| /* Operations with very long integers. |
| Copyright (C) 2012-2015 Free Software Foundation, Inc. |
| Contributed by Kenneth Zadeck <zadeck@naturalbridge.com> |
| |
| 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 3, or (at your option) any |
| later version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT |
| ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "tm.h" |
| #include "hwint.h" |
| #include "wide-int.h" |
| #include "hash-set.h" |
| #include "machmode.h" |
| #include "vec.h" |
| #include "double-int.h" |
| #include "input.h" |
| #include "alias.h" |
| #include "symtab.h" |
| #include "inchash.h" |
| #include "tree.h" |
| #include "dumpfile.h" |
| |
| |
| #define HOST_BITS_PER_HALF_WIDE_INT 32 |
| #if HOST_BITS_PER_HALF_WIDE_INT == HOST_BITS_PER_LONG |
| # define HOST_HALF_WIDE_INT long |
| #elif HOST_BITS_PER_HALF_WIDE_INT == HOST_BITS_PER_INT |
| # define HOST_HALF_WIDE_INT int |
| #else |
| #error Please add support for HOST_HALF_WIDE_INT |
| #endif |
| |
| #define W_TYPE_SIZE HOST_BITS_PER_WIDE_INT |
| /* Do not include longlong.h when compiler is clang-based. See PR61146. */ |
| #if GCC_VERSION >= 3000 && (W_TYPE_SIZE == 32 || defined (__SIZEOF_INT128__)) && !defined(__clang__) |
| typedef unsigned HOST_HALF_WIDE_INT UHWtype; |
| typedef unsigned HOST_WIDE_INT UWtype; |
| typedef unsigned int UQItype __attribute__ ((mode (QI))); |
| typedef unsigned int USItype __attribute__ ((mode (SI))); |
| typedef unsigned int UDItype __attribute__ ((mode (DI))); |
| #if W_TYPE_SIZE == 32 |
| typedef unsigned int UDWtype __attribute__ ((mode (DI))); |
| #else |
| typedef unsigned int UDWtype __attribute__ ((mode (TI))); |
| #endif |
| #include "longlong.h" |
| #endif |
| |
| static const HOST_WIDE_INT zeros[WIDE_INT_MAX_ELTS] = {}; |
| |
| /* |
| * Internal utilities. |
| */ |
| |
| /* Quantities to deal with values that hold half of a wide int. Used |
| in multiply and divide. */ |
| #define HALF_INT_MASK (((HOST_WIDE_INT) 1 << HOST_BITS_PER_HALF_WIDE_INT) - 1) |
| |
| #define BLOCK_OF(TARGET) ((TARGET) / HOST_BITS_PER_WIDE_INT) |
| #define BLOCKS_NEEDED(PREC) \ |
| (PREC ? (((PREC) + HOST_BITS_PER_WIDE_INT - 1) / HOST_BITS_PER_WIDE_INT) : 1) |
| #define SIGN_MASK(X) ((HOST_WIDE_INT) (X) < 0 ? -1 : 0) |
| |
| /* Return the value a VAL[I] if I < LEN, otherwise, return 0 or -1 |
| based on the top existing bit of VAL. */ |
| |
| static unsigned HOST_WIDE_INT |
| safe_uhwi (const HOST_WIDE_INT *val, unsigned int len, unsigned int i) |
| { |
| return i < len ? val[i] : val[len - 1] < 0 ? (HOST_WIDE_INT) -1 : 0; |
| } |
| |
| /* Convert the integer in VAL to canonical form, returning its new length. |
| LEN is the number of blocks currently in VAL and PRECISION is the number |
| of bits in the integer it represents. |
| |
| This function only changes the representation, not the value. */ |
| static unsigned int |
| canonize (HOST_WIDE_INT *val, unsigned int len, unsigned int precision) |
| { |
| unsigned int blocks_needed = BLOCKS_NEEDED (precision); |
| HOST_WIDE_INT top; |
| int i; |
| |
| if (len > blocks_needed) |
| len = blocks_needed; |
| |
| if (len == 1) |
| return len; |
| |
| top = val[len - 1]; |
| if (len * HOST_BITS_PER_WIDE_INT > precision) |
| val[len - 1] = top = sext_hwi (top, precision % HOST_BITS_PER_WIDE_INT); |
| if (top != 0 && top != (HOST_WIDE_INT)-1) |
| return len; |
| |
| /* At this point we know that the top is either 0 or -1. Find the |
| first block that is not a copy of this. */ |
| for (i = len - 2; i >= 0; i--) |
| { |
| HOST_WIDE_INT x = val[i]; |
| if (x != top) |
| { |
| if (SIGN_MASK (x) == top) |
| return i + 1; |
| |
| /* We need an extra block because the top bit block i does |
| not match the extension. */ |
| return i + 2; |
| } |
| } |
| |
| /* The number is 0 or -1. */ |
| return 1; |
| } |
| |
| /* |
| * Conversion routines in and out of wide_int. |
| */ |
| |
| /* Copy XLEN elements from XVAL to VAL. If NEED_CANON, canonize the |
| result for an integer with precision PRECISION. Return the length |
| of VAL (after any canonization. */ |
| unsigned int |
| wi::from_array (HOST_WIDE_INT *val, const HOST_WIDE_INT *xval, |
| unsigned int xlen, unsigned int precision, bool need_canon) |
| { |
| for (unsigned i = 0; i < xlen; i++) |
| val[i] = xval[i]; |
| return need_canon ? canonize (val, xlen, precision) : xlen; |
| } |
| |
| /* Construct a wide int from a buffer of length LEN. BUFFER will be |
| read according to byte endianess and word endianess of the target. |
| Only the lower BUFFER_LEN bytes of the result are set; the remaining |
| high bytes are cleared. */ |
| wide_int |
| wi::from_buffer (const unsigned char *buffer, unsigned int buffer_len) |
| { |
| unsigned int precision = buffer_len * BITS_PER_UNIT; |
| wide_int result = wide_int::create (precision); |
| unsigned int words = buffer_len / UNITS_PER_WORD; |
| |
| /* We have to clear all the bits ourself, as we merely or in values |
| below. */ |
| unsigned int len = BLOCKS_NEEDED (precision); |
| HOST_WIDE_INT *val = result.write_val (); |
| for (unsigned int i = 0; i < len; ++i) |
| val[i] = 0; |
| |
| for (unsigned int byte = 0; byte < buffer_len; byte++) |
| { |
| unsigned int offset; |
| unsigned int index; |
| unsigned int bitpos = byte * BITS_PER_UNIT; |
| unsigned HOST_WIDE_INT value; |
| |
| if (buffer_len > UNITS_PER_WORD) |
| { |
| unsigned int word = byte / UNITS_PER_WORD; |
| |
| if (WORDS_BIG_ENDIAN) |
| word = (words - 1) - word; |
| |
| offset = word * UNITS_PER_WORD; |
| |
| if (BYTES_BIG_ENDIAN) |
| offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD); |
| else |
| offset += byte % UNITS_PER_WORD; |
| } |
| else |
| offset = BYTES_BIG_ENDIAN ? (buffer_len - 1) - byte : byte; |
| |
| value = (unsigned HOST_WIDE_INT) buffer[offset]; |
| |
| index = bitpos / HOST_BITS_PER_WIDE_INT; |
| val[index] |= value << (bitpos % HOST_BITS_PER_WIDE_INT); |
| } |
| |
| result.set_len (canonize (val, len, precision)); |
| |
| return result; |
| } |
| |
| /* Sets RESULT from X, the sign is taken according to SGN. */ |
| void |
| wi::to_mpz (const wide_int_ref &x, mpz_t result, signop sgn) |
| { |
| int len = x.get_len (); |
| const HOST_WIDE_INT *v = x.get_val (); |
| int excess = len * HOST_BITS_PER_WIDE_INT - x.get_precision (); |
| |
| if (wi::neg_p (x, sgn)) |
| { |
| /* We use ones complement to avoid -x80..0 edge case that - |
| won't work on. */ |
| HOST_WIDE_INT *t = XALLOCAVEC (HOST_WIDE_INT, len); |
| for (int i = 0; i < len; i++) |
| t[i] = ~v[i]; |
| if (excess > 0) |
| t[len - 1] = (unsigned HOST_WIDE_INT) t[len - 1] << excess >> excess; |
| mpz_import (result, len, -1, sizeof (HOST_WIDE_INT), 0, 0, t); |
| mpz_com (result, result); |
| } |
| else if (excess > 0) |
| { |
| HOST_WIDE_INT *t = XALLOCAVEC (HOST_WIDE_INT, len); |
| for (int i = 0; i < len - 1; i++) |
| t[i] = v[i]; |
| t[len - 1] = (unsigned HOST_WIDE_INT) v[len - 1] << excess >> excess; |
| mpz_import (result, len, -1, sizeof (HOST_WIDE_INT), 0, 0, t); |
| } |
| else |
| mpz_import (result, len, -1, sizeof (HOST_WIDE_INT), 0, 0, v); |
| } |
| |
| /* Returns X converted to TYPE. If WRAP is true, then out-of-range |
| values of VAL will be wrapped; otherwise, they will be set to the |
| appropriate minimum or maximum TYPE bound. */ |
| wide_int |
| wi::from_mpz (const_tree type, mpz_t x, bool wrap) |
| { |
| size_t count, numb; |
| unsigned int prec = TYPE_PRECISION (type); |
| wide_int res = wide_int::create (prec); |
| |
| if (!wrap) |
| { |
| mpz_t min, max; |
| |
| mpz_init (min); |
| mpz_init (max); |
| get_type_static_bounds (type, min, max); |
| |
| if (mpz_cmp (x, min) < 0) |
| mpz_set (x, min); |
| else if (mpz_cmp (x, max) > 0) |
| mpz_set (x, max); |
| |
| mpz_clear (min); |
