all: minor cleanups

src/util/cxxlib.h

@@ -180,7 +180,7 @@ inline constexpr bool is_same_any_v = is_same_any<T, Ts...>::value;
 
 template <class T>
 forceinline constexpr bool has_single_bit(T x) noexcept {
-    return x != 0 && (x & (x - 1)) == 0;
+    return !(x == 0) && (x & (x - 1)) == 0;
 }
 
 /*************************************************************************
@@ -191,21 +191,30 @@ template <class T>
 inline constexpr T align_down(const T &x, const T &alignment) noexcept {
     // assert_noexcept(has_single_bit(alignment)); // (not constexpr)
     T r = {};
-    r = (x / alignment) * alignment;
+    r = x - (x & (alignment - 1));
+    return r;
+}
+template <class T>
+inline constexpr T align_down_gap(const T &x, const T &alignment) noexcept {
+    // assert_noexcept(has_single_bit(alignment)); // (not constexpr)
+    T r = {};
+    r = x & (alignment - 1);
     return r;
 }
 template <class T>
 inline constexpr T align_up(const T &x, const T &alignment) noexcept {
     // assert_noexcept(has_single_bit(alignment)); // (not constexpr)
     T r = {};
-    r = ((x + (alignment - 1)) / alignment) * alignment;
+    constexpr T zero = {};
+    r = x + ((zero - x) & (alignment - 1));
     return r;
 }
 template <class T>
-inline constexpr T align_gap(const T &x, const T &alignment) noexcept {
+inline constexpr T align_up_gap(const T &x, const T &alignment) noexcept {
     // assert_noexcept(has_single_bit(alignment)); // (not constexpr)
     T r = {};
-    r = align_up(x, alignment) - x;
+    constexpr T zero = {};
+    r = (zero - x) & (alignment - 1);
     return r;
 }
 

src/util/system_headers.h

@@ -82,6 +82,9 @@ static_assert(sizeof(void *) == sizeof(long));
 #pragma warning(disable : 4244) // W3: conversion from 'type1' to 'type2', possible loss of data
 #pragma warning(disable : 4267) // W3: conversion from 'size_t' to 'type', possible loss of data
 #pragma warning(disable : 4820) // W4: padding added after data member
+#if _MSC_VER >= 1800
+#pragma warning(disable : 4464) // W4: relative include path contains '..'
+#endif
 #endif
 
 #undef snprintf

src/util/util.cpp

@@ -292,7 +292,8 @@ void *upx_calloc(size_t n, size_t element_size) may_throw {
 }
 
 // simple unoptimized memswap()
-// TODO later: CHERI clang bug/miscompilation with upx_memswap() ???
+// TODO later: CHERI clang-14 bug/miscompilation with upx_memswap(); or
+//   maybe caused by tagged-memory issues ???
 void upx_memswap(void *aa, void *bb, size_t bytes) noexcept {
     if (aa != bb && bytes != 0) {
         byte *a = (byte *) aa;
@@ -448,11 +449,24 @@ TEST_CASE("upx_memswap") {
         memset(array, 0xfb, sizeof(array));
         array[1] = &a;
         array[3] = &b;
+        CHECK(*array[1] == 11);
+        CHECK(*array[3] == 22);
+#if defined(__CHERI__) && defined(__CHERI_PURE_CAPABILITY__)
+        // TODO later: CHERI clang-14 bug/miscompilation with upx_memswap(); or
+        //   maybe caused by tagged-memory issues ???
+        memswap_no_overlap((byte *) array, (byte *) (array + 2), 2 * sizeof(array[0]));
+#else
         upx_memswap(array, array + 2, 2 * sizeof(array[0]));
-        assert(array[1] == &b);
-        assert(array[3] == &a);
-        assert(*array[1] == 22);
-        assert(*array[3] == 11);
+#endif
+        CHECK(array[1] == &b);
+        CHECK(array[3] == &a);
+        CHECK(*array[1] == 22);
+        CHECK(*array[3] == 11);
+        memswap_no_overlap((byte *) array, (byte *) (array + 2), 2 * sizeof(array[0]));
+        CHECK(array[1] == &a);
+        CHECK(array[3] == &b);
+        CHECK(*array[1] == 11);
+        CHECK(*array[3] == 22);
     }
 }
 

src/util/util.h

@@ -110,6 +110,10 @@ forceinline bool ptr_is_aligned(const void *p) noexcept {
     static_assert(upx::has_single_bit(Alignment));
     return (ptr_get_address(p) & (Alignment - 1)) == 0;
 }
+forceinline bool ptr_is_aligned(const void *p, size_t alignment) noexcept {
+    assert_noexcept(upx::has_single_bit(alignment));
+    return (ptr_get_address(p) & (alignment - 1)) == 0;
+}
 
 // ptrdiff_t with nullptr checks and asserted size; will throw on failure
 // NOTE: returns size_in_bytes, not number of elements!