[Qemu-devel] [5404] Optimize 64 bit bswap

[malc]

Revision: 5404
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5404
Author:   malc
Date:     2008-10-02 20:02:31 +0000 (Thu, 02 Oct 2008)

Log Message:
-----------
Optimize 64 bit bswap

Use rldimi instead of rldicr/or pair, saves us one instruction.
Suggested by Hollis Blanchard.

Modified Paths:
--------------
    trunk/tcg/ppc64/tcg-target.c

Modified: trunk/tcg/ppc64/tcg-target.c
===================================================================
--- trunk/tcg/ppc64/tcg-target.c        2008-10-02 20:02:27 UTC (rev 5403)
+++ trunk/tcg/ppc64/tcg-target.c        2008-10-02 20:02:31 UTC (rev 5404)
@@ -303,6 +303,7 @@
 
 #define RLDICL XO30(  0)
 #define RLDICR XO30(  1)
+#define RLDIMI XO30(  3)
 
 #define BCLR   XO19( 16)
 #define BCCTR  XO19(528)
@@ -691,11 +692,10 @@
         break;
     case 3:
         if (bswap) {
-            tcg_out32 (s, LWBRX | RT (0) | RB (r0));
-            tcg_out32 (s, ADDI | RT (r1) | RA (r0) | 4);
-            tcg_out32 (s, LWBRX | RT (data_reg) | RB (r1));
-            tcg_out_rld (s, RLDICR, data_reg, data_reg, 32, 31);
-            tcg_out32 (s, OR | SAB (0, data_reg, data_reg));
+            tcg_out_movi32 (s, 0, 4);
+            tcg_out32 (s, LWBRX | RT (data_reg) | RB (r0));
+            tcg_out32 (s, LWBRX | RT (      r1) | RA (r0));
+            tcg_out_rld (s, RLDIMI, data_reg, r1, 32, 0);
         }
         else tcg_out32 (s, LD | RT (data_reg) | RA (r0));
         break;