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tim-onetim-one
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Cray J90 fixes for long ints.
This was a convenient excuse to create the pyport.h file recently discussed! Please use new Py_ARITHMETIC_RIGHT_SHIFT when right-shifting a signed int and you *need* sign-extension. This is #define'd in pyport.h, keying off new config symbol SIGNED_RIGHT_SHIFT_ZERO_FILLS. If you're running on a platform that needs that symbol #define'd, the std tests never would have worked for you (in particular, at least test_long would have failed). The autoconfig stuff got added to Python after my Unix days, so I don't know how that works. Would someone please look into doing & testing an auto-config of the SIGNED_RIGHT_SHIFT_ZERO_FILLS symbol? It needs to be defined if & only if, e.g., (-1) >> 3 is not -1.
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Lines changed: 76 additions & 12 deletions

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‎Include/Python.h‎

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@@ -31,6 +31,7 @@ redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
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#include "patchlevel.h"
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#include "config.h"
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#include "pyport.h"
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/* config.h may or may not define DL_IMPORT */
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#ifndef DL_IMPORT /* declarations for DLL import/export */

‎Include/longintrepr.h‎

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@@ -18,7 +18,7 @@ redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
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/* Parameters of the long integer representation.
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These shouldn't have to be changed as C should guarantee that a short
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contains at least 16 bits, but it's made changeable any way.
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contains at least 16 bits, but it's made changeable anyway.
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Note: 'digit' should be able to hold 2*MASK+1, and 'twodigits'
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should be able to hold the intermediate results in 'mul'
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(at most MASK << SHIFT).
@@ -28,8 +28,9 @@ redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
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typedef unsigned short digit;
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typedef unsigned int wdigit; /* digit widened to parameter size */
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typedef unsigned long twodigits;
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typedef long stwodigits; /* signed variant of twodigits */
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#define BASE_TWODIGITS_TYPE long
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typedef unsigned BASE_TWODIGITS_TYPE twodigits;
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typedef BASE_TWODIGITS_TYPE stwodigits; /* signed variant of twodigits */
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#define SHIFT 15
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#define BASE ((digit)1 << SHIFT)

‎Include/pyport.h‎

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@@ -0,0 +1,57 @@
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/***********************************************************
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Copyright (c) 2000, BeOpen.com.
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All rights reserved.
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See the file "Misc/COPYRIGHT" for information on usage and
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redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
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******************************************************************/
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#ifndef Py_PYPORT_H
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#define Py_PYPORT_H 1
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/**************************************************************************
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Symbols and macros to supply platform-independent interfaces to basic
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C-language operations whose spellings vary across platforms.
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Please try to make documentation here as clear as possible: by definition,
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the stuff here is trying to illuminate C's darkest corners.
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Config #defines referenced here:
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SIGNED_RIGHT_SHIFT_ZERO_FILLS
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Meaning: To be defined iff i>>j does not extend the sign bit when i is a
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signed integral type and i < 0.
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Used in: Py_ARITHMETIC_RIGHT_SHIFT
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**************************************************************************/
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* Py_ARITHMETIC_RIGHT_SHIFT
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* C doesn't define whether a right-shift of a signed integer sign-extends
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* or zero-fills. Here a macro to force sign extension:
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* Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J)
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* Return I >> J, forcing sign extension.
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* Requirements:
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* I is of basic signed type TYPE (char, short, int, long, or long long).
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* TYPE is one of char, short, int, long, or long long, although long long
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* must not be used except on platforms that support it.
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* J is an integer >= 0 and strictly less than the number of bits in TYPE
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* (because C doesn't define what happens for J outside that range either).
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* Caution:
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* I may be evaluated more than once.
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*/
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#ifdef SIGNED_RIGHT_SHIFT_ZERO_FILLS
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#define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) \
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((I) < 0 ? ~((~(unsigned TYPE)(I)) >> (J)) : (I) >> (J))
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#else
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#define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) ((I) >> (J))
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#endif
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#ifdef __cplusplus
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}
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#endif
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#endif /* Py_PYPORT_H */

‎Objects/intobject.c‎

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@@ -721,10 +721,7 @@ int_rshift(v, w)
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a = 0;
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}
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else {
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if (a < 0)
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a = ~( ~(unsigned long)a >> b );
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else
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a = (unsigned long)a >> b;
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a = Py_ARITHMETIC_RIGHT_SHIFT(long, a, b);
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}
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return PyInt_FromLong(a);
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}

‎Objects/longobject.c‎

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@@ -571,7 +571,8 @@ long_format(PyObject *aa, int base, int addL)
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int last = abs(a->ob_size);
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int basebits = 1;
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i = base;
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while ((i >>= 1) > 1) ++basebits;
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while ((i >>= 1) > 1)
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++basebits;
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i = 0;
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for (;;) {
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carry += v->ob_digit[i+k] - z
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+ ((twodigits)zz << SHIFT);
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v->ob_digit[i+k] = carry & MASK;
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carry = (carry >> SHIFT) - zz;
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carry = Py_ARITHMETIC_RIGHT_SHIFT(BASE_TWODIGITS_TYPE,
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carry, SHIFT);
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carry -= zz;
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}
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if (i+k < size_v) {
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for (i = 0; i < size_w && i+k < size_v; ++i) {
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carry += v->ob_digit[i+k] + w->ob_digit[i];
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v->ob_digit[i+k] = carry & MASK;
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carry >>= SHIFT;
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carry = Py_ARITHMETIC_RIGHT_SHIFT(
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BASE_TWODIGITS_TYPE,
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carry, SHIFT);
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}
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}
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} /* for j, k */
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for (i = 0; i < size_b; ++i) {
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carry += a->ob_digit[i] + b->ob_digit[i];
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z->ob_digit[i] = carry & MASK;
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/* The following assumes unsigned shifts don't
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propagate the sign bit. */
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carry >>= SHIFT;
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}
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for (; i < size_a; ++i) {

‎acconfig.h‎

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@@ -169,5 +169,10 @@
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/* Defined when any dynamic module loading is enabled */
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#undef HAVE_DYNAMIC_LOADING
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/* Define if i>>j for signed int i does not extend the sign bit
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when i < 0
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*/
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#undef SIGNED_RIGHT_SHIFT_ZERO_FILLS
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/* Leave that blank line there-- autoheader needs it! */

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