rajamesandClaude Opus 5.5
1ce705783c
(Q.REDUCE) is v3's q48_reduce_angle: the angle as one cell in [-pi, pi]. x / 2pi does not fit a cell, but only the remainder is needed, and |x| mod 2pi is two UM/MOD steps (high cell first, its remainder leading the low cell); then the sign of x and one step of 2pi back into range. Q.SIN is v3's q48_sin_approx on the reduced angle: the odd Taylor series to n = 11, each term the last times x^2 over n(n-1), stopping below 10 ulp. After the reduction every value fits one cell, so the 6-cell variable (QT) holds single cells. The loop is laid out for Q.COS to jump into, so the pair share it without an extra call level. Checked bit for bit against v3 (both functions ported into the test) on 33 edge angles -- around +-pi/2, +-pi, +-2pi, the 32-bit seam and both 64-bit extremes -- and 3000 pseudo-random angles of every size and sign, at 32- and 64-bit cells, optimised and ASan+UBSan (`make test`, `make sanitize`). Mutating either range boundary, the series length or the sign alternation fails. Moving the 10-ulp stop to 11 fails nothing, and a scan of all 205888 reduced angles in C shows why: no input's result depends on it, for sine or cosine. Headroom (data under arg / return): (Q.REDUCE) 5/5, Q.SIN 3/2. Test results on the amd64 host only. This is a development check, not acceptance (JUSTIFICATION.md section 16). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
v4/
StarForth v4: the 32-instruction F18-derived core. The design lives in
docs/v4.0.0/JUSTIFICATION.md (why) and docs/v4.0.0/DECOMPOSITION.md
(every v3 word mapped to a v4 fate).
The first deliverable is the hosted C99 golden model (JUSTIFICATION.md §10,
step 1). It must pass POST and hold K≡1.0 with 32- and 64-bit cells on all
three host ISAs.
Acceptance (JUSTIFICATION.md §16): v4 must be equivalent to v3 at any point
in time, with the same vocabularies and behaviour, on the F18-derived engine;
and every ISA, hosted and bare metal, must still reach its ok prompt.
make -C v4 test passing is a development check, not acceptance.
What exists so far is the single node: registers, circular stacks, memory, all
32 opcodes, and per-opcode and per-call-target heat. make -C v4 test builds
and runs the tests at both cell widths; make -C v4 sanitize repeats them
under ASan and UBSan. There is no compiler capsule, no POST and no K
measurement yet.