 @@
 // (load (addi base, off1), off2) -> (load base, off1+off2)
 // (store val, (addi base, off1), off2) -> (store val, base, off1+off2)
 // This is possible when off1+off2 fits a 12-bit immediate.
-void RISCVDAGToDAGISel::doPeepholeLoadStoreADDI() {
-  SelectionDAG::allnodes_iterator Position(CurDAG->getRoot().getNode());
-  ++Position;
+bool RISCVDAGToDAGISel::doPeepholeLoadStoreADDI(SDNode *N) {
+  int OffsetOpIdx;
+  int BaseOpIdx;
 
-  while (Position != CurDAG->allnodes_begin()) {
-    SDNode *N = &*--Position;
-    // Skip dead nodes and any non-machine opcodes.
-    if (N->use_empty() || !N->isMachineOpcode())
-      continue;
+  // Only attempt this optimisation for I-type loads and S-type stores.
+  switch (N->getMachineOpcode()) {
+  default:
+    return false;
+  case RISCV::LB:
+  case RISCV::LH:
+  case RISCV::LW:
+  case RISCV::LBU:
+  case RISCV::LHU:
+  case RISCV::LWU:
+  case RISCV::LD:
+  case RISCV::FLH:
+  case RISCV::FLW:
+  case RISCV::FLD:
+    BaseOpIdx = 0;
+    OffsetOpIdx = 1;
+    break;
+  case RISCV::SB:
+  case RISCV::SH:
+  case RISCV::SW:
+  case RISCV::SD:
+  case RISCV::FSH:
+  case RISCV::FSW:
+  case RISCV::FSD:
+    BaseOpIdx = 1;
+    OffsetOpIdx = 2;
+    break;
+  }
 
-    int OffsetOpIdx;
-    int BaseOpIdx;
+  if (!isa<ConstantSDNode>(N->getOperand(OffsetOpIdx)))
+    return false;
 
-    // Only attempt this optimisation for I-type loads and S-type stores.
-    switch (N->getMachineOpcode()) {
-    default:
-      continue;
-    case RISCV::LB:
-    case RISCV::LH:
-    case RISCV::LW:
-    case RISCV::LBU:
-    case RISCV::LHU:
-    case RISCV::LWU:
-    case RISCV::LD:
-    case RISCV::FLH:
-    case RISCV::FLW:
-    case RISCV::FLD:
-      BaseOpIdx = 0;
-      OffsetOpIdx = 1;
-      break;
-    case RISCV::SB:
-    case RISCV::SH:
-    case RISCV::SW:
-    case RISCV::SD:
-    case RISCV::FSH:
-    case RISCV::FSW:
-    case RISCV::FSD:
-      BaseOpIdx = 1;
-      OffsetOpIdx = 2;
-      break;
-    }
+  SDValue Base = N->getOperand(BaseOpIdx);
 
-    if (!isa<ConstantSDNode>(N->getOperand(OffsetOpIdx)))
-      continue;
+  // If the base is an ADDI, we can merge it in to the load/store.
+  if (!Base.isMachineOpcode() || Base.getMachineOpcode() != RISCV::ADDI)
+    return false;
 
-    SDValue Base = N->getOperand(BaseOpIdx);
+  SDValue ImmOperand = Base.getOperand(1);
+  uint64_t Offset2 = N->getConstantOperandVal(OffsetOpIdx);
 
