Added gccHEADmaster

1 files changed, 681 insertions, 0 deletions

diff --git a/gcc-1.40/rtlanal.c b/gcc-1.40/rtlanal.c
new file mode 100644
index 0000000..17ee75e
--- /dev/null
+++ b/gcc-1.40/rtlanal.c
@@ -0,0 +1,681 @@
+/* Analyze RTL for C-Compiler
+   Copyright (C) 1987, 1988 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 1, 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.  */
+
+
+#include "config.h"
+#include "rtl.h"
+
+extern void note_stores ();
+static int reg_set_p ();
+
+/* Return 1 if the value of X is unstable
+   (would be different at a different point in the program).
+   The frame pointer, arg pointer, etc. are considered stable
+   (within one function) and so is anything marked `unchanging'.  */
+
+int
+rtx_unstable_p (x)
+     rtx x;
+{
+  register RTX_CODE code = GET_CODE (x);
+  register int i;
+  register char *fmt;
+
+  if (code == MEM)
+    return ! RTX_UNCHANGING_P (x);
+
+  if (code == QUEUED)
+    return 1;
+
+  if (code == CONST || code == CONST_INT)
+    return 0;
+
+  if (code == REG)
+    return ! (REGNO (x) == FRAME_POINTER_REGNUM
+	      || REGNO (x) == ARG_POINTER_REGNUM
+	      || RTX_UNCHANGING_P (x));
+
+  fmt = GET_RTX_FORMAT (code);
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    if (fmt[i] == 'e')
+      if (rtx_unstable_p (XEXP (x, i)))
+	return 1;
+  return 0;
+}
+
+/* Return 1 if X has a value that can vary even between two
+   executions of the program.  0 means X can be compared reliably
+   against certain constants or near-constants.
+   The frame pointer and the arg pointer are considered constant.  */
+
+int
+rtx_varies_p (x)
+     rtx x;
+{
+  register RTX_CODE code = GET_CODE (x);
+  register int i;
+  register char *fmt;
+
+  if (code == MEM)
+    return 1;
+
+  if (code == QUEUED)
+    return 1;
+
+  if (code == CONST || code == CONST_INT)
+    return 0;
+
+  if (code == REG)
+    return ! (REGNO (x) == FRAME_POINTER_REGNUM
+	      || REGNO (x) == ARG_POINTER_REGNUM);
+
+  fmt = GET_RTX_FORMAT (code);
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    if (fmt[i] == 'e')
+      if (rtx_varies_p (XEXP (x, i)))
+	return 1;
+  return 0;
+}
+
+/* Return 1 if X refers to a memory location whose address 
+   cannot be compared reliably with constant addresses,
+   or if X refers to a BLKmode memory object.  */
+
+int
+rtx_addr_varies_p (x)
+     rtx x;
+{
+  register enum rtx_code code;
+  register int i;
+  register char *fmt;
+
+  if (x == 0)
+    return 0;
+
+  code = GET_CODE (x);
+  if (code == MEM)
+    return GET_MODE (x) == BLKmode || rtx_varies_p (XEXP (x, 0));
+
+  fmt = GET_RTX_FORMAT (code);
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    if (fmt[i] == 'e')
+      if (rtx_addr_varies_p (XEXP (x, i)))
+	return 1;
+  return 0;
+}
+
+/* Nonzero if register REG appears somewhere within IN.
