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bug#65491: [PATCH] Improve performance allocating vectors
From: |
Po Lu |
Subject: |
bug#65491: [PATCH] Improve performance allocating vectors |
Date: |
Mon, 18 Sep 2023 10:19:09 +0800 |
User-agent: |
Gnus/5.13 (Gnus v5.13) |
Stefan Monnier <monnier@iro.umontreal.ca> writes:
> Even converting them back to their original pointer (which is what we do
> with tag/untag pairs) is documented to be well-defined if you compile
> using GCC.
Only if the consequent pointer designates the same object as the initial
pointer (of which I see no scrutable definition within GCC's
documentation.) But in practice, this doesn't matter, or so I thought.
> In contrast the pointer arithmetic on NULL pointers appears to be
> something which compilers have started to (ab)use as an assumption for
> their optimizations. Hence the need to update our code.
Hmm? Where in this thread was that fact established?
Thanks.
- 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, Eli Zaretskii, 2023/09/16
- 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, 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 <=
- 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, 2023/09/16
- 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