[CIR][CIRGen][Builtin][Neon] Lower neon_vaddlv_s8 and neon_vaddlv_u8 (llvm#1671)

Hi, This is my first here! Tried to mirror some of the patterns already
presented in both the codegen lib and its tests

I'm very excited to start contributing and potentially making an impact
in this project! feedback is much appreciated.

Author: RiverDave

clang/lib/CIR/CodeGen/CIRGenBuiltinAArch64.cpp

@@ -4397,9 +4397,6 @@ CIRGenFunction::emitAArch64BuiltinExpr(unsigned BuiltinID, const CallExpr *E,
   case NEON::BI__builtin_neon_vmul_n_f64: {
     llvm_unreachable("NEON::BI__builtin_neon_vmul_n_f64 NYI");
   }
-  case NEON::BI__builtin_neon_vaddlv_u8: {
-    llvm_unreachable("NEON::BI__builtin_neon_vaddlv_u8 NYI");
-  }
   case NEON::BI__builtin_neon_vaddlvq_u8: {
     llvm_unreachable("NEON::BI__builtin_neon_vaddlvq_u8 NYI");
   }
@@ -4413,8 +4410,16 @@ CIRGenFunction::emitAArch64BuiltinExpr(unsigned BuiltinID, const CallExpr *E,
                         usgn ? "aarch64.neon.uaddlv" : "aarch64.neon.saddlv",
                         usgn ? UInt32Ty : SInt32Ty, getLoc(E->getExprLoc()));
   }
+  case NEON::BI__builtin_neon_vaddlv_u8:
+    usgn = true;
+    [[fallthrough]];
   case NEON::BI__builtin_neon_vaddlv_s8: {
-    llvm_unreachable("NEON::BI__builtin_neon_vaddlv_s8 NYI");
+    cir::VectorType vTy = cir::VectorType::get(usgn ? UInt8Ty : SInt8Ty, 8);
+    Ops.push_back(emitScalarExpr(E->getArg(0)));
+    Ops[0] = emitNeonCall(builder, {vTy}, Ops,
+                          usgn ? "aarch64.neon.uaddlv" : "aarch64.neon.saddlv",
+                          usgn ? UInt32Ty : SInt32Ty, getLoc(E->getExprLoc()));
+    return builder.createIntCast(Ops[0], usgn ? UInt16Ty : SInt16Ty);
   }
   case NEON::BI__builtin_neon_vaddlv_u16:
     usgn = true;

clang/test/CIR/CodeGen/AArch64/neon-arith.c

@@ -906,6 +906,29 @@ int32_t test_vaddlvq_s16(int16x8_t a) {
   // LLVM: ret i32 [[VADDLV_I]]
 }
 
+int16_t test_vaddlv_s8(int8x8_t a) {
+  return vaddlv_s8(a);
+
+  // CIR-LABEL: vaddlv_s8
+  // CIR: cir.llvm.intrinsic "aarch64.neon.saddlv" {{%.*}}: (!cir.vector<!s8i x 8>) -> !s32i
+
+  // LLVM: {{.*}}test_vaddlv_s8(<8 x i8>{{.*}}[[A:%.*]])
+  // LLVM: [[VADDLV_I:%.*]] = call i32 @llvm.aarch64.neon.saddlv.i32.v8i8(<8 x i8> [[A]])
+  // LLVM-NEXT: [[TMP0:%.*]] = trunc i32 [[VADDLV_I]] to i16
+  // LLVM-NEXT: ret i16 [[TMP0]]
+}
+
+uint16_t test_vaddlv_u8(uint8x8_t a) {
+  return vaddlv_u8(a);
+
+  // CIR-LABEL: vaddlv_u8
+  // CIR: cir.llvm.intrinsic "aarch64.neon.uaddlv" {{%.*}}: (!cir.vector<!u8i x 8>) -> !u32i
+
+  // LLVM: {{.*}}test_vaddlv_u8(<8 x i8>{{.*}}[[A:%.*]])
+  // LLVM: [[VADDLV_I:%.*]] = call i32 @llvm.aarch64.neon.uaddlv.i32.v8i8(<8 x i8> [[A]])
+  // LLVM-NEXT: [[TMP0:%.*]] = trunc i32 [[VADDLV_I]] to i16
+  // LLVM-NEXT: ret i16 [[TMP0]]
+}
 
 int32_t test_vaddlv_s16(int16x4_t a) {
   return vaddlv_s16(a);