func TestCtz64(t *testing.T) {
for i := uint(0); i <= 64; i++ {
x := uint64(5) << i
if got := sys.Ctz64(x); got != uint64(i) {
t.Errorf("Ctz64(%d)=%d, want %d", x, got, i)
}
}
}
func test(i, x uint64) {
t := T.Ctz64(x) // ERROR "intrinsic substitution for Ctz64"
if i != t {
logf("Ctz64(0x%x) expected %d but got %d\n", x, i, t)
}
x = -x
t = T.Ctz64(x) // ERROR "intrinsic substitution for Ctz64"
if i != t {
logf("Ctz64(0x%x) expected %d but got %d\n", x, i, t)
}
if i <= 32 {
x32 := uint32(x)
t32 := T.Ctz32(x32) // ERROR "intrinsic substitution for Ctz32"
if uint32(i) != t32 {
logf("Ctz32(0x%x) expected %d but got %d\n", x32, i, t32)
}
x32 = -x32
t32 = T.Ctz32(x32) // ERROR "intrinsic substitution for Ctz32"
if uint32(i) != t32 {
logf("Ctz32(0x%x) expected %d but got %d\n", x32, i, t32)
}
}
if i <= 16 {
x16 := uint16(x)
t16 := T.Ctz16(x16) // ERROR "intrinsic substitution for Ctz16"
if uint16(i) != t16 {
logf("Ctz16(0x%x) expected %d but got %d\n", x16, i, t16)
}
x16 = -x16
t16 = T.Ctz16(x16) // ERROR "intrinsic substitution for Ctz16"
if uint16(i) != t16 {
logf("Ctz16(0x%x) expected %d but got %d\n", x16, i, t16)
}
}
}
func main() {
// Test Bswap first because the other test relies on it
// working correctly (to implement bit reversal).
for i := range A {
x := A[i]
y := B[i]
X := T.Bswap64(x) // ERROR "intrinsic substitution for Bswap64"
Y := T.Bswap64(y) // ERROR "intrinsic substitution for Bswap64"
if y != X {
logf("Bswap64(0x%08x) expected 0x%08x but got 0x%08x\n", x, y, X)
}
if x != Y {
logf("Bswap64(0x%08x) expected 0x%08x but got 0x%08x\n", y, x, Y)
}
x32 := uint32(X)
y32 := uint32(Y >> 32)
X32 := T.Bswap32(x32) // ERROR "intrinsic substitution for Bswap32"
Y32 := T.Bswap32(y32) // ERROR "intrinsic substitution for Bswap32"
if y32 != X32 {
logf("Bswap32(0x%08x) expected 0x%08x but got 0x%08x\n", x32, y32, X32)
}
if x32 != Y32 {
logf("Bswap32(0x%08x) expected 0x%08x but got 0x%08x\n", y32, x32, Y32)
}
}
// Zero is a special case, be sure it is done right.
if T.Ctz16(0) != 16 { // ERROR "intrinsic substitution for Ctz16"
logf("ctz16(0) != 16")
}
if T.Ctz32(0) != 32 { // ERROR "intrinsic substitution for Ctz32"
logf("ctz32(0) != 32")
}
if T.Ctz64(0) != 64 { // ERROR "intrinsic substitution for Ctz64"
logf("ctz64(0) != 64")
}
for i := uint64(0); i <= 64; i++ {
for j := uint64(1); j <= 255; j += 2 {
for k := uint64(1); k <= 65537; k += 128 {
x := (j * k) << i
test(i, x)
}
}
}
}
// nextFreeFast returns the next free object if one is quickly available.
// Otherwise it returns 0.
func nextFreeFast(s *mspan) gclinkptr {
theBit := sys.Ctz64(s.allocCache) // Is there a free object in the allocCache?
if theBit < 64 {
result := s.freeindex + uintptr(theBit)
if result < s.nelems {
freeidx := result + 1
if freeidx%64 == 0 && freeidx != s.nelems {
return 0
}
s.allocCache >>= (theBit + 1)
s.freeindex = freeidx
v := gclinkptr(result*s.elemsize + s.base())
s.allocCount++
return v
}
}
return 0
}