-    // If the base is an ADDI, we can merge it in to the load/store.
-    if (!Base.isMachineOpcode() || Base.getMachineOpcode() != RISCV::ADDI)
-      continue;
+  if (auto *Const = dyn_cast<ConstantSDNode>(ImmOperand)) {
+    int64_t Offset1 = Const->getSExtValue();
+    int64_t CombinedOffset = Offset1 + Offset2;
+    if (!isInt<12>(CombinedOffset))
+      return false;
+    ImmOperand = CurDAG->getTargetConstant(CombinedOffset, SDLoc(ImmOperand),
+                                           ImmOperand.getValueType());
+  } else if (auto *GA = dyn_cast<GlobalAddressSDNode>(ImmOperand)) {
+    // If the off1 in (addi base, off1) is a global variable's address (its
+    // low part, really), then we can rely on the alignment of that variable
+    // to provide a margin of safety before off1 can overflow the 12 bits.
+    // Check if off2 falls within that margin; if so off1+off2 can't overflow.
+    const DataLayout &DL = CurDAG->getDataLayout();
+    Align Alignment = GA->getGlobal()->getPointerAlignment(DL);
+    if (Offset2 != 0 && Alignment <= Offset2)
+      return false;
+    int64_t Offset1 = GA->getOffset();
+    int64_t CombinedOffset = Offset1 + Offset2;
+    ImmOperand = CurDAG->getTargetGlobalAddress(
+        GA->getGlobal(), SDLoc(ImmOperand), ImmOperand.getValueType(),
+        CombinedOffset, GA->getTargetFlags());
+  } else if (auto *CP = dyn_cast<ConstantPoolSDNode>(ImmOperand)) {
+    // Ditto.
+    Align Alignment = CP->getAlign();
+    if (Offset2 != 0 && Alignment <= Offset2)
+      return false;
+    int64_t Offset1 = CP->getOffset();
+    int64_t CombinedOffset = Offset1 + Offset2;
+    ImmOperand = CurDAG->getTargetConstantPool(
+        CP->getConstVal(), ImmOperand.getValueType(), CP->getAlign(),
+        CombinedOffset, CP->getTargetFlags());
+  } else {
+    return false;
+  }
 
-    SDValue ImmOperand = Base.getOperand(1);
-    uint64_t Offset2 = N->getConstantOperandVal(OffsetOpIdx);
-
-    if (auto *Const = dyn_cast<ConstantSDNode>(ImmOperand)) {
-      int64_t Offset1 = Const->getSExtValue();
-      int64_t CombinedOffset = Offset1 + Offset2;
-      if (!isInt<12>(CombinedOffset))
-        continue;
-      ImmOperand = CurDAG->getTargetConstant(CombinedOffset, SDLoc(ImmOperand),
-                                             ImmOperand.getValueType());
-    } else if (auto *GA = dyn_cast<GlobalAddressSDNode>(ImmOperand)) {
-      // If the off1 in (addi base, off1) is a global variable's address (its
-      // low part, really), then we can rely on the alignment of that variable
-      // to provide a margin of safety before off1 can overflow the 12 bits.
-      // Check if off2 falls within that margin; if so off1+off2 can't overflow.
-      const DataLayout &DL = CurDAG->getDataLayout();
-      Align Alignment = GA->getGlobal()->getPointerAlignment(DL);
-      if (Offset2 != 0 && Alignment <= Offset2)
-        continue;
-      int64_t Offset1 = GA->getOffset();
-      int64_t CombinedOffset = Offset1 + Offset2;
-      ImmOperand = CurDAG->getTargetGlobalAddress(
-          GA->getGlobal(), SDLoc(ImmOperand), ImmOperand.getValueType(),
-          CombinedOffset, GA->getTargetFlags());
-    } else if (auto *CP = dyn_cast<ConstantPoolSDNode>(ImmOperand)) {
-      // Ditto.
-      Align Alignment = CP->getAlign();
-      if (Offset2 != 0 && Alignment <= Offset2)
-        continue;
-      int64_t Offset1 = CP->getOffset();
-      int64_t CombinedOffset = Offset1 + Offset2;
-      ImmOperand = CurDAG->getTargetConstantPool(
-          CP->getConstVal(), ImmOperand.getValueType(), CP->getAlign(),
-          CombinedOffset, CP->getTargetFlags());
-    } else {
-      continue;
+  LLVM_DEBUG(dbgs() << "Folding add-immediate into mem-op:\nBase:    ");
+  LLVM_DEBUG(Base->dump(CurDAG));
+  LLVM_DEBUG(dbgs() << "\nN: ");
+  LLVM_DEBUG(N->dump(CurDAG));
+  LLVM_DEBUG(dbgs() << "\n");
+
+  // Modify the offset operand of the load/store.
+  if (BaseOpIdx == 0) // Load
+    CurDAG->UpdateNodeOperands(N, Base.getOperand(0), ImmOperand,
+                               N->getOperand(2));
+  else // Store
+    CurDAG->UpdateNodeOperands(N, N->getOperand(0), Base.getOperand(0),
+                               ImmOperand, N->getOperand(3));
+
+  return true;
+}
+
+// Try to remove sext.w if the input is a W instruction or can be made into
+// a W instruction cheaply.
+bool RISCVDAGToDAGISel::doPeepholeSExtW(SDNode *N) {
+  // Look for the sext.w pattern, addiw rd, rs1, 0.
+  if (N->getMachineOpcode() != RISCV::ADDIW ||
+      !isNullConstant(N->getOperand(1)))
+    return false;
+
+  SDValue N0 = N->getOperand(0);
+  if (!N0.isMachineOpcode())
+    return false;
+
+  switch (N0.getMachineOpcode()) {
+  default:
+    break;
+  case RISCV::ADD:
+  case RISCV::ADDI:
+  case RISCV::SUB:
+  case RISCV::MUL:
+  case RISCV::SLLI: {
+    // Convert sext.w+add/sub/mul to their W instructions. This will create
+    // a new independent instruction. This improves latency.
+    unsigned Opc;
+    switch (N0.getMachineOpcode()) {
+    default:
+      llvm_unreachable("Unexpected opcode!");
+    case RISCV::ADD:  Opc = RISCV::ADDW;  break;
+    case RISCV::ADDI: Opc = RISCV::ADDIW; break;
+    case RISCV::SUB:  Opc = RISCV::SUBW;  break;
+    case RISCV::MUL:  Opc = RISCV::MULW;  break;
+    case RISCV::SLLI: Opc = RISCV::SLLIW; break;
     }
 
-    LLVM_DEBUG(dbgs() << "Folding add-immediate into mem-op:\nBase:    ");
-    LLVM_DEBUG(Base->dump(CurDAG));
-    LLVM_DEBUG(dbgs() << "\nN: ");
-    LLVM_DEBUG(N->dump(CurDAG));
-    LLVM_DEBUG(dbgs() << "\n");
-
-    // Modify the offset operand of the load/store.
-    if (BaseOpIdx == 0) // Load
-      CurDAG->UpdateNodeOperands(N, Base.getOperand(0), ImmOperand,
-                                 N->getOperand(2));
-    else // Store
-      CurDAG->UpdateNodeOperands(N, N->getOperand(0), Base.getOperand(0),
-                                 ImmOperand, N->getOperand(3));
-
-    // The add-immediate may now be dead, in which case remove it.
-    if (Base.getNode()->use_empty())
-      CurDAG->RemoveDeadNode(Base.getNode());
+    SDValue N00 = N0.getOperand(0);
+    SDValue N01 = N0.getOperand(1);
+
+    // Shift amount needs to be uimm5.
+    if (N0.getMachineOpcode() == RISCV::SLLI &&
+        !isUInt<5>(cast<ConstantSDNode>(N01)->getSExtValue()))
+      break;
+
+    SDNode *Result =
+        CurDAG->getMachineNode(Opc, SDLoc(N), N->getValueType(0),
+                               N00, N01);
+    ReplaceUses(N, Result);
+    return true;
   }
+  case RISCV::ADDW:
+  case RISCV::ADDIW:
+  case RISCV::SUBW:
+  case RISCV::MULW:
+  case RISCV::SLLIW:
+    // Result is already sign extended just remove the sext.w.
+    // NOTE: We only handle the nodes that are selected with hasAllWUsers.
+    ReplaceUses(N, N0.getNode());
+    return true;
+  }
+
+  return false;
 }
 
 // This pass converts a legalized DAG into a RISCV-specific DAG, ready
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.td b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
@@ -1275,14 +1275,6 @@
 
