[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [5464] Optimize some host-utils function with gcc builtins
From: |
Aurelien Jarno |
Subject: |
[Qemu-devel] [5464] Optimize some host-utils function with gcc builtins |
Date: |
Sun, 12 Oct 2008 00:53:08 +0000 |
Revision: 5464
http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5464
Author: aurel32
Date: 2008-10-12 00:53:08 +0000 (Sun, 12 Oct 2008)
Log Message:
-----------
Optimize some host-utils function with gcc builtins
Signed-off-by: Aurelien Jarno <address@hidden>
Modified Paths:
--------------
trunk/host-utils.h
Modified: trunk/host-utils.h
===================================================================
--- trunk/host-utils.h 2008-10-12 00:52:58 UTC (rev 5463)
+++ trunk/host-utils.h 2008-10-12 00:53:08 UTC (rev 5464)
@@ -47,14 +47,16 @@
void mulu64(uint64_t *phigh, uint64_t *plow, uint64_t a, uint64_t b);
#endif
-/* Note that some of those functions may end up calling libgcc functions,
- depending on the host machine. It is up to the target emulation to
- cope with that. */
-
/* Binary search for leading zeros. */
static always_inline int clz32(uint32_t val)
{
+#if defined(__GNUC__)
+ if (val)
+ return __builtin_clz(val);
+ else
+ return 32;
+#else
int cnt = 0;
if (!(val & 0xFFFF0000U)) {
@@ -81,6 +83,7 @@
cnt++;
}
return cnt;
+#endif
}
static always_inline int clo32(uint32_t val)
@@ -90,6 +93,12 @@
static always_inline int clz64(uint64_t val)
{
+#if defined(__GNUC__)
+ if (val)
+ return __builtin_clzll(val);
+ else
+ return 64;
+#else
int cnt = 0;
if (!(val >> 32)) {
@@ -99,6 +108,7 @@
}
return cnt + clz32(val);
+#endif
}
static always_inline int clo64(uint64_t val)
@@ -108,6 +118,12 @@
static always_inline int ctz32 (uint32_t val)
{
+#if defined(__GNUC__)
+ if (val)
+ return __builtin_ctz(val);
+ else
+ return 32;
+#else
int cnt;
cnt = 0;
@@ -136,6 +152,7 @@
}
return cnt;
+#endif
}
static always_inline int cto32 (uint32_t val)
@@ -145,6 +162,12 @@
static always_inline int ctz64 (uint64_t val)
{
+#if defined(__GNUC__)
+ if (val)
+ return __builtin_ctz(val);
+ else
+ return 64;
+#else
int cnt;
cnt = 0;
@@ -154,6 +177,7 @@
}
return cnt + ctz32(val);
+#endif
}
static always_inline int cto64 (uint64_t val)
@@ -182,6 +206,9 @@
static always_inline int ctpop32 (uint32_t val)
{
+#if defined(__GNUC__)
+ return __builtin_popcount(val);
+#else
val = (val & 0x55555555) + ((val >> 1) & 0x55555555);
val = (val & 0x33333333) + ((val >> 2) & 0x33333333);
val = (val & 0x0f0f0f0f) + ((val >> 4) & 0x0f0f0f0f);
@@ -189,10 +216,14 @@
val = (val & 0x0000ffff) + ((val >> 16) & 0x0000ffff);
return val;
+#endif
}
static always_inline int ctpop64 (uint64_t val)
{
+#if defined(__GNUC__)
+ return __builtin_popcountll(val);
+#else
val = (val & 0x5555555555555555ULL) + ((val >> 1) &
0x5555555555555555ULL);
val = (val & 0x3333333333333333ULL) + ((val >> 2) &
0x3333333333333333ULL);
val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
0x0f0f0f0f0f0f0f0fULL);
@@ -201,4 +232,5 @@
val = (val & 0x00000000ffffffffULL) + ((val >> 32) &
0x00000000ffffffffULL);
return val;
+#endif
}
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Qemu-devel] [5464] Optimize some host-utils function with gcc builtins,
Aurelien Jarno <=