Index: llvm/lib/Target/RISCV/RISCVISelLowering.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -3899,16 +3899,28 @@
                                                  SDValue C) const {
   // Check integral scalar types.
   if (VT.isScalarInteger()) {
-    // Do not perform the transformation on riscv32 with the M extension.
-    if (!Subtarget.is64Bit() && Subtarget.hasStdExtM())
+    // Omit the optimization if the sub target has the M extension and the data
+    // size exceeds XLen.
+    if (Subtarget.hasStdExtM() && VT.getSizeInBits() > Subtarget.getXLen())
       return false;
     if (auto *ConstNode = dyn_cast<ConstantSDNode>(C.getNode())) {
-      if (ConstNode->getAPIntValue().getBitWidth() > 8 * sizeof(int64_t))
+      // Break the MUL to a SLLI and an ADD/SUB.
+      const APInt &Imm = ConstNode->getAPIntValue();
+      if ((Imm + 1).isPowerOf2() || (Imm - 1).isPowerOf2() ||
+          (1 - Imm).isPowerOf2() || (-1 - Imm).isPowerOf2())
+        return true;
+      // Omit the following optimization if the sub target has the M extension
+      // and the data size >= XLen.
+      if (Subtarget.hasStdExtM() && VT.getSizeInBits() >= Subtarget.getXLen())
         return false;
-      int64_t Imm = ConstNode->getSExtValue();
-      if (isPowerOf2_64(Imm + 1) || isPowerOf2_64(Imm - 1) ||
-          isPowerOf2_64(1 - Imm) || isPowerOf2_64(-1 - Imm))
+      // Break the MUL to two SLLI instructions and an ADD/SUB, if Imm needs
+      // a pair of LUI/ADDI.
+      if (!Imm.isSignedIntN(12) && Imm.countTrailingZeros() < 12) {
+        APInt ImmS = Imm.ashr(Imm.countTrailingZeros());
+        if ((ImmS + 1).isPowerOf2() || (ImmS - 1).isPowerOf2() ||
+            (1 - ImmS).isPowerOf2())
         return true;
+      }
     }
   }
 
Index: llvm/test/CodeGen/RISCV/mul.ll
===================================================================
--- llvm/test/CodeGen/RISCV/mul.ll
+++ llvm/test/CodeGen/RISCV/mul.ll
@@ -85,8 +85,8 @@
 ;
 ; RV32IM-LABEL: mul_constant:
 ; RV32IM:       # %bb.0:
-; RV32IM-NEXT:    addi a1, zero, 5
-; RV32IM-NEXT:    mul a0, a0, a1
+; RV32IM-NEXT:    slli a1, a0, 2
+; RV32IM-NEXT:    add a0, a1, a0
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: mul_constant:
@@ -182,10 +182,12 @@
 ; RV32IM-LABEL: mul64_constant:
 ; RV32IM:       # %bb.0:
 ; RV32IM-NEXT:    addi a2, zero, 5
-; RV32IM-NEXT:    mul a1, a1, a2
-; RV32IM-NEXT:    mulhu a3, a0, a2
+; RV32IM-NEXT:    mulhu a2, a0, a2
+; RV32IM-NEXT:    slli a3, a1, 2
 ; RV32IM-NEXT:    add a1, a3, a1
-; RV32IM-NEXT:    mul a0, a0, a2
+; RV32IM-NEXT:    add a1, a2, a1
+; RV32IM-NEXT:    slli a2, a0, 2
+; RV32IM-NEXT:    add a0, a2, a0