| mpz_clear (max); |
| } |
| |
| /* Determine the number of unsigned HOST_WIDE_INTs that are required |
| for representing the absolute value. The code to calculate count is |
| extracted from the GMP manual, section "Integer Import and Export": |
| http://gmplib.org/manual/Integer-Import-and-Export.html */ |
| numb = CHAR_BIT * sizeof (HOST_WIDE_INT); |
| count = (mpz_sizeinbase (x, 2) + numb - 1) / numb; |
| HOST_WIDE_INT *val = res.write_val (); |
| /* Read the absolute value. |
| |
| Write directly to the wide_int storage if possible, otherwise leave |
| GMP to allocate the memory for us. It might be slightly more efficient |
| to use mpz_tdiv_r_2exp for the latter case, but the situation is |
| pathological and it seems safer to operate on the original mpz value |
| in all cases. */ |
| void *valres = mpz_export (count <= WIDE_INT_MAX_ELTS ? val : 0, |
| &count, -1, sizeof (HOST_WIDE_INT), 0, 0, x); |
| if (count < 1) |
| { |
| val[0] = 0; |
| count = 1; |
| } |
| count = MIN (count, BLOCKS_NEEDED (prec)); |
| if (valres != val) |
| { |
| memcpy (val, valres, count * sizeof (HOST_WIDE_INT)); |
| free (valres); |
| } |
| /* Zero-extend the absolute value to PREC bits. */ |
| if (count < BLOCKS_NEEDED (prec) && val[count - 1] < 0) |
| val[count++] = 0; |
| else |
| count = canonize (val, count, prec); |
| res.set_len (count); |
| |
| if (mpz_sgn (x) < 0) |
| res = -res; |
| |
| return res; |
| } |
| |
| /* |
| * Largest and smallest values in a mode. |
| */ |
| |
| /* Return the largest SGNed number that is representable in PRECISION bits. |
| |
| TODO: There is still code from the double_int era that trys to |
| make up for the fact that double int's could not represent the |
| min and max values of all types. This code should be removed |
| because the min and max values can always be represented in |
| wide_ints and int-csts. */ |
| wide_int |
| wi::max_value (unsigned int precision, signop sgn) |
| { |
| gcc_checking_assert (precision != 0); |
| if (sgn == UNSIGNED) |
| /* The unsigned max is just all ones. */ |
| return shwi (-1, precision); |
| else |
| /* The signed max is all ones except the top bit. This must be |
| explicitly represented. */ |
| return mask (precision - 1, false, precision); |
| } |
| |
| /* Return the largest SGNed number that is representable in PRECISION bits. */ |
| wide_int |
| wi::min_value (unsigned int precision, signop sgn) |
| { |
| gcc_checking_assert (precision != 0); |
| if (sgn == UNSIGNED) |
| return uhwi (0, precision); |
| else |
| /* The signed min is all zeros except the top bit. This must be |
| explicitly represented. */ |
| return wi::set_bit_in_zero (precision - 1, precision); |
| } |
| |
| /* |
| * Public utilities. |
| */ |
| |
| /* Convert the number represented by XVAL, XLEN and XPRECISION, which has |
| signedness SGN, to an integer that has PRECISION bits. Store the blocks |
| in VAL and return the number of blocks used. |
| |
| This function can handle both extension (PRECISION > XPRECISION) |
| and truncation (PRECISION < XPRECISION). */ |
| unsigned int |
| wi::force_to_size (HOST_WIDE_INT *val, const HOST_WIDE_INT *xval, |
| unsigned int xlen, unsigned int xprecision, |
| unsigned int precision, signop sgn) |
| { |
| unsigned int blocks_needed = BLOCKS_NEEDED (precision); |
| unsigned int len = blocks_needed < xlen ? blocks_needed : xlen; |
| for (unsigned i = 0; i < len; i++) |
| val[i] = xval[i]; |
| |
| if (precision > xprecision) |
| { |
| unsigned int small_xprecision = xprecision % HOST_BITS_PER_WIDE_INT; |
| |
| /* Expanding. */ |
| if (sgn == UNSIGNED) |
| { |
| if (small_xprecision && len == BLOCKS_NEEDED (xprecision)) |
| val[len - 1] = zext_hwi (val[len - 1], small_xprecision); |
| else if (val[len - 1] < 0) |
| { |
| while (len < BLOCKS_NEEDED (xprecision)) |
| val[len++] = -1; |
| if (small_xprecision) |
| val[len - 1] = zext_hwi (val[len - 1], small_xprecision); |
| else |
| val[len++] = 0; |
| } |
| } |
| else |
| { |
| if (small_xprecision && len == BLOCKS_NEEDED (xprecision)) |
| val[len - 1] = sext_hwi (val[len - 1], small_xprecision); |
| } |
| } |
| len = canonize (val, len, precision); |
| |
| return len; |
| } |
| |
| /* This function hides the fact that we cannot rely on the bits beyond |
| the precision. This issue comes up in the relational comparisions |
| where we do allow comparisons of values of different precisions. */ |
| static inline HOST_WIDE_INT |
| selt (const HOST_WIDE_INT *a, unsigned int len, |
| unsigned int blocks_needed, unsigned int small_prec, |
| unsigned int index, signop sgn) |
| { |
| HOST_WIDE_INT val; |
| if (index < len) |
| val = a[index]; |
| else if (index < blocks_needed || sgn == SIGNED) |
| /* Signed or within the precision. */ |
| val = SIGN_MASK (a[len - 1]); |
| else |
| /* Unsigned extension beyond the precision. */ |
| val = 0; |
| |
| if (small_prec && index == blocks_needed - 1) |
| return (sgn == SIGNED |
| ? sext_hwi (val, small_prec) |
| : zext_hwi (val, small_prec)); |
| else |
| return val; |
| } |
| |
| /* Find the highest bit represented in a wide int. This will in |
| general have the same value as the sign bit. */ |
| static inline HOST_WIDE_INT |
| top_bit_of (const HOST_WIDE_INT *a, unsigned int len, unsigned int prec) |
| { |
| int excess = len * HOST_BITS_PER_WIDE_INT - prec; |
| unsigned HOST_WIDE_INT val = a[len - 1]; |
| if (excess > 0) |
| val <<= excess; |
| return val >> (HOST_BITS_PER_WIDE_INT - 1); |
| } |
| |
| /* |
| * Comparisons, note that only equality is an operator. The other |
| * comparisons cannot be operators since they are inherently signed or |
| * unsigned and C++ has no such operators. |
| */ |
| |
| /* Return true if OP0 == OP1. */ |
| bool |
| wi::eq_p_large (const HOST_WIDE_INT *op0, unsigned int op0len, |
| const HOST_WIDE_INT *op1, unsigned int op1len, |
| unsigned int prec) |
| { |
| int l0 = op0len - 1; |
| unsigned int small_prec = prec & (HOST_BITS_PER_WIDE_INT - 1); |
| |
| if (op0len != op1len) |
| return false; |
| |
| if (op0len == BLOCKS_NEEDED (prec) && small_prec) |
| { |
| /* It does not matter if we zext or sext here, we just have to |
| do both the same way. */ |
| if (zext_hwi (op0 [l0], small_prec) != zext_hwi (op1 [l0], small_prec)) |
| return false; |
| l0--; |
| } |
| |
| while (l0 >= 0) |
| if (op0[l0] != op1[l0]) |
| return false; |
| else |
| l0--; |
| |
| return true; |
| } |
| |
| /* Return true if OP0 < OP1 using signed comparisons. */ |
| bool |
| wi::lts_p_large (const HOST_WIDE_INT *op0, unsigned int op0len, |
| unsigned int precision, |
| const HOST_WIDE_INT *op1, unsigned int op1len) |
| { |
| HOST_WIDE_INT s0, s1; |
| unsigned HOST_WIDE_INT u0, u1; |
| unsigned int blocks_needed = BLOCKS_NEEDED (precision); |
| unsigned int small_prec = precision & (HOST_BITS_PER_WIDE_INT - 1); |
| int l = MAX (op0len - 1, op1len - 1); |
| |
| /* Only the top block is compared as signed. The rest are unsigned |
| comparisons. */ |
| s0 = selt (op0, op0len, blocks_needed, small_prec, l, SIGNED); |
| s1 = selt (op1, op1len, blocks_needed, small_prec, l, SIGNED); |
| if (s0 < s1) |
| return true; |
| if (s0 > s1) |
| return false; |
| |
| l--; |
| while (l >= 0) |
| { |
| u0 = selt (op0, op0len, blocks_needed, small_prec, l, SIGNED); |
| u1 = selt (op1, op1len, blocks_needed, small_prec, l, SIGNED); |
| |
| if (u0 < u1) |
| return true; |
| if (u0 > u1) |
| return false; |
| l--; |
| } |
| |
| return false; |
| } |
| |
| /* Returns -1 if OP0 < OP1, 0 if OP0 == OP1 and 1 if OP0 > OP1 using |
| signed compares. */ |
| int |
| wi::cmps_large (const HOST_WIDE_INT *op0, unsigned int op0len, |
| unsigned int precision, |
| const HOST_WIDE_INT *op1, unsigned int op1len) |
| { |
| HOST_WIDE_INT s0, s1; |
