diff --git a/llvm/docs/RISCVUsage.rst b/llvm/docs/RISCVUsage.rst
--- a/llvm/docs/RISCVUsage.rst
+++ b/llvm/docs/RISCVUsage.rst
@@ -169,6 +169,9 @@
 
 The current vendor extensions supported are:
 
+``XTHeadBa``
+  LLVM implements `the THeadBa (address-generation) vendor-defined instructions specified in <https://github.com/T-head-Semi/thead-extension-spec/releases/download/2.2.2/xthead-2023-01-30-2.2.2.pdf>`_  by T-HEAD of Alibaba.  Instructions are prefixed with `th.` as described in the specification.
+
 ``XTHeadVdot``
   LLVM implements `version 1.0.0 of the THeadV-family custom instructions specification <https://github.com/T-head-Semi/thead-extension-spec/releases/download/2.2.0/xthead-2022-12-04-2.2.0.pdf>`_ by T-HEAD of Alibaba.  All instructions are prefixed with `th.` as described in the specification, and the riscv-toolchain-convention document linked above.
 
diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -108,6 +108,7 @@
 * Zca, Zcf, and Zcd extensions were upgraded to version 1.0.1.
 * vsetvli intrinsics no longer have side effects. They may now be combined,
   moved, deleted, etc. by optimizations.
+* Adds support for the vendor-defined XTHeadBa (address-generation) extension.
 
 Changes to the WebAssembly Backend
 ----------------------------------
diff --git a/llvm/lib/Support/RISCVISAInfo.cpp b/llvm/lib/Support/RISCVISAInfo.cpp
--- a/llvm/lib/Support/RISCVISAInfo.cpp
+++ b/llvm/lib/Support/RISCVISAInfo.cpp
@@ -109,6 +109,7 @@
     {"svinval", RISCVExtensionVersion{1, 0}},
 
     // vendor-defined ('X') extensions
+    {"xtheadba", RISCVExtensionVersion{1, 0}},
     {"xtheadvdot", RISCVExtensionVersion{1, 0}},
     {"xventanacondops", RISCVExtensionVersion{1, 0}},
 };
diff --git a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
--- a/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
+++ b/llvm/lib/Target/RISCV/Disassembler/RISCVDisassembler.cpp
@@ -471,6 +471,13 @@
       if (Result != MCDisassembler::Fail)
         return Result;
     }
+    if (STI.getFeatureBits()[RISCV::FeatureVendorXTHeadBa]) {
+      LLVM_DEBUG(dbgs() << "Trying XTHeadBa custom opcode table:\n");
+      Result = decodeInstruction(DecoderTableTHeadBa32, MI, Insn, Address, this,
+                                 STI);
+      if (Result != MCDisassembler::Fail)
+        return Result;
+    }
     if (STI.getFeatureBits()[RISCV::FeatureVendorXTHeadVdot]) {
       LLVM_DEBUG(dbgs() << "Trying XTHeadVdot custom opcode table:\n");
       Result =
diff --git a/llvm/lib/Target/RISCV/RISCVFeatures.td b/llvm/lib/Target/RISCV/RISCVFeatures.td
--- a/llvm/lib/Target/RISCV/RISCVFeatures.td
+++ b/llvm/lib/Target/RISCV/RISCVFeatures.td
@@ -463,6 +463,13 @@
                                 AssemblerPredicate<(all_of FeatureVendorXVentanaCondOps),
                                 "'XVentanaCondOps' (Ventana Conditional Ops)">;
 
+def FeatureVendorXTHeadBa
+    : SubtargetFeature<"xtheadba", "HasVendorXTHeadBa", "true",
+                       "'xtheadba' (T-Head address calculation instructions)">;
+def HasVendorXTHeadBa : Predicate<"Subtarget->hasVendorXTHeadBa()">,
+                                  AssemblerPredicate<(all_of FeatureVendorXTHeadBa),
+                                  "'xtheadba' (T-Head address calculation instructions)">;
+
 def FeatureVendorXTHeadVdot
     : SubtargetFeature<"xtheadvdot", "HasVendorXTHeadVdot", "true",
                        "'xtheadvdot' (T-Head Vector Extensions for Dot)",
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoXTHead.td b/llvm/lib/Target/RISCV/RISCVInstrInfoXTHead.td
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoXTHead.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoXTHead.td
@@ -43,6 +43,17 @@
                    opcodestr, "$vd, $rs1, $vs2$vm">;
 } // hasSideEffects = 0, mayLoad = 0, mayStore = 0
 
+let Predicates = [HasVendorXTHeadBa], DecoderNamespace = "THeadBa",
+  hasSideEffects = 0, mayLoad = 0, mayStore = 0 in
+class THShiftALU_rri<bits<3> funct3, string opcodestr>
+    : RVInstR<0, funct3, OPC_CUSTOM_0, (outs GPR:$rd),
+              (ins GPR:$rs1, GPR:$rs2, uimm2:$uimm2),
+	      opcodestr, "$rd, $rs1, $rs2, $uimm2"> {
+  bits<2> uimm2;
+  let Inst{31-27} = 0;
+  let Inst{26-25} = uimm2;
+}
+
 //===----------------------------------------------------------------------===//
 // Combination of instruction classes.
