diff --git a/cpp/src/arrow/compute/row/compare_internal_avx2.cc b/cpp/src/arrow/compute/row/compare_internal_avx2.cc
index 1b291dd60ce28..627ee2e8fa071 100644
--- a/cpp/src/arrow/compute/row/compare_internal_avx2.cc
+++ b/cpp/src/arrow/compute/row/compare_internal_avx2.cc
@@ -268,9 +268,9 @@ inline __m256i UnsignedOffsetSafeGather32(int const* base, __m256i offset,
   return _mm256_i32gather_epi32(normalized_base, normalized_offset, 1);
 }
 
-inline __m256i UnsignedOffsetSafeGather64(long long const* base, __m128i offset,
-                                          const int scale = 1) {
-  auto normalized_base = base + 0x80000000ull / sizeof(long long);
+inline __m256i UnsignedOffsetSafeGather64(arrow::util::int64_for_gather_t const* base,
+                                          __m128i offset, const int scale = 1) {
+  auto normalized_base = base + 0x80000000ull / sizeof(arrow::util::int64_for_gather_t);
   __m128i normalized_offset = _mm_sub_epi32(offset, _mm_set1_epi32(0x80000000));
   return _mm256_i32gather_epi64(normalized_base, normalized_offset, 1);
 }
diff --git a/cpp/src/arrow/compute/row/compare_test.cc b/cpp/src/arrow/compute/row/compare_test.cc
index 08c92d054cd9f..bbc81fc9bb25c 100644
--- a/cpp/src/arrow/compute/row/compare_test.cc
+++ b/cpp/src/arrow/compute/row/compare_test.cc
@@ -173,9 +173,9 @@ TEST(KeyCompare, CompareColumnsToRowsLarge) {
     GTEST_SKIP() << "Test only works on 64-bit platforms";
   }
 
-  // The idea of this case is to create a row table using several fixed length columns one
-  // var length column (so the row is hence var length and has offset buffer), with the
-  // overall data size exceeding 2GB. Then compare each row with itself.
+  // The idea of this case is to create a row table using several fixed length columns and
+  // one var length column (so the row is hence var length and has offset buffer), with
+  // the overall data size exceeding 2GB. Then compare each row with itself.
   constexpr int64_t two_gb = 2ll * 1024ll * 1024ll * 1024ll;
   // The compare function requires the row id of the left column to be uint16_t, hence the
   // number of rows.