reload1.c (gen_reload): When synthesizing a 3 operand add sequence...

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        * reload1.c (gen_reload): When synthesizing a 3 operand add
        sequence, improve test for when to reload OP1 into the reload
        register instead of OP0.

From-SVN: r27987

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 23f4f431f369cd91d615168ad2fa5c1e40886abb..7c17ec4fad825f1c2db9ecedcd361a218e3eff74 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+Wed Jul  7 02:00:04 1999  Franz Sirl  <Franz.Sirl-kernel@lauterbach.com>
+
+       * reload1.c (gen_reload): When synthesizing a 3 operand add
+       sequence, improve test for when to reload OP1 into the reload
+       register instead of OP0.
+
 Wed Jul  7 01:38:03 1999  Jim Wilson  <wilson@cygnus.com>
 
        * unroll.c (unroll_loop): Don't delete NOTE_INSN_DELETED_LABEL notes.

diff --git a/gcc/reload1.c b/gcc/reload1.c
index f16ed109875142d92d8dc774b379fbd8065e52b0..123cbf5edd317eb136ca57b1defd01f90aa3e40b 100644 (file)
--- a/gcc/reload1.c
+++ b/gcc/reload1.c
@@ -7811,17 +7811,27 @@ gen_reload (out, in, opnum, type)
       delete_insns_since (last);
 
       /* If that failed, we must use a conservative two-insn sequence.
-        use move to copy constant, MEM, or pseudo register to the reload
-        register since "move" will be able to handle an arbitrary operand,
-        unlike add which can't, in general.  Then add the registers.
+
+        Use a move to copy one operand into the reload register.  Prefer
+        to reload a constant, MEM or pseudo since the move patterns can
+        handle an arbitrary operand.  If OP1 is not a constant, MEM or
+        pseudo and OP1 is not a valid operand for an add instruction, then
+        reload OP1.
+
+        After reloading one of the operands into the reload register, add
+        the reload register to the output register.
 
         If there is another way to do this for a specific machine, a
         DEFINE_PEEPHOLE should be specified that recognizes the sequence
         we emit below.  */
 
+      code = (int) add_optab->handlers[(int) GET_MODE (out)].insn_code;
+
       if (CONSTANT_P (op1) || GET_CODE (op1) == MEM || GET_CODE (op1) == SUBREG
          || (GET_CODE (op1) == REG
-             && REGNO (op1) >= FIRST_PSEUDO_REGISTER))
+             && REGNO (op1) >= FIRST_PSEUDO_REGISTER)
+         || (code != CODE_FOR_nothing
+             && ! (*insn_operand_predicate[code][2]) (op1, insn_operand_mode[code][2])))
        tem = op0, op0 = op1, op1 = tem;
 
       gen_reload (out, op0, opnum, type);