6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2024-06-25 18:30:07 +00:00
Code Issues Projects Releases Wiki Activity

Clean up ASL/ASR/LSL/LSRm.

Browse Source
This commit is contained in:
Thomas Harte 2022-10-17 11:18:10 -04:00
parent 47e8f3c0f1
commit cc55f0586d
1 changed files with 28 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
InstructionSets/M68k/Implementation/PerformImplementation.hpp
View File

@ -830,6 +830,34 @@ template <
/*
Shifts and rotates.
*/
case Operation::ASLm:
status.extend_flag = status.carry_flag = src.w & Primitive::top_bit<uint16_t>();
status.overflow_flag = (src.w ^ (src.w << 1)) & Primitive::top_bit<uint16_t>();
src.w <<= 1;
Primitive::set_neg_zero(src.w, status);
break;
case Operation::LSLm:
status.extend_flag = status.carry_flag = src.w & Primitive::top_bit<uint16_t>();
status.overflow_flag = 0;
src.w <<= 1;
Primitive::set_neg_zero(src.w, status);
break;
case Operation::ASRm:
status.extend_flag = status.carry_flag = src.w & 1;
status.overflow_flag = 0;
src.w = (src.w & Primitive::top_bit<uint16_t>()) | (src.w >> 1);
Primitive::set_neg_zero(src.w, status);
break;
case Operation::LSRm:
status.extend_flag = status.carry_flag = src.w & 1;
status.overflow_flag = 0;
src.w >>= 1;
Primitive::set_neg_zero(src.w, status);
break;
#define set_neg_zero(v, m) \
status.zero_result = Status::FlagT(v); \
status.negative_flag = status.zero_result & Status::FlagT(m);
@ -847,42 +875,18 @@ template <
#define set_flags_w(t) set_flags(src.w, 0x8000, t)
case Operation::ASLm: {
const auto value = src.w;
src.w = uint16_t(value << 1);
status.extend_flag = status.carry_flag = value & 0x8000;
set_neg_zero_overflow(src.w, 0x8000);
} break;
case Operation::ASLb: Primitive::shift<Operation::ASLb>(src.l, dest.b, status, flow_controller); break;
case Operation::ASLw: Primitive::shift<Operation::ASLw>(src.l, dest.w, status, flow_controller); break;
case Operation::ASLl: Primitive::shift<Operation::ASLl>(src.l, dest.l, status, flow_controller); break;
case Operation::ASRm: {
const auto value = src.w;
src.w = (value&0x8000) | (value >> 1);
status.extend_flag = status.carry_flag = value & 1;
set_neg_zero_overflow(src.w, 0x8000);
} break;
case Operation::ASRb: Primitive::shift<Operation::ASRb>(src.l, dest.b, status, flow_controller); break;
case Operation::ASRw: Primitive::shift<Operation::ASRw>(src.l, dest.w, status, flow_controller); break;
case Operation::ASRl: Primitive::shift<Operation::ASRl>(src.l, dest.l, status, flow_controller); break;
case Operation::LSLm: {
const auto value = src.w;
src.w = uint16_t(value << 1);
status.extend_flag = status.carry_flag = value & 0x8000;
set_neg_zero_overflow(src.w, 0x8000);
} break;
case Operation::LSLb: Primitive::shift<Operation::LSLb>(src.l, dest.b, status, flow_controller); break;
case Operation::LSLw: Primitive::shift<Operation::LSLw>(src.l, dest.w, status, flow_controller); break;
case Operation::LSLl: Primitive::shift<Operation::LSLl>(src.l, dest.l, status, flow_controller); break;
case Operation::LSRm: {
const auto value = src.w;
src.w = value >> 1;
status.extend_flag = status.carry_flag = value & 1;
set_neg_zero_overflow(src.w, 0x8000);
} break;
case Operation::LSRb: Primitive::shift<Operation::LSRb>(src.l, dest.b, status, flow_controller); break;
case Operation::LSRw: Primitive::shift<Operation::LSRw>(src.l, dest.w, status, flow_controller); break;
case Operation::LSRl: Primitive::shift<Operation::LSRl>(src.l, dest.l, status, flow_controller); break;