[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [5592] target-ppc: optimize popcntb
From: |
Aurelien Jarno |
Subject: |
[Qemu-devel] [5592] target-ppc: optimize popcntb |
Date: |
Sat, 01 Nov 2008 00:54:34 +0000 |
Revision: 5592
http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5592
Author: aurel32
Date: 2008-11-01 00:54:33 +0000 (Sat, 01 Nov 2008)
Log Message:
-----------
target-ppc: optimize popcntb
Suggested by Andrzej Zaborowski.
Signed-off-by: Aurelien Jarno <address@hidden>
Modified Paths:
--------------
trunk/target-ppc/op_helper.c
Modified: trunk/target-ppc/op_helper.c
===================================================================
--- trunk/target-ppc/op_helper.c 2008-11-01 00:54:23 UTC (rev 5591)
+++ trunk/target-ppc/op_helper.c 2008-11-01 00:54:33 UTC (rev 5592)
@@ -222,25 +222,19 @@
target_ulong helper_popcntb (target_ulong val)
{
- uint32_t ret;
- int i;
-
- ret = 0;
- for (i = 0; i < 32; i += 8)
- ret |= ctpop8((val >> i) & 0xFF) << i;
- return ret;
+ val = (val & 0x55555555) + ((val >> 1) & 0x55555555);
+ val = (val & 0x33333333) + ((val >> 2) & 0x33333333);
+ val = (val & 0x0f0f0f0f) + ((val >> 4) & 0x0f0f0f0f);
+ return val;
}
#if defined(TARGET_PPC64)
target_ulong helper_popcntb_64 (target_ulong val)
{
- uint64_t ret;
- int i;
-
- ret = 0;
- for (i = 0; i < 64; i += 8)
- ret |= ctpop8((val >> i) & 0xFF) << i;
- return ret;
+ val = (val & 0x5555555555555555ULL) + ((val >> 1) &
0x5555555555555555ULL);
+ val = (val & 0x3333333333333333ULL) + ((val >> 2) &
0x3333333333333333ULL);
+ val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
0x0f0f0f0f0f0f0f0fULL);
+ return val;
}
#endif
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Qemu-devel] [5592] target-ppc: optimize popcntb,
Aurelien Jarno <=