From: Georg-Johann Lay <avr@gjlay.de>
Date: Mon, 10 Oct 2011 09:57:02 +0000 (+0000)
Subject: avr.md (*mulhi3_enh): Treat squaring smarter.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=beddf669bb9117e6425aae6908e8d339aec37ffd;p=gcc.git

avr.md (*mulhi3_enh): Treat squaring smarter.

	* config/avr/avr.md (*mulhi3_enh): Treat squaring smarter.

From-SVN: r179739
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7e7d6b28826..6dc29639b28 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2011-10-10  Georg-Johann Lay  <avr@gjlay.de>
+
+	* config/avr/avr.md (*mulhi3_enh): Treat squaring smarter.
+
 2011-10-10  Georg-Johann Lay  <avr@gjlay.de>
 
 	PR target/50652
diff --git a/gcc/config/avr/avr.md b/gcc/config/avr/avr.md
index f1ac95d7f00..e17f7f2f263 100644
--- a/gcc/config/avr/avr.md
+++ b/gcc/config/avr/avr.md
@@ -1560,13 +1560,11 @@
 	(mult:HI (match_operand:HI 1 "register_operand" "r")
 		 (match_operand:HI 2 "register_operand" "r")))]
   "AVR_HAVE_MUL"
-  "mul %A1,%A2
-	movw %0,r0
-	mul %A1,%B2
-	add %B0,r0
-	mul %B1,%A2
-	add %B0,r0
-	clr r1"
+  {
+    return REGNO (operands[1]) == REGNO (operands[2])
+           ? "mul %A1,%A1\;movw %0,r0\;mul %A1,%B1\;add %B0,r0\;add %B0,r0\;clr r1"
+           : "mul %A1,%A2\;movw %0,r0\;mul %A1,%B2\;add %B0,r0\;mul %B1,%A2\;add %B0,r0\;clr r1";
+  }
   [(set_attr "length" "7")
    (set_attr "cc" "clobber")])