/* Analyze RTL for C-Compiler
- Copyright (C) 1987, 88, 92-97, 1998 Free Software Foundation, Inc.
+ Copyright (C) 1987, 88, 92-98, 1999 Free Software Foundation, Inc.
This file is part of GNU CC.
#include "rtl.h"
static int rtx_addr_can_trap_p PROTO((rtx));
+static void reg_set_p_1 PROTO((rtx, rtx));
+static void reg_set_last_1 PROTO((rtx, rtx));
/* Forward declarations */
return 1;
}
+/* Return 1 if in between BEG and END, exclusive of BEG and END, there is
+ no JUMP_INSN insn. */
+
+int
+no_jumps_between_p (beg, end)
+ rtx beg, end;
+{
+ register rtx p;
+ for (p = NEXT_INSN (beg); p != end; p = NEXT_INSN (p))
+ if (GET_CODE (p) == JUMP_INSN)
+ return 0;
+ return 1;
+}
+
/* Nonzero if register REG is used in an insn between
FROM_INSN and TO_INSN (exclusive of those two). */
static void
reg_set_p_1 (x, pat)
- rtx x, pat;
+ rtx x;
+ rtx pat ATTRIBUTE_UNUSED;
{
/* We don't want to return 1 if X is a MEM that contains a register
within REG_SET_REG. */
}
/* Similar to reg_set_between_p, but check all registers in X. Return 0
+ only if none of them are modified between START and END. Do not
+ consider non-registers one way or the other. */
+
+int
+regs_set_between_p (x, start, end)
+ rtx x;
+ rtx start, end;
+{
+ enum rtx_code code = GET_CODE (x);
+ char *fmt;
+ int i, j;
+
+ switch (code)
+ {
+ case CONST_INT:
+ case CONST_DOUBLE:
+ case CONST:
+ case SYMBOL_REF:
+ case LABEL_REF:
+ case PC:
+ case CC0:
+ return 0;
+
+ case REG:
+ return reg_set_between_p (x, start, end);
+
+ default:
+ break;
+ }
+
+ fmt = GET_RTX_FORMAT (code);
+ for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+ {
+ if (fmt[i] == 'e' && regs_set_between_p (XEXP (x, i), start, end))
+ return 1;
+
+ else if (fmt[i] == 'E')
+ for (j = XVECLEN (x, i) - 1; j >= 0; j--)
+ if (regs_set_between_p (XVECEXP (x, i, j), start, end))
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Similar to reg_set_between_p, but check all registers in X. Return 0
only if none of them are modified between START and END. Return 1 if
X contains a MEM; this routine does not perform any memory aliasing. */
return 0;
}
+
+/* Given an INSN, return nonzero if it has more than one SET, else return
+ zero. */
+
+int
+multiple_sets (insn)
+ rtx insn;
+{
+ int found;
+ int i;
+
+ /* INSN must be an insn. */
+ if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
+ return 0;
+
+ /* Only a PARALLEL can have multiple SETs. */
+ if (GET_CODE (PATTERN (insn)) == PARALLEL)
+ {
+ for (i = 0, found = 0; i < XVECLEN (PATTERN (insn), 0); i++)
+ if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET)
+ {
+ /* If we have already found a SET, then return now. */
+ if (found)
+ return 1;
+ else
+ found = 1;
+ }
+ }
+
+ /* Either zero or one SET. */
+ return 0;
+}
\f
/* Return the last thing that X was assigned from before *PINSN. Verify that
the object is not modified up to VALID_TO. If it was, if we hit
a partial assignment to X, or hit a CODE_LABEL first, return X. If we
- found an assignment, update *PINSN to point to it. */
+ found an assignment, update *PINSN to point to it.
