diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -1012,13 +1012,22 @@
     setOperationAction(ISD::MUL, MVT::v1i64, Expand);
 
     // AArch64 doesn't have a direct vector ->f32 conversion instructions for
-    // elements smaller than i32, so promote the input to i32 first.
+    // elements smaller than i32. With fp16 support, it is best to extend the
+    // operand to i16 for v8i8 and v16i8 (done by the custom lowering).
+    // Otherrwise promote the input to i32 first.
     setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v4i8, MVT::v4i32);
     setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v4i8, MVT::v4i32);
-    setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v8i8, MVT::v8i32);
-    setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v8i8, MVT::v8i32);
-    setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v16i8, MVT::v16i32);
-    setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v16i8, MVT::v16i32);
+    if (Subtarget->hasFullFP16()) {
+      setOperationAction(ISD::SINT_TO_FP, MVT::v8i8, Custom);
+      setOperationAction(ISD::UINT_TO_FP, MVT::v8i8, Custom);
+      setOperationAction(ISD::SINT_TO_FP, MVT::v16i8, Custom);
+      setOperationAction(ISD::UINT_TO_FP, MVT::v16i8, Custom);
+    } else {
+      setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v8i8, MVT::v8i32);
+      setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v8i8, MVT::v8i32);
+      setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v16i8, MVT::v16i32);
+      setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v16i8, MVT::v16i32);
+    }
 
     // Similarly, there is no direct i32 -> f64 vector conversion instruction.
     setOperationAction(ISD::SINT_TO_FP, MVT::v2i32, Custom);
diff --git a/llvm/test/CodeGen/AArch64/fp16-v8-instructions.ll b/llvm/test/CodeGen/AArch64/fp16-v8-instructions.ll
--- a/llvm/test/CodeGen/AArch64/fp16-v8-instructions.ll
+++ b/llvm/test/CodeGen/AArch64/fp16-v8-instructions.ll
@@ -414,41 +414,55 @@
 }
 
 define <8 x half> @sitofp_v8i8(<8 x i8> %a) #0 {
-; CHECK-LABEL: sitofp_v8i8:
-; CHECK:       // %bb.0:
-; CHECK-NEXT:    sshll v0.8h, v0.8b, #0
-; CHECK-NEXT:    sshll2 v1.4s, v0.8h, #0
-; CHECK-NEXT:    sshll v0.4s, v0.4h, #0
-; CHECK-NEXT:    scvtf v1.4s, v1.4s
-; CHECK-NEXT:    scvtf v0.4s, v0.4s
-; CHECK-NEXT:    fcvtn v1.4h, v1.4s
-; CHECK-NEXT:    fcvtn v0.4h, v0.4s
-; CHECK-NEXT:    mov v0.d[1], v1.d[0]
-; CHECK-NEXT:    ret
+; CHECK-CVT-LABEL: sitofp_v8i8:
+; CHECK-CVT:       // %bb.0:
+; CHECK-CVT-NEXT:    sshll v0.8h, v0.8b, #0
+; CHECK-CVT-NEXT:    sshll2 v1.4s, v0.8h, #0
+; CHECK-CVT-NEXT:    sshll v0.4s, v0.4h, #0
+; CHECK-CVT-NEXT:    scvtf v1.4s, v1.4s
+; CHECK-CVT-NEXT:    scvtf v0.4s, v0.4s
+; CHECK-CVT-NEXT:    fcvtn v1.4h, v1.4s
+; CHECK-CVT-NEXT:    fcvtn v0.4h, v0.4s
+; CHECK-CVT-NEXT:    mov v0.d[1], v1.d[0]
+; CHECK-CVT-NEXT:    ret
+;
+; CHECK-FP16-LABEL: sitofp_v8i8:
+; CHECK-FP16:       // %bb.0:
+; CHECK-FP16-NEXT:    sshll v0.8h, v0.8b, #0
+; CHECK-FP16-NEXT:    scvtf v0.8h, v0.8h
+; CHECK-FP16-NEXT:    ret
   %1 = sitofp <8 x i8> %a to <8 x half>
   ret <8 x half> %1
 }
 
