return OSBitwiseAtomic((UInt32) -1, 0, mask, value);
}
-
-static Boolean OSCompareAndSwap8(UInt8 oldValue8, UInt8 newValue8, UInt8 * value8)
+static Boolean OSCompareAndSwap8(UInt8 oldValue8, UInt8 newValue8, UInt8 * value8)
{
- UInt32 mask = 0x000000ff;
- UInt32 newbits = (UInt32) newValue8;
- int shift;
- UInt32 alignment = ((UInt32) value8) & (sizeof(UInt32) - 1);
- UInt32 oldValue;
- UInt32 newValue;
- UInt32 * value;
-
- switch (alignment) {
- default:
- // assert(false);
- case 0:
- value = (UInt32 *) value8;
- shift = 24;
- break;
- case 1:
- value = (UInt32 *) (value8 + 1);
- shift = 16;
- break;
- case 2:
- value = (UInt32 *) (value8 + 2);
- shift = 8;
- break;
- case 3:
- value = (UInt32 *) (value8 + 3);
- shift = 0;
- break;
- }
+ UInt32 mask = 0x000000ff;
+ UInt32 alignment = ((UInt32) value8) & (sizeof(UInt32) - 1);
+ UInt32 shiftValues = (24 << 24) | (16 << 16) | (8 << 8);
+ int shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment);
+ UInt32 * value32 = (UInt32 *) (value8 - alignment);
+ UInt32 oldValue;
+ UInt32 newValue;
- mask <<= shift;
- newbits <<= shift;
-
- oldValue = *value;
- newValue = (oldValue & ~mask) | (newbits & mask);
-
- return OSCompareAndSwap(oldValue, newValue, value);
+ mask <<= shift;
+
+ oldValue = *value32;
+ oldValue = (oldValue & ~mask) | (oldValue8 << shift);
+ newValue = (oldValue & ~mask) | (newValue8 << shift);
+
+ return OSCompareAndSwap(oldValue, newValue, value32);
}
static Boolean OSTestAndSetClear(UInt32 bit, Boolean wantSet, UInt8 * startAddress)
return OSBitwiseAtomic8((UInt32) -1, 0, mask, value);
}
-
-static Boolean OSCompareAndSwap16(UInt16 oldValue16, UInt16 newValue16, UInt16 * value16)
+static Boolean OSCompareAndSwap16(UInt16 oldValue16, UInt16 newValue16, UInt16 * value16)
{
- UInt32 mask = 0x0000ffff;
- UInt32 newbits = (UInt32) newValue16;
- int shift;
- UInt32 alignment = ((UInt32) value16) & (sizeof(UInt32) - 1);
- UInt32 oldValue;
- UInt32 newValue;
- UInt32 * value;
-
- if (alignment == 2) {
- value = (UInt32 *) (value16 - 1);
- shift = 0;
- }
- else {
- // assert(alignment == 0);
- value = (UInt32 *) value16;
- shift = 16;
- }
-
- mask <<= shift;
- newbits <<= shift;
-
- oldValue = *value;
- newValue = (oldValue & ~mask) | (newbits & mask);
-
- return OSCompareAndSwap(oldValue, newValue, value);
+ UInt32 mask = 0x0000ffff;
+ UInt32 alignment = ((UInt32) value16) & (sizeof(UInt32) - 1);
+ UInt32 shiftValues = (16 << 24) | (16 << 16);
+ UInt32 shift = (UInt32) *(((UInt8 *) &shiftValues) + alignment);
+ UInt32 * value32 = (UInt32 *) (((UInt32) value16) - alignment);
+ UInt32 oldValue;
+ UInt32 newValue;
+
+ mask <<= shift;
+
+ oldValue = *value32;
+ oldValue = (oldValue & ~mask) | (oldValue16 << shift);
+ newValue = (oldValue & ~mask) | (newValue16 << shift);
+
+ return OSCompareAndSwap(oldValue, newValue, value32);
}
SInt16 OSIncrementAtomic16(SInt16 * value)