| unsigned HOST_WIDE_INT u0, u1; |
| unsigned int blocks_needed = BLOCKS_NEEDED (precision); |
| unsigned int small_prec = precision & (HOST_BITS_PER_WIDE_INT - 1); |
| int l = MAX (op0len - 1, op1len - 1); |
| |
| /* Only the top block is compared as signed. The rest are unsigned |
| comparisons. */ |
| s0 = selt (op0, op0len, blocks_needed, small_prec, l, SIGNED); |
| s1 = selt (op1, op1len, blocks_needed, small_prec, l, SIGNED); |
| if (s0 < s1) |
| return -1; |
| if (s0 > s1) |
| return 1; |
| |
| l--; |
| while (l >= 0) |
| { |
| u0 = selt (op0, op0len, blocks_needed, small_prec, l, SIGNED); |
| u1 = selt (op1, op1len, blocks_needed, small_prec, l, SIGNED); |
| |
| if (u0 < u1) |
| return -1; |
| if (u0 > u1) |
| return 1; |
| l--; |
| } |
| |
| return 0; |
| } |
| |
| /* Return true if OP0 < OP1 using unsigned comparisons. */ |
| bool |
| wi::ltu_p_large (const HOST_WIDE_INT *op0, unsigned int op0len, |
| unsigned int precision, |
| const HOST_WIDE_INT *op1, unsigned int op1len) |
| { |
| unsigned HOST_WIDE_INT x0; |
| unsigned HOST_WIDE_INT x1; |
| unsigned int blocks_needed = BLOCKS_NEEDED (precision); |
| unsigned int small_prec = precision & (HOST_BITS_PER_WIDE_INT - 1); |
| int l = MAX (op0len - 1, op1len - 1); |
| |
| while (l >= 0) |
| { |
| x0 = selt (op0, op0len, blocks_needed, small_prec, l, UNSIGNED); |
| x1 = selt (op1, op1len, blocks_needed, small_prec, l, UNSIGNED); |
| if (x0 < x1) |
| return true; |
| if (x0 > x1) |
| return false; |
| l--; |
| } |
| |
| return false; |
| } |
| |
| /* Returns -1 if OP0 < OP1, 0 if OP0 == OP1 and 1 if OP0 > OP1 using |
| unsigned compares. */ |
| int |
| wi::cmpu_large (const HOST_WIDE_INT *op0, unsigned int op0len, |
| unsigned int precision, |
| const HOST_WIDE_INT *op1, unsigned int op1len) |
| { |
| unsigned HOST_WIDE_INT x0; |
| unsigned HOST_WIDE_INT x1; |
| unsigned int blocks_needed = BLOCKS_NEEDED (precision); |
| unsigned int small_prec = precision & (HOST_BITS_PER_WIDE_INT - 1); |
| int l = MAX (op0len - 1, op1len - 1); |
| |
| while (l >= 0) |
| { |
| x0 = selt (op0, op0len, blocks_needed, small_prec, l, UNSIGNED); |
| x1 = selt (op1, op1len, blocks_needed, small_prec, l, UNSIGNED); |
| if (x0 < x1) |
| return -1; |
| if (x0 > x1) |
| return 1; |
| l--; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Extension. |
| */ |
| |
| /* Sign-extend the number represented by XVAL and XLEN into VAL, |
| starting at OFFSET. Return the number of blocks in VAL. Both XVAL |
| and VAL have PRECISION bits. */ |
| unsigned int |
| wi::sext_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *xval, |
| unsigned int xlen, unsigned int precision, unsigned int offset) |
| { |
| unsigned int len = offset / HOST_BITS_PER_WIDE_INT; |
| /* Extending beyond the precision is a no-op. If we have only stored |
| OFFSET bits or fewer, the rest are already signs. */ |
| if (offset >= precision || len >= xlen) |
| { |
| for (unsigned i = 0; i < xlen; ++i) |
| val[i] = xval[i]; |
| return xlen; |
| } |
| unsigned int suboffset = offset % HOST_BITS_PER_WIDE_INT; |
| for (unsigned int i = 0; i < len; i++) |
| val[i] = xval[i]; |
| if (suboffset > 0) |
| { |
| val[len] = sext_hwi (xval[len], suboffset); |
| len += 1; |
| } |
| return canonize (val, len, precision); |
| } |
| |
| /* Zero-extend the number represented by XVAL and XLEN into VAL, |
| starting at OFFSET. Return the number of blocks in VAL. Both XVAL |
| and VAL have PRECISION bits. */ |
| unsigned int |
| wi::zext_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *xval, |
| unsigned int xlen, unsigned int precision, unsigned int offset) |
| { |
| unsigned int len = offset / HOST_BITS_PER_WIDE_INT; |
| /* Extending beyond the precision is a no-op. If we have only stored |
| OFFSET bits or fewer, and the upper stored bit is zero, then there |
| is nothing to do. */ |
| if (offset >= precision || (len >= xlen && xval[xlen - 1] >= 0)) |
| { |
| for (unsigned i = 0; i < xlen; ++i) |
| val[i] = xval[i]; |
| return xlen; |
| } |
| unsigned int suboffset = offset % HOST_BITS_PER_WIDE_INT; |
| for (unsigned int i = 0; i < len; i++) |
| val[i] = i < xlen ? xval[i] : -1; |
| if (suboffset > 0) |
| val[len] = zext_hwi (len < xlen ? xval[len] : -1, suboffset); |
| else |
| val[len] = 0; |
| return canonize (val, len + 1, precision); |
| } |
| |
| /* |
| * Masking, inserting, shifting, rotating. |
| */ |
| |
| /* Insert WIDTH bits from Y into X starting at START. */ |
| wide_int |
| wi::insert (const wide_int &x, const wide_int &y, unsigned int start, |
| unsigned int width) |
| { |
| wide_int result; |
| wide_int mask; |
| wide_int tmp; |
| |
| unsigned int precision = x.get_precision (); |
| if (start >= precision) |
| return x; |
| |
| gcc_checking_assert (precision >= width); |
| |
| if (start + width >= precision) |
| width = precision - start; |
| |
| mask = wi::shifted_mask (start, width, false, precision); |
| tmp = wi::lshift (wide_int::from (y, precision, UNSIGNED), start); |
| result = tmp & mask; |
| |
| tmp = wi::bit_and_not (x, mask); |
| result = result | tmp; |
| |
| return result; |
| } |
| |
| /* Copy the number represented by XVAL and XLEN into VAL, setting bit BIT. |
| Return the number of blocks in VAL. Both XVAL and VAL have PRECISION |
| bits. */ |
| unsigned int |
| wi::set_bit_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *xval, |
| unsigned int xlen, unsigned int precision, unsigned int bit) |
| { |
| unsigned int block = bit / HOST_BITS_PER_WIDE_INT; |
| unsigned int subbit = bit % HOST_BITS_PER_WIDE_INT; |
| |
| if (block + 1 >= xlen) |
| { |
| /* The operation either affects the last current block or needs |
| a new block. */ |
| unsigned int len = block + 1; |
| for (unsigned int i = 0; i < len; i++) |
| val[i] = safe_uhwi (xval, xlen, i); |
| val[block] |= (unsigned HOST_WIDE_INT) 1 << subbit; |
| |
| /* If the bit we just set is at the msb of the block, make sure |
| that any higher bits are zeros. */ |
| if (bit + 1 < precision && subbit == HOST_BITS_PER_WIDE_INT - 1) |
| val[len++] = 0; |
| return len; |
| } |
| else |
| { |
| for (unsigned int i = 0; i < xlen; i++) |
| val[i] = xval[i]; |
| val[block] |= (unsigned HOST_WIDE_INT) 1 << subbit; |
| return canonize (val, xlen, precision); |
| } |
| } |
| |
| /* bswap THIS. */ |
| wide_int |
| wide_int_storage::bswap () const |
| { |
| wide_int result = wide_int::create (precision); |
| unsigned int i, s; |
| unsigned int len = BLOCKS_NEEDED (precision); |
| unsigned int xlen = get_len (); |
| const HOST_WIDE_INT *xval = get_val (); |
| HOST_WIDE_INT *val = result.write_val (); |
| |
| /* This is not a well defined operation if the precision is not a |
| multiple of 8. */ |
| gcc_assert ((precision & 0x7) == 0); |
| |
| for (i = 0; i < len; i++) |
| val[i] = 0; |
| |
| /* Only swap the bytes that are not the padding. */ |
| for (s = 0; s < precision; s += 8) |
| { |
| unsigned int d = precision - s - 8; |
| unsigned HOST_WIDE_INT byte; |
| |
| unsigned int block = s / HOST_BITS_PER_WIDE_INT; |
| unsigned int offset = s & (HOST_BITS_PER_WIDE_INT - 1); |
| |
| byte = (safe_uhwi (xval, xlen, block) >> offset) & 0xff; |
| |
| block = d / HOST_BITS_PER_WIDE_INT; |
| offset = d & (HOST_BITS_PER_WIDE_INT - 1); |
| |
| val[block] |= byte << offset; |
| } |
| |
| result.set_len (canonize (val, len, precision)); |
| return result; |
| } |
| |
| /* Fill VAL with a mask where the lower WIDTH bits are ones and the bits |
| above that up to PREC are zeros. The result is inverted if NEGATE |
| is true. Return the number of blocks in VAL. */ |
| unsigned int |
| wi::mask (HOST_WIDE_INT *val, unsigned int width, bool negate, |
| unsigned int prec) |
| { |
| if (width >= prec) |
| { |
| val[0] = negate ? 0 : -1; |
| return 1; |
| } |
| else if (width == 0) |
