diff --git a/include/simdjson/common_defs.h b/include/simdjson/common_defs.h
index 0fa3301de..c3d6e2cc3 100644
--- a/include/simdjson/common_defs.h
+++ b/include/simdjson/common_defs.h
@@ -70,7 +70,7 @@ constexpr size_t DEFAULT_MAX_DEPTH = 1024;
 
 #define SIMDJSON_ISALIGNED_N(ptr, n) (((uintptr_t)(ptr) & ((n)-1)) == 0)
 
-#if defined(SIMDJSON_REGULAR_VISUAL_STUDIO)
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
 
   #define simdjson_really_inline __forceinline
   #define simdjson_never_inline __declspec(noinline)
@@ -155,7 +155,7 @@ constexpr size_t DEFAULT_MAX_DEPTH = 1024;
 
   #define SIMDJSON_PRAGMA(P) _Pragma(#P)
   #define SIMDJSON_DISABLE_GCC_WARNING(WARNING) SIMDJSON_PRAGMA(GCC diagnostic ignored #WARNING)
-  #if defined(SIMDJSON_CLANG_VISUAL_STUDIO)
+  #if SIMDJSON_CLANG_VISUAL_STUDIO
   #define SIMDJSON_DISABLE_UNDESIRED_WARNINGS SIMDJSON_DISABLE_GCC_WARNING(-Wmicrosoft-include)
   #else
   #define SIMDJSON_DISABLE_UNDESIRED_WARNINGS
@@ -180,7 +180,7 @@ constexpr size_t DEFAULT_MAX_DEPTH = 1024;
   #define simdjson_inline simdjson_really_inline
 #endif
 
-#if defined(SIMDJSON_VISUAL_STUDIO)
+#if SIMDJSON_VISUAL_STUDIO
     /**
      * Windows users need to do some extra work when building
      * or using a dynamic library (DLL). When building, we need
diff --git a/include/simdjson/dom/parser-inl.h b/include/simdjson/dom/parser-inl.h
index b69bcb035..8da133915 100644
--- a/include/simdjson/dom/parser-inl.h
+++ b/include/simdjson/dom/parser-inl.h
@@ -43,7 +43,7 @@ inline simdjson_result<size_t> parser::read_file(const std::string &path) noexce
 
   // Get the file size
   int ret;
-#if defined(SIMDJSON_VISUAL_STUDIO) && !SIMDJSON_IS_32BITS
+#if SIMDJSON_VISUAL_STUDIO && !SIMDJSON_IS_32BITS
   ret = _fseeki64(fp, 0, SEEK_END);
 #else
   ret = std::fseek(fp, 0, SEEK_END);
@@ -52,7 +52,7 @@ inline simdjson_result<size_t> parser::read_file(const std::string &path) noexce
     std::fclose(fp);
     return IO_ERROR;
   }
-#if defined(SIMDJSON_VISUAL_STUDIO) && !SIMDJSON_IS_32BITS
+#if SIMDJSON_VISUAL_STUDIO && !SIMDJSON_IS_32BITS
   __int64 len = _ftelli64(fp);
   if(len == -1L) {
     std::fclose(fp);
diff --git a/include/simdjson/generic/jsoncharutils.h b/include/simdjson/generic/jsoncharutils.h
index 2316c3178..254b8795d 100644
--- a/include/simdjson/generic/jsoncharutils.h
+++ b/include/simdjson/generic/jsoncharutils.h
@@ -72,7 +72,7 @@ simdjson_inline size_t codepoint_to_utf8(uint32_t cp, uint8_t *c) {
   return 0; // bad r
 }
 
-#ifdef SIMDJSON_IS_32BITS // _umul128 for x86, arm
+#if SIMDJSON_IS_32BITS // _umul128 for x86, arm
 // this is a slow emulation routine for 32-bit
 //
 static simdjson_inline uint64_t __emulu(uint32_t x, uint32_t y) {
@@ -94,7 +94,7 @@ using internal::value128;
 
 simdjson_inline value128 full_multiplication(uint64_t value1, uint64_t value2) {
   value128 answer;
-#if defined(SIMDJSON_REGULAR_VISUAL_STUDIO) || defined(SIMDJSON_IS_32BITS)
+#if SIMDJSON_REGULAR_VISUAL_STUDIO || SIMDJSON_IS_32BITS
 #ifdef _M_ARM64
   // ARM64 has native support for 64-bit multiplications, no need to emultate
   answer.high = __umulh(value1, value2);
@@ -102,7 +102,7 @@ simdjson_inline value128 full_multiplication(uint64_t value1, uint64_t value2) {
 #else
   answer.low = _umul128(value1, value2, &answer.high); // _umul128 not available on ARM64
 #endif // _M_ARM64
-#else // defined(SIMDJSON_REGULAR_VISUAL_STUDIO) || defined(SIMDJSON_IS_32BITS)
+#else // SIMDJSON_REGULAR_VISUAL_STUDIO || SIMDJSON_IS_32BITS
   __uint128_t r = (static_cast<__uint128_t>(value1)) * value2;
   answer.low = uint64_t(r);
   answer.high = uint64_t(r >> 64);
diff --git a/include/simdjson/haswell/bitmanipulation.h b/include/simdjson/haswell/bitmanipulation.h
index 1617061de..5e0423992 100644
--- a/include/simdjson/haswell/bitmanipulation.h
+++ b/include/simdjson/haswell/bitmanipulation.h
@@ -10,7 +10,7 @@ namespace {
 // Sadly, sanitizers are not smart enough to figure it out.
 SIMDJSON_NO_SANITIZE_UNDEFINED
 simdjson_inline int trailing_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   return (int)_tzcnt_u64(input_num);
 #else // SIMDJSON_REGULAR_VISUAL_STUDIO
   ////////
@@ -32,7 +32,7 @@ simdjson_inline int leading_zeroes(uint64_t input_num) {
   return int(_lzcnt_u64(input_num));
 }
 
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
 simdjson_inline unsigned __int64 count_ones(uint64_t input_num) {
   // note: we do not support legacy 32-bit Windows
   return __popcnt64(input_num);// Visual Studio wants two underscores
@@ -45,7 +45,7 @@ simdjson_inline long long int count_ones(uint64_t input_num) {
 
 simdjson_inline bool add_overflow(uint64_t value1, uint64_t value2,
                                 uint64_t *result) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   return _addcarry_u64(0, value1, value2,
                        reinterpret_cast<unsigned __int64 *>(result));
 #else
diff --git a/include/simdjson/haswell/intrinsics.h b/include/simdjson/haswell/intrinsics.h
index 8db2e2b64..6d007ec06 100644
--- a/include/simdjson/haswell/intrinsics.h
+++ b/include/simdjson/haswell/intrinsics.h
@@ -3,14 +3,14 @@
 
 #include "simdjson/base.h"
 
-#ifdef SIMDJSON_VISUAL_STUDIO
+#if SIMDJSON_VISUAL_STUDIO
 // under clang within visual studio, this will include <x86intrin.h>
 #include <intrin.h>  // visual studio or clang
 #else
 #include <x86intrin.h> // elsewhere
 #endif // SIMDJSON_VISUAL_STUDIO
 
-#ifdef SIMDJSON_CLANG_VISUAL_STUDIO
+#if SIMDJSON_CLANG_VISUAL_STUDIO
 /**
  * You are not supposed, normally, to include these
  * headers directly. Instead you should either include intrin.h
diff --git a/include/simdjson/icelake/bitmanipulation.h b/include/simdjson/icelake/bitmanipulation.h
index be998a46c..91d75ffa5 100644
--- a/include/simdjson/icelake/bitmanipulation.h
+++ b/include/simdjson/icelake/bitmanipulation.h
@@ -10,7 +10,7 @@ namespace {
 // Sadly, sanitizers are not smart enough to figure it out.
 SIMDJSON_NO_SANITIZE_UNDEFINED
 simdjson_inline int trailing_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   return (int)_tzcnt_u64(input_num);
 #else // SIMDJSON_REGULAR_VISUAL_STUDIO
   ////////
@@ -32,7 +32,7 @@ simdjson_inline int leading_zeroes(uint64_t input_num) {
   return int(_lzcnt_u64(input_num));
 }
 
