re PR rtl-optimization/10914 (unswitch loops does not work on powerpc)

2003-09-12  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>

        PR optimization/10914
        * expr.h (get_condition, canonicalize_condition): Declaration changed.
        * cfgloopanal.c (simple_loop_exit_p): Add parameter to a get_condition
        and canonicalize_condition calls.
        * gcse.c (fis_get_condition, delete_null_pointer_checks_1,
        delete_null_pointer_checks): Ditto.
        * ifcvt.c (noce_get_alt_condition, noce_get_condition): Ditto.
        * predict.c (estimate_probability, expected_value_to_br_prob): Ditto.
        * loop.c (check_dbra_loop, get_condition_for_loop): Ditto.
        (canonicalize_condition, get_condition): Allow to return comparisons
        of cc mode registers.
        * loop-unswitch.c (may_unswitch_on_p, unswitch_single_loop): Allow
        cc mode registers comparison in condition.

From-SVN: r71398

gcc/ChangeLog

+2003-09-12  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>
+
+	PR optimization/10914
+	* expr.h (get_condition, canonicalize_condition): Declaration changed.
+	* cfgloopanal.c (simple_loop_exit_p): Add parameter to a get_condition
+	and canonicalize_condition calls.
+	* gcse.c (fis_get_condition, delete_null_pointer_checks_1,
+	delete_null_pointer_checks): Ditto.
+	* ifcvt.c (noce_get_alt_condition, noce_get_condition): Ditto.
+	* predict.c (estimate_probability, expected_value_to_br_prob): Ditto.
+	* loop.c (check_dbra_loop, get_condition_for_loop): Ditto.
+	(canonicalize_condition, get_condition): Allow to return comparisons
+	of cc mode registers.
+	* loop-unswitch.c (may_unswitch_on_p, unswitch_single_loop): Allow
+	cc mode registers comparison in condition.
+
 2003-09-12  Mark Mitchell  <mark@codesourcery.com>
 
 	* coverage.c (create_coverage): Do not call pushlevel/poplevel.

gcc/cfgloopanal.c

@@ -775,7 +775,7 @@ simple_loop_exit_p (struct loops *loops, struct loop *loop, edge exit_edge,
 
   /* Condition must be a simple comparison in that one of operands
      is register and the other one is invariant.  */
-  if (!(condition = get_condition (exit_bb->end, NULL)))
+  if (!(condition = get_condition (exit_bb->end, NULL, false)))
     return false;
 
   if (!simple_condition_p (loop, condition, invariant_regs, desc))

gcc/expr.h

@@ -317,11 +317,11 @@ extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 
 /* Given an insn and condition, return a canonical description of
    the test being made.  */
-extern rtx canonicalize_condition (rtx, rtx, int, rtx *, rtx);
+extern rtx canonicalize_condition (rtx, rtx, int, rtx *, rtx, int);
 
 /* Given a JUMP_INSN, return a canonical description of the test
    being made.  */
-extern rtx get_condition (rtx, rtx *);
+extern rtx get_condition (rtx, rtx *, int);
 
 /* Generate a conditional trap instruction.  */
 extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);

gcc/gcse.c

@@ -4480,7 +4480,8 @@ fis_get_condition (rtx jump)
 
   /* Use canonicalize_condition to do the dirty work of manipulating
      MODE_CC values and COMPARE rtx codes.  */
-  tmp = canonicalize_condition (jump, cond, reverse, &earliest, NULL_RTX);
+  tmp = canonicalize_condition (jump, cond, reverse, &earliest, NULL_RTX,
+				false);
   if (!tmp)
     return NULL_RTX;
 
@@ -4498,7 +4499,8 @@ fis_get_condition (rtx jump)
   tmp = XEXP (tmp, 0);
   if (!REG_P (tmp) || GET_MODE_CLASS (GET_MODE (tmp)) != MODE_INT)
     return NULL_RTX;
-  tmp = canonicalize_condition (jump, cond, reverse, &earliest, tmp);
+  tmp = canonicalize_condition (jump, cond, reverse, &earliest, tmp,
+				false);
   if (!tmp)
     return NULL_RTX;
 
@@ -5880,7 +5882,7 @@ delete_null_pointer_checks_1 (unsigned int *block_reg, sbitmap *nonnull_avin,
 	continue;
 
       /* LAST_INSN is a conditional jump.  Get its condition.  */
-      condition = get_condition (last_insn, &earliest);
+      condition = get_condition (last_insn, &earliest, false);
 
       /* If we can't determine the condition then skip.  */
       if (! condition)
@@ -5994,7 +5996,7 @@ delete_null_pointer_checks (rtx f ATTRIBUTE_UNUSED)
 	continue;
 
       /* LAST_INSN is a conditional jump.  Get its condition.  */
-      condition = get_condition (last_insn, &earliest);
+      condition = get_condition (last_insn, &earliest, false);
 
       /* If we were unable to get the condition, or it is not an equality
 	 comparison against zero then there's nothing we can do.  */

gcc/ifcvt.c

@@ -1397,7 +1397,7 @@ noce_get_alt_condition (struct noce_if_info *if_info, rtx target,
     }
 
   cond = canonicalize_condition (if_info->jump, cond, reverse,
-				 earliest, target);
+				 earliest, target, false);
   if (! cond || ! reg_mentioned_p (target, cond))
     return NULL;
 
@@ -1671,7 +1671,8 @@ noce_get_condition (rtx jump, rtx *earliest)
   /* Otherwise, fall back on canonicalize_condition to do the dirty
      work of manipulating MODE_CC values and COMPARE rtx codes.  */
 
-  tmp = canonicalize_condition (jump, cond, reverse, earliest, NULL_RTX);
+  tmp = canonicalize_condition (jump, cond, reverse, earliest, NULL_RTX,
+				false);
   if (!tmp)
     return NULL_RTX;
 
