diff options
Diffstat (limited to 'gcc/hwint.c')
-rw-r--r-- | gcc/hwint.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/gcc/hwint.c b/gcc/hwint.c index 85c1326..a128dc1 100644 --- a/gcc/hwint.c +++ b/gcc/hwint.c @@ -21,6 +21,7 @@ along with GCC; see the file COPYING3. If not see #include "config.h" #include "system.h" +#include "diagnostic-core.h" #if GCC_VERSION < 3004 @@ -98,3 +99,76 @@ ffs_hwi (unsigned HOST_WIDE_INT x) } #endif /* GCC_VERSION < 3004 */ + +/* Compute the absolute value of X. */ + +HOST_WIDE_INT +abs_hwi (HOST_WIDE_INT x) +{ + gcc_checking_assert (x != HOST_WIDE_INT_MIN); + return x >= 0 ? x : -x; +} + +/* Compute the greatest common divisor of two numbers A and B using + Euclid's algorithm. */ + +HOST_WIDE_INT +gcd (HOST_WIDE_INT a, HOST_WIDE_INT b) +{ + HOST_WIDE_INT x, y, z; + + x = abs_hwi (a); + y = abs_hwi (b); + + while (x > 0) + { + z = y % x; + y = x; + x = z; + } + + return y; +} + +/* For X and Y positive integers, return X multiplied by Y and check + that the result does not overflow. */ + +HOST_WIDE_INT +pos_mul_hwi (HOST_WIDE_INT x, HOST_WIDE_INT y) +{ + if (x != 0) + gcc_checking_assert ((HOST_WIDE_INT_MAX) / x >= y); + + return x * y; +} + +/* Return X multiplied by Y and check that the result does not + overflow. */ + +HOST_WIDE_INT +mul_hwi (HOST_WIDE_INT x, HOST_WIDE_INT y) +{ + gcc_checking_assert (x != HOST_WIDE_INT_MIN + && y != HOST_WIDE_INT_MIN); + + if (x >= 0) + { + if (y >= 0) + return pos_mul_hwi (x, y); + + return -pos_mul_hwi (x, -y); + } + + if (y >= 0) + return -pos_mul_hwi (-x, y); + + return pos_mul_hwi (-x, -y); +} + +/* Compute the least common multiple of two numbers A and B . */ + +HOST_WIDE_INT +least_common_multiple (HOST_WIDE_INT a, HOST_WIDE_INT b) +{ + return mul_hwi (abs_hwi (a) / gcd (a, b), abs_hwi (b)); +} |