Re: Parsing timestamps?

On Sat, 5 Jul 2025 14:24:37 +0000, minforth wrote:

Am 05.07.2025 um 14:41 schrieb minforth:

Am 05.07.2025 um 14:21 schrieb albert@spenarnc.xs4all.nl:

I investigated the instruction set, and I found no way to detect
if the 8 registers stack is full.
This would offer the possibility to spill registers to memory only
if it is needed.
>

>
IIRC signaling and handling fp-stack overflow is not an easy task.
At most, the computer would crash.
IOW, spilling makes sense.

>
A deep dive into the manual
>
... the C1 condition code flag is used for a variety of functions.
When both the IE and SF flags in the x87 FPU status word are set,
indicating a stack overflow or underflow exception (#IS), the C1
flag distinguishes between overflow (C1=1) and underflow (C1=0).

This definitely does not work (I tried it). That manual is fabulating.
iForth has its FP stack in memory. However, inside colon definitions
the compiler tracks the hardware stack. Only when inlining is not
possible, or would lead to excessive size, HW stack items are
flushed/reloaded to/from memory. Anyway, a software stack is necessary
when calling C libraries or the OS.
The mental cost of writing the FP compiler was insane, but I
found it justified.
BTW, the transputer had the same problem (and solution).
-marcel
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