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//------------------------------------------------------------------------------
// GB_int64_mult: multiplying two integer values safely; result z is int64_t
//------------------------------------------------------------------------------
// SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2025, All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
//------------------------------------------------------------------------------
// This macro computes the same thing as GB_uint64_multiply, except that it
// does not return a boolean ok flag to indicate whether or not integer
// overflow is detected. Instead, it just computes c as INT64_MAX if overflow
// occurs. Both inputs x and y must be >= 0.
#ifndef GB_INT64_MULT
#define GB_INT64_MULT(z,x,y) \
{ \
uint64_t a = (uint64_t) (x) ; \
uint64_t b = (uint64_t) (y) ; \
if (a == 0 || b == 0) \
{ \
(z) = 0 ; \
} \
else \
{ \
uint64_t a1 = a >> 30 ; \
uint64_t b1 = b >> 30 ; \
if (a1 > 0 && b1 > 0) \
{ \
(z) = INT64_MAX ; \
} \
else \
{ \
uint64_t a0 = a & 0x3FFFFFFFL ; \
uint64_t b0 = b & 0x3FFFFFFFL ; \
uint64_t t0 = a1*b0 ; \
uint64_t t1 = a0*b1 ; \
if (t0 >= 0x40000000L || t1 >= 0x40000000L) \
{ \
(z) = INT64_MAX ; \
} \
else \
{ \
uint64_t t2 = t0 + t1 ; \
uint64_t c = (t2 << 30) + a0*b0 ; \
(z) = (int64_t) c ; \
} \
} \
} \
}
#endif
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