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
 simdjson_inline unsigned __int64 count_ones(uint64_t input_num) {
   // note: we do not support legacy 32-bit Windows
   return __popcnt64(input_num);// Visual Studio wants two underscores
@@ -45,7 +45,7 @@ simdjson_inline long long int count_ones(uint64_t input_num) {
 
 simdjson_inline bool add_overflow(uint64_t value1, uint64_t value2,
                                 uint64_t *result) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   return _addcarry_u64(0, value1, value2,
                        reinterpret_cast<unsigned __int64 *>(result));
 #else
diff --git a/include/simdjson/icelake/intrinsics.h b/include/simdjson/icelake/intrinsics.h
index 2a09d1679..28d90350a 100644
--- a/include/simdjson/icelake/intrinsics.h
+++ b/include/simdjson/icelake/intrinsics.h
@@ -3,14 +3,14 @@
 
 #include "simdjson/base.h"
 
-#ifdef SIMDJSON_VISUAL_STUDIO
+#if SIMDJSON_VISUAL_STUDIO
 // under clang within visual studio, this will include <x86intrin.h>
 #include <intrin.h>  // visual studio or clang
 #else
 #include <x86intrin.h> // elsewhere
 #endif // SIMDJSON_VISUAL_STUDIO
 
-#ifdef SIMDJSON_CLANG_VISUAL_STUDIO
+#if SIMDJSON_CLANG_VISUAL_STUDIO
 /**
  * You are not supposed, normally, to include these
  * headers directly. Instead you should either include intrin.h
diff --git a/include/simdjson/implementations.h b/include/simdjson/implementations.h
index a55035243..034106aae 100644
--- a/include/simdjson/implementations.h
+++ b/include/simdjson/implementations.h
@@ -51,8 +51,13 @@
 // Default Haswell to on if this is x86-64. Even if we're not compiled for it, it could be selected
 // at runtime.
 #ifndef SIMDJSON_IMPLEMENTATION_HASWELL
+#if SIMDJSON_CAN_ALWAYS_RUN_ICELAKE
+// if icelake is always available, never enable haswell.
+#define SIMDJSON_IMPLEMENTATION_HASWELL 0
+#else
 #define SIMDJSON_IMPLEMENTATION_HASWELL SIMDJSON_IS_X86_64
 #endif
+#endif
 #ifdef _MSC_VER
 // To see why  (__BMI__) && (__PCLMUL__) && (__LZCNT__) are not part of this next line, see
 // https://github.com/simdjson/simdjson/issues/1247
@@ -61,9 +66,14 @@
 #define SIMDJSON_CAN_ALWAYS_RUN_HASWELL ((SIMDJSON_IMPLEMENTATION_HASWELL) && (SIMDJSON_IS_X86_64) && (__AVX2__) && (__BMI__) && (__PCLMUL__) && (__LZCNT__))
 #endif
 
-// Default Westmere to on if this is x86-64. Note that the macro SIMDJSON_REQUIRES_HASWELL appears unused.
+// Default Westmere to on if this is x86-64.
 #ifndef SIMDJSON_IMPLEMENTATION_WESTMERE
-#define SIMDJSON_IMPLEMENTATION_WESTMERE (SIMDJSON_IS_X86_64 && !SIMDJSON_REQUIRES_HASWELL)
+#if SIMDJSON_CAN_ALWAYS_RUN_ICELAKE || SIMDJSON_CAN_ALWAYS_RUN_HASWELL
+// if icelake or haswell are always available, never enable westmere.
+#define SIMDJSON_IMPLEMENTATION_WESTMERE 0
+#else
+#define SIMDJSON_IMPLEMENTATION_WESTMERE SIMDJSON_IS_X86_64
+#endif
 #endif
 #define SIMDJSON_CAN_ALWAYS_RUN_WESTMERE (SIMDJSON_IMPLEMENTATION_WESTMERE && SIMDJSON_IS_X86_64 && __SSE4_2__ && __PCLMUL__)
 
@@ -74,7 +84,12 @@
 
 // Default Fallback to on unless a builtin implementation has already been selected.
 #ifndef SIMDJSON_IMPLEMENTATION_FALLBACK
-#define SIMDJSON_IMPLEMENTATION_FALLBACK 1 // (!SIMDJSON_CAN_ALWAYS_RUN_ARM64 && !SIMDJSON_CAN_ALWAYS_RUN_HASWELL && !SIMDJSON_CAN_ALWAYS_RUN_WESTMERE && !SIMDJSON_CAN_ALWAYS_RUN_PPC64)
+#if SIMDJSON_CAN_ALWAYS_RUN_ARM64 || SIMDJSON_CAN_ALWAYS_RUN_ICELAKE || SIMDJSON_CAN_ALWAYS_RUN_HASWELL || SIMDJSON_CAN_ALWAYS_RUN_WESTMERE || SIMDJSON_CAN_ALWAYS_RUN_PPC64
+// if anything at all except fallback can always run, then disable fallback.
+#define SIMDJSON_IMPLEMENTATION_FALLBACK 0
+#else
+#define SIMDJSON_IMPLEMENTATION_FALLBACK 1
+#endif
 #endif
 #define SIMDJSON_CAN_ALWAYS_RUN_FALLBACK SIMDJSON_IMPLEMENTATION_FALLBACK
 