 define <16 x half> @sitofp_v16i8(<16 x i8> %a) #0 {
-; CHECK-LABEL: sitofp_v16i8:
-; CHECK:       // %bb.0:
-; CHECK-NEXT:    sshll2 v1.8h, v0.16b, #0
-; CHECK-NEXT:    sshll v0.8h, v0.8b, #0
-; CHECK-NEXT:    sshll2 v2.4s, v1.8h, #0
-; CHECK-NEXT:    sshll v1.4s, v1.4h, #0
-; CHECK-NEXT:    sshll2 v3.4s, v0.8h, #0
-; CHECK-NEXT:    sshll v0.4s, v0.4h, #0
-; CHECK-NEXT:    scvtf v2.4s, v2.4s
-; CHECK-NEXT:    scvtf v1.4s, v1.4s
-; CHECK-NEXT:    scvtf v3.4s, v3.4s
-; CHECK-NEXT:    scvtf v0.4s, v0.4s
-; CHECK-NEXT:    fcvtn v2.4h, v2.4s
-; CHECK-NEXT:    fcvtn v1.4h, v1.4s
-; CHECK-NEXT:    fcvtn v3.4h, v3.4s
-; CHECK-NEXT:    fcvtn v0.4h, v0.4s
-; CHECK-NEXT:    mov v1.d[1], v2.d[0]
-; CHECK-NEXT:    mov v0.d[1], v3.d[0]
-; CHECK-NEXT:    ret
+; CHECK-CVT-LABEL: sitofp_v16i8:
+; CHECK-CVT:       // %bb.0:
+; CHECK-CVT-NEXT:    sshll2 v1.8h, v0.16b, #0
+; CHECK-CVT-NEXT:    sshll v0.8h, v0.8b, #0
+; CHECK-CVT-NEXT:    sshll2 v2.4s, v1.8h, #0
+; CHECK-CVT-NEXT:    sshll v1.4s, v1.4h, #0
+; CHECK-CVT-NEXT:    sshll2 v3.4s, v0.8h, #0
+; CHECK-CVT-NEXT:    sshll v0.4s, v0.4h, #0
+; CHECK-CVT-NEXT:    scvtf v2.4s, v2.4s
+; CHECK-CVT-NEXT:    scvtf v1.4s, v1.4s
+; CHECK-CVT-NEXT:    scvtf v3.4s, v3.4s
+; CHECK-CVT-NEXT:    scvtf v0.4s, v0.4s
+; CHECK-CVT-NEXT:    fcvtn v2.4h, v2.4s
+; CHECK-CVT-NEXT:    fcvtn v1.4h, v1.4s
+; CHECK-CVT-NEXT:    fcvtn v3.4h, v3.4s
+; CHECK-CVT-NEXT:    fcvtn v0.4h, v0.4s
+; CHECK-CVT-NEXT:    mov v1.d[1], v2.d[0]
+; CHECK-CVT-NEXT:    mov v0.d[1], v3.d[0]
+; CHECK-CVT-NEXT:    ret
+;
+; CHECK-FP16-LABEL: sitofp_v16i8:
+; CHECK-FP16:       // %bb.0:
+; CHECK-FP16-NEXT:    sshll2 v1.8h, v0.16b, #0
+; CHECK-FP16-NEXT:    sshll v0.8h, v0.8b, #0
+; CHECK-FP16-NEXT:    scvtf v1.8h, v1.8h
+; CHECK-FP16-NEXT:    scvtf v0.8h, v0.8h
+; CHECK-FP16-NEXT:    ret
   %1 = sitofp <16 x i8> %a to <16 x half>
   ret <16 x half> %1
 }
@@ -525,41 +539,55 @@
 }
 
 define <8 x half> @uitofp_v8i8(<8 x i8> %a) #0 {
-; CHECK-LABEL: uitofp_v8i8:
-; CHECK:       // %bb.0:
-; CHECK-NEXT:    ushll v0.8h, v0.8b, #0
-; CHECK-NEXT:    ushll2 v1.4s, v0.8h, #0
-; CHECK-NEXT:    ushll v0.4s, v0.4h, #0
-; CHECK-NEXT:    ucvtf v1.4s, v1.4s
-; CHECK-NEXT:    ucvtf v0.4s, v0.4s
-; CHECK-NEXT:    fcvtn v1.4h, v1.4s
-; CHECK-NEXT:    fcvtn v0.4h, v0.4s
-; CHECK-NEXT:    mov v0.d[1], v1.d[0]
-; CHECK-NEXT:    ret
+; CHECK-CVT-LABEL: uitofp_v8i8:
+; CHECK-CVT:       // %bb.0:
+; CHECK-CVT-NEXT:    ushll v0.8h, v0.8b, #0
+; CHECK-CVT-NEXT:    ushll2 v1.4s, v0.8h, #0
+; CHECK-CVT-NEXT:    ushll v0.4s, v0.4h, #0
+; CHECK-CVT-NEXT:    ucvtf v1.4s, v1.4s
+; CHECK-CVT-NEXT:    ucvtf v0.4s, v0.4s
+; CHECK-CVT-NEXT:    fcvtn v1.4h, v1.4s
+; CHECK-CVT-NEXT:    fcvtn v0.4h, v0.4s
+; CHECK-CVT-NEXT:    mov v0.d[1], v1.d[0]
+; CHECK-CVT-NEXT:    ret
+;
+; CHECK-FP16-LABEL: uitofp_v8i8:
+; CHECK-FP16:       // %bb.0:
+; CHECK-FP16-NEXT:    ushll v0.8h, v0.8b, #0
+; CHECK-FP16-NEXT:    ucvtf v0.8h, v0.8h
+; CHECK-FP16-NEXT:    ret
   %1 = uitofp <8 x i8> %a to <8 x half>
   ret <8 x half> %1
 }
 