 // Use these multiclasses to define instructions more easily.
@@ -59,6 +70,11 @@
 //===----------------------------------------------------------------------===//
 // Instructions
 //===----------------------------------------------------------------------===//
+let Predicates = [HasVendorXTHeadBa] in {
+def TH_ADDSL : THShiftALU_rri<0b001, "th.addsl">,
+               Sched<[WriteSHXADD, ReadSHXADD, ReadSHXADD]>;
+} // Predicates = [HasVendorXTHeadBa]
+
 let Predicates = [HasVendorXTHeadVdot],
     Constraints = "@earlyclobber $vd",
     RVVConstraint = WidenV in {
@@ -134,6 +150,80 @@
 //===----------------------------------------------------------------------===//
 // Pseudo-instructions and codegen patterns
 //===----------------------------------------------------------------------===//
+let Predicates = [HasVendorXTHeadBa] in {
+def : Pat<(add GPR:$rs1, (shl GPR:$rs2, uimm2:$uimm2)),
+          (TH_ADDSL GPR:$rs1, GPR:$rs2, uimm2:$uimm2)>;
+
+// Reuse complex patterns from StdExtZba
+def : Pat<(add sh1add_op:$rs1, non_imm12:$rs2),
+          (TH_ADDSL GPR:$rs2, sh1add_op:$rs1, 1)>;
+def : Pat<(add sh2add_op:$rs1, non_imm12:$rs2),
+          (TH_ADDSL GPR:$rs2, sh2add_op:$rs1, 2)>;
+def : Pat<(add sh3add_op:$rs1, non_imm12:$rs2),
+          (TH_ADDSL GPR:$rs2, sh3add_op:$rs1, 3)>;
+
+def : Pat<(add (mul_oneuse GPR:$rs1, (XLenVT 6)), GPR:$rs2),
+          (TH_ADDSL GPR:$rs2, (TH_ADDSL GPR:$rs1, GPR:$rs1, 1), 1)>;
+def : Pat<(add (mul_oneuse GPR:$rs1, (XLenVT 10)), GPR:$rs2),
+          (TH_ADDSL GPR:$rs2, (TH_ADDSL GPR:$rs1, GPR:$rs1, 2), 1)>;
+def : Pat<(add (mul_oneuse GPR:$rs1, (XLenVT 18)), GPR:$rs2),
+          (TH_ADDSL GPR:$rs2, (TH_ADDSL GPR:$rs1, GPR:$rs1, 3), 1)>;
+def : Pat<(add (mul_oneuse GPR:$rs1, (XLenVT 12)), GPR:$rs2),
+          (TH_ADDSL GPR:$rs2, (TH_ADDSL GPR:$rs1, GPR:$rs1, 1), 2)>;
+def : Pat<(add (mul_oneuse GPR:$rs1, (XLenVT 20)), GPR:$rs2),
+          (TH_ADDSL GPR:$rs2, (TH_ADDSL GPR:$rs1, GPR:$rs1, 2), 2)>;
+def : Pat<(add (mul_oneuse GPR:$rs1, (XLenVT 36)), GPR:$rs2),
+          (TH_ADDSL GPR:$rs2, (TH_ADDSL GPR:$rs1, GPR:$rs1, 3), 2)>;
+def : Pat<(add (mul_oneuse GPR:$rs1, (XLenVT 24)), GPR:$rs2),
+          (TH_ADDSL GPR:$rs2, (TH_ADDSL GPR:$rs1, GPR:$rs1, 1), 3)>;
+def : Pat<(add (mul_oneuse GPR:$rs1, (XLenVT 40)), GPR:$rs2),
+          (TH_ADDSL GPR:$rs2, (TH_ADDSL GPR:$rs1, GPR:$rs1, 2), 3)>;
+def : Pat<(add (mul_oneuse GPR:$rs1, (XLenVT 72)), GPR:$rs2),
+          (TH_ADDSL GPR:$rs2, (TH_ADDSL GPR:$rs1, GPR:$rs1, 3), 3)>;
+
+def : Pat<(add GPR:$r, CSImm12MulBy4:$i),
+          (TH_ADDSL GPR:$r, (ADDI X0, (SimmShiftRightBy2XForm CSImm12MulBy4:$i)), 2)>;
+def : Pat<(add GPR:$r, CSImm12MulBy8:$i),
+          (TH_ADDSL GPR:$r, (ADDI X0, (SimmShiftRightBy3XForm CSImm12MulBy8:$i)), 3)>;
+
+def : Pat<(mul GPR:$r, C3LeftShift:$i),
+          (SLLI (TH_ADDSL GPR:$r, GPR:$r, 1),
+                (TrailingZeros C3LeftShift:$i))>;
