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| author | Nebuleon Fumika | 2012-12-31 13:46:47 -0500 |
|---|---|---|
| committer | Nebuleon Fumika | 2012-12-31 13:46:47 -0500 |
| commit | c5d385d6643e157d6f90d3608004f0f37b64ab75 (patch) | |
| tree | 1f703aa40e11aded99b4e0a4476a21bd25074d61 /source/cpuaddr.h | |
| parent | 22fa90a3b3383cc5ba24ce61a7de1d9c64b6601b (diff) | |
| download | snes9x2005-c5d385d6643e157d6f90d3608004f0f37b64ab75.tar.gz snes9x2005-c5d385d6643e157d6f90d3608004f0f37b64ab75.tar.bz2 snes9x2005-c5d385d6643e157d6f90d3608004f0f37b64ab75.zip | |
MIPS requires 2-byte reads to be aligned to even addresses. #define FAST_ALIGNED_LSB_WORD_ACCESS and use it to read absolute 24-bit addresses as either 1 byte & 1 halfword, or 1 halfword & 1 byte.
Diffstat (limited to 'source/cpuaddr.h')
| -rw-r--r-- | source/cpuaddr.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/source/cpuaddr.h b/source/cpuaddr.h index 34fb41b..91a0347 100644 --- a/source/cpuaddr.h +++ b/source/cpuaddr.h @@ -256,6 +256,11 @@ static void AbsoluteLong (AccessMode a, InternalOp op) long Addr; #ifdef FAST_LSB_WORD_ACCESS Addr = (*(uint32 *) CPU.PC) & 0xffffff; +#elif defined FAST_ALIGNED_LSB_WORD_ACCESS + if (((int) CPU.PC & 1) == 0) + Addr = (*(uint16 *) CPU.PC) + (*(CPU.PC + 2) << 16); + else + Addr = *CPU.PC + ((*(uint16 *) (CPU.PC + 1)) << 8); #else Addr = *CPU.PC + (*(CPU.PC + 1) << 8) + (*(CPU.PC + 2) << 16); #endif @@ -434,6 +439,11 @@ static void AbsoluteLongIndexedX (AccessMode a, InternalOp op) long Addr; #ifdef FAST_LSB_WORD_ACCESS Addr = (*(uint32 *) CPU.PC + ICPU.Registers.X.W) & 0xffffff; +#elif defined FAST_ALIGNED_LSB_WORD_ACCESS + if (((int) CPU.PC & 1) == 0) + Addr = ((*(uint16 *) CPU.PC) + (*(CPU.PC + 2) << 16) + ICPU.Registers.X.W) & 0xFFFFFF; + else + Addr = (*CPU.PC + ((*(uint16 *) (CPU.PC + 1)) << 8) + ICPU.Registers.X.W) & 0xFFFFFF; #else Addr = (*CPU.PC + (*(CPU.PC + 1) << 8) + (*(CPU.PC + 2) << 16) + ICPU.Registers.X.W) & 0xffffff; #endif |