@@ -1690,7 +1691,8 @@ noce_get_condition (rtx jump, rtx *earliest)
   tmp = XEXP (tmp, 0);
   if (!REG_P (tmp) || GET_MODE_CLASS (GET_MODE (tmp)) != MODE_INT)
     return NULL_RTX;
-  tmp = canonicalize_condition (jump, cond, reverse, earliest, tmp);
+  tmp = canonicalize_condition (jump, cond, reverse, earliest, tmp,
+				false);
   if (!tmp)
     return NULL_RTX;
 

gcc/loop-unswitch.c

@@ -141,7 +141,7 @@ may_unswitch_on_p (struct loops *loops, basic_block bb, struct loop *loop,
 
   /* Condition must be invariant.  We use just a stupid test of invariantness
      of the condition: all used regs must not be modified inside loop body.  */
-  test = get_condition (bb->end, NULL);
+  test = get_condition (bb->end, NULL, true);
   if (!test)
     return false;
 
@@ -248,7 +248,7 @@ unswitch_single_loop (struct loops *loops, struct loop *loop,
 	  return;
 	}
 
-      if (!(cond = get_condition (bbs[i]->end, &split_before)))
+      if (!(cond = get_condition (bbs[i]->end, &split_before, true)))
 	abort ();
       rcond = reversed_condition (cond);
 

gcc/loop.c

@@ -7980,7 +7980,7 @@ check_dbra_loop (struct loop *loop, int insn_count)
 
   /* Try to compute whether the compare/branch at the loop end is one or
      two instructions.  */
-  get_condition (jump, &first_compare);
+  get_condition (jump, &first_compare, false);
   if (first_compare == jump)
     compare_and_branch = 1;
   else if (first_compare == prev_nonnote_insn (jump))
@@ -9143,11 +9143,12 @@ update_reg_last_use (rtx x, rtx insn)
 
    If WANT_REG is nonzero, we wish the condition to be relative to that
    register, if possible.  Therefore, do not canonicalize the condition
-   further.  */
+   further.  If ALLOW_CC_MODE is nonzero, allow the condition returned 
+   to be a compare to a CC mode register.  */
 
 rtx
 canonicalize_condition (rtx insn, rtx cond, int reverse, rtx *earliest,
-			rtx want_reg)
+			rtx want_reg, int allow_cc_mode)
 {
   enum rtx_code code;
   rtx prev = insn;
@@ -9326,14 +9327,16 @@ canonicalize_condition (rtx insn, rtx cond, int reverse, rtx *earliest,
 
   /* If OP0 is the result of a comparison, we weren't able to find what
      was really being compared, so fail.  */
-  if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_CC)
+  if (!allow_cc_mode
+      && GET_MODE_CLASS (GET_MODE (op0)) == MODE_CC)
     return 0;
 
   /* Canonicalize any ordered comparison with integers involving equality
      if we can do computations in the relevant mode and we do not
      overflow.  */
 
-  if (GET_CODE (op1) == CONST_INT
+  if (GET_MODE_CLASS (GET_MODE (op0)) != MODE_CC
+      && GET_CODE (op1) == CONST_INT
       && GET_MODE (op0) != VOIDmode
       && GET_MODE_BITSIZE (GET_MODE (op0)) <= HOST_BITS_PER_WIDE_INT)
     {
@@ -9388,10 +9391,13 @@ canonicalize_condition (rtx insn, rtx cond, int reverse, rtx *earliest,
    If EARLIEST is nonzero, it is a pointer to a place where the earliest
    insn used in locating the condition was found.  If a replacement test
    of the condition is desired, it should be placed in front of that
-   insn and we will be sure that the inputs are still valid.  */
+   insn and we will be sure that the inputs are still valid.  
+
+   If ALLOW_CC_MODE is nonzero, allow the condition returned to be a
+   compare CC mode register.  */
 
 rtx
-get_condition (rtx jump, rtx *earliest)
+get_condition (rtx jump, rtx *earliest, int allow_cc_mode)
 {
   rtx cond;
   int reverse;
@@ -9411,7 +9417,8 @@ get_condition (rtx jump, rtx *earliest)
     = GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
       && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump);
 
-  return canonicalize_condition (jump, cond, reverse, earliest, NULL_RTX);
+  return canonicalize_condition (jump, cond, reverse, earliest, NULL_RTX,
+				 allow_cc_mode);
 }
 
 /* Similar to above routine, except that we also put an invariant last
@@ -9420,7 +9427,7 @@ get_condition (rtx jump, rtx *earliest)
 rtx
 get_condition_for_loop (const struct loop *loop, rtx x)
 {
-  rtx comparison = get_condition (x, (rtx*) 0);
+  rtx comparison = get_condition (x, (rtx*) 0, false);
 
   if (comparison == 0
       || ! loop_invariant_p (loop, XEXP (comparison, 0))

gcc/predict.c

@@ -522,7 +522,7 @@ estimate_probability (struct loops *loops_info)
 	    }
 	}
 
-      cond = get_condition (last_insn, &earliest);
+      cond = get_condition (last_insn, &earliest, false);
       if (! cond)
 	continue;
 
@@ -678,7 +678,7 @@ expected_value_to_br_prob (void)
 		(lt r70, r71)
 	 Could use cselib to try and reduce this further.  */
       cond = XEXP (SET_SRC (pc_set (insn)), 0);
-      cond = canonicalize_condition (insn, cond, 0, NULL, ev_reg);
+      cond = canonicalize_condition (insn, cond, 0, NULL, ev_reg, false);
       if (! cond || XEXP (cond, 0) != ev_reg
 	  || GET_CODE (XEXP (cond, 1)) != CONST_INT)
 	continue;