2b6e2d13ff
2011-01-24 Kenneth Zadeck <zadeck@naturalbridge.com> * machmode.def: Fixed comments. From-SVN: r169179
253 lines
9.2 KiB
Modula-2
253 lines
9.2 KiB
Modula-2
/* This file contains the definitions and documentation for the
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machine modes used in the GNU compiler.
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Copyright (C) 1987, 1992, 1994, 1997, 1998, 2000, 2003, 2004, 2005,
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2007, 2010 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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/* This file defines all the MACHINE MODES used by GCC.
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A machine mode specifies a size and format of data
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at the machine level.
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Each RTL expression has a machine mode.
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At the syntax tree level, each ..._TYPE and each ..._DECL node
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has a machine mode which describes data of that type or the
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data of the variable declared. */
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/* This file is included by the genmodes program. Its text is the
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body of a function. Do not rely on this, it will change in the
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future.
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The following statements can be used in this file -- all have
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the form of a C macro call. In their arguments:
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A CLASS argument must be one of the constants defined in
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mode-classes.def, less the leading MODE_ prefix; some statements
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that take CLASS arguments have restrictions on which classes are
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acceptable. For instance, INT.
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A MODE argument must be the printable name of a machine mode,
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without quotation marks or trailing "mode". For instance, SI.
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A PRECISION, BYTESIZE, or COUNT argument must be a positive integer
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constant.
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A FORMAT argument must be one of the real_mode_format structures
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declared in real.h, or else a literal 0. Do not put a leading &
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on the argument.
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An EXPR argument must be a syntactically valid C expression.
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If an EXPR contains commas, you may need to write an extra pair of
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parentheses around it, so it appears to be a single argument to the
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statement.
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This file defines only those modes which are of use on almost all
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machines. Other modes can be defined in the target-specific
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mode definition file, config/ARCH/ARCH-modes.def.
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Order matters in this file in so far as statements which refer to
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other modes must appear after the modes they refer to. However,
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statements which do not refer to other modes may appear in any
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order.
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RANDOM_MODE (MODE);
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declares MODE to be of class RANDOM.
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CC_MODE (MODE);
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declares MODE to be of class CC.
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INT_MODE (MODE, BYTESIZE);
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declares MODE to be of class INT and BYTESIZE bytes wide.
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All of the bits of its representation are significant.
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FRACTIONAL_INT_MODE (MODE, PRECISION, BYTESIZE);
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declares MODE to be of class INT, BYTESIZE bytes wide in
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storage, but with only PRECISION significant bits.
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FLOAT_MODE (MODE, BYTESIZE, FORMAT);
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declares MODE to be of class FLOAT and BYTESIZE bytes wide,
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using floating point format FORMAT.
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All of the bits of its representation are significant.
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FRACTIONAL_FLOAT_MODE (MODE, PRECISION, BYTESIZE, FORMAT);
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declares MODE to be of class FLOAT, BYTESIZE bytes wide in
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storage, but with only PRECISION significant bits, using
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floating point format FORMAT.
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DECIMAL_FLOAT_MODE (MODE, BYTESIZE, FORMAT);
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declares MODE to be of class DECIMAL_FLOAT and BYTESIZE bytes
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wide. All of the bits of its representation are significant.
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FRACTIONAL_DECIMAL_FLOAT_MODE (MODE, BYTESIZE, FORMAT);
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declares MODE to be of class DECIMAL_FLOAT and BYTESIZE bytes
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wide. All of the bits of its representation are significant.
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FRACT_MODE (MODE, BYTESIZE, FBIT);
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declares MODE to be of class FRACT and BYTESIZE bytes wide
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with FBIT fractional bits. There may be padding bits.
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UFRACT_MODE (MODE, BYTESIZE, FBIT);
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declares MODE to be of class UFRACT and BYTESIZE bytes wide
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with FBIT fractional bits. There may be padding bits.
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ACCUM_MODE (MODE, BYTESIZE, IBIT, FBIT);
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declares MODE to be of class ACCUM and BYTESIZE bytes wide
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with IBIT integral bits and FBIT fractional bits.
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There may be padding bits.
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UACCUM_MODE (MODE, BYTESIZE, IBIT, FBIT);
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declares MODE to be of class UACCUM and BYTESIZE bytes wide
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with IBIT integral bits and FBIT fractional bits.
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There may be padding bits.
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RESET_FLOAT_FORMAT (MODE, FORMAT);
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changes the format of MODE, which must be class FLOAT,
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to FORMAT. Use in an ARCH-modes.def to reset the format
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of one of the float modes defined in this file.
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PARTIAL_INT_MODE (MODE);
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declares a mode of class PARTIAL_INT with the same size as
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MODE (which must be an INT mode). The name of the new mode
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is made by prefixing a P to the name MODE. This statement
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may grow a PRECISION argument in the future.
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VECTOR_MODE (CLASS, MODE, COUNT);
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Declare a vector mode whose component mode is MODE (of class
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CLASS) with COUNT components. CLASS must be INT or FLOAT.
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The name of the vector mode takes the form VnX where n is
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COUNT in decimal and X is MODE.