 define <16 x half> @uitofp_v16i8(<16 x i8> %a) #0 {
-; CHECK-LABEL: uitofp_v16i8:
-; CHECK:       // %bb.0:
-; CHECK-NEXT:    ushll2 v1.8h, v0.16b, #0
-; CHECK-NEXT:    ushll v0.8h, v0.8b, #0
-; CHECK-NEXT:    ushll2 v2.4s, v1.8h, #0
-; CHECK-NEXT:    ushll v1.4s, v1.4h, #0
-; CHECK-NEXT:    ushll2 v3.4s, v0.8h, #0
-; CHECK-NEXT:    ushll v0.4s, v0.4h, #0
-; CHECK-NEXT:    ucvtf v2.4s, v2.4s
-; CHECK-NEXT:    ucvtf v1.4s, v1.4s
-; CHECK-NEXT:    ucvtf v3.4s, v3.4s
-; CHECK-NEXT:    ucvtf v0.4s, v0.4s
-; CHECK-NEXT:    fcvtn v2.4h, v2.4s
-; CHECK-NEXT:    fcvtn v1.4h, v1.4s
-; CHECK-NEXT:    fcvtn v3.4h, v3.4s
-; CHECK-NEXT:    fcvtn v0.4h, v0.4s
-; CHECK-NEXT:    mov v1.d[1], v2.d[0]
-; CHECK-NEXT:    mov v0.d[1], v3.d[0]
-; CHECK-NEXT:    ret
+; CHECK-CVT-LABEL: uitofp_v16i8:
+; CHECK-CVT:       // %bb.0:
+; CHECK-CVT-NEXT:    ushll2 v1.8h, v0.16b, #0
+; CHECK-CVT-NEXT:    ushll v0.8h, v0.8b, #0
+; CHECK-CVT-NEXT:    ushll2 v2.4s, v1.8h, #0
+; CHECK-CVT-NEXT:    ushll v1.4s, v1.4h, #0
+; CHECK-CVT-NEXT:    ushll2 v3.4s, v0.8h, #0
+; CHECK-CVT-NEXT:    ushll v0.4s, v0.4h, #0
+; CHECK-CVT-NEXT:    ucvtf v2.4s, v2.4s
+; CHECK-CVT-NEXT:    ucvtf v1.4s, v1.4s
+; CHECK-CVT-NEXT:    ucvtf v3.4s, v3.4s
+; CHECK-CVT-NEXT:    ucvtf v0.4s, v0.4s
+; CHECK-CVT-NEXT:    fcvtn v2.4h, v2.4s
+; CHECK-CVT-NEXT:    fcvtn v1.4h, v1.4s
+; CHECK-CVT-NEXT:    fcvtn v3.4h, v3.4s
+; CHECK-CVT-NEXT:    fcvtn v0.4h, v0.4s
+; CHECK-CVT-NEXT:    mov v1.d[1], v2.d[0]
+; CHECK-CVT-NEXT:    mov v0.d[1], v3.d[0]
+; CHECK-CVT-NEXT:    ret
+;
+; CHECK-FP16-LABEL: uitofp_v16i8:
+; CHECK-FP16:       // %bb.0:
+; CHECK-FP16-NEXT:    ushll2 v1.8h, v0.16b, #0
+; CHECK-FP16-NEXT:    ushll v0.8h, v0.8b, #0
+; CHECK-FP16-NEXT:    ucvtf v1.8h, v1.8h
+; CHECK-FP16-NEXT:    ucvtf v0.8h, v0.8h
+; CHECK-FP16-NEXT:    ret
   %1 = uitofp <16 x i8> %a to <16 x half>
   ret <16 x half> %1
 }