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: mul64_constant:
@@ -300,8 +302,8 @@
 ;
 ; RV32IM-LABEL: muli32_p65:
 ; RV32IM:       # %bb.0:
-; RV32IM-NEXT:    addi a1, zero, 65
-; RV32IM-NEXT:    mul a0, a0, a1
+; RV32IM-NEXT:    slli a1, a0, 6
+; RV32IM-NEXT:    add a0, a1, a0
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: muli32_p65:
@@ -328,8 +330,8 @@
 ;
 ; RV32IM-LABEL: muli32_p63:
 ; RV32IM:       # %bb.0:
-; RV32IM-NEXT:    addi a1, zero, 63
-; RV32IM-NEXT:    mul a0, a0, a1
+; RV32IM-NEXT:    slli a1, a0, 6
+; RV32IM-NEXT:    sub a0, a1, a0
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: muli32_p63:
@@ -364,10 +366,12 @@
 ; RV32IM-LABEL: muli64_p65:
 ; RV32IM:       # %bb.0:
 ; RV32IM-NEXT:    addi a2, zero, 65
-; RV32IM-NEXT:    mul a1, a1, a2
-; RV32IM-NEXT:    mulhu a3, a0, a2
+; RV32IM-NEXT:    mulhu a2, a0, a2
+; RV32IM-NEXT:    slli a3, a1, 6
 ; RV32IM-NEXT:    add a1, a3, a1
-; RV32IM-NEXT:    mul a0, a0, a2
+; RV32IM-NEXT:    add a1, a2, a1
+; RV32IM-NEXT:    slli a2, a0, 6
+; RV32IM-NEXT:    add a0, a2, a0
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: muli64_p65:
@@ -401,10 +405,12 @@
 ; RV32IM-LABEL: muli64_p63:
 ; RV32IM:       # %bb.0:
 ; RV32IM-NEXT:    addi a2, zero, 63
-; RV32IM-NEXT:    mul a1, a1, a2
-; RV32IM-NEXT:    mulhu a3, a0, a2
-; RV32IM-NEXT:    add a1, a3, a1
-; RV32IM-NEXT:    mul a0, a0, a2
+; RV32IM-NEXT:    mulhu a2, a0, a2
+; RV32IM-NEXT:    slli a3, a1, 6
+; RV32IM-NEXT:    sub a1, a3, a1
+; RV32IM-NEXT:    add a1, a2, a1
+; RV32IM-NEXT:    slli a2, a0, 6
+; RV32IM-NEXT:    sub a0, a2, a0
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: muli64_p63:
@@ -431,8 +437,8 @@
 ;
 ; RV32IM-LABEL: muli32_m63:
 ; RV32IM:       # %bb.0:
-; RV32IM-NEXT:    addi a1, zero, -63
-; RV32IM-NEXT:    mul a0, a0, a1
+; RV32IM-NEXT:    slli a1, a0, 6
+; RV32IM-NEXT:    sub a0, a0, a1
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: muli32_m63:
@@ -460,8 +466,9 @@
 ;
 ; RV32IM-LABEL: muli32_m65:
 ; RV32IM:       # %bb.0:
-; RV32IM-NEXT:    addi a1, zero, -65
-; RV32IM-NEXT:    mul a0, a0, a1
+; RV32IM-NEXT:    slli a1, a0, 6
+; RV32IM-NEXT:    add a0, a1, a0
+; RV32IM-NEXT:    neg a0, a0
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: muli32_m65:
@@ -496,12 +503,14 @@
 ;
 ; RV32IM-LABEL: muli64_m63:
 ; RV32IM:       # %bb.0:
+; RV32IM-NEXT:    slli a2, a1, 6
+; RV32IM-NEXT:    sub a1, a1, a2
 ; RV32IM-NEXT:    addi a2, zero, -63
-; RV32IM-NEXT:    mul a1, a1, a2
-; RV32IM-NEXT:    mulhu a3, a0, a2
-; RV32IM-NEXT:    sub a3, a3, a0
-; RV32IM-NEXT:    add a1, a3, a1
-; RV32IM-NEXT:    mul a0, a0, a2
+; RV32IM-NEXT:    mulhu a2, a0, a2