+def : Pat<(mul GPR:$r, C5LeftShift:$i),
+          (SLLI (TH_ADDSL GPR:$r, GPR:$r, 2),
+                (TrailingZeros C5LeftShift:$i))>;
+def : Pat<(mul GPR:$r, C9LeftShift:$i),
+          (SLLI (TH_ADDSL GPR:$r, GPR:$r, 3),
+                (TrailingZeros C9LeftShift:$i))>;
+
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 11)),
+	  (TH_ADDSL GPR:$r, (TH_ADDSL GPR:$r, GPR:$r, 2), 1)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 19)),
+	  (TH_ADDSL GPR:$r, (TH_ADDSL GPR:$r, GPR:$r, 3), 1)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 13)),
+	  (TH_ADDSL GPR:$r, (TH_ADDSL GPR:$r, GPR:$r, 1), 2)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 21)),
+	  (TH_ADDSL GPR:$r, (TH_ADDSL GPR:$r, GPR:$r, 2), 2)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 37)),
+	  (TH_ADDSL GPR:$r, (TH_ADDSL GPR:$r, GPR:$r, 3), 2)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 25)),
+	  (TH_ADDSL (TH_ADDSL GPR:$r, GPR:$r, 2), (TH_ADDSL GPR:$r, GPR:$r, 2), 2)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 41)),
+	  (TH_ADDSL GPR:$r, (TH_ADDSL GPR:$r, GPR:$r, 2), 3)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 73)),
+	  (TH_ADDSL GPR:$r, (TH_ADDSL GPR:$r, GPR:$r, 3), 3)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 27)),
+	  (TH_ADDSL (TH_ADDSL GPR:$r, GPR:$r, 3), (TH_ADDSL GPR:$r, GPR:$r, 3), 1)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 45)),
+	  (TH_ADDSL (TH_ADDSL GPR:$r, GPR:$r, 3), (TH_ADDSL GPR:$r, GPR:$r, 3), 2)>;
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 81)),
+	  (TH_ADDSL (TH_ADDSL GPR:$r, GPR:$r, 3), (TH_ADDSL GPR:$r, GPR:$r, 3), 3)>;
+
+def : Pat<(mul_const_oneuse GPR:$r, (XLenVT 200)),
+	  (SLLI (TH_ADDSL (TH_ADDSL GPR:$r, GPR:$r, 2),
+		       (TH_ADDSL GPR:$r, GPR:$r, 2), 2), 3)>;
+} // Predicates = [HasVendorXTHeadBa]
+
 defm PseudoTHVdotVMAQA      : VPseudoVMAQA_VV_VX;
 defm PseudoTHVdotVMAQAU     : VPseudoVMAQA_VV_VX;
 defm PseudoTHVdotVMAQASU    : VPseudoVMAQA_VV_VX;
diff --git a/llvm/test/CodeGen/RISCV/attributes.ll b/llvm/test/CodeGen/RISCV/attributes.ll
--- a/llvm/test/CodeGen/RISCV/attributes.ll
+++ b/llvm/test/CodeGen/RISCV/attributes.ll
@@ -86,6 +86,7 @@
 ; RUN: llc -mtriple=riscv64 -mattr=+svpbmt %s -o - | FileCheck --check-prefix=RV64SVPBMT %s
 ; RUN: llc -mtriple=riscv64 -mattr=+svinval %s -o - | FileCheck --check-prefix=RV64SVINVAL %s
 ; RUN: llc -mtriple=riscv64 -mattr=+xventanacondops %s -o - | FileCheck --check-prefix=RV64XVENTANACONDOPS %s
+; RUN: llc -mtriple=riscv64 -mattr=+xtheadba %s -o - | FileCheck --check-prefix=RV64XTHEADBA %s
 ; RUN: llc -mtriple=riscv64 -mattr=+xtheadvdot %s -o - | FileCheck --check-prefix=RV64XTHEADVDOT %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zawrs %s -o - | FileCheck --check-prefix=RV64ZAWRS %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-ztso %s -o - | FileCheck --check-prefix=RV64ZTSO %s