| { |
| val[0] = negate ? -1 : 0; |
| return 1; |
| } |
| |
| unsigned int i = 0; |
| while (i < width / HOST_BITS_PER_WIDE_INT) |
| val[i++] = negate ? 0 : -1; |
| |
| unsigned int shift = width & (HOST_BITS_PER_WIDE_INT - 1); |
| if (shift != 0) |
| { |
| HOST_WIDE_INT last = ((unsigned HOST_WIDE_INT) 1 << shift) - 1; |
| val[i++] = negate ? ~last : last; |
| } |
| else |
| val[i++] = negate ? -1 : 0; |
| |
| return i; |
| } |
| |
| /* Fill VAL with a mask where the lower START bits are zeros, the next WIDTH |
| bits are ones, and the bits above that up to PREC are zeros. The result |
| is inverted if NEGATE is true. Return the number of blocks in VAL. */ |
| unsigned int |
| wi::shifted_mask (HOST_WIDE_INT *val, unsigned int start, unsigned int width, |
| bool negate, unsigned int prec) |
| { |
| if (start >= prec || width == 0) |
| { |
| val[0] = negate ? -1 : 0; |
| return 1; |
| } |
| |
| if (width > prec - start) |
| width = prec - start; |
| unsigned int end = start + width; |
| |
| unsigned int i = 0; |
| while (i < start / HOST_BITS_PER_WIDE_INT) |
| val[i++] = negate ? -1 : 0; |
| |
| unsigned int shift = start & (HOST_BITS_PER_WIDE_INT - 1); |
| if (shift) |
| { |
| HOST_WIDE_INT block = ((unsigned HOST_WIDE_INT) 1 << shift) - 1; |
| shift += width; |
| if (shift < HOST_BITS_PER_WIDE_INT) |
| { |
| /* case 000111000 */ |
| block = ((unsigned HOST_WIDE_INT) 1 << shift) - block - 1; |
| val[i++] = negate ? ~block : block; |
| return i; |
| } |
| else |
| /* ...111000 */ |
| val[i++] = negate ? block : ~block; |
| } |
| |
| while (i < end / HOST_BITS_PER_WIDE_INT) |
| /* 1111111 */ |
| val[i++] = negate ? 0 : -1; |
| |
| shift = end & (HOST_BITS_PER_WIDE_INT - 1); |
| if (shift != 0) |
| { |
| /* 000011111 */ |
| HOST_WIDE_INT block = ((unsigned HOST_WIDE_INT) 1 << shift) - 1; |
| val[i++] = negate ? ~block : block; |
| } |
| else if (end < prec) |
| val[i++] = negate ? -1 : 0; |
| |
| return i; |
| } |
| |
| /* |
| * logical operations. |
| */ |
| |
| /* Set VAL to OP0 & OP1. Return the number of blocks used. */ |
| unsigned int |
| wi::and_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *op0, |
| unsigned int op0len, const HOST_WIDE_INT *op1, |
| unsigned int op1len, unsigned int prec) |
| { |
| int l0 = op0len - 1; |
| int l1 = op1len - 1; |
| bool need_canon = true; |
| |
| unsigned int len = MAX (op0len, op1len); |
| if (l0 > l1) |
| { |
| HOST_WIDE_INT op1mask = -top_bit_of (op1, op1len, prec); |
| if (op1mask == 0) |
| { |
| l0 = l1; |
| len = l1 + 1; |
| } |
| else |
| { |
| need_canon = false; |
| while (l0 > l1) |
| { |
| val[l0] = op0[l0]; |
| l0--; |
| } |
| } |
| } |
| else if (l1 > l0) |
| { |
| HOST_WIDE_INT op0mask = -top_bit_of (op0, op0len, prec); |
| if (op0mask == 0) |
| len = l0 + 1; |
| else |
| { |
| need_canon = false; |
| while (l1 > l0) |
| { |
| val[l1] = op1[l1]; |
| l1--; |
| } |
| } |
| } |
| |
| while (l0 >= 0) |
| { |
| val[l0] = op0[l0] & op1[l0]; |
| l0--; |
| } |
| |
| if (need_canon) |
| len = canonize (val, len, prec); |
| |
| return len; |
| } |
| |
| /* Set VAL to OP0 & ~OP1. Return the number of blocks used. */ |
| unsigned int |
| wi::and_not_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *op0, |
| unsigned int op0len, const HOST_WIDE_INT *op1, |
| unsigned int op1len, unsigned int prec) |
| { |
| wide_int result; |
| int l0 = op0len - 1; |
| int l1 = op1len - 1; |
| bool need_canon = true; |
| |
| unsigned int len = MAX (op0len, op1len); |
| if (l0 > l1) |
| { |
| HOST_WIDE_INT op1mask = -top_bit_of (op1, op1len, prec); |
| if (op1mask != 0) |
| { |
| l0 = l1; |
| len = l1 + 1; |
| } |
| else |
| { |
| need_canon = false; |
| while (l0 > l1) |
| { |
| val[l0] = op0[l0]; |
| l0--; |
| } |
| } |
| } |
| else if (l1 > l0) |
| { |
| HOST_WIDE_INT op0mask = -top_bit_of (op0, op0len, prec); |
| if (op0mask == 0) |
| len = l0 + 1; |
| else |
| { |
| need_canon = false; |
| while (l1 > l0) |
| { |
| val[l1] = ~op1[l1]; |
| l1--; |
| } |
| } |
| } |
| |
| while (l0 >= 0) |
| { |
| val[l0] = op0[l0] & ~op1[l0]; |
| l0--; |
| } |
| |
| if (need_canon) |
| len = canonize (val, len, prec); |
| |
| return len; |
| } |
| |
| /* Set VAL to OP0 | OP1. Return the number of blocks used. */ |
| unsigned int |
| wi::or_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *op0, |
| unsigned int op0len, const HOST_WIDE_INT *op1, |
| unsigned int op1len, unsigned int prec) |
| { |
| wide_int result; |
| int l0 = op0len - 1; |
| int l1 = op1len - 1; |
| bool need_canon = true; |
| |
| unsigned int len = MAX (op0len, op1len); |
| if (l0 > l1) |
| { |
| HOST_WIDE_INT op1mask = -top_bit_of (op1, op1len, prec); |
| if (op1mask != 0) |
| { |
| l0 = l1; |
| len = l1 + 1; |
| } |
| else |
| { |
| need_canon = false; |
| while (l0 > l1) |
| { |
| val[l0] = op0[l0]; |
| l0--; |
| } |
| } |
| } |
| else if (l1 > l0) |
| { |
| HOST_WIDE_INT op0mask = -top_bit_of (op0, op0len, prec); |
| if (op0mask != 0) |
| len = l0 + 1; |
| else |
| { |
| need_canon = false; |
| while (l1 > l0) |
| { |
| val[l1] = op1[l1]; |
| l1--; |
| } |
| } |
| } |
| |
| while (l0 >= 0) |
| { |
| val[l0] = op0[l0] | op1[l0]; |
| l0--; |
| } |
| |
| if (need_canon) |
| len = canonize (val, len, prec); |
| |
| return len; |
| } |
| |
| /* Set VAL to OP0 | ~OP1. Return the number of blocks used. */ |
| unsigned int |
| wi::or_not_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *op0, |
| unsigned int op0len, const HOST_WIDE_INT *op1, |
| unsigned int op1len, unsigned int prec) |
| { |
| wide_int result; |
| int l0 = op0len - 1; |
| int l1 = op1len - 1; |
| bool need_canon = true; |
| |
| unsigned int len = MAX (op0len, op1len); |
| if (l0 > l1) |
| { |
| HOST_WIDE_INT op1mask = -top_bit_of (op1, op1len, prec); |
| if (op1mask == 0) |
| { |
| l0 = l1; |
| len = l1 + 1; |
| } |
| else |
| { |
| need_canon = false; |
| while (l0 > l1) |
| { |
| val[l0] = op0[l0]; |
| l0--; |
| } |
| } |
| } |
| else if (l1 > l0) |
| { |
| HOST_WIDE_INT op0mask = -top_bit_of (op0, op0len, prec); |
| if (op0mask != 0) |
| len = l0 + 1; |
| else |
| { |
| need_canon = false; |
| while (l1 > l0) |
| { |
| val[l1] = ~op1[l1]; |
| l1--; |
| } |
| } |
| } |
| |
| while (l0 >= 0) |
| { |
| val[l0] = op0[l0] | ~op1[l0]; |
| l0--; |
| } |
| |
| if (need_canon) |
| len = canonize (val, len, prec); |
| |
| return len; |
| } |
| |
| /* Set VAL to OP0 ^ OP1. Return the number of blocks used. */ |
| unsigned int |
| wi::xor_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *op0, |
| unsigned int op0len, const HOST_WIDE_INT *op1, |
| unsigned int op1len, unsigned int prec) |
| { |
| wide_int result; |
| int l0 = op0len - 1; |
| int l1 = op1len - 1; |
| |
| unsigned int len = MAX (op0len, op1len); |
| if (l0 > l1) |
| { |
| HOST_WIDE_INT op1mask = -top_bit_of (op1, op1len, prec); |
| while (l0 > l1) |
| { |
| val[l0] = op0[l0] ^ op1mask; |
| l0--; |
| } |
| } |
| |
| if (l1 > l0) |
| { |
| HOST_WIDE_INT op0mask = -top_bit_of (op0, op0len, prec); |
| while (l1 > l0) |
| { |
| val[l1] = op0mask ^ op1[l1]; |
| l1--; |
| } |
| } |
| |
| while (l0 >= 0) |
| { |
| val[l0] = op0[l0] ^ op1[l0]; |
| l0--; |
| } |
| |
| return canonize (val, len, prec); |
| } |
| |
| /* |
| * math |
| */ |
| |
| /* Set VAL to OP0 + OP1. If OVERFLOW is nonnull, record in *OVERFLOW |
| whether the result overflows when OP0 and OP1 are treated as having |
| signedness SGN. Return the number of blocks in VAL. */ |
| unsigned int |
| wi::add_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *op0, |
| unsigned int op0len, const HOST_WIDE_INT *op1, |
| unsigned int op1len, unsigned int prec, |
| signop sgn, bool *overflow) |
| { |
| unsigned HOST_WIDE_INT o0 = 0; |
| unsigned HOST_WIDE_INT o1 = 0; |
| unsigned HOST_WIDE_INT x = 0; |
