/* Analyze RTL for C-Compiler
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
This file is part of GCC.
#include "output.h"
#include "tm_p.h"
#include "flags.h"
-#include "basic-block.h"
#include "real.h"
#include "regs.h"
#include "function.h"
static unsigned int num_sign_bit_copies1 (rtx, enum machine_mode, rtx,
enum machine_mode, unsigned int);
+/* Offset of the first 'e', 'E' or 'V' operand for each rtx code, or
+ -1 if a code has no such operand. */
+static int non_rtx_starting_operands[NUM_RTX_CODE];
+
/* Bit flags that specify the machine subtype we are compiling for.
Bits are tested using macros TARGET_... defined in the tm.h file
and set by `-m...' switches. Must be defined in rtlanal.c. */
}
/* 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 (rtx x, rtx start, rtx end)
-{
- enum rtx_code code = GET_CODE (x);
- const char *fmt;
- int i, j;
-
- switch (code)
- {
- case CONST_INT:
- case CONST_DOUBLE:
- case CONST_VECTOR:
- 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 usememory aliasing. */
return 1;
case MEM:
- if (MEM_READONLY_P (x))
- return 0;
if (modified_between_p (XEXP (x, 0), start, end))
return 1;
+ if (MEM_READONLY_P (x))
+ return 0;
for (insn = NEXT_INSN (start); insn != end; insn = NEXT_INSN (insn))
if (memory_modified_in_insn_p (x, insn))
return 1;
return 1;
case MEM:
- if (MEM_READONLY_P (x))
- return 0;
if (modified_in_p (XEXP (x, 0), insn))
return 1;
+ if (MEM_READONLY_P (x))
+ return 0;
if (memory_modified_in_insn_p (x, insn))
return 1;
return 0;
if (MEM_P (dst) && MEM_P (src))
return rtx_equal_p (dst, src) && !side_effects_p (dst);
- if (GET_CODE (dst) == SIGN_EXTRACT
- || GET_CODE (dst) == ZERO_EXTRACT)
+ if (GET_CODE (dst) == ZERO_EXTRACT)
return rtx_equal_p (XEXP (dst, 0), src)
&& ! BYTES_BIG_ENDIAN && XEXP (dst, 2) == const0_rtx
&& !side_effects_p (src);
&& (!REG_P (SUBREG_REG (dest))
|| REGNO (SUBREG_REG (dest)) >= FIRST_PSEUDO_REGISTER))
|| GET_CODE (dest) == ZERO_EXTRACT
- || GET_CODE (dest) == SIGN_EXTRACT
|| GET_CODE (dest) == STRICT_LOW_PART)
dest = XEXP (dest, 0);
This will be true if X is (cc0) or if X is a register and
X dies in INSN or because INSN entirely sets X.
- "Entirely set" means set directly and not through a SUBREG,
- ZERO_EXTRACT or SIGN_EXTRACT, so no trace of the old contents remains.
+ "Entirely set" means set directly and not through a SUBREG, or
+ ZERO_EXTRACT, so no trace of the old contents remains.
Likewise, REG_INC does not count.
