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SCI: Adapt the segment and offset getters/setters for SCI3

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This is by no means complete, but it's a good start. It is based on an
earlier discussion on the subject, and it allows us to use the highest
two bits from the segment for offset addresses
This commit is contained in:
Filippos Karapetis 2014-02-17 12:05:40 +02:00
parent ed400d57fc
commit 715a5f9bbe
2 changed files with 44 additions and 18 deletions
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37
engines/sci/engine/vm_types.cpp
View File

@ -28,6 +28,43 @@
namespace Sci {
SegmentId reg_t::getSegment() const {
if (getSciVersion() <= SCI_VERSION_2_1) {
return _segment;
} else {
// Return the lower 14 bits of the segment
return (_segment & 0x3FFF);
}
}
void reg_t::setSegment(SegmentId segment) {
if (getSciVersion() <= SCI_VERSION_2_1) {
_segment = segment;
} else {
// Set the lower 14 bits of the segment, and preserve the upper 2 ones for the offset
_segment = (_segment & 0xC000) | (segment & 0x3FFF);
}
}
uint32 reg_t::getOffset() const {
if (getSciVersion() <= SCI_VERSION_2_1) {
return _offset;
} else {
// Return the lower 16 bits from the offset, and the 17th and 18th bits from the segment
return ((_segment & 0xC000) << 2) | _offset;
}
}
void reg_t::setOffset(uint32 offset) {
if (getSciVersion() <= SCI_VERSION_2_1) {
_offset = offset;
} else {
// Store the lower 16 bits in the offset, and the 17th and 18th bits in the segment
_offset = offset & 0xFFFF;
_segment = ((offset & 0x30000) >> 2) | (_segment & 0x3FFF);
}
}
reg_t reg_t::lookForWorkaround(const reg_t right, const char *operation) const {
SciTrackOriginReply originReply;
SciWorkaroundSolution solution = trackOriginAndFindWorkaround(0, arithmeticWorkarounds, &originReply);

25
engines/sci/engine/vm_types.h
View File

@ -35,36 +35,25 @@ struct reg_t {
SegmentId _segment;
uint16 _offset;
inline SegmentId getSegment() const {
return _segment;
}
inline void setSegment(SegmentId segment) {
_segment = segment;
}
inline uint16 getOffset() const {
return _offset;
}
inline void setOffset(uint16 offset) {
_offset = offset;
}
SegmentId getSegment() const;
void setSegment(SegmentId segment);
uint32 getOffset() const;
void setOffset(uint32 offset);
inline void incOffset(int16 offset) {
setOffset(getOffset() + offset);
}
inline bool isNull() const {
return (_offset | getSegment()) == 0;
return (getOffset() | getSegment()) == 0;
}
inline uint16 toUint16() const {
return _offset;
return (uint16)getOffset();
}
inline int16 toSint16() const {
return (int16)_offset;
return (int16)getOffset();
}
bool isNumber() const {