+; RV32IM-NEXT:    sub a2, a2, a0
+; RV32IM-NEXT:    add a1, a2, a1
+; RV32IM-NEXT:    slli a2, a0, 6
+; RV32IM-NEXT:    sub a0, a0, a2
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: muli64_m63:
@@ -538,12 +547,15 @@
 ;
 ; RV32IM-LABEL: muli64_m65:
 ; RV32IM:       # %bb.0:
+; RV32IM-NEXT:    slli a2, a1, 6
+; RV32IM-NEXT:    add a1, a2, a1
 ; RV32IM-NEXT:    addi a2, zero, -65
-; RV32IM-NEXT:    mul a1, a1, a2
-; RV32IM-NEXT:    mulhu a3, a0, a2
-; RV32IM-NEXT:    sub a3, a3, a0
-; RV32IM-NEXT:    add a1, a3, a1
-; RV32IM-NEXT:    mul a0, a0, a2
+; RV32IM-NEXT:    mulhu a2, a0, a2
+; RV32IM-NEXT:    sub a2, a2, a0
+; RV32IM-NEXT:    sub a1, a2, a1
+; RV32IM-NEXT:    slli a2, a0, 6
+; RV32IM-NEXT:    add a0, a2, a0
+; RV32IM-NEXT:    neg a0, a0
 ; RV32IM-NEXT:    ret
 ;
 ; RV64I-LABEL: muli64_m65:
@@ -638,13 +650,9 @@
 define i32 @muli32_p4352(i32 %a) nounwind {
 ; RV32I-LABEL: muli32_p4352:
 ; RV32I:       # %bb.0:
-; RV32I-NEXT:    addi sp, sp, -16
-; RV32I-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    lui a1, 1
-; RV32I-NEXT:    addi a1, a1, 256
-; RV32I-NEXT:    call __mulsi3@plt
-; RV32I-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    addi sp, sp, 16
+; RV32I-NEXT:    slli a1, a0, 8
+; RV32I-NEXT:    slli a0, a0, 12
+; RV32I-NEXT:    add a0, a0, a1
 ; RV32I-NEXT:    ret
 ;
 ; RV32IM-LABEL: muli32_p4352:
@@ -656,20 +664,16 @@
 ;
 ; RV64I-LABEL: muli32_p4352:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    addi sp, sp, -16
-; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    lui a1, 1
-; RV64I-NEXT:    addiw a1, a1, 256
-; RV64I-NEXT:    call __muldi3@plt
-; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
-; RV64I-NEXT:    addi sp, sp, 16
+; RV64I-NEXT:    slli a1, a0, 8
+; RV64I-NEXT:    slli a0, a0, 12
+; RV64I-NEXT:    addw a0, a0, a1
 ; RV64I-NEXT:    ret
 ;
 ; RV64IM-LABEL: muli32_p4352:
 ; RV64IM:       # %bb.0:
-; RV64IM-NEXT:    lui a1, 1
-; RV64IM-NEXT:    addiw a1, a1, 256
-; RV64IM-NEXT:    mul a0, a0, a1
+; RV64IM-NEXT:    slli a1, a0, 8
+; RV64IM-NEXT:    slli a0, a0, 12
+; RV64IM-NEXT:    addw a0, a0, a1
 ; RV64IM-NEXT:    ret
   %1 = mul i32 %a, 4352
   ret i32 %1
@@ -678,13 +682,9 @@
 define i32 @muli32_p3840(i32 %a) nounwind {
 ; RV32I-LABEL: muli32_p3840:
 ; RV32I:       # %bb.0:
-; RV32I-NEXT:    addi sp, sp, -16
-; RV32I-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    lui a1, 1
-; RV32I-NEXT:    addi a1, a1, -256
-; RV32I-NEXT:    call __mulsi3@plt
-; RV32I-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    addi sp, sp, 16
+; RV32I-NEXT:    slli a1, a0, 8
+; RV32I-NEXT:    slli a0, a0, 12