+   Also works if REG is not a register; in this case it checks
+   for a subexpression of IN that is Lisp "equal" to REG.  */
+
+int
+reg_mentioned_p (reg, in)
+     register rtx reg, in;
+{
+  register char *fmt;
+  register int i;
+  register enum rtx_code code;
+
+  if (in == 0)
+    return 0;
+
+  if (reg == in)
+    return 1;
+
+  code = GET_CODE (in);
+
+  switch (code)
+    {
+      /* Compare registers by number.  */
+    case REG:
+      return GET_CODE (reg) == REG && REGNO (in) == REGNO (reg);
+
+      /* These codes have no constituent expressions
+	 and are unique.  */
+    case CC0:
+    case PC:
+      return 0;
+
+    case CONST_INT:
+      return GET_CODE (reg) == CONST_INT && INTVAL (in) == INTVAL (reg);
+    }
+
+  if (GET_CODE (reg) == code && rtx_equal_p (reg, in))
+    return 1;
+
+  fmt = GET_RTX_FORMAT (code);
+
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    {
+      if (fmt[i] == 'E')
+	{
+	  register int j;
+	  for (j = XVECLEN (in, i) - 1; j >= 0; j--)
+	    if (reg_mentioned_p (reg, XVECEXP (in, i, j)))
+	      return 1;
+	}
+      else if (fmt[i] == 'e'
+	       && reg_mentioned_p (reg, XEXP (in, i)))
+	return 1;
+    }
+  return 0;
+}
+
+/* Nonzero if register REG is used in an insn between
+   FROM_INSN and TO_INSN (exclusive of those two).  */
+
+int
+reg_used_between_p (reg, from_insn, to_insn)
+     rtx reg, from_insn, to_insn;
+{
+  register rtx insn;
+  register RTX_CODE code;
+  for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn))
+    if (((code = GET_CODE (insn)) == INSN
+	 || code == JUMP_INSN || code == CALL_INSN)
+	&& reg_mentioned_p (reg, PATTERN (insn)))
+      return 1;
+  return 0;
+}
+
+/* Nonzero if register REG is set or clobbered in an insn between
+   FROM_INSN and TO_INSN (exclusive of those two).
+   Does not notice increments, only SET and CLOBBER.  */
+
+int
+reg_set_between_p (reg, from_insn, to_insn)
+     rtx reg, from_insn, to_insn;
+{
+  register rtx insn;
+  register RTX_CODE code;
+  for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn))
+    if (((code = GET_CODE (insn)) == INSN
+	 || code == JUMP_INSN || code == CALL_INSN)
+	&& reg_set_p (reg, PATTERN (insn)))
+      return 1;
+  return 0;
+}
+
+/* Internals of reg_set_between_p.  */
+
+static rtx reg_set_reg;
+static int reg_set_flag;
+
+static void
+reg_set_p_1 (x)
+     rtx x;
+{
+  if (reg_overlap_mentioned_p (reg_set_reg, x))
+    reg_set_flag = 1;
+}
+
+static int
+reg_set_p (reg, insn)
+     rtx reg, insn;
+{
+  reg_set_reg = reg;
+  reg_set_flag = 0;
+  note_stores (insn, reg_set_p_1);
+  return reg_set_flag;
+}
+
+/* Return nonzero if hard register in range [REGNO, ENDREGNO)
+   appears either explicitly or implicitly in X
+   other than being stored into.
+
+   References contained within the substructure at LOC do not count.