REG may be a hard or pseudo reg. Renumbering is not taken into account,
case UMOD:
if (HONOR_SNANS (GET_MODE (x)))
return 1;
- if (! CONSTANT_P (XEXP (x, 1))
- || (GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT
- && flag_trapping_math))
- return 1;
- if (XEXP (x, 1) == const0_rtx)
+ if (GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT)
+ return flag_trapping_math;
+ if (!CONSTANT_P (XEXP (x, 1)) || (XEXP (x, 1) == const0_rtx))
return 1;
break;
return 0;
}
+/* Optimized loop of for_each_rtx, trying to avoid useless recursive
+ calls. Processes the subexpressions of EXP and passes them to F. */
+static int
+for_each_rtx_1 (rtx exp, int n, rtx_function f, void *data)
+{
+ int result, i, j;
+ const char *format = GET_RTX_FORMAT (GET_CODE (exp));
+ rtx *x;
+
+ for (; format[n] != '\0'; n++)
+ {
+ switch (format[n])
+ {
+ case 'e':
+ /* Call F on X. */
+ x = &XEXP (exp, n);
+ result = (*f) (x, data);
+ if (result == -1)
+ /* Do not traverse sub-expressions. */
+ continue;
+ else if (result != 0)
+ /* Stop the traversal. */
+ return result;
+
+ if (*x == NULL_RTX)
+ /* There are no sub-expressions. */
+ continue;
+
+ i = non_rtx_starting_operands[GET_CODE (*x)];
+ if (i >= 0)
+ {
+ result = for_each_rtx_1 (*x, i, f, data);
+ if (result != 0)
+ return result;
+ }
+ break;
+
+ case 'V':
+ case 'E':
+ if (XVEC (exp, n) == 0)
+ continue;
+ for (j = 0; j < XVECLEN (exp, n); ++j)
+ {
+ /* Call F on X. */
+ x = &XVECEXP (exp, n, j);
+ result = (*f) (x, data);
+ if (result == -1)
+ /* Do not traverse sub-expressions. */
+ continue;
+ else if (result != 0)
+ /* Stop the traversal. */
+ return result;
+
+ if (*x == NULL_RTX)
+ /* There are no sub-expressions. */
+ continue;
+
+ i = non_rtx_starting_operands[GET_CODE (*x)];
+ if (i >= 0)
+ {
+ result = for_each_rtx_1 (*x, i, f, data);
+ if (result != 0)
+ return result;
+ }
+ }
+ break;
+
+ default:
+ /* Nothing to do. */
+ break;
+ }
+ }
+
+ 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
for_each_rtx (rtx *x, rtx_function f, void *data)
{
int result;
- int length;
- const char *format;
int i;
/* Call F on X. */
/* 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;
- }
-
- }
+ i = non_rtx_starting_operands[GET_CODE (*x)];
+ if (i < 0)
+ return 0;
- return 0;
+ return for_each_rtx_1 (*x, i, f, data);
}
+
/* Searches X for any reference to REGNO, returning the rtx of the
reference found if any. Otherwise, returns NULL_RTX. */
}
/* Look backward for first parameter to be loaded.
+ Note that loads of all parameters will not necessarily be
+ found if CSE has eliminated some of them (e.g., an argument
+ to the outer function is passed down as a parameter).
Do not skip BOUNDARY. */
rtx
find_first_parameter_load (rtx call_insn, rtx boundary)
{
struct parms_set_data parm;
- rtx p, before;
+ rtx p, before, first_set;
/* Since different machines initialize their parameter registers
in different orders, assume nothing. Collect the set of all
parm.nregs++;
}
before = call_insn;
+ first_set = call_insn;
/* Search backward for the first set of a register in this set. */
while (parm.nregs && before != boundary)
}
if (INSN_P (before))
- note_stores (PATTERN (before), parms_set, &parm);
+ {
+ int nregs_old = parm.nregs;
+ note_stores (PATTERN (before), parms_set, &parm);
+ /* If we found something that did not set a parameter reg,
+ we're done. Do not keep going, as that might result
+ in hoisting an insn before the setting of a pseudo
+ that is used by the hoisted insn. */
+ if (nregs_old != parm.nregs)
+ first_set = before;
+ else
+ break;
+ }
}
- return before;
+ return first_set;
}
/* Return true if we should avoid inserting code between INSN and preceding
return 0;
case SUBREG:
+ total = 0;
/* If we can't tie these modes, make this expensive. The larger
the mode, the more expensive it is. */
if (! MODES_TIEABLE_P (GET_MODE (x), GET_MODE (SUBREG_REG (x))))
allow_cc_mode, valid_at_insn_p);
}
+\f
+/* Initialize non_rtx_starting_operands, which is used to speed up
+ for_each_rtx. */
+void
+init_rtlanal (void)
+{
+ int i;
+ for (i = 0; i < NUM_RTX_CODE; i++)
+ {
+ const char *format = GET_RTX_FORMAT (i);
+ const char *first = strpbrk (format, "eEV");
+ non_rtx_starting_operands[i] = first ? first - format : -1;
+ }
+}
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