// VI is an in-loop instruction that uses Visitor.V, a loop invariant. Check whether any
// iteration will require the value. Assume it is used if we're synthesising an unspecialised
// copy of the loop for any reason.
void PeelIteration::visitVariant(ShadowInstructionInvar* VI, DIVisitor& Visitor) {
const ShadowLoopInvar* immediateChild = immediateChildLoop(L, VI->parent->outerScope);
PeelAttempt* LPA = getPeelAttempt(immediateChild);
if(LPA && LPA->isEnabled())
LPA->visitVariant(VI, Visitor);
else
Visitor.notifyUsersMissed();
}
void IntegrationAttempt::visitUser(ShadowInstIdx& User, DIVisitor& Visitor) {
// Figure out what context cares about this value. The only possibilities are: this loop iteration, the next iteration of this loop (latch edge of header phi),
// a child loop (defer to it to decide what to do), or a parent loop (again defer).
// Note that nested cases (e.g. this is an invariant two children deep) are taken care of in the immediate child or parent's logic.
if(User.blockIdx == INVALID_BLOCK_IDX || User.instIdx == INVALID_INSTRUCTION_IDX)
return;
ShadowInstructionInvar* SII = getInstInvar(User.blockIdx, User.instIdx);
const ShadowLoopInvar* UserL = SII->parent->outerScope;
if(UserL == L) {
if(!visitNextIterationPHI(SII, Visitor)) {
// Just an ordinary user in the same iteration (or out of any loop!).
Visitor.visit(getInst(User.blockIdx, User.instIdx), this, User.blockIdx, User.instIdx);
}
}
else {
if((!L) || L->contains(UserL)) {
const ShadowLoopInvar* outermostChildLoop = immediateChildLoop(L, UserL);
// Used in a child loop. Check if that child exists at all and defer to it.
PeelAttempt* LPA = getPeelAttempt(outermostChildLoop);
if(LPA && LPA->isEnabled())
LPA->visitVariant(SII, Visitor);
else if((!getBB(outermostChildLoop->headerIdx)))
Visitor.visit(0, this, User.blockIdx, User.instIdx); // Loop not explored, but a failed version may exist
else
Visitor.notifyUsersMissed();
}
else {
visitExitPHI(SII, Visitor);
}
}
}