diff --git a/include/simdjson/padded_string-inl.h b/include/simdjson/padded_string-inl.h
index 434d8e307..29a3018dc 100644
--- a/include/simdjson/padded_string-inl.h
+++ b/include/simdjson/padded_string-inl.h
@@ -128,7 +128,7 @@ inline simdjson_result<padded_string> padded_string::load(std::string_view filen
 
   // Get the file size
   int ret;
-#if defined(SIMDJSON_VISUAL_STUDIO) && !SIMDJSON_IS_32BITS
+#if SIMDJSON_VISUAL_STUDIO && !SIMDJSON_IS_32BITS
   ret = _fseeki64(fp, 0, SEEK_END);
 #else
   ret = std::fseek(fp, 0, SEEK_END);
@@ -137,7 +137,7 @@ inline simdjson_result<padded_string> padded_string::load(std::string_view filen
     std::fclose(fp);
     return IO_ERROR;
   }
-#if defined(SIMDJSON_VISUAL_STUDIO) && !SIMDJSON_IS_32BITS
+#if SIMDJSON_VISUAL_STUDIO && !SIMDJSON_IS_32BITS
   __int64 llen = _ftelli64(fp);
   if(llen == -1L) {
     std::fclose(fp);
diff --git a/include/simdjson/portability.h b/include/simdjson/portability.h
index af896b5d7..85a0dd908 100644
--- a/include/simdjson/portability.h
+++ b/include/simdjson/portability.h
@@ -32,7 +32,7 @@
 #endif // __clang__
 #endif // _MSC_VER
 
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
 // https://en.wikipedia.org/wiki/C_alternative_tokens
 // This header should have no effect, except maybe
 // under Visual Studio.
@@ -59,8 +59,11 @@
 #endif
 
 #endif // defined(__x86_64__) || defined(_M_AMD64)
+#ifndef SIMDJSON_IS_32BITS
+#define SIMDJSON_IS_32BITS 0
+#endif
 
-#ifdef SIMDJSON_IS_32BITS
+#if SIMDJSON_IS_32BITS
 #ifndef SIMDJSON_NO_PORTABILITY_WARNING
 #pragma message("The simdjson library is designed \
 for 64-bit processors and it seems that you are not \
@@ -91,7 +94,7 @@ use a 64-bit target such as x64, 64-bit ARM or 64-bit PPC.")
 //
 
 // We are going to use runtime dispatch.
-#ifdef SIMDJSON_IS_X86_64
+#if SIMDJSON_IS_X86_64
 #ifdef __clang__
 // clang does not have GCC push pop
 // warning: clang attribute push can't be used within a namespace in clang up
@@ -145,7 +148,7 @@ use a 64-bit target such as x64, 64-bit ARM or 64-bit PPC.")
 #define SIMDJSON_NO_SANITIZE_UNDEFINED
 #endif
 
-#ifdef SIMDJSON_VISUAL_STUDIO
+#if SIMDJSON_VISUAL_STUDIO
 // This is one case where we do not distinguish between
 // regular visual studio and clang under visual studio.
 // clang under Windows has _stricmp (like visual studio) but not strcasecmp (as clang normally has)
@@ -161,7 +164,7 @@ use a 64-bit target such as x64, 64-bit ARM or 64-bit PPC.")
 
