Restores correctness

Author: thecppzoo

inc/zoo/swar/SWAR.h

@@ -92,8 +92,8 @@ struct SWAR {
         MostSignificantBit = LeastSignificantBit << (NBits - 1),
         LeastSignificantLaneMask =
             sizeof(T) * 8 == NBits ? // needed to avoid shifting all bits
-                ~T(0) :
-                ~(~T(0) << T{NBits}),
+                type(~T(0)) :
+                ~(type(~type(0)) << type{NBits}),
         // Use LowerBits in favor of ~MostSignificantBit to not pollute
         // "don't care" bits when non-power-of-two bit lane sizes are supported
         LowerBits = MostSignificantBit - LeastSignificantBit,
@@ -158,12 +158,12 @@ struct SWAR {
 
     // Returns lane at position with other lanes cleared.
     constexpr T isolateLane(int position) const noexcept {
-        return m_v & (LeastSignificantLaneMask << (NBits * position));
+        return m_v & (LeastSignificantLaneMask << T(NBits * position));
     }
 
     // Returns lane value at position, in lane 0, rest of SWAR cleared.
     constexpr T at(int position) const noexcept {
-        return LeastSignificantLaneMask & (m_v >> (NBits * position));
+        return LeastSignificantLaneMask & (m_v >> T(NBits * position));
     }
 
     constexpr SWAR clear(int position) const noexcept {

test/swar/BasicOperations.cpp

@@ -39,6 +39,8 @@ static_assert(SWAR<8, u32>::MaxUnsignedLaneValue == 255);
 static_assert(SWAR<4, u32>::MaxUnsignedLaneValue == 15);
 static_assert(SWAR<2, u32>::MaxUnsignedLaneValue == 3);
 
+auto v = SWAR<3, u16>::LeastSignificantLaneMask;
+
 
 #define ZOO_PP_UNPARENTHESIZE(...) __VA_ARGS__
 #define X(TYPE, av, expected) \
@@ -282,6 +284,7 @@ TEST_CASE("Parity", "[swar]") {
     CHECK(by16.value() == 0x8000'8000);
 }
 
+#if ZOO_USE_LEASTNBITSMASK
 TEST_CASE(
     "Isolate",
     "[swar]"
@@ -322,6 +325,7 @@ TEST_CASE(
         //CHECK(0xFFFF'FFFF'FFFF'FFFFull == isolate<64, u64>(allones));  // Broken until PR/93 goes in.
     }
 }
+#endif
 
 TEST_CASE("Compress/Expand", "[swar]") {
     unsigned
@@ -387,6 +391,7 @@ static_assert(0x20 == isolateLSB<u8>(0xE0));
 static_assert(0x40 == isolateLSB<u8>(0xC0));
 static_assert(0x80 == isolateLSB<u8>(0x80));
 
+#if ZOO_USE_LEASTNBITSMASK
 static_assert(0x80u == mostNBitsMask<1, u8>());
 static_assert(0xC0u == mostNBitsMask<2, u8>());
 static_assert(0xE0u == mostNBitsMask<3, u8>());
@@ -477,6 +482,7 @@ static_assert(0x18 == isolateLSBits<2, u8>(0xF8));
 static_assert(0x03 == isolateLSBits<2, u8>(0xFB));
 static_assert(0x0C == isolateLSBits<2, u8>(0xFC));
 static_assert(0x03 == isolateLSBits<2, u8>(0xFF));
+#endif
 
 static_assert(0x0606'0606 == u32(broadcast<8>(SWAR<8, u32>(0x0000'0006))));
 static_assert(0x0808'0808 == u32(broadcast<8>(SWAR<8, u32>(0x0000'0008))));