+   LOC may be zero, meaning don't ignore anything.  */
+
+int
+refers_to_regno_p (regno, endregno, x, loc)
+     int regno, endregno;
+     rtx x;
+     rtx *loc;
+{
+  register int i;
+  register RTX_CODE code;
+  register char *fmt;
+
+ repeat:
+  code = GET_CODE (x);
+  if (code == REG)
+    {
+      i = REGNO (x);
+      return (endregno > i && regno < i + HARD_REGNO_NREGS (i, GET_MODE (x)));
+    }
+
+  if (code == SET)
+    {
+      /* Note setting a SUBREG counts as referring to the REG it is in!  */
+      if (GET_CODE (SET_DEST (x)) != REG
+	  && refers_to_regno_p (regno, endregno, SET_DEST (x), loc))
+	return 1;
+      if (loc == &SET_SRC (x))
+	return 0;
+      x = SET_SRC (x);
+      goto repeat;
+    }
+
+  if (code == CLOBBER)
+    {
+      if (GET_CODE (SET_DEST (x)) != REG
+	  && refers_to_regno_p (regno, endregno, SET_DEST (x), loc))
+	return 1;
+      return 0;
+    }
+
+  /* X does not match, so try its subexpressions.  */
+
+  fmt = GET_RTX_FORMAT (code);
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    {
+      if (fmt[i] == 'e' && loc != &XEXP (x, i))
+	{
+	  if (i == 0)
+	    {
+	      x = XEXP (x, 0);
+	      goto repeat;
+	    }
+	  else
+	    if (refers_to_regno_p (regno, endregno, XEXP (x, i), loc))
+	      return 1;
+	}
+      else if (fmt[i] == 'E')
+	{
+	  register int j;
+	  for (j = XVECLEN (x, i) - 1; j >=0; j--)
+	    if (loc != &XVECEXP (x, i, j)
+		&& refers_to_regno_p (regno, endregno, XVECEXP (x, i, j), loc))
+	      return 1;
+	}
+    }
+  return 0;
+}
+
+/* Nonzero if X contains any reg that overlaps hard register REG.  */
+
+int
+reg_overlap_mentioned_p (reg, x)
+     rtx reg, x;
+{
+  int regno = REGNO (reg);
+  int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg));
+  return refers_to_regno_p (regno, endregno, x, 0);
+}
+
+/* This is 1 until after reload pass.  */
+int rtx_equal_function_value_matters;
+
+/* Return 1 if X and Y are identical-looking rtx's.
+   This is the Lisp function EQUAL for rtx arguments.  */
+
+int
+rtx_equal_p (x, y)
+     rtx x, y;
+{
+  register int i;
+  register int j;
+  register enum rtx_code code;
+  register char *fmt;
+
+  if (x == y)
+    return 1;
+  if (x == 0 || y == 0)
+    return 0;
+
+  code = GET_CODE (x);
+  /* Rtx's of different codes cannot be equal.  */
+  if (code != GET_CODE (y))
+    return 0;
+
+  /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
+     (REG:SI x) and (REG:HI x) are NOT equivalent.  */
+
+  if (GET_MODE (x) != GET_MODE (y))
+    return 0;
+
+  /* These three types of rtx's can be compared nonrecursively.  */
+  /* Until the end of reload,
+     don't consider the a reference to the return register of the current
+     function the same as the return from a called function.  This eases
+     the job of function integration.  Once the distinction no longer
+     matters, the insn will be deleted.  */
+  if (code == REG)
+    return (REGNO (x) == REGNO (y)
+	    && (! rtx_equal_function_value_matters
+		|| REG_FUNCTION_VALUE_P (x) == REG_FUNCTION_VALUE_P (y)));
+  if (code == LABEL_REF)
+    return XEXP (x, 0) == XEXP (y, 0);
+  if (code == SYMBOL_REF)
+    return XSTR (x, 0) == XSTR (y, 0);
+
+  /* Compare the elements.  If any pair of corresponding elements
+     fail to match, return 0 for the whole things.  */
+
+  fmt = GET_RTX_FORMAT (code);
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    {
+      switch (fmt[i])
+	{
+	case 'i':
+	  if (XINT (x, i) != XINT (y, i))
+	    return 0;
+	  break;
+
+	case 'E':
+	  /* Two vectors must have the same length.  */
+	  if (XVECLEN (x, i) != XVECLEN (y, i))
+	    return 0;
+
+	  /* And the corresponding elements must match.  */
+	  for (j = 0; j < XVECLEN (x, i); j++)
+	    if (rtx_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j)) == 0)
+	      return 0;
+	  break;
+
+	case 'e':
+	  if (rtx_equal_p (XEXP (x, i), XEXP (y, i)) == 0)
+	    return 0;
+	  break;
+
+	case 's':
+	  if (strcmp (XSTR (x, i), XSTR (y, i)))
+	    return 0;
+	  break;
+
+	case 'u':
+	  /* These are just backpointers, so they don't matter.  */
+	  break;
+
+	case '0':
+	  break;
+
+	  /* It is believed that rtx's at this level will never
+	     contain anything but integers and other rtx's,
+	     except for within LABEL_REFs and SYMBOL_REFs.  */
+	default:
+	  abort ();
+	}
+    }
+  return 1;
+}
+
+/* Call FUN on each register or MEM that is stored into or clobbered by X.
