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| From | Kragen Javier Sitaker <kragen@canonical.org> |
| Newsgroups | comp.lang.forth |
| Subject | Re: First result in riscv optimiser |
| Date | Tue, 08 Sep 2026 02:21:32 -0300 |
| Organization | Primarily biological and memetic |
| Lines | 40 |
| Message-ID | <87y0dcgvxf.fsf@debian> (permalink) |
| References | <nnd$172defd2$1b2df6f6@e430673098f06a19> <2026Sep1.173341@mips.complang.tuwien.ac.at> <87ecf96ljg.fsf@debian> <nnd$23c5006f$6f768ed1@9c6c99f017e8c6d5> |
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albert@spenarnc.xs4all.nl writes: > In article <87ecf96ljg.fsf@debian>, > Kragen Javier Sitaker <kragen@canonical.org> wrote: >>anton@mips.complang.tuwien.ac.at (Anton Ertl) writes: >>> (...) in general I don't think that full constant folding will trigger >>> often, (...) >> >>This is contextual. (...) > > You bet it is. > This is a test of the optimiser for i86 (that is unfinished but > partly working) > ------------------------------------- > \ Test of annihilating. > : test6 BASE @ IF SWAP THEN 2DROP ; > > ... > > : test6 > DROP DROP > ; > > After inlining of code words: > > POP|X, AX| > POP|X, AX| This is not quite constant folding, but it’s a related optimization. I don’t remember if it has an accepted name — it’s close to register allocation, but of course you aren’t allocating any registers. Clearly it makes a great improvement in `test6`. However, how does such code arise? You surely wouldn’t intentionally write it that way in production code. Conditional compilation with [ifdef] and the like? Subroutine inlining? That is, this kind of optimization can be extremely powerful — but generally only in synergy with other optimizations which create opportunities for it. Kragen
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First result in riscv optimiser albert@spenarnc.xs4all.nl - 2026-09-01 10:49 +0200
Re: First result in riscv optimiser anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2026-09-01 15:33 +0000
Re: First result in riscv optimiser albert@spenarnc.xs4all.nl - 2026-09-01 18:54 +0200
Re: First result in riscv optimiser albert@spenarnc.xs4all.nl - 2026-09-02 11:18 +0200
Re: First result in riscv optimiser Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-04 13:14 -0300
Re: First result in riscv optimiser albert@spenarnc.xs4all.nl - 2026-09-05 13:06 +0200
Re: First result in riscv optimiser Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-08 02:21 -0300
Re: First result in riscv optimiser albert@spenarnc.xs4all.nl - 2026-09-08 12:38 +0200
Re: First result in riscv optimiser Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-11 07:50 -0300
Re: First result in riscv optimiser Paul Rubin <no.email@nospam.invalid> - 2026-09-11 17:09 -0700
Re: First result in riscv optimiser albert@spenarnc.xs4all.nl - 2026-09-13 14:03 +0200
Re: First result in riscv optimiser antispam@fricas.org (Waldek Hebisch) - 2026-09-13 02:53 +0000
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