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Marks intent for operand/displacement.

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This commit is contained in:
Thomas Harte 2021-01-08 22:45:27 -05:00
parent 97a64db5e0
commit 68fe16a092
1 changed files with 17 additions and 10 deletions
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11
Processors/Decoders/x86/x86.cpp
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@ -254,7 +254,7 @@ std::pair<int, Instruction> Decoder::decode(const uint8_t *source, size_t length
modregrm_format_ = ModRegRMFormat::MemRegROL_to_SAR; modregrm_format_ = ModRegRMFormat::MemRegROL_to_SAR;
operation_size_ = 1 + (instr_ & 1); operation_size_ = 1 + (instr_ & 1);
source_ = Source::Immediate; source_ = Source::Immediate;
// TODO: set operand to 1. operand_ = 1;
break; break;
case 0xd2: case 0xd3: case 0xd2: case 0xd3:
phase_ = Phase::ModRegRM; phase_ = Phase::ModRegRM;
@ -512,14 +512,20 @@ std::pair<int, Instruction> Decoder::decode(const uint8_t *source, size_t length
// MARK: - Displacement and operand. // MARK: - Displacement and operand.
if(phase_ == Phase::AwaitingDisplacementOrOperand && source != end) { if(phase_ == Phase::AwaitingDisplacementOrOperand && source != end) {
// TODO: calculate number of expected operands.
const int required_bytes = displacement_size_ + operand_size_; const int required_bytes = displacement_size_ + operand_size_;
if(!required_bytes) {
phase_ = Phase::ReadyToPost;
} else {
const int outstanding_bytes = required_bytes - operand_bytes_; const int outstanding_bytes = required_bytes - operand_bytes_;
const int bytes_to_consume = std::min(int(end - source), outstanding_bytes); const int bytes_to_consume = std::min(int(end - source), outstanding_bytes);
// TODO: fill displacement_ and operand_ here... efficiently?
source += bytes_to_consume; source += bytes_to_consume;
consumed_ += bytes_to_consume; consumed_ += bytes_to_consume;
operand_bytes_ += bytes_to_consume; operand_bytes_ += bytes_to_consume;
if(bytes_to_consume == outstanding_bytes) { if(bytes_to_consume == outstanding_bytes) {
phase_ = Phase::ReadyToPost; phase_ = Phase::ReadyToPost;
} else { } else {
@ -527,6 +533,7 @@ std::pair<int, Instruction> Decoder::decode(const uint8_t *source, size_t length
return std::make_pair(-(outstanding_bytes - bytes_to_consume), Instruction()); return std::make_pair(-(outstanding_bytes - bytes_to_consume), Instruction());
} }
} }
}
// MARK: - Check for completion. // MARK: - Check for completion.