+; RV32I-NEXT:    sub a0, a0, a1
 ; RV32I-NEXT:    ret
 ;
 ; RV32IM-LABEL: muli32_p3840:
@@ -696,20 +696,16 @@
 ;
 ; RV64I-LABEL: muli32_p3840:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    addi sp, sp, -16
-; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    lui a1, 1
-; RV64I-NEXT:    addiw a1, a1, -256
-; RV64I-NEXT:    call __muldi3@plt
-; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
-; RV64I-NEXT:    addi sp, sp, 16
+; RV64I-NEXT:    slli a1, a0, 8
+; RV64I-NEXT:    slli a0, a0, 12
+; RV64I-NEXT:    subw a0, a0, a1
 ; RV64I-NEXT:    ret
 ;
 ; RV64IM-LABEL: muli32_p3840:
 ; RV64IM:       # %bb.0:
-; RV64IM-NEXT:    lui a1, 1
-; RV64IM-NEXT:    addiw a1, a1, -256
-; RV64IM-NEXT:    mul a0, a0, a1
+; RV64IM-NEXT:    slli a1, a0, 8
+; RV64IM-NEXT:    slli a0, a0, 12
+; RV64IM-NEXT:    subw a0, a0, a1
 ; RV64IM-NEXT:    ret
   %1 = mul i32 %a, 3840
   ret i32 %1
@@ -718,13 +714,9 @@
 define i32 @muli32_m3840(i32 %a) nounwind {
 ; RV32I-LABEL: muli32_m3840:
 ; RV32I:       # %bb.0:
-; RV32I-NEXT:    addi sp, sp, -16
-; RV32I-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    lui a1, 1048575
-; RV32I-NEXT:    addi a1, a1, 256
-; RV32I-NEXT:    call __mulsi3@plt
-; RV32I-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    addi sp, sp, 16
+; RV32I-NEXT:    slli a1, a0, 12
+; RV32I-NEXT:    slli a0, a0, 8
+; RV32I-NEXT:    sub a0, a0, a1
 ; RV32I-NEXT:    ret
 ;
 ; RV32IM-LABEL: muli32_m3840:
@@ -736,20 +728,16 @@
 ;
 ; RV64I-LABEL: muli32_m3840:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    addi sp, sp, -16
-; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    lui a1, 1048575
-; RV64I-NEXT:    addiw a1, a1, 256
-; RV64I-NEXT:    call __muldi3@plt
-; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
-; RV64I-NEXT:    addi sp, sp, 16
+; RV64I-NEXT:    slli a1, a0, 12
+; RV64I-NEXT:    slli a0, a0, 8
+; RV64I-NEXT:    subw a0, a0, a1
 ; RV64I-NEXT:    ret
 ;
 ; RV64IM-LABEL: muli32_m3840:
 ; RV64IM:       # %bb.0:
-; RV64IM-NEXT:    lui a1, 1048575
-; RV64IM-NEXT:    addiw a1, a1, 256
-; RV64IM-NEXT:    mul a0, a0, a1
+; RV64IM-NEXT:    slli a1, a0, 12
+; RV64IM-NEXT:    slli a0, a0, 8
+; RV64IM-NEXT:    subw a0, a0, a1
 ; RV64IM-NEXT:    ret
   %1 = mul i32 %a, -3840
   ret i32 %1
@@ -798,14 +786,18 @@
 define i64 @muli64_p4352(i64 %a) nounwind {
 ; RV32I-LABEL: muli64_p4352:
 ; RV32I:       # %bb.0:
-; RV32I-NEXT:    addi sp, sp, -16
-; RV32I-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    lui a2, 1
-; RV32I-NEXT:    addi a2, a2, 256
-; RV32I-NEXT:    mv a3, zero
-; RV32I-NEXT:    call __muldi3@plt
-; RV32I-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    addi sp, sp, 16