+   (X would be the pattern of an insn).
+   FUN receives two arguments:
+     the REG, MEM, CC0 or PC being stored in or clobbered,
+     the SET or CLOBBER rtx that does the store.  */
+     
+void
+note_stores (x, fun)
+     register rtx x;
+     void (*fun) ();
+{
+  if ((GET_CODE (x) == SET || GET_CODE (x) == CLOBBER))
+    {
+      register rtx dest = SET_DEST (x);
+      while (GET_CODE (dest) == SUBREG
+	     || GET_CODE (dest) == ZERO_EXTRACT
+	     || GET_CODE (dest) == SIGN_EXTRACT
+	     || GET_CODE (dest) == STRICT_LOW_PART)
+	dest = XEXP (dest, 0);
+      (*fun) (dest, x);
+    }
+  else if (GET_CODE (x) == PARALLEL)
+    {
+      register int i;
+      for (i = XVECLEN (x, 0) - 1; i >= 0; i--)
+	{
+	  register rtx y = XVECEXP (x, 0, i);
+	  if (GET_CODE (y) == SET || GET_CODE (y) == CLOBBER)
+	    {
+	      register rtx dest = SET_DEST (y);
+	      while (GET_CODE (dest) == SUBREG
+		     || GET_CODE (dest) == ZERO_EXTRACT
+		     || GET_CODE (dest) == SIGN_EXTRACT
+		     || GET_CODE (dest) == STRICT_LOW_PART)
+		dest = XEXP (dest, 0);
+	      (*fun) (dest, XVECEXP (x, 0, i));
+	    }
+	}
+    }
+}
+
+/* Return nonzero if register REG's old contents don't survive after INSN.
+   This can be because REG dies in INSN or because INSN entirely sets REG.
+
+   "Entirely set" means set directly and not through a SUBREG,
+   ZERO_EXTRACT or SIGN_EXTRACT, so no trace of the old contents remains.
+
+   REG may be a hard or pseudo reg.  Renumbering is not taken into account,
+   but for this use that makes no difference, since regs don't overlap
+   during their lifetimes.  Therefore, this function may be used
+   at any time after deaths have been computed (in flow.c).  */
+
+int
+dead_or_set_p (insn, reg)
+     rtx insn;
+     rtx reg;
+{
+  register rtx link;
+  register int regno = REGNO (reg);
+
+  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+    if ((REG_NOTE_KIND (link) == REG_DEAD
+	 || REG_NOTE_KIND (link) == REG_INC)
+	&& REGNO (XEXP (link, 0)) == regno)
+      return 1;
+
+  if (GET_CODE (PATTERN (insn)) == SET)
+    return (GET_CODE (SET_DEST (PATTERN (insn))) == REG
+	    && REGNO (SET_DEST (PATTERN (insn))) == regno);
+  else if (GET_CODE (PATTERN (insn)) == PARALLEL)
+    {
+      register int i;
+      for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
+	{
+	  if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET
+	      && GET_CODE (SET_DEST (XVECEXP (PATTERN (insn), 0, i))) == REG
+              && REGNO (SET_DEST (XVECEXP (PATTERN (insn), 0, i))) == regno)
+	    return 1;
+	}
+    }
+  return 0;
+}
+
+/* Return the reg-note of kind KIND in insn INSN, if there is one.