+ ALLOW_HWREG is set to 1 if hardware registers are allowed to be the src. */
rtx
-find_last_value (x, pinsn, valid_to)
+find_last_value (x, pinsn, valid_to, allow_hwreg)
rtx x;
rtx *pinsn;
rtx valid_to;
+ int allow_hwreg;
{
rtx p;
if (! modified_between_p (src, PREV_INSN (p), valid_to)
/* Reject hard registers because we don't usually want
to use them; we'd rather use a pseudo. */
- && ! (GET_CODE (src) == REG
- && REGNO (src) < FIRST_PSEUDO_REGISTER))
+ && (! (GET_CODE (src) == REG
+ && REGNO (src) < FIRST_PSEUDO_REGISTER) || allow_hwreg))
{
*pinsn = p;
return src;
{
int regno, endregno;
- if (GET_CODE (x) == SUBREG)
+ /* Overly conservative. */
+ if (GET_CODE (x) == STRICT_LOW_PART)
+ x = XEXP (x, 0);
+
+ /* If either argument is a constant, then modifying X can not affect IN. */
+ if (CONSTANT_P (x) || CONSTANT_P (in))
+ return 0;
+ else if (GET_CODE (x) == SUBREG)
{
regno = REGNO (SUBREG_REG (x));
if (regno < FIRST_PSEUDO_REGISTER)
}
else if (GET_CODE (x) == REG)
regno = REGNO (x);
- else if (CONSTANT_P (x))
- return 0;
else if (GET_CODE (x) == MEM)
{
char *fmt;
else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC
|| GET_CODE (x) == CC0)
return reg_mentioned_p (x, in);
+ else if (GET_CODE (x) == PARALLEL
+ && GET_MODE (x) == BLKmode)
+ {
+ register int i;
+
+ /* If any register in here refers to it
+ we return true. */
+ for (i = XVECLEN (x, 0) - 1; i >= 0; i--)
+ if (reg_overlap_mentioned_p (SET_DEST (XVECEXP (x, 0, i)), in))
+ return 1;
+ return 0;
+ }
else
abort ();
void
note_stores (x, fun)
register rtx x;
- void (*fun) ();
+ void (*fun) PROTO ((rtx, rtx));
{
if ((GET_CODE (x) == SET || GET_CODE (x) == CLOBBER))
{
|| GET_CODE (dest) == SIGN_EXTRACT
|| GET_CODE (dest) == STRICT_LOW_PART)
dest = XEXP (dest, 0);
- (*fun) (dest, x);
+
+ if (GET_CODE (dest) == PARALLEL
+ && GET_MODE (dest) == BLKmode)
+ {
+ register int i;
+ for (i = XVECLEN (dest, 0) - 1; i >= 0; i--)
+ (*fun) (SET_DEST (XVECEXP (dest, 0, i)), x);
+ }
+ else
+ (*fun) (dest, x);
}
else if (GET_CODE (x) == PARALLEL)
{
|| GET_CODE (dest) == SIGN_EXTRACT
|| GET_CODE (dest) == STRICT_LOW_PART)
dest = XEXP (dest, 0);
- (*fun) (dest, y);
+ if (GET_CODE (dest) == PARALLEL
+ && GET_MODE (dest) == BLKmode)
+ {
+ register int i;
+ for (i = XVECLEN (dest, 0) - 1; i >= 0; i--)
+ (*fun) (SET_DEST (XVECEXP (dest, 0, i)), y);
+ }
+ else
+ (*fun) (dest, y);
}
}
}
int regno, endregno;
rtx link;
- /* REG_READ notes are not normally maintained after reload, so we
- ignore them if the are invalid. */
- if (! reload_completed
-#ifdef PRESERVE_DEATH_INFO_REGNO_P
- || PRESERVE_DEATH_INFO_REGNO_P (test_regno)
-#endif
- )
+ /* See if there is a death note for something that includes
+ TEST_REGNO. */
+ for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
{
- /* See if there is a death note for something that includes
- TEST_REGNO. */
- for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
- {
- if (REG_NOTE_KIND (link) != REG_DEAD
- || GET_CODE (XEXP (link, 0)) != REG)
- continue;
+ if (REG_NOTE_KIND (link) != REG_DEAD
+ || GET_CODE (XEXP (link, 0)) != REG)
+ continue;
- regno = REGNO (XEXP (link, 0));
- endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1
- : regno + HARD_REGNO_NREGS (regno,
- GET_MODE (XEXP (link, 0))));
+ regno = REGNO (XEXP (link, 0));
+ endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1
+ : regno + HARD_REGNO_NREGS (regno,
+ GET_MODE (XEXP (link, 0))));
- if (test_regno >= regno && test_regno < endregno)
- return 1;
- }
+ if (test_regno >= regno && test_regno < endregno)
+ return 1;
}
if (GET_CODE (insn) == CALL_INSN
/* A value is totally replaced if it is the destination or the
destination is a SUBREG of REGNO that does not change the number of
words in it. */
- if (GET_CODE (dest) == SUBREG
+ if (GET_CODE (dest) == SUBREG
&& (((GET_MODE_SIZE (GET_MODE (dest))
+ UNITS_PER_WORD - 1) / UNITS_PER_WORD)
== ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
{
register rtx link;
+ /* Ignore anything that is not an INSN, JUMP_INSN or CALL_INSN. */
+ if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
+ return 0;
+
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) == kind
&& (datum == 0 || datum == XEXP (link, 0)))
{
register rtx link;
+ /* Ignore anything that is not an INSN, JUMP_INSN or CALL_INSN. */
+ if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
+ return 0;
+
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) == kind
/* Verify that it is a register, so that scratch and MEM won't cause a
return 0;
}
\f
-/* Replace any occurrence of FROM in X with TO.
