h8300.md (movsi_h8300hs): Optimize loading of several special constants.

	* h8300.md (movsi_h8300hs): Optimize loading of several
	special constants.

From-SVN: r45261

1 files changed, 24 insertions, 5 deletions

diff --git a/gcc/config/h8300/h8300.md b/gcc/config/h8300/h8300.md
index c93a6eb..216524e 100644
--- a/gcc/config/h8300/h8300.md
+++ b/gcc/config/h8300/h8300.md
@@ -436,12 +436,31 @@
 	      return \"sub.l\\t%S0,%S0\;add.b\\t%1,%x0\";
 	    }
 
-	  /* Now look for small negative numbers.  We can subtract them
-	     from zero to get the desired constant.  */
-	  if (val == -4 || val == -2 || val == -1)
+	  /* Look for constants that can be obtained by subs, inc, and
+             dec to 0.  */
+	  switch (val)
 	    {
-	      operands[1] = GEN_INT (-INTVAL (operands[1]));
-	      return \"sub.l\\t%S0,%S0\;subs\\t%1,%S0\";
+	    case 0xffffffff:
+	      return \"sub.l\\t%S0,%S0\;subs\\t#1,%S0\";
+	    case 0xfffffffe:
+	      return \"sub.l\\t%S0,%S0\;subs\\t#2,%S0\";
+	    case 0xfffffffc:
+	      return \"sub.l\\t%S0,%S0\;subs\\t#4,%S0\";
+
+	    case 0x0000ffff:
+	      return \"sub.l\\t%S0,%S0\;dec.w\\t#1,%f0\";
+	    case 0x0000fffe:
+	      return \"sub.l\\t%S0,%S0\;dec.w\\t#2,%f0\";
+
+	    case 0xffff0000:
+	      return \"sub.l\\t%S0,%S0\;dec.w\\t#1,%e0\";
+	    case 0xfffe0000:
+	      return \"sub.l\\t%S0,%S0\;dec.w\\t#2,%e0\";
+
+	    case 0x00010000:
+	      return \"sub.l\\t%S0,%S0\;inc.w\\t#1,%e0\";
+	    case 0x00020000:
+	      return \"sub.l\\t%S0,%S0\;inc.w\\t#2,%e0\";
 	    }
 	}
     }