 /// ALU operations
 
-def : Pat<(sext_inreg (add GPR:$rs1, GPR:$rs2), i32),
-          (ADDW GPR:$rs1, GPR:$rs2)>;
-def : Pat<(sext_inreg (add GPR:$rs1, simm12:$imm12), i32),
-          (ADDIW GPR:$rs1, simm12:$imm12)>;
-def : Pat<(sext_inreg (sub GPR:$rs1, GPR:$rs2), i32),
-          (SUBW GPR:$rs1, GPR:$rs2)>;
-def : Pat<(sext_inreg (shl GPR:$rs1, uimm5:$shamt), i32),
-          (SLLIW GPR:$rs1, uimm5:$shamt)>;
 def : Pat<(i64 (srl (and GPR:$rs1, 0xffffffff), uimm5:$shamt)),
           (SRLIW GPR:$rs1, uimm5:$shamt)>;
 def : Pat<(i64 (srl (shl GPR:$rs1, (i64 32)), uimm6gt32:$shamt)),
@@ -1343,7 +1335,8 @@
                 (AddiPairImmA GPR:$rs2))>;
 
 let Predicates = [IsRV64] in {
-def : Pat<(sext_inreg (add_oneuse GPR:$rs1, (AddiPair:$rs2)), i32),
+// Select W instructions if only the lower 32-bits of the result are used.
+def : Pat<(addw GPR:$rs1, (AddiPair:$rs2)),
           (ADDIW (ADDIW GPR:$rs1, (AddiPairImmB AddiPair:$rs2)),
                  (AddiPairImmA AddiPair:$rs2))>;
 }
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoM.td b/llvm/lib/Target/RISCV/RISCVInstrInfoM.td
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoM.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoM.td
@@ -77,9 +77,6 @@
 }]>;
 
 let Predicates = [HasStdExtM, IsRV64] in {
-def : Pat<(sext_inreg (mul GPR:$rs1, GPR:$rs2), i32),
-          (MULW GPR:$rs1, GPR:$rs2)>;
-
 // Select W instructions without sext_inreg if only the lower 32-bits of the
 // result are used.
 def : Pat<(mulw GPR:$rs1, GPR:$rs2), (MULW GPR:$rs1, GPR:$rs2)>;
@@ -114,11 +111,4 @@
 // still be better off shifting both left by 32.
 def : Pat<(i64 (mul (and GPR:$rs1, 0xffffffff), (and GPR:$rs2, 0xffffffff))),
           (MULHU (SLLI GPR:$rs1, 32), (SLLI GPR:$rs2, 32))>;
-// Prevent matching the first part of this pattern to mulw. The mul here has
-// additionals users or the ANDs would have been removed. The above pattern
-// will be used for the other users. If we form a mulw we'll keep the ANDs alive
-// and they'll still become SLLI+SRLI.
-def : Pat<(sext_inreg (mul (and GPR:$rs1, 0xffffffff),
-                           (and GPR:$rs2, 0xffffffff)), i32),
-          (ADDIW (MULHU (SLLI GPR:$rs1, 32), (SLLI GPR:$rs2, 32)), 0)>;
 } // Predicates = [HasStdExtM, IsRV64, NotHasStdExtZba]
diff --git a/llvm/test/CodeGen/RISCV/add-imm.ll b/llvm/test/CodeGen/RISCV/add-imm.ll
--- a/llvm/test/CodeGen/RISCV/add-imm.ll
+++ b/llvm/test/CodeGen/RISCV/add-imm.ll
@@ -178,9 +178,8 @@
 ;
 ; RV64I-LABEL: add32_sext_reject_on_rv64:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    lui a1, 1
-; RV64I-NEXT:    addiw a1, a1, -1096
-; RV64I-NEXT:    addw a0, a0, a1
+; RV64I-NEXT:    addiw a0, a0, 1500
+; RV64I-NEXT:    addiw a0, a0, 1500
 ; RV64I-NEXT:    lui a1, %hi(gv0)
 ; RV64I-NEXT:    sw a0, %lo(gv0)(a1)
 ; RV64I-NEXT:    ret
diff --git a/llvm/test/CodeGen/RISCV/rv64zba.ll b/llvm/test/CodeGen/RISCV/rv64zba.ll
--- a/llvm/test/CodeGen/RISCV/rv64zba.ll
+++ b/llvm/test/CodeGen/RISCV/rv64zba.ll
@@ -1254,14 +1254,14 @@
 ;
 ; RV64B-LABEL: mulw192:
 ; RV64B:       # %bb.0:
-; RV64B-NEXT:    addi a1, zero, 192
-; RV64B-NEXT:    mulw a0, a0, a1
+; RV64B-NEXT:    sh1add a0, a0, a0
+; RV64B-NEXT:    slliw a0, a0, 6
 ; RV64B-NEXT:    ret
 ;
 ; RV64ZBA-LABEL: mulw192:
 ; RV64ZBA:       # %bb.0:
-; RV64ZBA-NEXT:    addi a1, zero, 192
-; RV64ZBA-NEXT:    mulw a0, a0, a1
+; RV64ZBA-NEXT:    sh1add a0, a0, a0
+; RV64ZBA-NEXT:    slliw a0, a0, 6
 ; RV64ZBA-NEXT:    ret
   %c = mul i32 %a, 192
   ret i32 %c
@@ -1276,14 +1276,14 @@
 ;
 ; RV64B-LABEL: mulw320:
 ; RV64B:       # %bb.0:
-; RV64B-NEXT:    addi a1, zero, 320
-; RV64B-NEXT:    mulw a0, a0, a1
+; RV64B-NEXT:    sh2add a0, a0, a0
+; RV64B-NEXT:    slliw a0, a0, 6
 ; RV64B-NEXT:    ret
 ;
 ; RV64ZBA-LABEL: mulw320:
 ; RV64ZBA:       # %bb.0:
-; RV64ZBA-NEXT:    addi a1, zero, 320
-; RV64ZBA-NEXT:    mulw a0, a0, a1
+; RV64ZBA-NEXT:    sh2add a0, a0, a0
+; RV64ZBA-NEXT:    slliw a0, a0, 6
 ; RV64ZBA-NEXT:    ret
   %c = mul i32 %a, 320
   ret i32 %c
@@ -1298,14 +1298,14 @@
 ;
 ; RV64B-LABEL: mulw576:
 ; RV64B:       # %bb.0:
-; RV64B-NEXT:    addi a1, zero, 576
-; RV64B-NEXT:    mulw a0, a0, a1
+; RV64B-NEXT:    sh3add a0, a0, a0
+; RV64B-NEXT:    slliw a0, a0, 6
 ; RV64B-NEXT:    ret
 ;
 ; RV64ZBA-LABEL: mulw576:
 ; RV64ZBA:       # %bb.0:
-; RV64ZBA-NEXT:    addi a1, zero, 576
-; RV64ZBA-NEXT:    mulw a0, a0, a1
+; RV64ZBA-NEXT:    sh3add a0, a0, a0
+; RV64ZBA-NEXT:    slliw a0, a0, 6
 ; RV64ZBA-NEXT:    ret
   %c = mul i32 %a, 576
   ret i32 %c
diff --git a/llvm/test/CodeGen/RISCV/xaluo.ll b/llvm/test/CodeGen/RISCV/xaluo.ll
--- a/llvm/test/CodeGen/RISCV/xaluo.ll
+++ b/llvm/test/CodeGen/RISCV/xaluo.ll
@@ -883,12 +883,12 @@
 ; RV64ZBA-LABEL: smulo2.i32:
 ; RV64ZBA:       # %bb.0: # %entry
 ; RV64ZBA-NEXT:    sext.w a0, a0
-; RV64ZBA-NEXT:    addi a2, zero, 13
-; RV64ZBA-NEXT:    mul a3, a0, a2
-; RV64ZBA-NEXT:    mulw a0, a0, a2
-; RV64ZBA-NEXT:    xor a0, a0, a3
+; RV64ZBA-NEXT:    sh1add a2, a0, a0
+; RV64ZBA-NEXT:    sh2add a2, a2, a0
+; RV64ZBA-NEXT:    sext.w a0, a2
+; RV64ZBA-NEXT:    xor a0, a0, a2
 ; RV64ZBA-NEXT:    snez a0, a0
-; RV64ZBA-NEXT:    sw a3, 0(a1)
+; RV64ZBA-NEXT:    sw a2, 0(a1)
 ; RV64ZBA-NEXT:    ret
 entry:
   %t = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %v1, i32 13)