+; RV32I-NEXT:    srli a2, a0, 24
+; RV32I-NEXT:    slli a3, a1, 8
+; RV32I-NEXT:    or a2, a3, a2
+; RV32I-NEXT:    srli a3, a0, 20
+; RV32I-NEXT:    slli a1, a1, 12
+; RV32I-NEXT:    or a1, a1, a3
+; RV32I-NEXT:    add a1, a1, a2
+; RV32I-NEXT:    slli a2, a0, 8
+; RV32I-NEXT:    slli a3, a0, 12
+; RV32I-NEXT:    add a0, a3, a2
+; RV32I-NEXT:    sltu a2, a0, a3
+; RV32I-NEXT:    add a1, a1, a2
 ; RV32I-NEXT:    ret
 ;
 ; RV32IM-LABEL: muli64_p4352:
@@ -820,13 +812,9 @@
 ;
 ; RV64I-LABEL: muli64_p4352:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    addi sp, sp, -16
-; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    lui a1, 1
-; RV64I-NEXT:    addiw a1, a1, 256
-; RV64I-NEXT:    call __muldi3@plt
-; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
-; RV64I-NEXT:    addi sp, sp, 16
+; RV64I-NEXT:    slli a1, a0, 8
+; RV64I-NEXT:    slli a0, a0, 12
+; RV64I-NEXT:    add a0, a0, a1
 ; RV64I-NEXT:    ret
 ;
 ; RV64IM-LABEL: muli64_p4352:
@@ -842,14 +830,18 @@
 define i64 @muli64_p3840(i64 %a) nounwind {
 ; RV32I-LABEL: muli64_p3840:
 ; RV32I:       # %bb.0:
-; RV32I-NEXT:    addi sp, sp, -16
-; RV32I-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    lui a2, 1
-; RV32I-NEXT:    addi a2, a2, -256
-; RV32I-NEXT:    mv a3, zero
-; RV32I-NEXT:    call __muldi3@plt
-; RV32I-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    addi sp, sp, 16
+; RV32I-NEXT:    srli a2, a0, 24
+; RV32I-NEXT:    slli a3, a1, 8
+; RV32I-NEXT:    or a2, a3, a2
+; RV32I-NEXT:    srli a3, a0, 20
+; RV32I-NEXT:    slli a1, a1, 12
+; RV32I-NEXT:    or a1, a1, a3
+; RV32I-NEXT:    sub a1, a1, a2
+; RV32I-NEXT:    slli a2, a0, 8
+; RV32I-NEXT:    slli a0, a0, 12
+; RV32I-NEXT:    sltu a3, a0, a2
+; RV32I-NEXT:    sub a1, a1, a3
+; RV32I-NEXT:    sub a0, a0, a2
 ; RV32I-NEXT:    ret
 ;
 ; RV32IM-LABEL: muli64_p3840:
@@ -864,13 +856,9 @@
 ;
 ; RV64I-LABEL: muli64_p3840:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    addi sp, sp, -16
-; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    lui a1, 1
-; RV64I-NEXT:    addiw a1, a1, -256
-; RV64I-NEXT:    call __muldi3@plt
-; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
-; RV64I-NEXT:    addi sp, sp, 16
+; RV64I-NEXT:    slli a1, a0, 8
+; RV64I-NEXT:    slli a0, a0, 12
+; RV64I-NEXT:    sub a0, a0, a1
 ; RV64I-NEXT:    ret
 ;
 ; RV64IM-LABEL: muli64_p3840:
@@ -931,14 +919,18 @@
 define i64 @muli64_m3840(i64 %a) nounwind {
 ; RV32I-LABEL: muli64_m3840:
 ; RV32I:       # %bb.0:
-; RV32I-NEXT:    addi sp, sp, -16
-; RV32I-NEXT:    sw ra, 12(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    lui a2, 1048575
