Commit Graph

8 Commits

Author SHA1 Message Date
Jessica Clarke dec0757549
bpo-43179: Generalise alignment for optimised string routines (GH-24624)
* Remove m68k-specific hack from ascii_decode

On m68k, alignments of primitives is more relaxed, with 4-byte and
8-byte types only requiring 2-byte alignment, thus using sizeof(size_t)
does not work. Instead, use the portable alternative.

Note that this is a minimal fix that only relaxes the assertion and the
condition for when to use the optimised version remains overly strict.
Such issues will be fixed tree-wide in the next commit.

NB: In C11 we could use _Alignof(size_t) instead, but for compatibility
we use autoconf.

* Optimise string routines for architectures with non-natural alignment

C only requires that sizeof(x) is a multiple of alignof(x), not that the
two are equal. Thus anywhere where we optimise based on alignment we
should be using alignof(x) not sizeof(x).

This is more annoying than it would be in C11 where we could just use
_Alignof(x) (and alignof(x) in C++11), but since we still require only
C99 we must plumb the information all the way from autoconf through the
various typedefs and defines.
2021-03-31 12:12:39 +02:00
Ma Lin a0c603cb9d
bpo-38252: Use 8-byte step to detect ASCII sequence in 64bit Windows build (GH-16334) 2020-10-18 17:48:38 +03:00
Andy Lester e6be9b59a9
closes bpo-39605: Fix some casts to not cast away const. (GH-18453)
gcc -Wcast-qual turns up a number of instances of casting away constness of pointers. Some of these can be safely modified, by either:

Adding the const to the type cast, as in:

-    return _PyUnicode_FromUCS1((unsigned char*)s, size);
+    return _PyUnicode_FromUCS1((const unsigned char*)s, size);

or, Removing the cast entirely, because it's not necessary (but probably was at one time), as in:

-    PyDTrace_FUNCTION_ENTRY((char *)filename, (char *)funcname, lineno);
+    PyDTrace_FUNCTION_ENTRY(filename, funcname, lineno);

These changes will not change code, but they will make it much easier to check for errors in consts
2020-02-11 18:28:35 -08:00
Serhiy Storchaka bcde10aa7e Issue #26765: Ensure that bytes- and unicode-specific stringlib files are used
with correct type.
2016-05-16 09:42:29 +03:00
Antoine Pitrou 9ed5f27266 Issue #18722: Remove uses of the "register" keyword in C code. 2013-08-13 20:18:52 +02:00
Antoine Pitrou ca8aa4acf6 Issue #15144: Fix possible integer overflow when handling pointers as integer values, by using Py_uintptr_t instead of size_t.
Patch by Serhiy Storchaka.
2012-09-20 20:56:47 +02:00
Mark Dickinson 01ac8b6ab1 Use correct types for ASCII_CHAR_MASK integer constants. 2012-07-07 14:08:48 +02:00
Antoine Pitrou dd4e2f0153 Issue #13155: Optimize finding the optimal character width of an unicode string 2011-10-13 00:02:27 +02:00