 #ifdef NDEBUG
 
-#ifdef SIMDJSON_VISUAL_STUDIO
+#if SIMDJSON_VISUAL_STUDIO
 #define SIMDJSON_UNREACHABLE() __assume(0)
 #define SIMDJSON_ASSUME(COND) __assume(COND)
 #else
diff --git a/include/simdjson/ppc64/bitmanipulation.h b/include/simdjson/ppc64/bitmanipulation.h
index d6e131263..1d9abc380 100644
--- a/include/simdjson/ppc64/bitmanipulation.h
+++ b/include/simdjson/ppc64/bitmanipulation.h
@@ -10,7 +10,7 @@ namespace {
 // Sadly, sanitizers are not smart enough to figure it out.
 SIMDJSON_NO_SANITIZE_UNDEFINED
 simdjson_inline int trailing_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   unsigned long ret;
   // Search the mask data from least significant bit (LSB)
   // to the most significant bit (MSB) for a set bit (1).
@@ -28,7 +28,7 @@ simdjson_inline uint64_t clear_lowest_bit(uint64_t input_num) {
 
 /* result might be undefined when input_num is zero */
 simdjson_inline int leading_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   unsigned long leading_zero = 0;
   // Search the mask data from most significant bit (MSB)
   // to least significant bit (LSB) for a set bit (1).
@@ -41,7 +41,7 @@ simdjson_inline int leading_zeroes(uint64_t input_num) {
 #endif // SIMDJSON_REGULAR_VISUAL_STUDIO
 }
 
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
 simdjson_inline int count_ones(uint64_t input_num) {
   // note: we do not support legacy 32-bit Windows
   return __popcnt64(input_num); // Visual Studio wants two underscores
@@ -54,7 +54,7 @@ simdjson_inline int count_ones(uint64_t input_num) {
 
 simdjson_inline bool add_overflow(uint64_t value1, uint64_t value2,
                                          uint64_t *result) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   *result = value1 + value2;
   return *result < value1;
 #else
diff --git a/include/simdjson/westmere/bitmanipulation.h b/include/simdjson/westmere/bitmanipulation.h
index e4f4372ef..609ce95de 100644
--- a/include/simdjson/westmere/bitmanipulation.h
+++ b/include/simdjson/westmere/bitmanipulation.h
@@ -10,7 +10,7 @@ namespace {
 // Sadly, sanitizers are not smart enough to figure it out.
 SIMDJSON_NO_SANITIZE_UNDEFINED
 simdjson_inline int trailing_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   unsigned long ret;
   // Search the mask data from least significant bit (LSB)
   // to the most significant bit (MSB) for a set bit (1).
@@ -28,7 +28,7 @@ simdjson_inline uint64_t clear_lowest_bit(uint64_t input_num) {
 
 /* result might be undefined when input_num is zero */
 simdjson_inline int leading_zeroes(uint64_t input_num) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   unsigned long leading_zero = 0;
   // Search the mask data from most significant bit (MSB)
   // to least significant bit (LSB) for a set bit (1).
@@ -41,7 +41,7 @@ simdjson_inline int leading_zeroes(uint64_t input_num) {
 #endif// SIMDJSON_REGULAR_VISUAL_STUDIO
 }
 
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
 simdjson_inline unsigned __int64 count_ones(uint64_t input_num) {
   // note: we do not support legacy 32-bit Windows
   return __popcnt64(input_num);// Visual Studio wants two underscores
@@ -54,7 +54,7 @@ simdjson_inline long long int count_ones(uint64_t input_num) {
 
 simdjson_inline bool add_overflow(uint64_t value1, uint64_t value2,
                                 uint64_t *result) {
-#ifdef SIMDJSON_REGULAR_VISUAL_STUDIO
+#if SIMDJSON_REGULAR_VISUAL_STUDIO
   return _addcarry_u64(0, value1, value2,
                        reinterpret_cast<unsigned __int64 *>(result));
 #else
diff --git a/include/simdjson/westmere/intrinsics.h b/include/simdjson/westmere/intrinsics.h
index 530e4c602..88bc8d578 100644
--- a/include/simdjson/westmere/intrinsics.h
+++ b/include/simdjson/westmere/intrinsics.h
@@ -1,7 +1,7 @@
 #ifndef SIMDJSON_WESTMERE_INTRINSICS_H
 #define SIMDJSON_WESTMERE_INTRINSICS_H
 
-#ifdef SIMDJSON_VISUAL_STUDIO
+#if SIMDJSON_VISUAL_STUDIO
 // under clang within visual studio, this will include <x86intrin.h>
 #include <intrin.h> // visual studio or clang
 #else
@@ -9,7 +9,7 @@
 #endif // SIMDJSON_VISUAL_STUDIO
 