| unsigned HOST_WIDE_INT carry = 0; |
| unsigned HOST_WIDE_INT old_carry = 0; |
| unsigned HOST_WIDE_INT mask0, mask1; |
| unsigned int i; |
| |
| unsigned int len = MAX (op0len, op1len); |
| mask0 = -top_bit_of (op0, op0len, prec); |
| mask1 = -top_bit_of (op1, op1len, prec); |
| /* Add all of the explicitly defined elements. */ |
| |
| for (i = 0; i < len; i++) |
| { |
| o0 = i < op0len ? (unsigned HOST_WIDE_INT) op0[i] : mask0; |
| o1 = i < op1len ? (unsigned HOST_WIDE_INT) op1[i] : mask1; |
| x = o0 + o1 + carry; |
| val[i] = x; |
| old_carry = carry; |
| carry = carry == 0 ? x < o0 : x <= o0; |
| } |
| |
| if (len * HOST_BITS_PER_WIDE_INT < prec) |
| { |
| val[len] = mask0 + mask1 + carry; |
| len++; |
| if (overflow) |
| *overflow = false; |
| } |
| else if (overflow) |
| { |
| unsigned int shift = -prec % HOST_BITS_PER_WIDE_INT; |
| if (sgn == SIGNED) |
| { |
| unsigned HOST_WIDE_INT x = (val[len - 1] ^ o0) & (val[len - 1] ^ o1); |
| *overflow = (HOST_WIDE_INT) (x << shift) < 0; |
| } |
| else |
| { |
| /* Put the MSB of X and O0 and in the top of the HWI. */ |
| x <<= shift; |
| o0 <<= shift; |
| if (old_carry) |
| *overflow = (x <= o0); |
| else |
| *overflow = (x < o0); |
| } |
| } |
| |
| return canonize (val, len, prec); |
| } |
| |
| /* Subroutines of the multiplication and division operations. Unpack |
| the first IN_LEN HOST_WIDE_INTs in INPUT into 2 * IN_LEN |
| HOST_HALF_WIDE_INTs of RESULT. The rest of RESULT is filled by |
| uncompressing the top bit of INPUT[IN_LEN - 1]. */ |
| static void |
| wi_unpack (unsigned HOST_HALF_WIDE_INT *result, const HOST_WIDE_INT *input, |
| unsigned int in_len, unsigned int out_len, |
| unsigned int prec, signop sgn) |
| { |
| unsigned int i; |
| unsigned int j = 0; |
| unsigned int small_prec = prec & (HOST_BITS_PER_WIDE_INT - 1); |
| unsigned int blocks_needed = BLOCKS_NEEDED (prec); |
| HOST_WIDE_INT mask; |
| |
| if (sgn == SIGNED) |
| { |
| mask = -top_bit_of ((const HOST_WIDE_INT *) input, in_len, prec); |
| mask &= HALF_INT_MASK; |
| } |
| else |
| mask = 0; |
| |
| for (i = 0; i < blocks_needed - 1; i++) |
| { |
| HOST_WIDE_INT x = safe_uhwi (input, in_len, i); |
| result[j++] = x; |
| result[j++] = x >> HOST_BITS_PER_HALF_WIDE_INT; |
| } |
| |
| HOST_WIDE_INT x = safe_uhwi (input, in_len, i); |
| if (small_prec) |
| { |
| if (sgn == SIGNED) |
| x = sext_hwi (x, small_prec); |
| else |
| x = zext_hwi (x, small_prec); |
| } |
| result[j++] = x; |
| result[j++] = x >> HOST_BITS_PER_HALF_WIDE_INT; |
| |
| /* Smear the sign bit. */ |
| while (j < out_len) |
| result[j++] = mask; |
| } |
| |
| /* The inverse of wi_unpack. IN_LEN is the number of input |
| blocks and PRECISION is the precision of the result. Return the |
| number of blocks in the canonicalized result. */ |
| static unsigned int |
| wi_pack (HOST_WIDE_INT *result, |
| const unsigned HOST_HALF_WIDE_INT *input, |
| unsigned int in_len, unsigned int precision) |
| { |
| unsigned int i = 0; |
| unsigned int j = 0; |
| unsigned int blocks_needed = BLOCKS_NEEDED (precision); |
| |
| while (i + 1 < in_len) |
| { |
| result[j++] = ((unsigned HOST_WIDE_INT) input[i] |
| | ((unsigned HOST_WIDE_INT) input[i + 1] |
| << HOST_BITS_PER_HALF_WIDE_INT)); |
| i += 2; |
| } |
| |
| /* Handle the case where in_len is odd. For this we zero extend. */ |
| if (in_len & 1) |
| result[j++] = (unsigned HOST_WIDE_INT) input[i]; |
| else if (j < blocks_needed) |
| result[j++] = 0; |
| return canonize (result, j, precision); |
| } |
| |
| /* Multiply Op1 by Op2. If HIGH is set, only the upper half of the |
| result is returned. |
| |
| If HIGH is not set, throw away the upper half after the check is |
| made to see if it overflows. Unfortunately there is no better way |
| to check for overflow than to do this. If OVERFLOW is nonnull, |
| record in *OVERFLOW whether the result overflowed. SGN controls |
| the signedness and is used to check overflow or if HIGH is set. */ |
| unsigned int |
| wi::mul_internal (HOST_WIDE_INT *val, const HOST_WIDE_INT *op1val, |
| unsigned int op1len, const HOST_WIDE_INT *op2val, |
| unsigned int op2len, unsigned int prec, signop sgn, |
| bool *overflow, bool high) |
| { |
| unsigned HOST_WIDE_INT o0, o1, k, t; |
| unsigned int i; |
| unsigned int j; |
| unsigned int blocks_needed = BLOCKS_NEEDED (prec); |
| unsigned int half_blocks_needed = blocks_needed * 2; |
| /* The sizes here are scaled to support a 2x largest mode by 2x |
| largest mode yielding a 4x largest mode result. This is what is |
| needed by vpn. */ |
| |
| unsigned HOST_HALF_WIDE_INT |
| u[4 * MAX_BITSIZE_MODE_ANY_INT / HOST_BITS_PER_HALF_WIDE_INT]; |
| unsigned HOST_HALF_WIDE_INT |
| v[4 * MAX_BITSIZE_MODE_ANY_INT / HOST_BITS_PER_HALF_WIDE_INT]; |
| /* The '2' in 'R' is because we are internally doing a full |
| multiply. */ |
| unsigned HOST_HALF_WIDE_INT |
| r[2 * 4 * MAX_BITSIZE_MODE_ANY_INT / HOST_BITS_PER_HALF_WIDE_INT]; |
| HOST_WIDE_INT mask = ((HOST_WIDE_INT)1 << HOST_BITS_PER_HALF_WIDE_INT) - 1; |
| |
| /* If the top level routine did not really pass in an overflow, then |
| just make sure that we never attempt to set it. */ |
| bool needs_overflow = (overflow != 0); |
| if (needs_overflow) |
| *overflow = false; |
| |
| wide_int_ref op1 = wi::storage_ref (op1val, op1len, prec); |
| wide_int_ref op2 = wi::storage_ref (op2val, op2len, prec); |
| |
| /* This is a surprisingly common case, so do it first. */ |
| if (op1 == 0 || op2 == 0) |
| { |
| val[0] = 0; |
| return 1; |
| } |
| |
| #ifdef umul_ppmm |
| if (sgn == UNSIGNED) |
| { |
| /* If the inputs are single HWIs and the output has room for at |
| least two HWIs, we can use umul_ppmm directly. */ |
| if (prec >= HOST_BITS_PER_WIDE_INT * 2 |
| && wi::fits_uhwi_p (op1) |
| && wi::fits_uhwi_p (op2)) |
| { |
| /* This case never overflows. */ |
| if (high) |
| { |
| val[0] = 0; |
| return 1; |
| } |
| umul_ppmm (val[1], val[0], op1.ulow (), op2.ulow ()); |
| if (val[1] < 0 && prec > HOST_BITS_PER_WIDE_INT * 2) |
| { |
| val[2] = 0; |
| return 3; |
| } |
| return 1 + (val[1] != 0 || val[0] < 0); |
| } |
| /* Likewise if the output is a full single HWI, except that the |
| upper HWI of the result is only used for determining overflow. |
| (We handle this case inline when overflow isn't needed.) */ |
| else if (prec == HOST_BITS_PER_WIDE_INT) |
| { |
| unsigned HOST_WIDE_INT upper; |
| umul_ppmm (upper, val[0], op1.ulow (), op2.ulow ()); |
| if (needs_overflow) |
| *overflow = (upper != 0); |
| if (high) |
| val[0] = upper; |
| return 1; |
| } |
| } |
| #endif |
| |
| /* Handle multiplications by 1. */ |
| if (op1 == 1) |
| { |
| if (high) |
| { |
| val[0] = wi::neg_p (op2, sgn) ? -1 : 0; |
| return 1; |
| } |
| for (i = 0; i < op2len; i++) |
| val[i] = op2val[i]; |
| return op2len; |
| } |
| if (op2 == 1) |
| { |
| if (high) |
| { |
| val[0] = wi::neg_p (op1, sgn) ? -1 : 0; |
| return 1; |
| } |
| for (i = 0; i < op1len; i++) |
| val[i] = op1val[i]; |
| return op1len; |
| } |
| |
| /* If we need to check for overflow, we can only do half wide |
| multiplies quickly because we need to look at the top bits to |
| check for the overflow. */ |
| if ((high || needs_overflow) |
| && (prec <= HOST_BITS_PER_HALF_WIDE_INT)) |
| { |
| unsigned HOST_WIDE_INT r; |
| |
| if (sgn == SIGNED) |
| { |
| o0 = op1.to_shwi (); |
| o1 = op2.to_shwi (); |
| } |
| else |
| { |
| o0 = op1.to_uhwi (); |
| o1 = op2.to_uhwi (); |
| } |
| |
| r = o0 * o1; |
| if (needs_overflow) |
| { |
| if (sgn == SIGNED) |
| { |
| if ((HOST_WIDE_INT) r != sext_hwi (r, prec)) |
| *overflow = true; |
| } |
| else |
| { |
| if ((r >> prec) != 0) |
| *overflow = true; |
| } |
| } |
| val[0] = high ? r >> prec : r; |
| return 1; |
| } |
| |
| /* We do unsigned mul and then correct it. */ |
