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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
This commit is contained in:
aurel32 2008-10-12 00:53:08 +00:00
parent bc7b5f873b
commit 7d01998021
1 changed files with 36 additions and 4 deletions
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40
host-utils.h
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@ -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
}