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[PATCH] ia64: use mux2 to rotate 32-bit quantities by 16 bits

Special-case rotating a 32-bit quantity by 16 bits, using a single mux2
rather
than multiple instructions.

Bootstrapped and tested on ia64-unknown-linux-gnu.

2005-12-02  Jan Beulich  <jbeulich@novell.com>

	* config/ia64/ia64.md (rotlsi3_internal): Don't split if
rotating by
	16 bits. Provide insn pattern for this case.

---
/home/jbeulich/src/gcc/trunk/2005-12-01/gcc/config/ia64/ia64.md	2005-12-01
10:48:28.000000000 +0100
+++ 2005-12-01/gcc/config/ia64/ia64.md	2005-12-02 08:29:02.856610572
+0100
@@ -4453,8 +4455,8 @@
 	(rotate:SI (match_operand:SI 1 "gr_register_operand" "r")
 		   (match_operand:SI 2 "shift_32bit_count_operand"
"n")))]
   ""
-  "#"
-  "reload_completed"
+  "mux2 %0 = %1, 0xe1"
+  "reload_completed && INTVAL (operands[2]) != 16"
   [(set (match_dup 3)
 	(ior:DI (zero_extend:DI (match_dup 1))
 		(ashift:DI (zero_extend:DI (match_dup 1)) (const_int
32))))
@@ -4463,7 +4465,8 @@
 {
   operands[3] = gen_rtx_REG (DImode, REGNO (operands[0]));
   operands[2] = GEN_INT (32 - INTVAL (operands[2]));
-})
+}
+  [(set_attr "itanium_class" "mmshf")])
 
 ;; ::::::::::::::::::::
 ;; ::

Attachment: gcc-trunk-ia64-rotlsi-half.patch
Description: Text document

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