Rotate 16-bit without using AND
Jeffrey Pfau jeffrey@endrift.com
Sat, 26 Oct 2013 16:40:31 -0700
1 files changed,
2 insertions(+),
2 deletions(-)
jump to
M
src/gba/gba-memory.c
→
src/gba/gba-memory.c
@@ -194,7 +194,7 @@ }
int16_t GBALoad16(struct ARMMemory* memory, uint32_t address, int* cycleCounter) { struct GBAMemory* gbaMemory = (struct GBAMemory*) memory; - int16_t value = 0; + uint16_t value = 0; int wait = 0; switch (address & ~OFFSET_MASK) {@@ -260,7 +260,7 @@ *cycleCounter += 2 + wait;
} // Unaligned 16-bit loads are "unpredictable", but the GBA rotates them, so we have to, too. int rotate = (address & 1) << 3; - return (value >> rotate) | ((value << rotate) & 0xFF00); + return (value >> rotate) | (value << (16 - rotate)); } uint8_t GBALoadU8(struct ARMMemory* memory, uint32_t address, int* cycleCounter) {