| wi_unpack (u, op1val, op1len, half_blocks_needed, prec, SIGNED); |
| wi_unpack (v, op2val, op2len, half_blocks_needed, prec, SIGNED); |
| |
| /* The 2 is for a full mult. */ |
| memset (r, 0, half_blocks_needed * 2 |
| * HOST_BITS_PER_HALF_WIDE_INT / CHAR_BIT); |
| |
| for (j = 0; j < half_blocks_needed; j++) |
| { |
| k = 0; |
| for (i = 0; i < half_blocks_needed; i++) |
| { |
| t = ((unsigned HOST_WIDE_INT)u[i] * (unsigned HOST_WIDE_INT)v[j] |
| + r[i + j] + k); |
| r[i + j] = t & HALF_INT_MASK; |
| k = t >> HOST_BITS_PER_HALF_WIDE_INT; |
| } |
| r[j + half_blocks_needed] = k; |
| } |
| |
| /* We did unsigned math above. For signed we must adjust the |
| product (assuming we need to see that). */ |
| if (sgn == SIGNED && (high || needs_overflow)) |
| { |
| unsigned HOST_WIDE_INT b; |
| if (wi::neg_p (op1)) |
| { |
| b = 0; |
| for (i = 0; i < half_blocks_needed; i++) |
| { |
| t = (unsigned HOST_WIDE_INT)r[i + half_blocks_needed] |
| - (unsigned HOST_WIDE_INT)v[i] - b; |
| r[i + half_blocks_needed] = t & HALF_INT_MASK; |
| b = t >> (HOST_BITS_PER_WIDE_INT - 1); |
| } |
| } |
| if (wi::neg_p (op2)) |
| { |
| b = 0; |
| for (i = 0; i < half_blocks_needed; i++) |
| { |
| t = (unsigned HOST_WIDE_INT)r[i + half_blocks_needed] |
| - (unsigned HOST_WIDE_INT)u[i] - b; |
| r[i + half_blocks_needed] = t & HALF_INT_MASK; |
| b = t >> (HOST_BITS_PER_WIDE_INT - 1); |
| } |
| } |
| } |
| |
| if (needs_overflow) |
| { |
| HOST_WIDE_INT top; |
| |
| /* For unsigned, overflow is true if any of the top bits are set. |
| For signed, overflow is true if any of the top bits are not equal |
| to the sign bit. */ |
| if (sgn == UNSIGNED) |
| top = 0; |
| else |
| { |
| top = r[(half_blocks_needed) - 1]; |
| top = SIGN_MASK (top << (HOST_BITS_PER_WIDE_INT / 2)); |
| top &= mask; |
| } |
| |
| for (i = half_blocks_needed; i < half_blocks_needed * 2; i++) |
| if (((HOST_WIDE_INT)(r[i] & mask)) != top) |
| *overflow = true; |
| } |
| |
| int r_offset = high ? half_blocks_needed : 0; |
| return wi_pack (val, &r[r_offset], half_blocks_needed, prec); |
| } |
| |
| /* Compute the population count of X. */ |
| int |
| wi::popcount (const wide_int_ref &x) |
| { |
| unsigned int i; |
| int count; |
| |
| /* The high order block is special if it is the last block and the |
| precision is not an even multiple of HOST_BITS_PER_WIDE_INT. We |
| have to clear out any ones above the precision before doing |
| popcount on this block. */ |
| count = x.precision - x.len * HOST_BITS_PER_WIDE_INT; |
| unsigned int stop = x.len; |
| if (count < 0) |
| { |
| count = popcount_hwi (x.uhigh () << -count); |
| stop -= 1; |
| } |
| else |
| { |
| if (x.sign_mask () >= 0) |
| count = 0; |
| } |
| |
| for (i = 0; i < stop; ++i) |
| count += popcount_hwi (x.val[i]); |
| |
| return count; |
| } |
| |
| /* Set VAL to OP0 - OP1. If OVERFLOW is nonnull, record in *OVERFLOW |
| whether the result overflows when OP0 and OP1 are treated as having |
| signedness SGN. Return the number of blocks in VAL. */ |
| unsigned int |
| wi::sub_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *op0, |
| unsigned int op0len, const HOST_WIDE_INT *op1, |
| unsigned int op1len, unsigned int prec, |
| signop sgn, bool *overflow) |
| { |
| unsigned HOST_WIDE_INT o0 = 0; |
| unsigned HOST_WIDE_INT o1 = 0; |
| unsigned HOST_WIDE_INT x = 0; |
| /* We implement subtraction as an in place negate and add. Negation |
| is just inversion and add 1, so we can do the add of 1 by just |
| starting the borrow in of the first element at 1. */ |
| unsigned HOST_WIDE_INT borrow = 0; |
| unsigned HOST_WIDE_INT old_borrow = 0; |
| |
| unsigned HOST_WIDE_INT mask0, mask1; |
| unsigned int i; |
| |
| unsigned int len = MAX (op0len, op1len); |
| mask0 = -top_bit_of (op0, op0len, prec); |
| mask1 = -top_bit_of (op1, op1len, prec); |
| |
| /* Subtract all of the explicitly defined elements. */ |
| for (i = 0; i < len; i++) |
| { |
| o0 = i < op0len ? (unsigned HOST_WIDE_INT)op0[i] : mask0; |
| o1 = i < op1len ? (unsigned HOST_WIDE_INT)op1[i] : mask1; |
| x = o0 - o1 - borrow; |
| val[i] = x; |
| old_borrow = borrow; |
| borrow = borrow == 0 ? o0 < o1 : o0 <= o1; |
| } |
| |
| if (len * HOST_BITS_PER_WIDE_INT < prec) |
| { |
| val[len] = mask0 - mask1 - borrow; |
| len++; |
| if (overflow) |
| *overflow = false; |
| } |
| else if (overflow) |
| { |
| unsigned int shift = -prec % HOST_BITS_PER_WIDE_INT; |
| if (sgn == SIGNED) |
| { |
| unsigned HOST_WIDE_INT x = (o0 ^ o1) & (val[len - 1] ^ o0); |
| *overflow = (HOST_WIDE_INT) (x << shift) < 0; |
| } |
| else |
| { |
| /* Put the MSB of X and O0 and in the top of the HWI. */ |
| x <<= shift; |
| o0 <<= shift; |
| if (old_borrow) |
| *overflow = (x >= o0); |
| else |
| *overflow = (x > o0); |
| } |
| } |
| |
| return canonize (val, len, prec); |
| } |
| |
| |
| /* |
| * Division and Mod |
| */ |
| |
| /* Compute B_QUOTIENT and B_REMAINDER from B_DIVIDEND/B_DIVISOR. The |
| algorithm is a small modification of the algorithm in Hacker's |
| Delight by Warren, which itself is a small modification of Knuth's |
| algorithm. M is the number of significant elements of U however |
| there needs to be at least one extra element of B_DIVIDEND |
| allocated, N is the number of elements of B_DIVISOR. */ |
| static void |
| divmod_internal_2 (unsigned HOST_HALF_WIDE_INT *b_quotient, |
| unsigned HOST_HALF_WIDE_INT *b_remainder, |
| unsigned HOST_HALF_WIDE_INT *b_dividend, |
| unsigned HOST_HALF_WIDE_INT *b_divisor, |
| int m, int n) |
| { |
| /* The "digits" are a HOST_HALF_WIDE_INT which the size of half of a |
| HOST_WIDE_INT and stored in the lower bits of each word. This |
| algorithm should work properly on both 32 and 64 bit |
| machines. */ |
| unsigned HOST_WIDE_INT b |
| = (unsigned HOST_WIDE_INT)1 << HOST_BITS_PER_HALF_WIDE_INT; |
| unsigned HOST_WIDE_INT qhat; /* Estimate of quotient digit. */ |
| unsigned HOST_WIDE_INT rhat; /* A remainder. */ |
| unsigned HOST_WIDE_INT p; /* Product of two digits. */ |
| HOST_WIDE_INT t, k; |
| int i, j, s; |
| |
| /* Single digit divisor. */ |
| if (n == 1) |
| { |
| k = 0; |
| for (j = m - 1; j >= 0; j--) |
| { |
| b_quotient[j] = (k * b + b_dividend[j])/b_divisor[0]; |
| k = ((k * b + b_dividend[j]) |
| - ((unsigned HOST_WIDE_INT)b_quotient[j] |
| * (unsigned HOST_WIDE_INT)b_divisor[0])); |
| } |
| b_remainder[0] = k; |
| return; |
| } |
| |
| s = clz_hwi (b_divisor[n-1]) - HOST_BITS_PER_HALF_WIDE_INT; /* CHECK clz */ |
| |
| if (s) |
| { |
| /* Normalize B_DIVIDEND and B_DIVISOR. Unlike the published |
| algorithm, we can overwrite b_dividend and b_divisor, so we do |
| that. */ |
| for (i = n - 1; i > 0; i--) |
| b_divisor[i] = (b_divisor[i] << s) |
| | (b_divisor[i-1] >> (HOST_BITS_PER_HALF_WIDE_INT - s)); |
| b_divisor[0] = b_divisor[0] << s; |
| |
| b_dividend[m] = b_dividend[m-1] >> (HOST_BITS_PER_HALF_WIDE_INT - s); |
| for (i = m - 1; i > 0; i--) |
| b_dividend[i] = (b_dividend[i] << s) |
| | (b_dividend[i-1] >> (HOST_BITS_PER_HALF_WIDE_INT - s)); |
| b_dividend[0] = b_dividend[0] << s; |
| } |
| |
| /* Main loop. */ |
| for (j = m - n; j >= 0; j--) |
| { |
| qhat = (b_dividend[j+n] * b + b_dividend[j+n-1]) / b_divisor[n-1]; |
| rhat = (b_dividend[j+n] * b + b_dividend[j+n-1]) - qhat * b_divisor[n-1]; |
| again: |
| if (qhat >= b || qhat * b_divisor[n-2] > b * rhat + b_dividend[j+n-2]) |
| { |
| qhat -= 1; |
| rhat += b_divisor[n-1]; |
| if (rhat < b) |
| goto again; |
| } |
| |
| /* Multiply and subtract. */ |
| k = 0; |
| for (i = 0; i < n; i++) |
| { |
| p = qhat * b_divisor[i]; |
| t = b_dividend[i+j] - k - (p & HALF_INT_MASK); |
| b_dividend[i + j] = t; |
| k = ((p >> HOST_BITS_PER_HALF_WIDE_INT) |
| - (t >> HOST_BITS_PER_HALF_WIDE_INT)); |
| } |
| t = b_dividend[j+n] - k; |
| b_dividend[j+n] = t; |
