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wip: initial work on mimalloc3 without segments

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daanx 2024-11-28 19:31:04 -08:00
parent 9b7537755a
commit 71cfa45e76
15 changed files with 3001 additions and 289 deletions
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67
src/libc.c
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@ -7,7 +7,7 @@ terms of the MIT license. A copy of the license can be found in the file
// --------------------------------------------------------
// This module defines various std libc functions to reduce
// the dependency on libc, and also prevent errors caused
// the dependency on libc, and also prevent errors caused
// by some libc implementations when called before `main`
// executes (due to malloc redirection)
// --------------------------------------------------------
@ -83,7 +83,7 @@ bool _mi_getenv(const char* name, char* result, size_t result_size) {
// Define our own limited `_mi_vsnprintf` and `_mi_snprintf`
// This is mostly to avoid calling these when libc is not yet
// initialized (and to reduce dependencies)
//
//
// format: d i, p x u, s
// prec: z l ll L
// width: 10
@ -130,7 +130,7 @@ static void mi_out_alignright(char fill, char* start, size_t len, size_t extra,
}
static void mi_out_num(uintmax_t x, size_t base, char prefix, char** out, char* end)
static void mi_out_num(uintmax_t x, size_t base, char prefix, char** out, char* end)
{
if (x == 0 || base == 0 || base > 16) {
if (prefix != 0) { mi_outc(prefix, out, end); }
@ -144,8 +144,8 @@ static void mi_out_num(uintmax_t x, size_t base, char prefix, char** out, char*
mi_outc((digit <= 9 ? '0' + digit : 'A' + digit - 10),out,end);
x = x / base;
}
if (prefix != 0) {
mi_outc(prefix, out, end);
if (prefix != 0) {
mi_outc(prefix, out, end);
}
size_t len = *out - start;
// and reverse in-place
@ -181,7 +181,7 @@ void _mi_vsnprintf(char* buf, size_t bufsize, const char* fmt, va_list args) {
size_t width = 0;
char numtype = 'd';
char numplus = 0;
bool alignright = true;
bool alignright = true;
if (c == '+' || c == ' ') { numplus = c; MI_NEXTC(); }
if (c == '-') { alignright = false; MI_NEXTC(); }
if (c == '0') { fill = '0'; MI_NEXTC(); }
@ -191,7 +191,7 @@ void _mi_vsnprintf(char* buf, size_t bufsize, const char* fmt, va_list args) {
width = (10 * width) + (c - '0'); MI_NEXTC();
}
if (c == 0) break; // extra check due to while
}
}
if (c == 'z' || c == 't' || c == 'L') { numtype = c; MI_NEXTC(); }
else if (c == 'l') {
numtype = c; MI_NEXTC();
@ -273,3 +273,56 @@ void _mi_snprintf(char* buf, size_t buflen, const char* fmt, ...) {
_mi_vsnprintf(buf, buflen, fmt, args);
va_end(args);
}
// --------------------------------------------------------
// generic trailing and leading zero count
// --------------------------------------------------------
static inline size_t mi_ctz_generic32(uint32_t x) {
// de Bruijn multiplication, see <http://supertech.csail.mit.edu/papers/debruijn.pdf>
static const uint8_t debruijn[32] = {
0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
};
if (x==0) return 32;
return debruijn[((x & -(int32_t)x) * 0x077CB531UL) >> 27];
}
static inline size_t mi_clz_generic32(uint32_t x) {
// de Bruijn multiplication, see <http://supertech.csail.mit.edu/papers/debruijn.pdf>
static const uint8_t debruijn[32] = {
31, 22, 30, 21, 18, 10, 29, 2, 20, 17, 15, 13, 9, 6, 28, 1,
23, 19, 11, 3, 16, 14, 7, 24, 12, 4, 8, 25, 5, 26, 27, 0
};
if (x==0) return 32;
x |= x >> 1;
x |= x >> 2;
x |= x >> 4;
x |= x >> 8;
x |= x >> 16;
return debruijn[(uint32_t)(x * 0x07C4ACDDUL) >> 27];
}
size_t _mi_clz_generic(size_t x) {
if (x==0) return MI_SIZE_BITS;
#if (MI_SIZE_BITS <= 32)
return mi_clz_generic32((uint32_t)x);
#else
const size_t count = mi_clz_generic32((uint32_t)(x >> 32));
if (count < 32) return count;
return (32 + mi_clz_generic32((uint32_t)x));
#endif
}
size_t _mi_ctz_generic(size_t x) {
if (x==0) return MI_SIZE_BITS;
#if (MI_SIZE_BITS <= 32)
return mi_ctz_generic32((uint32_t)x);
#else
const size_t count = mi_ctz_generic32((uint32_t)x);
if (count < 32) return count;
return (32 + mi_ctz_generic32((uint32_t)(x>>32)));
#endif
}