Add define_split to simplify "(unsigned) x > 0xffffff".

From-SVN: r6988

diff --git a/gcc/config/alpha/alpha.md b/gcc/config/alpha/alpha.md
index bf56286ddefc9118a9ecd7992179c202d8c3a764..7f2999f9c684375b08cfb794411826818a03ee0a 100644 (file)
--- a/gcc/config/alpha/alpha.md
+++ b/gcc/config/alpha/alpha.md
@@ -2232,6 +2232,30 @@
   operands[6] = gen_rtx (GET_CODE (operands[1]), VOIDmode,
                         operands[4], const0_rtx);
 }")
+
+;; We can convert such things as "a > 0xffff" to "t = a & 0xffff; t != 0".
+;; This eliminates one, and sometimes two, insns when the AND can be done
+;; with a ZAP.
+(define_split
+  [(set (match_operand:DI 0 "register_operand" "")
+       (match_operator 1 "comparison_operator"
+                       [(match_operand:DI 2 "register_operand" "")
+                        (match_operand:DI 3 "const_int_operand" "")]))
+   (clobber (match_operand:DI 4 "register_operand" ""))]
+  "exact_log2 (INTVAL (operands[3]) + 1) >= 0
+   && (GET_CODE (operands[1]) == GTU
+       || GET_CODE (operands[1]) == LEU
+       || ((GET_CODE (operands[1]) == GT || GET_CODE (operands[1]) == LE)
+          && extended_count (operands[2], DImode, 1) > 0))"
+  [(set (match_dup 4) (and:DI (match_dup 2) (match_dup 3)))
+   (set (match_dup 0) (match_dup 5))]
+  "
+{
+  operands[5] = gen_rtx (((GET_CODE (operands[1]) == GTU
+                          || GET_CODE (operands[1]) == GE)
+                         ? NE : LE),
+                        DImode, operands[4], const0_rtx);
+}")
 \f
 ;; Here are the CALL and unconditional branch insns.