Index: llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h
===================================================================
--- llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h
+++ llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h
@@ -1865,6 +1865,12 @@
     return buildInstr(TargetOpcode::G_BITREVERSE, {Dst}, {Src});
   }
 
+  /// Build and insert \p Dst = G_ISNAN \p Src
+  MachineInstrBuilder buildIsNaN(const DstOp &Dst, const SrcOp &Src,
+                                 Optional<unsigned> Flags = None) {
+    return buildInstr(TargetOpcode::G_ISNAN, {Dst}, {Src}, Flags);
+  }
+
   virtual MachineInstrBuilder buildInstr(unsigned Opc, ArrayRef<DstOp> DstOps,
                                          ArrayRef<SrcOp> SrcOps,
                                          Optional<unsigned> Flags = None);
Index: llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -2228,6 +2228,14 @@
 
     return true;
   }
+  case Intrinsic::isnan: {
+    Register Src = getOrCreateVReg(*CI.getArgOperand(0));
+    unsigned Flags = MachineInstr::copyFlagsFromInstruction(CI);
+    if (!CI.getFunction()->getAttributes().hasFnAttr(llvm::Attribute::StrictFP))
+      Flags |= MachineInstr::NoFPExcept;
+    MIRBuilder.buildIsNaN(getOrCreateVReg(CI), Src, Flags);
+    return true;
+  }
 #define INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC)  \
   case Intrinsic::INTRINSIC:
 #include "llvm/IR/ConstrainedOps.def"
Index: llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-isnan.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-isnan.ll
@@ -0,0 +1,45 @@
+; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+; RUN: llc -global-isel -mtriple=aarch64-unknown-unknown -stop-after=irtranslator -verify-machineinstrs -o - %s | FileCheck %s
+declare i1 @llvm.isnan.f16(half)
+declare <4 x i1> @llvm.isnan.v4f16(<4 x half>)
+
+define i1 @s16(half %x) {
+  ; CHECK-LABEL: name: s16
+  ; CHECK: bb.1 (%ir-block.0):
+  ; CHECK:   liveins: $h0
+  ; CHECK:   [[COPY:%[0-9]+]]:_(s16) = COPY $h0
+  ; CHECK:   %1:_(s1) = nofpexcept G_ISNAN [[COPY]](s16)
+  ; CHECK:   [[ZEXT:%[0-9]+]]:_(s8) = G_ZEXT %1(s1)
+  ; CHECK:   [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[ZEXT]](s8)
+  ; CHECK:   $w0 = COPY [[ANYEXT]](s32)
+  ; CHECK:   RET_ReallyLR implicit $w0
+  %isnan = tail call i1 @llvm.isnan.f16(half %x)
+  ret i1 %isnan
+}
+
+define <4 x i1> @v4s16(<4 x half> %x) {
+  ; CHECK-LABEL: name: v4s16
+  ; CHECK: bb.1 (%ir-block.0):
+  ; CHECK:   liveins: $d0
+  ; CHECK:   [[COPY:%[0-9]+]]:_(<4 x s16>) = COPY $d0
+  ; CHECK:   %1:_(<4 x s1>) = nofpexcept G_ISNAN [[COPY]](<4 x s16>)
+  ; CHECK:   [[ANYEXT:%[0-9]+]]:_(<4 x s16>) = G_ANYEXT %1(<4 x s1>)
+  ; CHECK:   $d0 = COPY [[ANYEXT]](<4 x s16>)
+  ; CHECK:   RET_ReallyLR implicit $d0
+  %isnan = tail call <4 x i1> @llvm.isnan.v4f16(<4 x half> %x)
+  ret <4 x i1> %isnan
+}
+
+define i1 @strictfp(half %x) strictfp {
+  ; CHECK-LABEL: name: strictfp
+  ; CHECK: bb.1 (%ir-block.0):
+  ; CHECK:   liveins: $h0
+  ; CHECK:   [[COPY:%[0-9]+]]:_(s16) = COPY $h0
+  ; CHECK:   [[ISNAN:%[0-9]+]]:_(s1) = G_ISNAN [[COPY]](s16)
+  ; CHECK:   [[ZEXT:%[0-9]+]]:_(s8) = G_ZEXT [[ISNAN]](s1)
+  ; CHECK:   [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[ZEXT]](s8)
+  ; CHECK:   $w0 = COPY [[ANYEXT]](s32)
+  ; CHECK:   RET_ReallyLR implicit $w0
+  %isnan = tail call i1 @llvm.isnan.f16(half %x)
+  ret i1 %isnan
+}