@@ -180,6 +181,7 @@
 ; RV64SVPBMT: .attribute 5, "rv64i2p0_svpbmt1p0"
 ; RV64SVINVAL: .attribute 5, "rv64i2p0_svinval1p0"
 ; RV64XVENTANACONDOPS: .attribute 5, "rv64i2p0_xventanacondops1p0"
+; RV64XTHEADBA: .attribute 5, "rv64i2p0_xtheadba1p0"
 ; RV64XTHEADVDOT: .attribute 5, "rv64i2p0_f2p0_d2p0_v1p0_zve32f1p0_zve32x1p0_zve64d1p0_zve64f1p0_zve64x1p0_zvl128b1p0_zvl32b1p0_zvl64b1p0_xtheadvdot1p0"
 ; RV64ZTSO: .attribute 5, "rv64i2p0_ztso0p1"
 ; RV64ZCA: .attribute 5, "rv64i2p0_zca1p0"
diff --git a/llvm/test/CodeGen/RISCV/rv32xtheadba.ll b/llvm/test/CodeGen/RISCV/rv32xtheadba.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/rv32xtheadba.ll
@@ -0,0 +1,323 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --extra_scrub
+; RUN: llc -mtriple=riscv32 -mattr=+m -verify-machineinstrs < %s \
+; RUN:   | FileCheck %s -check-prefixes=RV32I
+; RUN: llc -mtriple=riscv32 -mattr=+m,+xtheadba -verify-machineinstrs < %s \
+; RUN:   | FileCheck %s -check-prefixes=RV32XTHEADBA
+
+define signext i16 @th_addsl_1(i64 %0, ptr %1) {
+; RV32I-LABEL: th_addsl_1:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    slli a0, a0, 1
+; RV32I-NEXT:    add a0, a2, a0
+; RV32I-NEXT:    lh a0, 0(a0)
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: th_addsl_1:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a2, a0, 1
+; RV32XTHEADBA-NEXT:    lh a0, 0(a0)
+; RV32XTHEADBA-NEXT:    ret
+  %3 = getelementptr inbounds i16, ptr %1, i64 %0
+  %4 = load i16, ptr %3
+  ret i16 %4
+}
+
+define signext i32 @th_addsl_2(i64 %0, ptr %1) {
+; RV32I-LABEL: th_addsl_2:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    slli a0, a0, 2
+; RV32I-NEXT:    add a0, a2, a0
+; RV32I-NEXT:    lw a0, 0(a0)
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: th_addsl_2:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a2, a0, 2
+; RV32XTHEADBA-NEXT:    lw a0, 0(a0)
+; RV32XTHEADBA-NEXT:    ret
+  %3 = getelementptr inbounds i32, ptr %1, i64 %0
+  %4 = load i32, ptr %3
+  ret i32 %4
+}
+
+define i64 @th_addsl_3(i64 %0, ptr %1) {
+; RV32I-LABEL: th_addsl_3:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    slli a0, a0, 3
+; RV32I-NEXT:    add a2, a2, a0
+; RV32I-NEXT:    lw a0, 0(a2)
+; RV32I-NEXT:    lw a1, 4(a2)
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: th_addsl_3:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a1, a2, a0, 3
+; RV32XTHEADBA-NEXT:    lw a0, 0(a1)
+; RV32XTHEADBA-NEXT:    lw a1, 4(a1)
+; RV32XTHEADBA-NEXT:    ret
+  %3 = getelementptr inbounds i64, ptr %1, i64 %0
+  %4 = load i64, ptr %3
+  ret i64 %4
+}
+
+; Type legalization inserts a sext_inreg after the first add. That add will be
+; selected as th.addsl which does not sign extend. SimplifyDemandedBits is unable
+; to remove the sext_inreg because it has multiple uses. The ashr will use the
+; sext_inreg to become sraiw. This leaves the sext_inreg only used by the shl.