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VECTOR_MODES (CLASS, WIDTH);
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For all modes presently declared in class CLASS, construct
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corresponding vector modes having width WIDTH. Modes whose
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byte sizes do not evenly divide WIDTH are ignored, as are
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modes that would produce vector modes with only one component,
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and modes smaller than one byte (if CLASS is INT) or smaller
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than two bytes (if CLASS is FLOAT). CLASS must be INT or
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FLOAT. The names follow the same rule as VECTOR_MODE uses.
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COMPLEX_MODES (CLASS);
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For all modes presently declared in class CLASS, construct
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corresponding complex modes. Modes smaller than one byte
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are ignored. For FLOAT modes, the names are derived by
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replacing the 'F' in the mode name with a 'C'. (It is an
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error if there is no 'F'. For INT modes, the names are
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derived by prefixing a C to the name.
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ADJUST_BYTESIZE (MODE, EXPR);
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ADJUST_ALIGNMENT (MODE, EXPR);
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ADJUST_FLOAT_FORMAT (MODE, EXPR);
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ADJUST_IBIT (MODE, EXPR);
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ADJUST_FBIT (MODE, EXPR);
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Arrange for the byte size, alignment, floating point format, ibit,
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or fbit of MODE to be adjustable at run time. EXPR will be executed
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once after processing all command line options, and should
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evaluate to the desired byte size, alignment, format, ibit or fbit.
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Unlike a FORMAT argument, if you are adjusting a float format
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you must put an & in front of the name of each format structure.
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Note: If a mode is ever made which is more than 255 bytes wide,
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machmode.h and genmodes.c will have to be changed to allocate
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more space for the mode_size and mode_alignment arrays. */
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/* VOIDmode is used when no mode needs to be specified,
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as for example on CONST_INT RTL expressions. */
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RANDOM_MODE (VOID);
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/* BLKmode is used for structures, arrays, etc.
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that fit no more specific mode. */
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RANDOM_MODE (BLK);
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/* Single bit mode used for booleans. */
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FRACTIONAL_INT_MODE (BI, 1, 1);
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/* Basic integer modes. We go up to TI in generic code (128 bits).
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The name OI is reserved for a 256-bit type (needed by some back ends).
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FIXME TI shouldn't be generically available either. */
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INT_MODE (QI, 1);
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INT_MODE (HI, 2);
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INT_MODE (SI, 4);
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INT_MODE (DI, 8);
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INT_MODE (TI, 16);
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/* No partial integer modes are defined by default. */
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/* Basic floating point modes. SF and DF are the only modes provided
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by default. The names QF, HF, XF, and TF are reserved for targets
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that need 1-word, 2-word, 80-bit, or 128-bit float types respectively.
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These are the IEEE mappings. They can be overridden with
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RESET_FLOAT_FORMAT or at runtime (in TARGET_OPTION_OVERRIDE). */
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FLOAT_MODE (SF, 4, ieee_single_format);
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FLOAT_MODE (DF, 8, ieee_double_format);
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/* Basic CC modes.
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FIXME define this only for targets that need it. */
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CC_MODE (CC);
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/* Fixed-point modes. */
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FRACT_MODE (QQ, 1, 7); /* s.7 */
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FRACT_MODE (HQ, 2, 15); /* s.15 */
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FRACT_MODE (SQ, 4, 31); /* s.31 */
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FRACT_MODE (DQ, 8, 63); /* s.63 */
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FRACT_MODE (TQ, 16, 127); /* s.127 */
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UFRACT_MODE (UQQ, 1, 8); /* .8 */
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UFRACT_MODE (UHQ, 2, 16); /* .16 */
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UFRACT_MODE (USQ, 4, 32); /* .32 */
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UFRACT_MODE (UDQ, 8, 64); /* .64 */
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UFRACT_MODE (UTQ, 16, 128); /* .128 */
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ACCUM_MODE (HA, 2, 8, 7); /* s8.7 */
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ACCUM_MODE (SA, 4, 16, 15); /* s16.15 */
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ACCUM_MODE (DA, 8, 32, 31); /* s32.31 */
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ACCUM_MODE (TA, 16, 64, 63); /* s64.63 */
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UACCUM_MODE (UHA, 2, 8, 8); /* 8.8 */
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UACCUM_MODE (USA, 4, 16, 16); /* 16.16 */
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UACCUM_MODE (UDA, 8, 32, 32); /* 32.32 */
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UACCUM_MODE (UTA, 16, 64, 64); /* 64.64 */
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/* Allow the target to specify additional modes of various kinds. */
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#if HAVE_EXTRA_MODES
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# include EXTRA_MODES_FILE
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#endif
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/* Complex modes. */
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COMPLEX_MODES (INT);
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COMPLEX_MODES (FLOAT);
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/* Decimal floating point modes. */
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DECIMAL_FLOAT_MODE (SD, 4, decimal_single_format);
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DECIMAL_FLOAT_MODE (DD, 8, decimal_double_format);
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DECIMAL_FLOAT_MODE (TD, 16, decimal_quad_format);
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/* The symbol Pmode stands for one of the above machine modes (usually SImode).
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The tm.h file specifies which one. It is not a distinct mode. */
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/*
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Local variables:
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mode:c
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version-control: t
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End:
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*/
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