-; RV32I-NEXT:    addi a2, a2, 256
-; RV32I-NEXT:    addi a3, zero, -1
-; RV32I-NEXT:    call __muldi3@plt
-; RV32I-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    addi sp, sp, 16
+; RV32I-NEXT:    srli a2, a0, 20
+; RV32I-NEXT:    slli a3, a1, 12
+; RV32I-NEXT:    or a2, a3, a2
+; RV32I-NEXT:    srli a3, a0, 24
+; RV32I-NEXT:    slli a1, a1, 8
+; RV32I-NEXT:    or a1, a1, a3
+; RV32I-NEXT:    sub a1, a1, a2
+; RV32I-NEXT:    slli a2, a0, 12
+; RV32I-NEXT:    slli a0, a0, 8
+; RV32I-NEXT:    sltu a3, a0, a2
+; RV32I-NEXT:    sub a1, a1, a3
+; RV32I-NEXT:    sub a0, a0, a2
 ; RV32I-NEXT:    ret
 ;
 ; RV32IM-LABEL: muli64_m3840:
@@ -954,13 +946,9 @@
 ;
 ; RV64I-LABEL: muli64_m3840:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    addi sp, sp, -16
-; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    lui a1, 1048575
-; RV64I-NEXT:    addiw a1, a1, 256
-; RV64I-NEXT:    call __muldi3@plt
-; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
-; RV64I-NEXT:    addi sp, sp, 16
+; RV64I-NEXT:    slli a1, a0, 12
+; RV64I-NEXT:    slli a0, a0, 8
+; RV64I-NEXT:    sub a0, a0, a1
 ; RV64I-NEXT:    ret
 ;
 ; RV64IM-LABEL: muli64_m3840:
@@ -976,40 +964,50 @@
 define i128 @muli128_m3840(i128 %a) nounwind {
 ; RV32I-LABEL: muli128_m3840:
 ; RV32I:       # %bb.0:
-; RV32I-NEXT:    addi sp, sp, -64
-; RV32I-NEXT:    sw ra, 60(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    sw s0, 56(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    lw a3, 0(a1)
 ; RV32I-NEXT:    lw a2, 4(a1)
-; RV32I-NEXT:    lw a4, 8(a1)
+; RV32I-NEXT:    lw a3, 8(a1)
+; RV32I-NEXT:    lw a4, 0(a1)
 ; RV32I-NEXT:    lw a1, 12(a1)
-; RV32I-NEXT:    mv s0, a0
-; RV32I-NEXT:    addi a0, zero, -1
-; RV32I-NEXT:    sw a0, 20(sp)
-; RV32I-NEXT:    sw a0, 16(sp)
-; RV32I-NEXT:    sw a0, 12(sp)
-; RV32I-NEXT:    lui a0, 1048575
-; RV32I-NEXT:    addi a0, a0, 256
-; RV32I-NEXT:    sw a0, 8(sp)
-; RV32I-NEXT:    sw a1, 36(sp)
-; RV32I-NEXT:    sw a4, 32(sp)
-; RV32I-NEXT:    sw a2, 28(sp)
-; RV32I-NEXT:    addi a0, sp, 40
-; RV32I-NEXT:    addi a1, sp, 24
-; RV32I-NEXT:    addi a2, sp, 8
-; RV32I-NEXT:    sw a3, 24(sp)
-; RV32I-NEXT:    call __multi3@plt
-; RV32I-NEXT:    lw a0, 52(sp)
-; RV32I-NEXT:    lw a1, 48(sp)
-; RV32I-NEXT:    lw a2, 44(sp)
-; RV32I-NEXT:    lw a3, 40(sp)
-; RV32I-NEXT:    sw a0, 12(s0)
-; RV32I-NEXT:    sw a1, 8(s0)
-; RV32I-NEXT:    sw a2, 4(s0)
-; RV32I-NEXT:    sw a3, 0(s0)
-; RV32I-NEXT:    lw s0, 56(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    lw ra, 60(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    addi sp, sp, 64
+; RV32I-NEXT:    srli a6, a2, 20
+; RV32I-NEXT:    slli a5, a3, 12