+; If the shl is selected as sllw, we don't need the sext_inreg.
+define i64 @th_addsl_2_extra_sext(i32 %x, i32 %y, i32 %z) {
+; RV32I-LABEL: th_addsl_2_extra_sext:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    slli a0, a0, 2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    sll a1, a2, a0
+; RV32I-NEXT:    srai a2, a0, 2
+; RV32I-NEXT:    mul a0, a1, a2
+; RV32I-NEXT:    mulh a1, a1, a2
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: th_addsl_2_extra_sext:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 2
+; RV32XTHEADBA-NEXT:    sll a1, a2, a0
+; RV32XTHEADBA-NEXT:    srai a2, a0, 2
+; RV32XTHEADBA-NEXT:    mul a0, a1, a2
+; RV32XTHEADBA-NEXT:    mulh a1, a1, a2
+; RV32XTHEADBA-NEXT:    ret
+  %a = shl i32 %x, 2
+  %b = add i32 %a, %y
+  %c = shl i32 %z, %b
+  %d = ashr i32 %b, 2
+  %e = sext i32 %c to i64
+  %f = sext i32 %d to i64
+  %g = mul i64 %e, %f
+  ret i64 %g
+}
+
+define i32 @addmul6(i32 %a, i32 %b) {
+; RV32I-LABEL: addmul6:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a2, 6
+; RV32I-NEXT:    mul a0, a0, a2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: addmul6:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 1
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 1
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 6
+  %d = add i32 %c, %b
+  ret i32 %d
+}
+
+define i32 @addmul10(i32 %a, i32 %b) {
+; RV32I-LABEL: addmul10:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a2, 10
+; RV32I-NEXT:    mul a0, a0, a2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: addmul10:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 1
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 10
+  %d = add i32 %c, %b
+  ret i32 %d
+}
+
+define i32 @addmul12(i32 %a, i32 %b) {
+; RV32I-LABEL: addmul12:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a2, 12
+; RV32I-NEXT:    mul a0, a0, a2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: addmul12:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 1
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 2
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 12
+  %d = add i32 %c, %b
+  ret i32 %d
+}
+
+define i32 @addmul18(i32 %a, i32 %b) {
+; RV32I-LABEL: addmul18:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a2, 18
+; RV32I-NEXT:    mul a0, a0, a2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: addmul18:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 3
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 1
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 18
+  %d = add i32 %c, %b
+  ret i32 %d
+}
+
+define i32 @addmul20(i32 %a, i32 %b) {
+; RV32I-LABEL: addmul20:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a2, 20
+; RV32I-NEXT:    mul a0, a0, a2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: addmul20:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 2
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 20
+  %d = add i32 %c, %b
+  ret i32 %d
+}
+
+define i32 @addmul24(i32 %a, i32 %b) {
+; RV32I-LABEL: addmul24:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a2, 24
+; RV32I-NEXT:    mul a0, a0, a2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: addmul24:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 1
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 3
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 24
+  %d = add i32 %c, %b
+  ret i32 %d
+}
+
+define i32 @addmul36(i32 %a, i32 %b) {
+; RV32I-LABEL: addmul36:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a2, 36
+; RV32I-NEXT:    mul a0, a0, a2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: addmul36:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 3
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 2
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 36
+  %d = add i32 %c, %b
+  ret i32 %d
+}
+
+define i32 @addmul40(i32 %a, i32 %b) {
+; RV32I-LABEL: addmul40:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a2, 40
+; RV32I-NEXT:    mul a0, a0, a2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: addmul40:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 3
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 40
+  %d = add i32 %c, %b
+  ret i32 %d
+}
+
+define i32 @addmul72(i32 %a, i32 %b) {
+; RV32I-LABEL: addmul72:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a2, 72
+; RV32I-NEXT:    mul a0, a0, a2
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: addmul72:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 3
+; RV32XTHEADBA-NEXT:    th.addsl a0, a1, a0, 3
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 72
+  %d = add i32 %c, %b
+  ret i32 %d
+}
+
+define i32 @mul96(i32 %a) {
+; RV32I-LABEL: mul96:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a1, 96
+; RV32I-NEXT:    mul a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: mul96:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 1
+; RV32XTHEADBA-NEXT:    slli a0, a0, 5
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 96
+  ret i32 %c
+}
+
+define i32 @mul160(i32 %a) {
+; RV32I-LABEL: mul160:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a1, 160
+; RV32I-NEXT:    mul a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: mul160:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV32XTHEADBA-NEXT:    slli a0, a0, 5
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 160
+  ret i32 %c
+}
+
+define i32 @mul200(i32 %a) {
+; RV32I-LABEL: mul200:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a1, 200
+; RV32I-NEXT:    mul a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: mul200:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV32XTHEADBA-NEXT:    slli a0, a0, 3
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 200
+  ret i32 %c
+}
+
+define i32 @mul288(i32 %a) {
+; RV32I-LABEL: mul288:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    li a1, 288
+; RV32I-NEXT:    mul a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBA-LABEL: mul288:
+; RV32XTHEADBA:       # %bb.0:
+; RV32XTHEADBA-NEXT:    th.addsl a0, a0, a0, 3
+; RV32XTHEADBA-NEXT:    slli a0, a0, 5
+; RV32XTHEADBA-NEXT:    ret
+  %c = mul i32 %a, 288
+  ret i32 %c
+}
+
diff --git a/llvm/test/CodeGen/RISCV/rv64xtheadba.ll b/llvm/test/CodeGen/RISCV/rv64xtheadba.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/rv64xtheadba.ll
@@ -0,0 +1,319 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --extra_scrub
+; RUN: llc -mtriple=riscv64 -mattr=+m -verify-machineinstrs < %s \
+; RUN:   | FileCheck %s -check-prefixes=RV64I
+; RUN: llc -mtriple=riscv64 -mattr=+m,+xtheadba -verify-machineinstrs < %s \
+; RUN:   | FileCheck %s -check-prefixes=RV64XTHEADBA
+
+define signext i16 @th_addsl_1(i64 %0, ptr %1) {
+; RV64I-LABEL: th_addsl_1:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a0, a0, 1
+; RV64I-NEXT:    add a0, a1, a0
+; RV64I-NEXT:    lh a0, 0(a0)
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: th_addsl_1:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 1
+; RV64XTHEADBA-NEXT:    lh a0, 0(a0)
+; RV64XTHEADBA-NEXT:    ret
+  %3 = getelementptr inbounds i16, ptr %1, i64 %0
+  %4 = load i16, ptr %3
+  ret i16 %4
+}
+
+define signext i32 @th_addsl_2(i64 %0, ptr %1) {
+; RV64I-LABEL: th_addsl_2:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a0, a0, 2
+; RV64I-NEXT:    add a0, a1, a0
+; RV64I-NEXT:    lw a0, 0(a0)
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: th_addsl_2:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 2
+; RV64XTHEADBA-NEXT:    lw a0, 0(a0)
+; RV64XTHEADBA-NEXT:    ret
+  %3 = getelementptr inbounds i32, ptr %1, i64 %0
+  %4 = load i32, ptr %3
+  ret i32 %4
+}
+
+define i64 @th_addsl_3(i64 %0, ptr %1) {
+; RV64I-LABEL: th_addsl_3:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a0, a0, 3
+; RV64I-NEXT:    add a0, a1, a0
+; RV64I-NEXT:    ld a0, 0(a0)
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: th_addsl_3:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 3
+; RV64XTHEADBA-NEXT:    ld a0, 0(a0)
+; RV64XTHEADBA-NEXT:    ret
+  %3 = getelementptr inbounds i64, ptr %1, i64 %0
+  %4 = load i64, ptr %3
+  ret i64 %4
+}
+
+; Type legalization inserts a sext_inreg after the first add. That add will be
+; selected as th.addsl which does not sign extend. SimplifyDemandedBits is unable
+; to remove the sext_inreg because it has multiple uses. The ashr will use the
+; sext_inreg to become sraiw. This leaves the sext_inreg only used by the shl.
+; If the shl is selected as sllw, we don't need the sext_inreg.
+define i64 @th_addsl_2_extra_sext(i32 %x, i32 %y, i32 %z) {
+; RV64I-LABEL: th_addsl_2_extra_sext:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a0, a0, 2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    sllw a1, a2, a0
+; RV64I-NEXT:    sraiw a0, a0, 2
+; RV64I-NEXT:    mul a0, a1, a0
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: th_addsl_2_extra_sext:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 2
+; RV64XTHEADBA-NEXT:    sllw a1, a2, a0
+; RV64XTHEADBA-NEXT:    sraiw a0, a0, 2
+; RV64XTHEADBA-NEXT:    mul a0, a1, a0
+; RV64XTHEADBA-NEXT:    ret
+  %a = shl i32 %x, 2
+  %b = add i32 %a, %y
+  %c = shl i32 %z, %b
+  %d = ashr i32 %b, 2
+  %e = sext i32 %c to i64
+  %f = sext i32 %d to i64
+  %g = mul i64 %e, %f
+  ret i64 %g
+}
+
+define i64 @addmul6(i64 %a, i64 %b) {
+; RV64I-LABEL: addmul6:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a2, 6
+; RV64I-NEXT:    mul a0, a0, a2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: addmul6:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 1
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 1
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 6
+  %d = add i64 %c, %b
+  ret i64 %d
+}
+
+define i64 @addmul10(i64 %a, i64 %b) {
+; RV64I-LABEL: addmul10:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a2, 10
+; RV64I-NEXT:    mul a0, a0, a2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: addmul10:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 1
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 10
+  %d = add i64 %c, %b
+  ret i64 %d
+}
+
+define i64 @addmul12(i64 %a, i64 %b) {
+; RV64I-LABEL: addmul12:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a2, 12
+; RV64I-NEXT:    mul a0, a0, a2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: addmul12:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 1
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 2
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 12
+  %d = add i64 %c, %b
+  ret i64 %d
+}
+
+define i64 @addmul18(i64 %a, i64 %b) {
+; RV64I-LABEL: addmul18:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a2, 18
+; RV64I-NEXT:    mul a0, a0, a2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: addmul18:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 3
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 1
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 18
+  %d = add i64 %c, %b
+  ret i64 %d
+}
+
+define i64 @addmul20(i64 %a, i64 %b) {
+; RV64I-LABEL: addmul20:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a2, 20
+; RV64I-NEXT:    mul a0, a0, a2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: addmul20:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 2
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 20
+  %d = add i64 %c, %b
+  ret i64 %d
+}
+
+define i64 @addmul24(i64 %a, i64 %b) {
+; RV64I-LABEL: addmul24:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a2, 24
+; RV64I-NEXT:    mul a0, a0, a2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: addmul24:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 1
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 3
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 24
+  %d = add i64 %c, %b
+  ret i64 %d
+}
+
+define i64 @addmul36(i64 %a, i64 %b) {
+; RV64I-LABEL: addmul36:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a2, 36
+; RV64I-NEXT:    mul a0, a0, a2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: addmul36:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 3
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 2
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 36
+  %d = add i64 %c, %b
+  ret i64 %d
+}
+
+define i64 @addmul40(i64 %a, i64 %b) {
+; RV64I-LABEL: addmul40:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a2, 40
+; RV64I-NEXT:    mul a0, a0, a2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: addmul40:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 3
