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xo-procedure2 stack: + report-gc-object-ages() primitive

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This commit is contained in:
Roland Conybeare 2026-03-30 14:51:51 -04:00
commit 0954945e16
1 changed files with 11 additions and 1 deletions
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12
include/xo/arena/AllocHeaderConfig.hpp
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@ -60,6 +60,12 @@ namespace xo {
std::uint64_t mkheader(std::uint64_t t,
std::uint64_t a,
std::uint64_t z) const noexcept {
// don't let age wrap around.
// Expect std::min() to compile to cmov (no branch)
//
a = std::min(a, this->max_age());
uint64_t tseq_bits = (t << (age_bits_ + size_bits_)) & tseq_mask();
uint64_t age_bits = (a << size_bits_) & age_mask();
uint64_t size_bits = z & size_mask();;
@ -75,12 +81,16 @@ namespace xo {
return ((1ul << tseq_bits_) - 1) << (age_bits_ + size_bits_);
}
std::uint64_t max_age() const noexcept {
return ((1ul << age_bits_) - 1);
}
std::uint64_t age_mask() const noexcept {
// e.g.
// 00 00 00 FF 00 00 00 00
// with age_bits=8, size_bits=32
//
return ((1ul << age_bits_) - 1) << size_bits_;
return this->max_age() << size_bits_;
}
std::uint64_t size_mask() const noexcept {