 
-#ifdef SIMDJSON_CLANG_VISUAL_STUDIO
+#if SIMDJSON_CLANG_VISUAL_STUDIO
 /**
  * You are not supposed, normally, to include these
  * headers directly. Instead you should either include intrin.h
diff --git a/singleheader/simdjson.cpp b/singleheader/simdjson.cpp
index 611411a4e..d6be70b9d 100644
--- a/singleheader/simdjson.cpp
+++ b/singleheader/simdjson.cpp
@@ -3783,7 +3783,7 @@ public:
     // it helps tremendously.
     if (bits == 0)
         return;
-#if defined(SIMDJSON_PREFER_REVERSE_BITS)
+#if SIMDJSON_PREFER_REVERSE_BITS
     /**
      * ARM lacks a fast trailing zero instruction, but it has a fast
      * bit reversal instruction and a fast leading zero instruction.
diff --git a/src/fallback/implementation.cpp b/src/fallback/implementation.cpp
index a794ae5e6..73365f720 100644
--- a/src/fallback/implementation.cpp
+++ b/src/fallback/implementation.cpp
@@ -1,5 +1,4 @@
 #include "simdjson/fallback/begin.h"
-
 namespace simdjson {
 namespace SIMDJSON_IMPLEMENTATION {
 
diff --git a/src/generic/stage1/json_structural_indexer.h b/src/generic/stage1/json_structural_indexer.h
index 8c75f65aa..4e5b23bba 100644
--- a/src/generic/stage1/json_structural_indexer.h
+++ b/src/generic/stage1/json_structural_indexer.h
@@ -37,7 +37,7 @@ public:
     // it helps tremendously.
     if (bits == 0)
         return;
-#if defined(SIMDJSON_PREFER_REVERSE_BITS)
+#if SIMDJSON_PREFER_REVERSE_BITS
     /**
      * ARM lacks a fast trailing zero instruction, but it has a fast
      * bit reversal instruction and a fast leading zero instruction.
diff --git a/tests/dom/basictests.cpp b/tests/dom/basictests.cpp
index 99a7df171..6c898c306 100644
--- a/tests/dom/basictests.cpp
+++ b/tests/dom/basictests.cpp
@@ -21,7 +21,9 @@
  */
 #if defined(SIMDJSON_REGULAR_VISUAL_STUDIO) || defined (__linux__) || defined (__APPLE__) || defined(__FreeBSD__)
 // Finally, we want to exclude legacy 32-bit systems.
-#ifndef SIMDJSON_IS_32BITS
+#if SIMDJSON_IS_32BITS
+// floating-point tests are omitted under 32-bit systems
+#else
 // So we only run some of the floating-point tests under 64-bit linux, apple, regular visual studio, freebsd.
 #define TEST_FLOATS
 #endif
diff --git a/tests/dom/numberparsingcheck.cpp b/tests/dom/numberparsingcheck.cpp
index 812f838cd..8f57ff74b 100644
--- a/tests/dom/numberparsingcheck.cpp
+++ b/tests/dom/numberparsingcheck.cpp
@@ -33,7 +33,9 @@ void found_unsigned_integer(uint64_t result, const uint8_t *buf);
 // or cygwin.
 //
 // Finally, we want to exclude legacy 32-bit systems.
-#ifndef SIMDJSON_IS_32BITS
+#if SIMDJSON_IS_32BITS
+// we omit 32-bit tests
+#else
 // So we only run some of the floating-point tests under 64-bit linux, apple, regular visual studio, freebsd.
 #define TEST_FLOATS
 // Apple and freebsd need a special header, typically.
diff --git a/tests/dom/random_string_number_tests.cpp b/tests/dom/random_string_number_tests.cpp
index 04b583e9d..4c2d3f37a 100644
--- a/tests/dom/random_string_number_tests.cpp
+++ b/tests/dom/random_string_number_tests.cpp
@@ -21,7 +21,9 @@
 // or cygwin.
 //
 // Finally, we want to exclude legacy 32-bit systems.
-#ifndef SIMDJSON_IS_32BITS
+#if SIMDJSON_IS_32BITS
+// we omit 32-bit tests
+#else
 // So we only run some of the floating-point tests under 64-bit linux, apple, regular visual studio, freebsd.
 #define TEST_FLOATS
 // Apple and freebsd need a special header, typically.