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Merge pull request #1903 from heapo/fmul_postfactor

Implement postfactor multiplication/division for fmul instructions
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bunnei 2018-12-17 22:00:43 -05:00 committed by GitHub
commit 95255899e7
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2 changed files with 21 additions and 5 deletions

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@ -575,7 +575,7 @@ union Instruction {
union {
BitField<39, 2, u64> tab5cb8_2;
BitField<41, 3, u64> tab5c68_1;
BitField<41, 3, u64> postfactor;
BitField<44, 2, u64> tab5c68_0;
BitField<48, 1, u64> negate_b;
} fmul;

View file

@ -1867,9 +1867,6 @@ private:
UNIMPLEMENTED_IF_MSG(instr.fmul.tab5cb8_2 != 0,
"FMUL tab5cb8_2({}) is not implemented",
instr.fmul.tab5cb8_2.Value());
UNIMPLEMENTED_IF_MSG(instr.fmul.tab5c68_1 != 0,
"FMUL tab5cb8_1({}) is not implemented",
instr.fmul.tab5c68_1.Value());
UNIMPLEMENTED_IF_MSG(
instr.fmul.tab5c68_0 != 1, "FMUL tab5cb8_0({}) is not implemented",
instr.fmul.tab5c68_0
@ -1879,7 +1876,26 @@ private:
op_b = GetOperandAbsNeg(op_b, false, instr.fmul.negate_b);
regs.SetRegisterToFloat(instr.gpr0, 0, op_a + " * " + op_b, 1, 1,
std::string postfactor_op;
if (instr.fmul.postfactor != 0) {
s8 postfactor = static_cast<s8>(instr.fmul.postfactor);
// postfactor encoded as 3-bit 1's complement in instruction,
// interpreted with below logic.
if (postfactor >= 4) {
postfactor = 7 - postfactor;
} else {
postfactor = 0 - postfactor;
}
if (postfactor > 0) {
postfactor_op = " * " + std::to_string(1 << postfactor);
} else {
postfactor_op = " / " + std::to_string(1 << -postfactor);
}
}
regs.SetRegisterToFloat(instr.gpr0, 0, op_a + " * " + op_b + postfactor_op, 1, 1,
instr.alu.saturate_d, 0, true);
break;
}