target/alpha: Use tcg_gen_movcond_i64 in gen_fold_mzero

The setcond + neg + and sequence is a complex method of
performing a conditional move.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/alpha/translate.c

@@ -517,10 +517,9 @@ static void gen_fold_mzero(TCGCond cond, TCGv dest, TCGv src)
 
     case TCG_COND_GE:
     case TCG_COND_LT:
-        /* For >= or <, map -0.0 to +0.0 via comparison and mask.  */
-        tcg_gen_setcondi_i64(TCG_COND_NE, dest, src, mzero);
-        tcg_gen_neg_i64(dest, dest);
-        tcg_gen_and_i64(dest, dest, src);
+        /* For >= or <, map -0.0 to +0.0. */
+        tcg_gen_movcond_i64(TCG_COND_NE, dest, src, tcg_constant_i64(mzero),
+                            src, tcg_constant_i64(0));
         break;
 
     default: