[wasm] Int64Lowering of Word64Popcnt.

test/cctest/wasm/test-run-wasm-64.cc

Index: test/cctest/wasm/test-run-wasm-64.cc
diff --git a/test/cctest/wasm/test-run-wasm-64.cc b/test/cctest/wasm/test-run-wasm-64.cc
index 3f4f100171c8a8e0c4d8b4f874a28ef40d302367..4875d2f6872149b68f776cd2e9cf9dce3ce9b1b1 100644
--- a/test/cctest/wasm/test-run-wasm-64.cc
+++ b/test/cctest/wasm/test-run-wasm-64.cc
@@ -262,6 +262,22 @@ TEST(Run_WasmI64UConvertI32) {
 // kExprI64Clz:
 // kExprI64Ctz:
 // kExprI64Popcnt:
+TEST(Run_WasmI64Popcnt) {
+  struct {
+    int64_t expected;
+    uint64_t input;
+  } values[] = {{64, 0xffffffffffffffff},
+                {0, 0x0000000000000000},
+                {2, 0x0000080000008000},
+                {26, 0x1123456782345678},
+                {38, 0xffedcba09edcba09}};
+
+  WasmRunner<int64_t> r(MachineType::Uint64());
+  BUILD(r, WASM_I64_POPCNT(WASM_GET_LOCAL(0)));
+  for (size_t i = 0; i < arraysize(values); i++) {
+    CHECK_EQ(values[i].expected, r.Call(values[i].input));
+  }
+}
 
 // kExprF32SConvertI64:
 TEST(Run_WasmF32SConvertI64) {