+/* Replace any occurrence of FROM in X with TO. The function does
+ not enter into CONST_DOUBLE for the replace.
Note that copying is not done so X must not be shared unless all copies
are to be modified. */
register int i, j;
register char *fmt;
+ /* The following prevents loops occurrence when we change MEM in
+ CONST_DOUBLE onto the same CONST_DOUBLE. */
+ if (x != 0 && GET_CODE (x) == CONST_DOUBLE)
+ return x;
+
if (x == from)
return to;
}
return 0;
}
+
+/* Traverse X via depth-first search, calling F for each
+ sub-expression (including X itself). F is also passed the DATA.
+ If F returns -1, do not traverse sub-expressions, but continue
+ traversing the rest of the tree. If F ever returns any other
+ non-zero value, stop the traversal, and return the value returned
+ by F. Otherwise, return 0. This function does not traverse inside
+ tree structure that contains RTX_EXPRs, or into sub-expressions
+ whose format code is `0' since it is not known whether or not those
+ codes are actually RTL.
+
+ This routine is very general, and could (should?) be used to
+ implement many of the other routines in this file. */
+
+int
+for_each_rtx (x, f, data)
+ rtx *x;
+ rtx_function f;
+ void *data;
+{
+ int result;
+ int length;
+ char* format;
+ int i;
+
+ /* Call F on X. */
+ result = (*f)(x, data);
+ if (result == -1)
+ /* Do not traverse sub-expressions. */
+ return 0;
+ else if (result != 0)
+ /* Stop the traversal. */
+ return result;
+
+ if (*x == NULL_RTX)
+ /* There are no sub-expressions. */
+ return 0;
+
+ length = GET_RTX_LENGTH (GET_CODE (*x));
+ format = GET_RTX_FORMAT (GET_CODE (*x));
+
+ for (i = 0; i < length; ++i)
+ {
+ switch (format[i])
+ {
+ case 'e':
+ result = for_each_rtx (&XEXP (*x, i), f, data);
+ if (result != 0)
+ return result;
+ break;
+
+ case 'V':
+ case 'E':
+ if (XVEC (*x, i) != 0)
+ {
+ int j;
+ for (j = 0; j < XVECLEN (*x, i); ++j)
+ {
+ result = for_each_rtx (&XVECEXP (*x, i, j), f, data);
+ if (result != 0)
+ return result;
+ }
+ }
+ break;
+
+ default:
+ /* Nothing to do. */
+ break;
+ }
+
+ }
+
+ return 0;
+}
+
+/* Searches X for any reference to REGNO, returning the rtx of the
+ reference found if any. Otherwise, returns NULL_RTX. */
+
+rtx
+regno_use_in (regno, x)
+ int regno;
+ rtx x;
+{
+ register char *fmt;
+ int i, j;
+ rtx tem;
+
+ if (GET_CODE (x) == REG && REGNO (x) == regno)
+ return x;
+
+ fmt = GET_RTX_FORMAT (GET_CODE (x));
+ for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
+ {
+ if (fmt[i] == 'e')
+ {
+ if ((tem = regno_use_in (regno, XEXP (x, i))))
+ return tem;
+ }
+ else if (fmt[i] == 'E')
+ for (j = XVECLEN (x, i) - 1; j >= 0; j--)
+ if ((tem = regno_use_in (regno , XVECEXP (x, i, j))))
+ return tem;
+ }
+
+ return NULL_RTX;
+}
+
+
+/* Return 1 if X is an autoincrement side effect and the register is
+ not the stack pointer. */
+int
+auto_inc_p (x)
+ rtx x;
+{
+ switch (GET_CODE (x))
+ {
+ case PRE_INC:
+ case POST_INC:
+ case PRE_DEC:
+ case POST_DEC:
+ case PRE_MODIFY:
+ case POST_MODIFY:
+ /* There are no REG_INC notes for SP. */
+ if (XEXP (x, 0) != stack_pointer_rtx)
+ return 1;
+ default:
+ break;
+ }
+ return 0;
+}
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