+   If DATUM is nonzero, look for one whose datum is DATUM.  */
+
+rtx
+find_reg_note (insn, kind, datum)
+     rtx insn;
+     enum reg_note kind;
+     rtx datum;
+{
+  register rtx link;
+
+  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+    if (REG_NOTE_KIND (link) == kind
+	&& (datum == 0 || datum == XEXP (link, 0)))
+      return link;
+  return 0;
+}
+
+/* Return the reg-note of kind KIND in insn INSN which applies to register
+   number REGNO, if any.  Return 0 if there is no such reg-note.  */
+
+rtx
+find_regno_note (insn, kind, regno)
+     rtx insn;
+     enum reg_note kind;
+     int regno;
+{
+  register rtx link;
+
+  for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
+    if (REG_NOTE_KIND (link) == kind
+	&& REGNO (XEXP (link, 0)) == regno)
+      return link;
+  return 0;
+}
+
+/* Nonzero if FROM precedes TO with no intervening labels.  */
+
+int
+no_labels_between (from, to)
+     register rtx from, to;
+{
+  register rtx p = to;
+
+  while (1)
+    {
+      p = PREV_INSN (p);
+      if (p == 0)
+	return 0;
+      if (p == from)
+	return 1;
+      if (GET_CODE (p) == CODE_LABEL)
+	return 0;
+    }
+}
+
+/* Nonzero if X contains any volatile memory references
+   or volatile ASM_OPERANDS expressions.  */
+
+int
+volatile_refs_p (x)
+     rtx x;
+{
+  register RTX_CODE code;
+
+  code = GET_CODE (x);
+  switch (code)
+    {
+    case LABEL_REF:
+    case SYMBOL_REF:
+    case CONST_INT:
+    case CONST:
+    case CONST_DOUBLE:
+    case CC0:
+    case PC:
+    case REG:
+    case CLOBBER:
+    case ASM_INPUT:
+    case ADDR_VEC:
+    case ADDR_DIFF_VEC:
+      return 0;
+
+    case CALL:
+      return 1;
+
+    case MEM:
+    case ASM_OPERANDS:
+      if (MEM_VOLATILE_P (x))
+	return 1;
+    }
+
+  /* Recursively scan the operands of this expression.  */
+
+  {
+    register char *fmt = GET_RTX_FORMAT (code);
+    register int i;
+    
+    for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+      {
+	if (fmt[i] == 'e')
+	  {
+	    if (volatile_refs_p (XEXP (x, i)))
+	      return 1;
+	  }
+	if (fmt[i] == 'E')
+	  {
+	    register int j;
+	    for (j = 0; j < XVECLEN (x, i); j++)
+	      if (volatile_refs_p (XVECEXP (x, i, j)))
+		return 1;
+	  }
+      }
+  }
+  return 0;
+}
+
+/* Return nonzero if evaluating rtx X might cause a trap.  */
+
+int
+may_trap_p (x)
+     rtx x;
+{
+  int i;
+  enum rtx_code code;
+  char *fmt;
+
+  if (x == 0)
+    return 0;
+  code = GET_CODE (x);
+  switch (code)
+    {
+      /* Handle these cases fast.  */
+    case CONST_INT:
+    case CONST_DOUBLE:
+    case SYMBOL_REF:
+    case LABEL_REF:
+    case CONST:
+    case PC:
+    case CC0:
+    case REG:
+      return 0;
+
+      /* Memory ref can trap unless it's a static var or a stack slot.  */
+    case MEM:
+      return rtx_varies_p (XEXP (x, 0));
+
+      /* Division by a non-constant might trap.  */
+    case DIV:
+    case MOD:
+    case UDIV:
+    case UMOD:
+      if (! CONSTANT_P (XEXP (x, 1))
+	  && GET_CODE (XEXP (x, 1)) != CONST_DOUBLE)
+	return 1;
+      if (XEXP (x, 1) == const0_rtx)
+	return 1;
+    default:
+      /* Any floating arithmetic may trap.  */
+      if (GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT)
+	return 1;
+    }
+
+  fmt = GET_RTX_FORMAT (code);
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    {
+      if (fmt[i] == 'e')
+	{
+	  if (may_trap_p (XEXP (x, i)))
+	    return 1;
+	}
+      else if (fmt[i] == 'E')
+	{
+	  register int j;
+	  for (j = 0; j < XVECLEN (x, i); j++)
+	    if (may_trap_p (XVECEXP (x, i, j)))
+	      return 1;
+	}
+    }
+  return 0;
+}