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author | mycroft <mycroft@138bc75d-0d04-0410-961f-82ee72b054a4> | 1992-03-14 05:04:03 +0000 |
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committer | mycroft <mycroft@138bc75d-0d04-0410-961f-82ee72b054a4> | 1992-03-14 05:04:03 +0000 |
commit | 966e4333fe31ffa43cf1e59be7d40d5c2f963f54 (patch) | |
tree | 0f59e4d249b2f0e3ff4b10937c31d800039597ea /gcc/conditions.h | |
parent | 7d946265e5a864043603e761d9c78aff66bead2f (diff) | |
download | gcc-966e4333fe31ffa43cf1e59be7d40d5c2f963f54.tar.gz |
entered into RCS
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@469 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/conditions.h')
-rw-r--r-- | gcc/conditions.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/gcc/conditions.h b/gcc/conditions.h new file mode 100644 index 00000000000..140fbd98544 --- /dev/null +++ b/gcc/conditions.h @@ -0,0 +1,111 @@ +/* Definitions for condition code handling in final.c and output routines. + Copyright (C) 1987 Free Software Foundation, Inc. + +This file is part of GNU CC. + +GNU CC 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 version. + +GNU CC 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 GNU CC; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* 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 + +typedef struct {int flags; rtx value1, value2; CC_STATUS_MDEP mdep;} CC_STATUS; + +/* 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. */ +#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 + +/* 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 |