f4131cf8a6
This was a bit trickier than it should be due to symbol conflicts with zig's compiler-rt implementation. We attempt to use weak linkage in our compiler-rt, but this does not seem to be working in all cases. I manually disabled export of the problematic compiler-rt math functions in order to cross compile musl's libc.so for all targets as input to `tools/gen_stubs.zig`. Other than that, this update went fairly smoothly. Quite a few additional symbols were added to the blacklist in `tools/gen_stubs.zig` due to recent reorganization of zig's compiler-rt.
61 lines
1.4 KiB
C
Vendored
61 lines
1.4 KiB
C
Vendored
#include <stdlib.h>
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#include <errno.h>
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#include "meta.h"
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void *aligned_alloc(size_t align, size_t len)
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{
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if ((align & -align) != align) {
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errno = EINVAL;
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return 0;
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}
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if (len > SIZE_MAX - align || align >= (1ULL<<31)*UNIT) {
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errno = ENOMEM;
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return 0;
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}
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if (DISABLE_ALIGNED_ALLOC) {
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errno = ENOMEM;
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return 0;
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}
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if (align <= UNIT) align = UNIT;
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unsigned char *p = malloc(len + align - UNIT);
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if (!p)
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return 0;
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struct meta *g = get_meta(p);
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int idx = get_slot_index(p);
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size_t stride = get_stride(g);
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unsigned char *start = g->mem->storage + stride*idx;
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unsigned char *end = g->mem->storage + stride*(idx+1) - IB;
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size_t adj = -(uintptr_t)p & (align-1);
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if (!adj) {
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set_size(p, end, len);
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return p;
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}
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p += adj;
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uint32_t offset = (size_t)(p-g->mem->storage)/UNIT;
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if (offset <= 0xffff) {
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*(uint16_t *)(p-2) = offset;
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p[-4] = 0;
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} else {
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// use a 32-bit offset if 16-bit doesn't fit. for this,
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// 16-bit field must be zero, [-4] byte nonzero.
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*(uint16_t *)(p-2) = 0;
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*(uint32_t *)(p-8) = offset;
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p[-4] = 1;
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}
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p[-3] = idx;
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set_size(p, end, len);
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// store offset to aligned enframing. this facilitates cycling
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// offset and also iteration of heap for debugging/measurement.
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// for extreme overalignment it won't fit but these are classless
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// allocations anyway.
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*(uint16_t *)(start - 2) = (size_t)(p-start)/UNIT;
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start[-3] = 7<<5;
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return p;
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}
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