/* Simple data type for positive real numbers for the GNU compiler.
- Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2007, 2010 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 2, or (at your option) any later
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
/* This library supports positive real numbers and 0;
inf and nan are NOT supported.
Value of sreal is
x = sig * 2 ^ exp
- where
+ where
sig = significant
(for < 64-bit machines sig = sig_lo + sig_hi * 2 ^ SREAL_PART_BITS)
exp = exponent
otherwise two HOST_WIDE_INTs are used for the significant.
Only a half of significant bits is used (in normalized sreals) so that we do
not have problems with overflow, for example when c->sig = a->sig * b->sig.
- So the precission for 64-bit and 32-bit machines is 32-bit.
-
+ So the precision for 64-bit and 32-bit machines is 32-bit.
+
Invariant: The numbers are normalized before and after each call of sreal_*.
Normalized sreals:
All numbers (except zero) meet following conditions:
SREAL_MIN_SIG <= sig && sig <= SREAL_MAX_SIG
- -SREAL_MAX_EXP <= exp && exp <= SREAL_MAX_EXP
+ -SREAL_MAX_EXP <= exp && exp <= SREAL_MAX_EXP
If the number would be too large, it is set to upper bounds of these
conditions.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
#include "sreal.h"
-void dump_sreal PARAMS ((FILE *, sreal *));
-static inline void copy PARAMS ((sreal *, sreal *));
-static inline void shift_right PARAMS ((sreal *, int));
-static void normalize PARAMS ((sreal *));
+static inline void copy (sreal *, sreal *);
+static inline void shift_right (sreal *, int);
+static void normalize (sreal *);
/* Print the content of struct sreal. */
void
-dump_sreal (file, x)
- FILE *file;
- sreal *x;
+dump_sreal (FILE *file, sreal *x)
{
#if SREAL_PART_BITS < 32
- fprintf (file, "((");
- fprintf (file, HOST_WIDE_INT_PRINT_UNSIGNED, x->sig_hi);
- fprintf (file, " * 2^16 + ");
- fprintf (file, HOST_WIDE_INT_PRINT_UNSIGNED, x->sig_lo);
- fprintf (file, ") * 2^%d)", x->exp);
+ fprintf (file, "((" HOST_WIDE_INT_PRINT_UNSIGNED " * 2^16 + "
+ HOST_WIDE_INT_PRINT_UNSIGNED ") * 2^%d)",
+ x->sig_hi, x->sig_lo, x->exp);
#else
- fprintf (file, "(");
- fprintf (file, HOST_WIDE_INT_PRINT_UNSIGNED, x->sig);
- fprintf (file, " * 2^%d)", x->exp);
+ fprintf (file, "(" HOST_WIDE_INT_PRINT_UNSIGNED " * 2^%d)", x->sig, x->exp);
#endif
}
/* Copy the sreal number. */
static inline void
-copy (r, a)
- sreal *r;
- sreal *a;
+copy (sreal *r, sreal *a)
{
#if SREAL_PART_BITS < 32
r->sig_lo = a->sig_lo;
When the most significant bit shifted out is 1, add 1 to X (rounding). */
static inline void
-shift_right (x, s)
- sreal *x;
- int s;
+shift_right (sreal *x, int s)
{
-#ifdef ENABLE_CHECKING
- if (s <= 0 || s > SREAL_BITS)
- abort ();
- if (x->exp + s > SREAL_MAX_EXP)
- {
- /* Exponent should never be so large because shift_right is used only by
- sreal_add and sreal_sub ant thus the number cannot be shifted out from
- exponent range. */
- abort ();
- }
-#endif
+ gcc_assert (s > 0);
+ gcc_assert (s <= SREAL_BITS);
+ /* Exponent should never be so large because shift_right is used only by
+ sreal_add and sreal_sub ant thus the number cannot be shifted out from
+ exponent range. */
+ gcc_assert (x->exp + s <= SREAL_MAX_EXP);
x->exp += s;
/* Normalize *X. */
static void
-normalize (x)
- sreal *x;
+normalize (sreal *x)
{
#if SREAL_PART_BITS < 32
int shift;
HOST_WIDE_INT mask;
-
+
if (x->sig_lo == 0 && x->sig_hi == 0)
{
x->exp = -SREAL_MAX_EXP;
/* Set *R to SIG * 2 ^ EXP. Return R. */
sreal *
-sreal_init (r, sig, exp)
- sreal *r;
- unsigned HOST_WIDE_INT sig;
- signed int exp;
+sreal_init (sreal *r, unsigned HOST_WIDE_INT sig, signed int exp)
{
#if SREAL_PART_BITS < 32
r->sig_lo = 0;
/* Return integer value of *R. */
HOST_WIDE_INT
-sreal_to_int (r)
- sreal *r;
+sreal_to_int (sreal *r)
{
#if SREAL_PART_BITS < 32
if (r->exp <= -SREAL_BITS)
/* Compare *A and *B. Return -1 if *A < *B, 1 if *A > *B and 0 if *A == *B. */
int
-sreal_compare (a, b)
- sreal *a;
- sreal *b;
+sreal_compare (sreal *a, sreal *b)
{
if (a->exp > b->exp)
return 1;
/* *R = *A + *B. Return R. */
sreal *
-sreal_add (r, a, b)
- sreal *r;
- sreal *a;
- sreal *b;
+sreal_add (sreal *r, sreal *a, sreal *b)
{
int dexp;
sreal tmp;
/* *R = *A - *B. Return R. */
sreal *
-sreal_sub (r, a, b)
- sreal *r;
- sreal *a;
- sreal *b;
+sreal_sub (sreal *r, sreal *a, sreal *b)
{
int dexp;
sreal tmp;
sreal *bb;
- if (sreal_compare (a, b) < 0)
- {
- abort ();
- }
+ gcc_assert (sreal_compare (a, b) >= 0);
dexp = a->exp - b->exp;
r->exp = a->exp;
/* *R = *A * *B. Return R. */
sreal *
-sreal_mul (r, a, b)
- sreal *r;
- sreal *a;
- sreal *b;
+sreal_mul (sreal *r, sreal *a, sreal *b)
{
#if SREAL_PART_BITS < 32
if (a->sig_hi < SREAL_MIN_SIG || b->sig_hi < SREAL_MIN_SIG)
/* *R = *A / *B. Return R. */
sreal *
-sreal_div (r, a, b)
- sreal *r;
- sreal *a;
- sreal *b;
+sreal_div (sreal *r, sreal *a, sreal *b)
{
#if SREAL_PART_BITS < 32
unsigned HOST_WIDE_INT tmp, tmp1, tmp2;
- if (b->sig_hi < SREAL_MIN_SIG)
- {
- abort ();
- }
- else if (a->sig_hi < SREAL_MIN_SIG)
+ gcc_assert (b->sig_hi >= SREAL_MIN_SIG);
+ if (a->sig_hi < SREAL_MIN_SIG)
{
r->sig_hi = 0;
r->sig_lo = 0;
normalize (r);
}
#else
- if (b->sig == 0)
- {
- abort ();
- }
- else
- {
- r->sig = (a->sig << SREAL_PART_BITS) / b->sig;
- r->exp = a->exp - b->exp - SREAL_PART_BITS;
- normalize (r);
- }
+ gcc_assert (b->sig != 0);
+ r->sig = (a->sig << SREAL_PART_BITS) / b->sig;
+ r->exp = a->exp - b->exp - SREAL_PART_BITS;
+ normalize (r);
#endif
return r;
}
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