| |
| b_quotient[j] = qhat; |
| if (t < 0) |
| { |
| b_quotient[j] -= 1; |
| k = 0; |
| for (i = 0; i < n; i++) |
| { |
| t = (HOST_WIDE_INT)b_dividend[i+j] + b_divisor[i] + k; |
| b_dividend[i+j] = t; |
| k = t >> HOST_BITS_PER_HALF_WIDE_INT; |
| } |
| b_dividend[j+n] += k; |
| } |
| } |
| if (s) |
| for (i = 0; i < n; i++) |
| b_remainder[i] = (b_dividend[i] >> s) |
| | (b_dividend[i+1] << (HOST_BITS_PER_HALF_WIDE_INT - s)); |
| else |
| for (i = 0; i < n; i++) |
| b_remainder[i] = b_dividend[i]; |
| } |
| |
| |
| /* Divide DIVIDEND by DIVISOR, which have signedness SGN, and truncate |
| the result. If QUOTIENT is nonnull, store the value of the quotient |
| there and return the number of blocks in it. The return value is |
| not defined otherwise. If REMAINDER is nonnull, store the value |
| of the remainder there and store the number of blocks in |
| *REMAINDER_LEN. If OFLOW is not null, store in *OFLOW whether |
| the division overflowed. */ |
| unsigned int |
| wi::divmod_internal (HOST_WIDE_INT *quotient, unsigned int *remainder_len, |
| HOST_WIDE_INT *remainder, |
| const HOST_WIDE_INT *dividend_val, |
| unsigned int dividend_len, unsigned int dividend_prec, |
| const HOST_WIDE_INT *divisor_val, unsigned int divisor_len, |
| unsigned int divisor_prec, signop sgn, |
| bool *oflow) |
| { |
| unsigned int dividend_blocks_needed = 2 * BLOCKS_NEEDED (dividend_prec); |
| unsigned int divisor_blocks_needed = 2 * BLOCKS_NEEDED (divisor_prec); |
| unsigned HOST_HALF_WIDE_INT |
| b_quotient[4 * MAX_BITSIZE_MODE_ANY_INT / HOST_BITS_PER_HALF_WIDE_INT]; |
| unsigned HOST_HALF_WIDE_INT |
| b_remainder[4 * MAX_BITSIZE_MODE_ANY_INT / HOST_BITS_PER_HALF_WIDE_INT]; |
| unsigned HOST_HALF_WIDE_INT |
| b_dividend[(4 * MAX_BITSIZE_MODE_ANY_INT / HOST_BITS_PER_HALF_WIDE_INT) + 1]; |
| unsigned HOST_HALF_WIDE_INT |
| b_divisor[4 * MAX_BITSIZE_MODE_ANY_INT / HOST_BITS_PER_HALF_WIDE_INT]; |
| unsigned int m, n; |
| bool dividend_neg = false; |
| bool divisor_neg = false; |
| bool overflow = false; |
| wide_int neg_dividend, neg_divisor; |
| |
| wide_int_ref dividend = wi::storage_ref (dividend_val, dividend_len, |
| dividend_prec); |
| wide_int_ref divisor = wi::storage_ref (divisor_val, divisor_len, |
| divisor_prec); |
| if (divisor == 0) |
| overflow = true; |
| |
| /* The smallest signed number / -1 causes overflow. The dividend_len |
| check is for speed rather than correctness. */ |
| if (sgn == SIGNED |
| && dividend_len == BLOCKS_NEEDED (dividend_prec) |
| && divisor == -1 |
| && wi::only_sign_bit_p (dividend)) |
| overflow = true; |
| |
| /* Handle the overflow cases. Viewed as unsigned value, the quotient of |
| (signed min / -1) has the same representation as the orignal dividend. |
| We have traditionally made division by zero act as division by one, |
| so there too we use the original dividend. */ |
| if (overflow) |
| { |
| if (remainder) |
| { |
| *remainder_len = 1; |
| remainder[0] = 0; |
| } |
| if (oflow != 0) |
| *oflow = true; |
| if (quotient) |
| for (unsigned int i = 0; i < dividend_len; ++i) |
| quotient[i] = dividend_val[i]; |
| return dividend_len; |
| } |
| |
| if (oflow) |
| *oflow = false; |
| |
| /* Do it on the host if you can. */ |
| if (sgn == SIGNED |
| && wi::fits_shwi_p (dividend) |
| && wi::fits_shwi_p (divisor)) |
| { |
| HOST_WIDE_INT o0 = dividend.to_shwi (); |
| HOST_WIDE_INT o1 = divisor.to_shwi (); |
| |
| if (o0 == HOST_WIDE_INT_MIN && o1 == -1) |
| { |
| gcc_checking_assert (dividend_prec > HOST_BITS_PER_WIDE_INT); |
| if (quotient) |
| { |
| quotient[0] = HOST_WIDE_INT_MIN; |
| quotient[1] = 0; |
| } |
| if (remainder) |
| { |
| remainder[0] = 0; |
| *remainder_len = 1; |
| } |
| return 2; |
| } |
| else |
| { |
| if (quotient) |
| quotient[0] = o0 / o1; |
| if (remainder) |
| { |
| remainder[0] = o0 % o1; |
| *remainder_len = 1; |
| } |
| return 1; |
| } |
| } |
| |
| if (sgn == UNSIGNED |
| && wi::fits_uhwi_p (dividend) |
| && wi::fits_uhwi_p (divisor)) |
| { |
| unsigned HOST_WIDE_INT o0 = dividend.to_uhwi (); |
| unsigned HOST_WIDE_INT o1 = divisor.to_uhwi (); |
| unsigned int quotient_len = 1; |
| |
| if (quotient) |
| { |
| quotient[0] = o0 / o1; |
| if (o1 == 1 |
| && (HOST_WIDE_INT) o0 < 0 |
| && dividend_prec > HOST_BITS_PER_WIDE_INT) |
| { |
| quotient[1] = 0; |
| quotient_len = 2; |
| } |
| } |
| if (remainder) |
| { |
| remainder[0] = o0 % o1; |
| if ((HOST_WIDE_INT) remainder[0] < 0 |
| && dividend_prec > HOST_BITS_PER_WIDE_INT) |
| { |
| remainder[1] = 0; |
| *remainder_len = 2; |
| } |
| else |
| *remainder_len = 1; |
| } |
| return quotient_len; |
| } |
| |
| /* Make the divisor and dividend positive and remember what we |
| did. */ |
| if (sgn == SIGNED) |
| { |
| if (wi::neg_p (dividend)) |
| { |
| neg_dividend = -dividend; |
| dividend = neg_dividend; |
| dividend_neg = true; |
| } |
| if (wi::neg_p (divisor)) |
| { |
| neg_divisor = -divisor; |
| divisor = neg_divisor; |
| divisor_neg = true; |
| } |
| } |
| |
| wi_unpack (b_dividend, dividend.get_val (), dividend.get_len (), |
| dividend_blocks_needed, dividend_prec, sgn); |
| wi_unpack (b_divisor, divisor.get_val (), divisor.get_len (), |
| divisor_blocks_needed, divisor_prec, sgn); |
| |
| m = dividend_blocks_needed; |
| b_dividend[m] = 0; |
| while (m > 1 && b_dividend[m - 1] == 0) |
| m--; |
| |
| n = divisor_blocks_needed; |
| while (n > 1 && b_divisor[n - 1] == 0) |
| n--; |
| |
| memset (b_quotient, 0, sizeof (b_quotient)); |
| |
| divmod_internal_2 (b_quotient, b_remainder, b_dividend, b_divisor, m, n); |
| |
| unsigned int quotient_len = 0; |
| if (quotient) |
| { |
| quotient_len = wi_pack (quotient, b_quotient, m, dividend_prec); |
| /* The quotient is neg if exactly one of the divisor or dividend is |
| neg. */ |
| if (dividend_neg != divisor_neg) |
| quotient_len = wi::sub_large (quotient, zeros, 1, quotient, |
| quotient_len, dividend_prec, |
| UNSIGNED, 0); |
| } |
| |
| if (remainder) |
| { |
| *remainder_len = wi_pack (remainder, b_remainder, n, dividend_prec); |
| /* The remainder is always the same sign as the dividend. */ |
| if (dividend_neg) |
| *remainder_len = wi::sub_large (remainder, zeros, 1, remainder, |
| *remainder_len, dividend_prec, |
| UNSIGNED, 0); |
| } |
| |
| return quotient_len; |
| } |
| |
| /* |
| * Shifting, rotating and extraction. |
| */ |
| |
| /* Left shift XVAL by SHIFT and store the result in VAL. Return the |
| number of blocks in VAL. Both XVAL and VAL have PRECISION bits. */ |
| unsigned int |
| wi::lshift_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *xval, |
| unsigned int xlen, unsigned int precision, |
| unsigned int shift) |
| { |
| /* Split the shift into a whole-block shift and a subblock shift. */ |
| unsigned int skip = shift / HOST_BITS_PER_WIDE_INT; |
| unsigned int small_shift = shift % HOST_BITS_PER_WIDE_INT; |
| |
| /* The whole-block shift fills with zeros. */ |
| unsigned int len = BLOCKS_NEEDED (precision); |
| for (unsigned int i = 0; i < skip; ++i) |
| val[i] = 0; |
| |
| /* It's easier to handle the simple block case specially. */ |
| if (small_shift == 0) |
| for (unsigned int i = skip; i < len; ++i) |
| val[i] = safe_uhwi (xval, xlen, i - skip); |
| else |
| { |
| /* The first unfilled output block is a left shift of the first |
| block in XVAL. The other output blocks contain bits from two |
| consecutive input blocks. */ |
| unsigned HOST_WIDE_INT carry = 0; |
| for (unsigned int i = skip; i < len; ++i) |
| { |
| unsigned HOST_WIDE_INT x = safe_uhwi (xval, xlen, i - skip); |
| val[i] = (x << small_shift) | carry; |
| carry = x >> (-small_shift % HOST_BITS_PER_WIDE_INT); |
| } |
| } |
| return canonize (val, len, precision); |
| } |
| |
| /* Right shift XVAL by SHIFT and store the result in VAL. Return the |
