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Simplify Microcycle helpers.

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This commit is contained in:
Thomas Harte 2022-06-16 21:33:03 -04:00
parent 37516e6f6b
commit b0ab5b7b62
1 changed files with 8 additions and 5 deletions
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13
Processors/68000Mk2/68000Mk2.hpp
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@ -144,7 +144,8 @@ struct Microcycle {
@returns 0 if this byte access wants the low part of a 16-bit word; 8 if it wants the high part.
*/
forceinline unsigned int byte_shift() const {
return (((*address) & 1) << 3) ^ 8;
static constexpr unsigned int shifts[] = {8, 0};
return shifts[*address & 1];
}
/*!
@ -153,7 +154,8 @@ struct Microcycle {
@returns 0x00ff if this byte access wants the low part of a 16-bit word; 0xff00 if it wants the high part.
*/
forceinline uint16_t byte_mask() const {
return uint16_t(0xff00) >> (((*address) & 1) << 3);
static constexpr uint16_t masks[] = {0xff00, 0x00ff};
return masks[*address & 1];
}
/*!
@ -163,7 +165,8 @@ struct Microcycle {
@returns 0xff00 if this byte access wants the low part of a 16-bit word; 0x00ff if it wants the high part.
*/
forceinline uint16_t untouched_byte_mask() const {
return uint16_t(uint16_t(0xff) << (((*address) & 1) << 3));
static constexpr uint16_t masks[] = {0x00ff, 0xff00};
return masks[*address & 1];
}
/*!
@ -264,7 +267,7 @@ struct Microcycle {
if(operation & Microcycle::SelectWord) {
value->w = uint16_t(0x00ff | (v << 8));
} else {
value->b = uint8_t(v | (0xff00 >> ((*address & 1) << 3)));
value->b = uint8_t(v | byte_mask());
}
}
@ -276,7 +279,7 @@ struct Microcycle {
if(operation & Microcycle::SelectWord) {
value->w = 0xff00 | v;
} else {
value->b = uint8_t(v | (0x00ff << ((*address & 1) << 3)));
value->b = uint8_t(v | untouched_byte_mask());
}
}