jump.c (jump_optimize_1): Do cmov opt on any single-set; force B into a register...

        * jump.c (jump_optimize_1): Do cmov opt on any single-set; force
        B into a register before emit_conditional_move.

From-SVN: r28830

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b6817cf..4920ebe 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Tue Aug 24 16:58:15 1999  Richard Henderson  <rth@cygnus.com>
+
+       * jump.c (jump_optimize_1): Do cmov opt on any single-set; force
+       B into a register before emit_conditional_move.
+
 Tue Aug 24 15:37:03 1999  Richard Henderson  <rth@cygnus.com>
 
        * fold-const.c (fold): Reassociate (+ (+ (* a b) c) (* d e))

diff --git a/gcc/jump.c b/gcc/jump.c
index e60286d..9a9e9b2 100644 (file)
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -874,12 +874,13 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
 
             INSN here is the jump around the store.  We set:
 
-            TEMP to the "x = b;" insn.
+            TEMP to the "x op= b;" insn.
             TEMP1 to X.
             TEMP2 to B.
             TEMP3 to A (X in the second case).
             TEMP4 to the condition being tested.
-            TEMP5 to the earliest insn used to find the condition.  */
+            TEMP5 to the earliest insn used to find the condition.
+            TEMP6 to the SET of TEMP.  */
 
          if (/* We can't do this after reload has completed.  */
              ! reload_completed
@@ -887,11 +888,11 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
              /* Set TEMP to the "x = b;" insn.  */
              && (temp = next_nonnote_insn (insn)) != 0
              && GET_CODE (temp) == INSN
-             && GET_CODE (PATTERN (temp)) == SET
-             && GET_CODE (temp1 = SET_DEST (PATTERN (temp))) == REG
+             && (temp6 = single_set (temp)) != NULL_RTX
+             && GET_CODE (temp1 = SET_DEST (temp6)) == REG
              && (! SMALL_REGISTER_CLASSES
                  || REGNO (temp1) >= FIRST_PSEUDO_REGISTER)
-             && ! side_effects_p (temp2 = SET_SRC (PATTERN (temp)))
+             && ! side_effects_p (temp2 = SET_SRC (temp6))
              && ! may_trap_p (temp2)
              /* Allow either form, but prefer the former if both apply. 
                 There is no point in using the old value of TEMP1 if
@@ -936,7 +937,7 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
                enum rtx_code code = GET_CODE (temp4);
                rtx var = temp1;
                rtx cond0, cond1, aval, bval;
-               rtx target;
+               rtx target, new_insn;
 
                /* Copy the compared variables into cond0 and cond1, so that
                   any side effects performed in or after the old comparison,
@@ -955,10 +956,28 @@ jump_optimize_1 (f, cross_jump, noop_moves, after_regscan, mark_labels_only)
                else
                  cond1 = gen_reg_rtx (GET_MODE (XEXP (temp4, 1)));
 
+               /* Careful about copying these values -- an IOR or what may
+                  need to do other things, like clobber flags.  */
+               /* ??? Assume for the moment that AVAL is ok.  */
                aval = temp3;
-               bval = temp2;
 
                start_sequence ();
+
+               /* If we're not dealing with a register or the insn is more
+                  complex than a simple SET, duplicate the computation and
+                  replace the destination with a new temporary.  */
+               if (register_operand (temp2, GET_MODE (var))
+                   && GET_CODE (PATTERN (temp)) == SET)
+                 bval = temp2;
+               else
+                 {
+                   bval = gen_reg_rtx (GET_MODE (var));
+                   new_insn = copy_rtx (temp);
+                   temp6 = single_set (new_insn);
+                   SET_DEST (temp6) = bval;
+                   emit_insn (PATTERN (new_insn));
+                 }
+                 
                target = emit_conditional_move (var, code,
                                                cond0, cond1, VOIDmode,
                                                aval, bval, GET_MODE (var),