pdp11.md (lshrsi3, lshrhi3): Use add for decrement.

* config/pdp11/pdp11.md (lshrsi3, lshrhi3): Use add for
decrement.

From-SVN: r166493

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index de4d484..5053dd7 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-09  Paul Koning  <ni1d@arrl.net>
+
+       * config/pdp11/pdp11.md (lshrsi3, lshrhi3): Use add for
+       decrement. 
+
 2010-11-09  Richard Guenther  <rguenther@suse.de>
 
        PR tree-optimization/46177

diff --git a/gcc/config/pdp11/pdp11.md b/gcc/config/pdp11/pdp11.md
index 552eb49..8f5f919 100644 (file)
--- a/gcc/config/pdp11/pdp11.md
+++ b/gcc/config/pdp11/pdp11.md
@@ -897,7 +897,7 @@
   if (GET_CODE (operands[2]) != CONST_INT)
     {
       r = gen_reg_rtx (HImode);
-      emit_insn (gen_subhi3 (r, operands [2], GEN_INT (1)));
+      emit_insn (gen_addhi3 (r, operands [2], GEN_INT (-1)));
       emit_insn (gen_ashrsi3 (operands[0], operands[0], r));
     }
   else if ((unsigned) INTVAL (operands[2]) != 1)
@@ -1043,7 +1043,7 @@
   if (GET_CODE (operands[2]) != CONST_INT)
     {
       r = gen_reg_rtx (HImode);
-      emit_insn (gen_subhi3 (r, operands [2], GEN_INT (1)));
+      emit_insn (gen_addhi3 (r, operands [2], GEN_INT (-1)));
       emit_insn (gen_ashrhi3 (operands[0], operands[0], r));
     }
   else if ((unsigned) INTVAL (operands[2]) != 1)