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authoraurel32 <aurel32@c046a42c-6fe2-441c-8c8c-71466251a162>2008-10-12 00:53:08 +0000
committeraurel32 <aurel32@c046a42c-6fe2-441c-8c8c-71466251a162>2008-10-12 00:53:08 +0000
commit7d01998021e38363d53bc93f198023a05d8a52bf (patch)
tree2b9349d8c9aeda85bf4e668e75f1f616a9a1d6c3 /host-utils.h
parentbc7b5f873b10b8c2e4a1b247a541ff66d6eaca35 (diff)
Optimize some host-utils function with gcc builtins
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5464 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'host-utils.h')
-rw-r--r--host-utils.h40
1 files changed, 36 insertions, 4 deletions
diff --git a/host-utils.h b/host-utils.h
index b1e799ed3..c907fe839 100644
--- a/host-utils.h
+++ b/host-utils.h
@@ -47,14 +47,16 @@ void muls64(uint64_t *phigh, uint64_t *plow, int64_t a, int64_t b);
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 @@ static always_inline int clz32(uint32_t val)
cnt++;
}
return cnt;
+#endif
}
static always_inline int clo32(uint32_t val)
@@ -90,6 +93,12 @@ static always_inline int clo32(uint32_t val)
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 @@ static always_inline int clz64(uint64_t val)
}
return cnt + clz32(val);
+#endif
}
static always_inline int clo64(uint64_t val)
@@ -108,6 +118,12 @@ static always_inline int clo64(uint64_t val)
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 @@ static always_inline int ctz32 (uint32_t val)
}
return cnt;
+#endif
}
static always_inline int cto32 (uint32_t val)
@@ -145,6 +162,12 @@ static always_inline int cto32 (uint32_t val)
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 @@ static always_inline int ctz64 (uint64_t val)
}
return cnt + ctz32(val);
+#endif
}
static always_inline int cto64 (uint64_t val)
@@ -182,6 +206,9 @@ static always_inline int ctpop16 (uint16_t val)
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 @@ static always_inline int ctpop32 (uint32_t val)
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 @@ static always_inline int ctpop64 (uint64_t val)
val = (val & 0x00000000ffffffffULL) + ((val >> 32) & 0x00000000ffffffffULL);
return val;
+#endif
}