[CIR][CIRGen][Builtin][Neon] Lower neon_vshrd_n_u64 (#1353)

Lower `neon_vshrd_n_u64`

Author: AmrDeveloper

clang/lib/CIR/CodeGen/CIRGenBuiltinAArch64.cpp

@@ -3857,7 +3857,15 @@ CIRGenFunction::emitAArch64BuiltinExpr(unsigned BuiltinID, const CallExpr *E,
     return builder.createShiftRight(Ops[0], bits);
   }
   case NEON::BI__builtin_neon_vshrd_n_u64: {
-    llvm_unreachable("NEON::BI__builtin_neon_vshrd_n_u64 NYI");
+    std::optional<llvm::APSInt> amt =
+        E->getArg(1)->getIntegerConstantExpr(getContext());
+    assert(amt && "Expected argument to be a constant");
+    uint64_t shiftAmt = amt->getZExtValue();
+    if (shiftAmt == 64)
+      return builder.getConstInt(getLoc(E->getExprLoc()), builder.getUInt64Ty(),
+                                 0);
+
+    return builder.createShiftRight(Ops[0], shiftAmt);
   }
   case NEON::BI__builtin_neon_vsrad_n_s64: {
     std::optional<llvm::APSInt> amt =

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

@@ -15174,18 +15174,40 @@ int64_t test_vshrd_n_s64(int64_t a) {
   // LLVM:   ret i64 [[SHRD_N]]
 }
 
-// NYI-LABEL: @test_vshrd_n_u64(
-// NYI:   ret i64 0
-// uint64_t test_vshrd_n_u64(uint64_t a) {
-//   return (uint64_t)vshrd_n_u64(a, 64);
-// }
+uint64_t test_vshrd_n_u64(uint64_t a) {
+   return (uint64_t)vshrd_n_u64(a, 64);
 
-// NYI-LABEL: @test_vshrd_n_u64_2(
-// NYI:   ret i64 0
-// uint64_t test_vshrd_n_u64_2() {
-//   uint64_t a = UINT64_C(0xf000000000000000);
-//   return vshrd_n_u64(a, 64);
-// }
+  // CIR-LABEL: vshrd_n_u64
+  // CIR: {{.*}} = cir.const #cir.int<0> : !u64i
+  // CIR: cir.return {{.*}} : !u64i
+
+  // LLVM-LABEL: @test_vshrd_n_u64(
+  // LLVM:   ret i64 0
+}
+
+uint64_t test_vshrd_n_u64_2() {
+  uint64_t a = UINT64_C(0xf000000000000000);
+  return vshrd_n_u64(a, 64);
+
+  // CIR-LABEL: vshrd_n_u64
+  // CIR: {{.*}} = cir.const #cir.int<0> : !u64i
+  // CIR: cir.return {{.*}} : !u64i
+
+  // LLVM-LABEL: @test_vshrd_n_u64_2(
+  // LLVM:   ret i64 0
+
+}
+
+uint64_t test_vshrd_n_u64_3(uint64_t a) {
+  return vshrd_n_u64(a, 1);
+
+  // CIR-LABEL: vshrd_n_u64
+  // CIR: {{%.*}} = cir.shift(right, {{%.*}} : !u64i, {{%.*}} : !u64i) -> !u64i
+
+  // LLVM-LABEL: @test_vshrd_n_u64_3(
+  // LLVM:   [[SHRD_N:%.*]] = lshr i64 %0, 1
+  // LLVM:   ret i64 [[SHRD_N]]
+}
 
 // NYI-LABEL: @test_vrshrd_n_s64(
 // NYI:   [[VRSHR_N:%.*]] = call i64 @llvm.aarch64.neon.srshl.i64(i64 %a, i64 -63)