+; RV32I-NEXT:    or a6, a5, a6
+; RV32I-NEXT:    srli a7, a2, 24
+; RV32I-NEXT:    slli a5, a3, 8
+; RV32I-NEXT:    or a7, a5, a7
+; RV32I-NEXT:    sltu t0, a7, a6
+; RV32I-NEXT:    srli t1, a3, 20
+; RV32I-NEXT:    slli a5, a1, 12
+; RV32I-NEXT:    or a5, a5, t1
+; RV32I-NEXT:    srli a3, a3, 24
+; RV32I-NEXT:    slli a1, a1, 8
+; RV32I-NEXT:    or a1, a1, a3
+; RV32I-NEXT:    sub t2, a1, a5
+; RV32I-NEXT:    srli a1, a4, 20
+; RV32I-NEXT:    slli a3, a2, 12
+; RV32I-NEXT:    or a3, a3, a1
+; RV32I-NEXT:    srli a1, a4, 24
+; RV32I-NEXT:    slli a2, a2, 8
+; RV32I-NEXT:    or a5, a2, a1
+; RV32I-NEXT:    slli t1, a4, 12
+; RV32I-NEXT:    slli t3, a4, 8
+; RV32I-NEXT:    sltu t4, t3, t1
+; RV32I-NEXT:    sub t0, t2, t0
+; RV32I-NEXT:    mv a2, t4
+; RV32I-NEXT:    beq a5, a3, .LBB26_2
+; RV32I-NEXT:  # %bb.1:
+; RV32I-NEXT:    sltu a2, a5, a3
+; RV32I-NEXT:  .LBB26_2:
+; RV32I-NEXT:    sub a1, a7, a6
+; RV32I-NEXT:    sltu a4, a1, a2
+; RV32I-NEXT:    sub a4, t0, a4
+; RV32I-NEXT:    sub a1, a1, a2
+; RV32I-NEXT:    sub a2, a5, a3
+; RV32I-NEXT:    sub a2, a2, t4
+; RV32I-NEXT:    sub a3, t3, t1
+; RV32I-NEXT:    sw a3, 0(a0)
+; RV32I-NEXT:    sw a2, 4(a0)
+; RV32I-NEXT:    sw a1, 8(a0)
+; RV32I-NEXT:    sw a4, 12(a0)
 ; RV32I-NEXT:    ret
 ;
 ; RV32IM-LABEL: muli128_m3840:
@@ -1052,14 +1050,18 @@
 ;
 ; RV64I-LABEL: muli128_m3840:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    addi sp, sp, -16
-; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    lui a2, 1048575
-; RV64I-NEXT:    addiw a2, a2, 256
-; RV64I-NEXT:    addi a3, zero, -1
-; RV64I-NEXT:    call __multi3@plt
-; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
-; RV64I-NEXT:    addi sp, sp, 16
+; RV64I-NEXT:    srli a2, a0, 52
+; RV64I-NEXT:    slli a3, a1, 12
+; RV64I-NEXT:    or a2, a3, a2
+; RV64I-NEXT:    srli a3, a0, 56
+; RV64I-NEXT:    slli a1, a1, 8
+; RV64I-NEXT:    or a1, a1, a3
+; RV64I-NEXT:    sub a1, a1, a2
+; RV64I-NEXT:    slli a2, a0, 12
+; RV64I-NEXT:    slli a0, a0, 8
+; RV64I-NEXT:    sltu a3, a0, a2
+; RV64I-NEXT:    sub a1, a1, a3
+; RV64I-NEXT:    sub a0, a0, a2
 ; RV64I-NEXT:    ret
 ;
 ; RV64IM-LABEL: muli128_m3840:
@@ -1079,39 +1081,40 @@
 define i128 @muli128_m63(i128 %a) nounwind {
 ; RV32I-LABEL: muli128_m63:
 ; RV32I:       # %bb.0:
-; RV32I-NEXT:    addi sp, sp, -64
-; RV32I-NEXT:    sw ra, 60(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    sw s0, 56(sp) # 4-byte Folded Spill
-; RV32I-NEXT:    lw a3, 0(a1)
-; RV32I-NEXT:    lw a2, 4(a1)
+; RV32I-NEXT:    lw a2, 0(a1)
+; RV32I-NEXT:    lw t0, 12(a1)
 ; RV32I-NEXT:    lw a4, 8(a1)
-; RV32I-NEXT:    lw a1, 12(a1)
