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- /* Definitions for condition code handling in final.c and output routines.
- Copyright (C) 1987-2015 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 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/>. */
- #ifndef GCC_CONDITIONS_H
- #define GCC_CONDITIONS_H
- /* None of the things in the files exist if we don't use CC0. */
- #ifdef HAVE_cc0
- /* The variable cc_status says how to interpret the condition code.
- It is set by output routines for an instruction that sets the cc's
- and examined by output routines for jump instructions.
- cc_status contains two components named `value1' and `value2'
- that record two equivalent expressions for the values that the
- condition codes were set from. (Either or both may be null if
- there is no useful expression to record.) These fields are
- used for eliminating redundant test and compare instructions
- in the cases where the condition codes were already set by the
- previous instruction.
- cc_status.flags contains flags which say that the condition codes
- were set in a nonstandard manner. The output of jump instructions
- uses these flags to compensate and produce the standard result
- with the nonstandard condition codes. Standard flags are defined here.
- The tm.h file can also define other machine-dependent flags.
- cc_status also contains a machine-dependent component `mdep'
- whose type, `CC_STATUS_MDEP', may be defined as a macro in the
- tm.h file. */
- #ifndef CC_STATUS_MDEP
- #define CC_STATUS_MDEP int
- #endif
- #ifndef CC_STATUS_MDEP_INIT
- #define CC_STATUS_MDEP_INIT 0
- #endif
- struct CC_STATUS {int flags; rtx value1, value2; CC_STATUS_MDEP mdep;};
- /* While outputting an insn as assembler code,
- this is the status BEFORE that insn. */
- extern CC_STATUS cc_prev_status;
- /* While outputting an insn as assembler code,
- this is being altered to the status AFTER that insn. */
- extern CC_STATUS cc_status;
- /* These are the machine-independent flags: */
- /* Set if the sign of the cc value is inverted:
- output a following jump-if-less as a jump-if-greater, etc. */
- #define CC_REVERSED 1
- /* This bit means that the current setting of the N bit is bogus
- and conditional jumps should use the Z bit in its place.
- This state obtains when an extraction of a signed single-bit field
- or an arithmetic shift right of a byte by 7 bits
- is turned into a btst, because btst does not set the N bit. */
- #define CC_NOT_POSITIVE 2
- /* This bit means that the current setting of the N bit is bogus
- and conditional jumps should pretend that the N bit is clear.
- Used after extraction of an unsigned bit
- or logical shift right of a byte by 7 bits is turned into a btst.
- The btst does not alter the N bit, but the result of that shift
- or extract is never negative. */
- #define CC_NOT_NEGATIVE 4
- /* This bit means that the current setting of the overflow flag
- is bogus and conditional jumps should pretend there is no overflow. */
- /* ??? Note that for most targets this macro is misnamed as it applies
- to the carry flag, not the overflow flag. */
- #define CC_NO_OVERFLOW 010
- /* This bit means that what ought to be in the Z bit
- should be tested as the complement of the N bit. */
- #define CC_Z_IN_NOT_N 020
- /* This bit means that what ought to be in the Z bit
- should be tested as the N bit. */
- #define CC_Z_IN_N 040
- /* Nonzero if we must invert the sense of the following branch, i.e.
- change EQ to NE. This is not safe for IEEE floating point operations!
- It is intended for use only when a combination of arithmetic
- or logical insns can leave the condition codes set in a fortuitous
- (though inverted) state. */
- #define CC_INVERTED 0100
- /* Nonzero if we must convert signed condition operators to unsigned.
- This is only used by machine description files. */
- #define CC_NOT_SIGNED 0200
- /* This is how to initialize the variable cc_status.
- final does this at appropriate moments. */
- #define CC_STATUS_INIT \
- (cc_status.flags = 0, cc_status.value1 = 0, cc_status.value2 = 0, \
- CC_STATUS_MDEP_INIT)
- #endif
- #endif /* GCC_CONDITIONS_H */
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