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bug#65491: [PATCH] Improve performance allocating vectors
From: |
Mattias Engdegård |
Subject: |
bug#65491: [PATCH] Improve performance allocating vectors |
Date: |
Sat, 16 Sep 2023 19:22:54 +0200 |
16 sep. 2023 kl. 19.09 skrev Eli Zaretskii <eliz@gnu.org>:
> Sorry, I cannot accept this kind of "discussions" when such tricky
> issues come up. What's the rush of installing changes when you still
> didn't answer my questions, and we still are not sure these changes
> are correct?
I'm confident that they are correct. Moreover, I'm also confident that the old
code was incorrect, which is why the change was carried out. Both the C
standard and modern C compilers agree.
There's nothing strange or unusual that the 32-bit --with-wide-int
configuration sees unexpected warnings when code is changed. You must have seen
that many times before. It doesn't mean that there is anything wrong with the
change; in this case it was just a somewhat pedantic GCC warning, quickly
silenced.
>>> It does, but LISP_WORD_TAG(type) is a 64=bit type with the only bits
>>> set above 32 bit, so how casting it to uintptr_t is TRT?
>>
>> Because XUNTAG is used to get the pointer part; we don't want the tag bits.
>
> Then just casting should do, no? Why the subtraction?
Because when Lisp_Object is pointer-sized we need to remove the tag bits from
the word. Only in the special configuration with a Lisp_Object that is larger
than pointers can we simply cast away the tag bits.
- bug#65491: [PATCH] Improve performance allocating vectors, (continued)
- bug#65491: [PATCH] Improve performance allocating vectors, Mattias Engdegård, 2023/09/16
- bug#65491: [PATCH] Improve performance allocating vectors, Eli Zaretskii, 2023/09/16
- bug#65491: [PATCH] Improve performance allocating vectors, Po Lu, 2023/09/16
- bug#65491: [PATCH] Improve performance allocating vectors, Stefan Monnier, 2023/09/17
- bug#65491: [PATCH] Improve performance allocating vectors, Po Lu, 2023/09/17
- bug#65491: [PATCH] Improve performance allocating vectors, Stefan Monnier, 2023/09/17
- bug#65491: [PATCH] Improve performance allocating vectors, Po Lu, 2023/09/17
- bug#65491: [PATCH] Improve performance allocating vectors, Stefan Monnier, 2023/09/18
- bug#65491: [PATCH] Improve performance allocating vectors, Mattias Engdegård, 2023/09/16
- bug#65491: [PATCH] Improve performance allocating vectors, Eli Zaretskii, 2023/09/16
- bug#65491: [PATCH] Improve performance allocating vectors,
Mattias Engdegård <=
- bug#65491: [PATCH] Improve performance allocating vectors, Eli Zaretskii, 2023/09/16
- bug#65491: [PATCH] Improve performance allocating vectors, Mattias Engdegård, 2023/09/16
- bug#65491: [PATCH] Improve performance allocating vectors, Paul Eggert, 2023/09/16
- bug#65491: [PATCH] Improve performance allocating vectors, Eli Zaretskii, 2023/09/17
- bug#65491: [PATCH] Improve performance allocating vectors, Paul Eggert, 2023/09/17
- bug#65491: [PATCH] Improve performance allocating vectors, Eli Zaretskii, 2023/09/17
- bug#65491: [PATCH] Improve performance allocating vectors, Paul Eggert, 2023/09/17
- bug#65491: [PATCH] Improve performance allocating vectors, Eli Zaretskii, 2023/09/17
- bug#65491: [PATCH] Improve performance allocating vectors, Mattias Engdegård, 2023/09/18
- bug#65491: [PATCH] Improve performance allocating vectors, Eli Zaretskii, 2023/09/18