all repos — mgba @ 337d4dc1e658e4efd6c111a05248a7116e0020b2

mGBA Game Boy Advance Emulator

Implement addressing mode 1 ROR with register
Jeffrey Pfau jeffrey@endrift.com
Tue, 30 Apr 2013 01:57:36 -0700
commit

337d4dc1e658e4efd6c111a05248a7116e0020b2

parent

e1963c6e60b006179284590f16373e972590e2d7

1 files changed, 22 insertions(+), 1 deletions(-)

jump to
M src/arm/isa-arm.csrc/arm/isa-arm.c

@@ -76,7 +76,28 @@ }

static inline void _shiftRORR(struct ARMCore* cpu, uint32_t opcode) { int rm = opcode & 0x0000000F; - ARM_STUB; + int rs = (opcode >> 8) & 0x0000000F; + ++cpu->cycles; + int shift = cpu->gprs[rs]; + if (rs == ARM_PC) { + shift += 4; + } + shift &= 0xFF; + int shiftVal = cpu->gprs[rm]; + if (rm == ARM_PC) { + shiftVal += 4; + } + int rotate = shift & 0x1F; + if (!shift) { + cpu->shifterOperand = shiftVal; + cpu->shifterCarryOut = cpu->cpsr.c; + } else if (rotate) { + cpu->shifterOperand = ARM_ROR(shiftVal, rotate); + cpu->shifterCarryOut = (shiftVal >> (rotate - 1)) & 1; + } else { + cpu->shifterOperand = shiftVal; + cpu->shifterCarryOut = ARM_SIGN(shiftVal); + } } static inline void _immediate(struct ARMCore* cpu, uint32_t opcode) {