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Diffstat (limited to 'src/devices/cpu/alpha/common.h')
-rw-r--r-- | src/devices/cpu/alpha/common.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/src/devices/cpu/alpha/common.h b/src/devices/cpu/alpha/common.h new file mode 100644 index 00000000000..0c9668f304a --- /dev/null +++ b/src/devices/cpu/alpha/common.h @@ -0,0 +1,19 @@ +// license:BSD-3-Clause +// copyright-holders:Patrick Mackinlay + +#ifndef MAME_CPU_ALPHA_COMMON_H +#define MAME_CPU_ALPHA_COMMON_H + +#pragma once + +// instruction field extraction +#define Ra(x) ((x >> 21) & 31) // 'a' register field +#define Rb(x) ((x >> 16) & 31) // 'b' register field +#define Rc(x) (x & 31) // 'c' register field +#define Im(x) (u64(u8(x >> 13))) // literal immediate field + +#define Disp_M(x) (s64(s16(x))) // memory instruction 16-bit signed offset +#define Disp_P(x) (s64(s16(x << 4)) >> 4) // hardware load/store 12-bit signed offset +#define Disp_B(x) (s64(s32(x << 11)) >> 9) // branch instruction offset + +#endif // MAME_CPU_ALPHA_COMMON_H |