-; RV32I-NEXT:    mv s0, a0
-; RV32I-NEXT:    addi a0, zero, -1
-; RV32I-NEXT:    sw a0, 20(sp)
-; RV32I-NEXT:    sw a0, 16(sp)
-; RV32I-NEXT:    sw a0, 12(sp)
-; RV32I-NEXT:    addi a0, zero, -63
-; RV32I-NEXT:    sw a0, 8(sp)
-; RV32I-NEXT:    sw a1, 36(sp)
-; RV32I-NEXT:    sw a4, 32(sp)
-; RV32I-NEXT:    sw a2, 28(sp)
-; RV32I-NEXT:    addi a0, sp, 40
-; RV32I-NEXT:    addi a1, sp, 24
-; RV32I-NEXT:    addi a2, sp, 8
-; RV32I-NEXT:    sw a3, 24(sp)
-; RV32I-NEXT:    call __multi3@plt
-; RV32I-NEXT:    lw a0, 52(sp)
-; RV32I-NEXT:    lw a1, 48(sp)
-; RV32I-NEXT:    lw a2, 44(sp)
-; RV32I-NEXT:    lw a3, 40(sp)
-; RV32I-NEXT:    sw a0, 12(s0)
-; RV32I-NEXT:    sw a1, 8(s0)
-; RV32I-NEXT:    sw a2, 4(s0)
-; RV32I-NEXT:    sw a3, 0(s0)
-; RV32I-NEXT:    lw s0, 56(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    lw ra, 60(sp) # 4-byte Folded Reload
-; RV32I-NEXT:    addi sp, sp, 64
+; RV32I-NEXT:    lw a3, 4(a1)
+; RV32I-NEXT:    slli a6, a2, 6
+; RV32I-NEXT:    sltu a7, a2, a6
+; RV32I-NEXT:    srli a1, a2, 26
+; RV32I-NEXT:    slli a5, a3, 6
+; RV32I-NEXT:    or t2, a5, a1
+; RV32I-NEXT:    mv t3, a7
+; RV32I-NEXT:    beq a3, t2, .LBB27_2
+; RV32I-NEXT:  # %bb.1:
+; RV32I-NEXT:    sltu t3, a3, t2
+; RV32I-NEXT:  .LBB27_2:
+; RV32I-NEXT:    srli t1, a3, 26
+; RV32I-NEXT:    slli a1, a4, 6
+; RV32I-NEXT:    or a1, a1, t1
+; RV32I-NEXT:    sub a5, a4, a1
+; RV32I-NEXT:    sltu t1, a5, t3
+; RV32I-NEXT:    sltu t4, a4, a1
+; RV32I-NEXT:    srli a4, a4, 26
+; RV32I-NEXT:    slli a1, t0, 6
+; RV32I-NEXT:    or a1, a1, a4
+; RV32I-NEXT:    sub a1, t0, a1
+; RV32I-NEXT:    sub a1, a1, t4
+; RV32I-NEXT:    sub a1, a1, t1
+; RV32I-NEXT:    sub a4, a5, t3
+; RV32I-NEXT:    sub a3, a3, t2
+; RV32I-NEXT:    sub a3, a3, a7
+; RV32I-NEXT:    sub a2, a2, a6
+; RV32I-NEXT:    sw a2, 0(a0)
+; RV32I-NEXT:    sw a3, 4(a0)
+; RV32I-NEXT:    sw a4, 8(a0)
+; RV32I-NEXT:    sw a1, 12(a0)
 ; RV32I-NEXT:    ret
 ;
 ; RV32IM-LABEL: muli128_m63:
@@ -1153,13 +1156,14 @@
 ;
 ; RV64I-LABEL: muli128_m63:
 ; RV64I:       # %bb.0:
-; RV64I-NEXT:    addi sp, sp, -16
-; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
-; RV64I-NEXT:    addi a2, zero, -63
-; RV64I-NEXT:    addi a3, zero, -1
-; RV64I-NEXT:    call __multi3@plt
-; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
-; RV64I-NEXT:    addi sp, sp, 16
+; RV64I-NEXT:    slli a2, a0, 6
+; RV64I-NEXT:    sltu a3, a0, a2
+; RV64I-NEXT:    srli a4, a0, 58
+; RV64I-NEXT:    slli a5, a1, 6
+; RV64I-NEXT:    or a4, a5, a4
+; RV64I-NEXT:    sub a1, a1, a4
+; RV64I-NEXT:    sub a1, a1, a3
+; RV64I-NEXT:    sub a0, a0, a2
 ; RV64I-NEXT:    ret
 ;
 ; RV64IM-LABEL: muli128_m63: