diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 6bf063998458..d0d62150b56c 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -18305,6 +18305,12 @@ RISCVTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
       // TODO: Support fixed vectors up to XLen for P extension?
       if (VT.isVector())
         break;
+      if (VT == MVT::f16 && Subtarget.hasStdExtZhinxOrZhinxmin())
+        return std::make_pair(0U, &RISCV::GPRF16RegClass);
+      if (VT == MVT::f32 && Subtarget.hasStdExtZfinx())
+        return std::make_pair(0U, &RISCV::GPRF32RegClass);
+      if (VT == MVT::f64 && Subtarget.hasStdExtZdinx() && !Subtarget.is64Bit())
+        return std::make_pair(0U, &RISCV::GPRPF64RegClass);
       return std::make_pair(0U, &RISCV::GPRNoX0RegClass);
     case 'f':
       if (Subtarget.hasStdExtZfhOrZfhmin() && VT == MVT::f16)
diff --git a/llvm/test/CodeGen/RISCV/zdinx-asm-constraint.ll b/llvm/test/CodeGen/RISCV/zdinx-asm-constraint.ll
new file mode 100644
index 000000000000..63c46ca4eafc
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/zdinx-asm-constraint.ll
@@ -0,0 +1,58 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 3
+; RUN: llc -mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs < %s \
+; RUN:   -target-abi=ilp32 -mattr=+zhinx | FileCheck %s
+define dso_local void @zdinx_asm(ptr nocapture noundef writeonly %a, double noundef %b, double noundef %c) nounwind {
+; CHECK-LABEL: zdinx_asm:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addi sp, sp, -16
+; CHECK-NEXT:    sw a1, 8(sp)
+; CHECK-NEXT:    sw a2, 12(sp)
+; CHECK-NEXT:    lw a6, 8(sp)
+; CHECK-NEXT:    lw a7, 12(sp)
+; CHECK-NEXT:    sw a3, 8(sp)
+; CHECK-NEXT:    sw a4, 12(sp)
+; CHECK-NEXT:    lw a2, 8(sp)
+; CHECK-NEXT:    lw a3, 12(sp)
+; CHECK-NEXT:    #APP
+; CHECK-NEXT:    fsgnjx.d a2, a6, a2
+; CHECK-NEXT:    #NO_APP
+; CHECK-NEXT:    sw a2, 8(a0)
+; CHECK-NEXT:    sw a3, 12(a0)
+; CHECK-NEXT:    addi sp, sp, 16
+; CHECK-NEXT:    ret
+entry:
+  %arrayidx = getelementptr inbounds double, ptr %a, i32 1
+  %0 = tail call double asm "fsgnjx.d $0, $1, $2", "=r,r,r"(double %b, double %c)
+  store double %0, ptr %arrayidx, align 8
+  ret void
+}
+
+define dso_local void @zfinx_asm(ptr nocapture noundef writeonly %a, float noundef %b, float noundef %c) nounwind {
+; CHECK-LABEL: zfinx_asm:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    #APP
+; CHECK-NEXT:    fsgnjx.s a1, a1, a2
+; CHECK-NEXT:    #NO_APP
+; CHECK-NEXT:    sw a1, 4(a0)
+; CHECK-NEXT:    ret
+entry:
+  %arrayidx = getelementptr inbounds float, ptr %a, i32 1
+  %0 = tail call float asm "fsgnjx.s $0, $1, $2", "=r,r,r"(float %b, float %c)
+  store float %0, ptr %arrayidx, align 8
+  ret void
+}
+
+define dso_local void @zhinx_asm(ptr nocapture noundef writeonly %a, half noundef %b, half noundef %c) nounwind {
+; CHECK-LABEL: zhinx_asm:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    #APP
+; CHECK-NEXT:    fsgnjx.h a1, a1, a2
+; CHECK-NEXT:    #NO_APP
+; CHECK-NEXT:    sh a1, 2(a0)
+; CHECK-NEXT:    ret
+entry:
+  %arrayidx = getelementptr inbounds half, ptr %a, i32 1
+  %0 = tail call half asm "fsgnjx.h $0, $1, $2", "=r,r,r"(half %b, half %c)
+  store half %0, ptr %arrayidx, align 8
+  ret void
+}