| number of blocks in VAL. The input has XPRECISION bits and the |
| output has XPRECISION - SHIFT bits. */ |
| static unsigned int |
| rshift_large_common (HOST_WIDE_INT *val, const HOST_WIDE_INT *xval, |
| unsigned int xlen, unsigned int xprecision, |
| unsigned int shift) |
| { |
| /* Split the shift into a whole-block shift and a subblock shift. */ |
| unsigned int skip = shift / HOST_BITS_PER_WIDE_INT; |
| unsigned int small_shift = shift % HOST_BITS_PER_WIDE_INT; |
| |
| /* Work out how many blocks are needed to store the significant bits |
| (excluding the upper zeros or signs). */ |
| unsigned int len = BLOCKS_NEEDED (xprecision - shift); |
| |
| /* It's easier to handle the simple block case specially. */ |
| if (small_shift == 0) |
| for (unsigned int i = 0; i < len; ++i) |
| val[i] = safe_uhwi (xval, xlen, i + skip); |
| else |
| { |
| /* Each output block but the last is a combination of two input blocks. |
| The last block is a right shift of the last block in XVAL. */ |
| unsigned HOST_WIDE_INT curr = safe_uhwi (xval, xlen, skip); |
| for (unsigned int i = 0; i < len; ++i) |
| { |
| val[i] = curr >> small_shift; |
| curr = safe_uhwi (xval, xlen, i + skip + 1); |
| val[i] |= curr << (-small_shift % HOST_BITS_PER_WIDE_INT); |
| } |
| } |
| return len; |
| } |
| |
| /* Logically right shift XVAL by SHIFT and store the result in VAL. |
| Return the number of blocks in VAL. XVAL has XPRECISION bits and |
| VAL has PRECISION bits. */ |
| unsigned int |
| wi::lrshift_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *xval, |
| unsigned int xlen, unsigned int xprecision, |
| unsigned int precision, unsigned int shift) |
| { |
| unsigned int len = rshift_large_common (val, xval, xlen, xprecision, shift); |
| |
| /* The value we just created has precision XPRECISION - SHIFT. |
| Zero-extend it to wider precisions. */ |
| if (precision > xprecision - shift) |
| { |
| unsigned int small_prec = (xprecision - shift) % HOST_BITS_PER_WIDE_INT; |
| if (small_prec) |
| val[len - 1] = zext_hwi (val[len - 1], small_prec); |
| else if (val[len - 1] < 0) |
| { |
| /* Add a new block with a zero. */ |
| val[len++] = 0; |
| return len; |
| } |
| } |
| return canonize (val, len, precision); |
| } |
| |
| /* Arithmetically right shift XVAL by SHIFT and store the result in VAL. |
| Return the number of blocks in VAL. XVAL has XPRECISION bits and |
| VAL has PRECISION bits. */ |
| unsigned int |
| wi::arshift_large (HOST_WIDE_INT *val, const HOST_WIDE_INT *xval, |
| unsigned int xlen, unsigned int xprecision, |
| unsigned int precision, unsigned int shift) |
| { |
| unsigned int len = rshift_large_common (val, xval, xlen, xprecision, shift); |
| |
| /* The value we just created has precision XPRECISION - SHIFT. |
| Sign-extend it to wider types. */ |
| if (precision > xprecision - shift) |
| { |
| unsigned int small_prec = (xprecision - shift) % HOST_BITS_PER_WIDE_INT; |
| if (small_prec) |
| val[len - 1] = sext_hwi (val[len - 1], small_prec); |
| } |
| return canonize (val, len, precision); |
| } |
| |
| /* Return the number of leading (upper) zeros in X. */ |
| int |
| wi::clz (const wide_int_ref &x) |
| { |
| /* Calculate how many bits there above the highest represented block. */ |
| int count = x.precision - x.len * HOST_BITS_PER_WIDE_INT; |
| |
| unsigned HOST_WIDE_INT high = x.uhigh (); |
| if (count < 0) |
| /* The upper -COUNT bits of HIGH are not part of the value. |
| Clear them out. */ |
| high = (high << -count) >> -count; |
| else if (x.sign_mask () < 0) |
| /* The upper bit is set, so there are no leading zeros. */ |
| return 0; |
| |
| /* We don't need to look below HIGH. Either HIGH is nonzero, |
| or the top bit of the block below is nonzero; clz_hwi is |
| HOST_BITS_PER_WIDE_INT in the latter case. */ |
| return count + clz_hwi (high); |
| } |
| |
| /* Return the number of redundant sign bits in X. (That is, the number |
| of bits immediately below the sign bit that have the same value as |
| the sign bit.) */ |
| int |
| wi::clrsb (const wide_int_ref &x) |
| { |
| /* Calculate how many bits there above the highest represented block. */ |
| int count = x.precision - x.len * HOST_BITS_PER_WIDE_INT; |
| |
| unsigned HOST_WIDE_INT high = x.uhigh (); |
| unsigned HOST_WIDE_INT mask = -1; |
| if (count < 0) |
| { |
| /* The upper -COUNT bits of HIGH are not part of the value. |
| Clear them from both MASK and HIGH. */ |
| mask >>= -count; |
| high &= mask; |
| } |
| |
| /* If the top bit is 1, count the number of leading 1s. If the top |
| bit is zero, count the number of leading zeros. */ |
| if (high > mask / 2) |
| high ^= mask; |
| |
| /* There are no sign bits below the top block, so we don't need to look |
| beyond HIGH. Note that clz_hwi is HOST_BITS_PER_WIDE_INT when |
| HIGH is 0. */ |
| return count + clz_hwi (high) - 1; |
| } |
| |
| /* Return the number of trailing (lower) zeros in X. */ |
| int |
| wi::ctz (const wide_int_ref &x) |
| { |
| if (x.len == 1 && x.ulow () == 0) |
| return x.precision; |
| |
| /* Having dealt with the zero case, there must be a block with a |
| nonzero bit. We don't care about the bits above the first 1. */ |
| unsigned int i = 0; |
| while (x.val[i] == 0) |
| ++i; |
| return i * HOST_BITS_PER_WIDE_INT + ctz_hwi (x.val[i]); |
| } |
| |
| /* If X is an exact power of 2, return the base-2 logarithm, otherwise |
| return -1. */ |
| int |
| wi::exact_log2 (const wide_int_ref &x) |
| { |
| /* Reject cases where there are implicit -1 blocks above HIGH. */ |
| if (x.len * HOST_BITS_PER_WIDE_INT < x.precision && x.sign_mask () < 0) |
| return -1; |
| |
| /* Set CRUX to the index of the entry that should be nonzero. |
| If the top block is zero then the next lowest block (if any) |
| must have the high bit set. */ |
| unsigned int crux = x.len - 1; |
| if (crux > 0 && x.val[crux] == 0) |
| crux -= 1; |
| |
| /* Check that all lower blocks are zero. */ |
| for (unsigned int i = 0; i < crux; ++i) |
| if (x.val[i] != 0) |
| return -1; |
| |
| /* Get a zero-extended form of block CRUX. */ |
| unsigned HOST_WIDE_INT hwi = x.val[crux]; |
| if ((crux + 1) * HOST_BITS_PER_WIDE_INT > x.precision) |
| hwi = zext_hwi (hwi, x.precision % HOST_BITS_PER_WIDE_INT); |
| |
| /* Now it's down to whether HWI is a power of 2. */ |
| int res = ::exact_log2 (hwi); |
| if (res >= 0) |
| res += crux * HOST_BITS_PER_WIDE_INT; |
| return res; |
| } |
| |
| /* Return the base-2 logarithm of X, rounding down. Return -1 if X is 0. */ |
| int |
| wi::floor_log2 (const wide_int_ref &x) |
| { |
| return x.precision - 1 - clz (x); |
| } |
| |
| /* Return the index of the first (lowest) set bit in X, counting from 1. |
| Return 0 if X is 0. */ |
| int |
| wi::ffs (const wide_int_ref &x) |
| { |
| return eq_p (x, 0) ? 0 : ctz (x) + 1; |
| } |
| |
| /* Return true if sign-extending X to have precision PRECISION would give |
| the minimum signed value at that precision. */ |
| bool |
| wi::only_sign_bit_p (const wide_int_ref &x, unsigned int precision) |
| { |
| return ctz (x) + 1 == int (precision); |
| } |
| |
| /* Return true if X represents the minimum signed value. */ |
| bool |
| wi::only_sign_bit_p (const wide_int_ref &x) |
| { |
| return only_sign_bit_p (x, x.precision); |
| } |
| |
| /* |
| * Private utilities. |
| */ |
| |
| void gt_ggc_mx (widest_int *) { } |
| void gt_pch_nx (widest_int *, void (*) (void *, void *), void *) { } |
| void gt_pch_nx (widest_int *) { } |
| |
| template void wide_int::dump () const; |
| template void generic_wide_int <wide_int_ref_storage <false> >::dump () const; |
| template void generic_wide_int <wide_int_ref_storage <true> >::dump () const; |
| template void offset_int::dump () const; |
| template void widest_int::dump () const; |