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 40
+  %d = add i64 %c, %b
+  ret i64 %d
+}
+
+define i64 @addmul72(i64 %a, i64 %b) {
+; RV64I-LABEL: addmul72:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a2, 72
+; RV64I-NEXT:    mul a0, a0, a2
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: addmul72:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 3
+; RV64XTHEADBA-NEXT:    th.addsl a0, a1, a0, 3
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 72
+  %d = add i64 %c, %b
+  ret i64 %d
+}
+
+define i64 @mul96(i64 %a) {
+; RV64I-LABEL: mul96:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a1, 96
+; RV64I-NEXT:    mul a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: mul96:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 1
+; RV64XTHEADBA-NEXT:    slli a0, a0, 5
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 96
+  ret i64 %c
+}
+
+define i64 @mul160(i64 %a) {
+; RV64I-LABEL: mul160:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a1, 160
+; RV64I-NEXT:    mul a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: mul160:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV64XTHEADBA-NEXT:    slli a0, a0, 5
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 160
+  ret i64 %c
+}
+
+define i64 @mul200(i64 %a) {
+; RV64I-LABEL: mul200:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a1, 200
+; RV64I-NEXT:    mul a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: mul200:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 2
+; RV64XTHEADBA-NEXT:    slli a0, a0, 3
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 200
+  ret i64 %c
+}
+
+define i64 @mul288(i64 %a) {
+; RV64I-LABEL: mul288:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    li a1, 288
+; RV64I-NEXT:    mul a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64XTHEADBA-LABEL: mul288:
+; RV64XTHEADBA:       # %bb.0:
+; RV64XTHEADBA-NEXT:    th.addsl a0, a0, a0, 3
+; RV64XTHEADBA-NEXT:    slli a0, a0, 5
+; RV64XTHEADBA-NEXT:    ret
+  %c = mul i64 %a, 288
+  ret i64 %c
+}
+
diff --git a/llvm/test/MC/RISCV/XTHeadBa-invalid.s b/llvm/test/MC/RISCV/XTHeadBa-invalid.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/MC/RISCV/XTHeadBa-invalid.s
@@ -0,0 +1,11 @@
+# RUN: not llvm-mc -triple riscv32 -mattr=+xtheadba < %s 2>&1 | FileCheck %s
+# RUN: not llvm-mc -triple riscv64 -mattr=+xtheadba < %s 2>&1 | FileCheck %s
+
+# Too few operands
+th.addsl t0, t1 # CHECK: :[[@LINE]]:1: error: too few operands for instruction
+# Too few operands
+th.addsl t0, t1, t2 # CHECK: :[[@LINE]]:1: error: too few operands for instruction
+# Immediate operand out of range
+th.addsl t0, t1, t2, 4 # CHECK: :[[@LINE]]:22: error: immediate must be an integer in the range [0, 3]
+# Immediate operand out of range
+th.addsl t0, t1, t2, -1 # CHECK: :[[@LINE]]:22: error: immediate must be an integer in the range [0, 3]
diff --git a/llvm/test/MC/RISCV/XTHeadBa-valid.s b/llvm/test/MC/RISCV/XTHeadBa-valid.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/MC/RISCV/XTHeadBa-valid.s
@@ -0,0 +1,24 @@
+# With XTHeadBa (address generation) extension:
+# RUN: llvm-mc %s -triple=riscv32 -mattr=+xtheadba -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc %s -triple=riscv64 -mattr=+xtheadba -show-encoding \
+# RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv32 -mattr=+xtheadba < %s \
+# RUN:     | llvm-objdump --mattr=+xtheadba -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+xtheadba < %s \
+# RUN:     | llvm-objdump --mattr=+xtheadba -d -r - \
+# RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
+
+# CHECK-ASM-AND-OBJ: th.addsl t0, t1, t2, 0
+# CHECK-ASM: encoding: [0x8b,0x12,0x73,0x00]
+th.addsl t0, t1, t2, 0
+# CHECK-ASM-AND-OBJ: th.addsl t0, t1, t2, 1
+# CHECK-ASM: encoding: [0x8b,0x12,0x73,0x02]
+th.addsl t0, t1, t2, 1
+# CHECK-ASM-AND-OBJ: th.addsl t0, t1, t2, 2
+# CHECK-ASM: encoding: [0x8b,0x12,0x73,0x04]
+th.addsl t0, t1, t2, 2
+# CHECK-ASM-AND-OBJ: th.addsl t0, t1, t2, 3
+# CHECK-ASM: encoding: [0x8b,0x12,0x73,0x06]
+th.addsl t0, t1, t2, 3