Index: llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
+++ llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
@@ -22,6 +22,7 @@
 #include "llvm/Support/KnownBits.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
+#include "set"
 
 using namespace llvm;
 
@@ -504,6 +505,52 @@
 
     break;
   }
+  case ISD::ADD: {
+    // Optimize (add (mul x, c0), c1) to (mul (add x, c1/c0), c0),
+    // if c1/c0 is simm12, while c1 is not, and c1%c0 is zero.
+    MVT VT = Node->getSimpleValueType(0);
+    // The type must be a scalar type.
+    if (VT.isVector())
+      break;
+    // The first operand node must be a MUL and has no other use.
+    SDValue N0 = Node->getOperand(0);
+    if (!N0->hasOneUse() || N0->getOpcode() != ISD::MUL)
+      break;
+    // Check c0 and c1.
+    auto *NC0 = dyn_cast<ConstantSDNode>(N0->getOperand(1));
+    if (!NC0)
+      break;
+    auto *NC1 = dyn_cast<ConstantSDNode>(Node->getOperand(1));
+    if (!NC1)
+      break;
+    int64_t C0 = NC0->getSExtValue();
+    int64_t C1 = NC1->getSExtValue();
+    // Check if c0 and c1 match the conditions mentioned above.
+    if (APInt(64, C1).isSignedIntN(12) || (C1 % C0) != 0 ||
+        !APInt(64, C1 / C0).isSignedIntN(12))
+      break;
+    // Skip specific c0 in the Zba extension.
+    if (Subtarget->hasStdExtZba()) {
+      int64_t Arr[] = {6, 10, 18, 12, 20, 36, 24, 40, 72, 11, 19, 13, 21, 37,
+                       25, 41, 73, 27, 45, 81};
+      std::set<int64_t> C0Ex(Arr, Arr + sizeof(Arr) / sizeof(*Arr));
+      if (C0Ex.count(C0) > 0)
+        break;
+      if (((C0 % 3) == 0 && APInt(64, C0 / 3).isPowerOf2()) ||
+          ((C0 % 5) == 0 && APInt(64, C0 / 5).isPowerOf2()) ||
+          ((C0 % 9) == 0 && APInt(64, C0 / 9).isPowerOf2()))
+        break;
+    }
+    // Build new nodes (mul (add x, c1/c0), c0).
+    SDLoc DL(Node);
+    SDNode *NA =
+        CurDAG->getMachineNode(RISCV::ADDI, DL, VT, N0->getOperand(0),
+                               CurDAG->getTargetConstant(C1 / C0, DL, VT));
+    SDNode *NM = CurDAG->getMachineNode(RISCV::MUL, DL, VT, SDValue(NA, 0),
+                                        N0->getOperand(1));
+    ReplaceNode(Node, NM);
+    return;
+  }
   case ISD::AND: {
     auto *N1C = dyn_cast<ConstantSDNode>(Node->getOperand(1));
     if (!N1C)
Index: llvm/test/CodeGen/RISCV/addimm-mulimm.ll
===================================================================
--- llvm/test/CodeGen/RISCV/addimm-mulimm.ll
+++ llvm/test/CodeGen/RISCV/addimm-mulimm.ll
@@ -146,20 +146,16 @@
 define i32 @add_mul_trans_accept_a1(i32 %x) {
 ; RV32IM-LABEL: add_mul_trans_accept_a1:
 ; RV32IM:       # %bb.0:
+; RV32IM-NEXT:    addi a0, a0, 1971
 ; RV32IM-NEXT:    addi a1, zero, 29
 ; RV32IM-NEXT:    mul a0, a0, a1
-; RV32IM-NEXT:    lui a1, 14
-; RV32IM-NEXT:    addi a1, a1, -185
-; RV32IM-NEXT:    add a0, a0, a1
 ; RV32IM-NEXT:    ret
 ;
 ; RV64IM-LABEL: add_mul_trans_accept_a1:
 ; RV64IM:       # %bb.0:
+; RV64IM-NEXT:    addi a0, a0, 1971
 ; RV64IM-NEXT:    addi a1, zero, 29
 ; RV64IM-NEXT:    mul a0, a0, a1
-; RV64IM-NEXT:    lui a1, 14
-; RV64IM-NEXT:    addiw a1, a1, -185
-; RV64IM-NEXT:    add a0, a0, a1
 ; RV64IM-NEXT:    ret
   %tmp0 = add i32 %x, 1971
   %tmp1 = mul i32 %tmp0, 29
@@ -169,11 +165,9 @@
 define signext i32 @add_mul_trans_accept_a2(i32 signext %x) {
 ; RV32IM-LABEL: add_mul_trans_accept_a2:
 ; RV32IM:       # %bb.0:
+; RV32IM-NEXT:    addi a0, a0, 1971
 ; RV32IM-NEXT:    addi a1, zero, 29
 ; RV32IM-NEXT:    mul a0, a0, a1
-; RV32IM-NEXT:    lui a1, 14
-; RV32IM-NEXT:    addi a1, a1, -185
-; RV32IM-NEXT:    add a0, a0, a1
 ; RV32IM-NEXT:    ret
 ;
 ; RV64IM-LABEL: add_mul_trans_accept_a2:
@@ -206,11 +200,9 @@
 ;
 ; RV64IM-LABEL: add_mul_trans_accept_a3:
 ; RV64IM:       # %bb.0:
+; RV64IM-NEXT:    addi a0, a0, 1971
 ; RV64IM-NEXT:    addi a1, zero, 29
 ; RV64IM-NEXT:    mul a0, a0, a1
-; RV64IM-NEXT:    lui a1, 14
-; RV64IM-NEXT:    addiw a1, a1, -185
-; RV64IM-NEXT:    add a0, a0, a1
 ; RV64IM-NEXT:    ret
   %tmp0 = add i64 %x, 1971
   %tmp1 = mul i64 %tmp0, 29