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Brush up some more code

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This commit is contained in:
Justine Tunney 2023-07-10 10:16:55 -07:00
parent ee6566a152
commit a2d269dc38
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GPG key ID: BE714B4575D6E328
32 changed files with 251 additions and 335 deletions
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2
libc/intrin/asan.c
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@ -743,7 +743,7 @@ static void __asan_report_memory_origin_image(intptr_t a, int z) {
r = n = st->count;
k = a - st->addr_base;
while (l < r) {
m = (l + r) >> 1;
m = (l & r) + ((l ^ r) >> 1); // floor((a+b)/2)
if (st->symbols[m].y < k) {
l = m + 1;
} else {

3
libc/intrin/findmemoryinterval.c
View file

@ -17,7 +17,6 @@
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/intrin/midpoint.h"
#include "libc/runtime/memtrack.internal.h"
noasan unsigned FindMemoryInterval(const struct MemoryIntervals *mm, int x) {
@ -25,7 +24,7 @@ noasan unsigned FindMemoryInterval(const struct MemoryIntervals *mm, int x) {
l = 0;
r = mm->i;
while (l < r) {
m = _midpoint(l, r);
m = (l & r) + ((l ^ r) >> 1); // floor((a+b)/2)
if (mm->p[m].y < x) {
l = m + 1;
} else {

2
libc/intrin/kprintf.greg.c
View file

@ -161,7 +161,7 @@ privileged static bool kismapped(int x) {
if (kismemtrackhosed()) return false;
r = _weaken(_mmi)->i;
while (l < r) {
m = (l + r) >> 1;
m = (l & r) + ((l ^ r) >> 1); // floor((a+b)/2)
if (_weaken(_mmi)->p[m].y < x) {
l = m + 1;
} else {

32
libc/intrin/midpoint.h
View file

@ -1,32 +0,0 @@
#ifndef COSMOPOLITAN_LIBC_BITS_MIDPOINT_H_
#define COSMOPOLITAN_LIBC_BITS_MIDPOINT_H_
#include "libc/assert.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
#if defined(__GNUC__) && !defined(__STRICT_ANSI__) && defined(__x86__)
/**
* Computes `(a + b) / 2` assuming unsigned.
*
* This implementation is the fastest on AMD Zen architecture.
*/
#define _midpoint(a, b) \
({ \
typeof((a) + (b)) a_ = (a); \
typeof(a_) b_ = (b); \
_unassert(a_ >= 0); \
_unassert(b_ >= 0); \
asm("add\t%1,%0\n\t" \
"rcr\t%0" \
: "+r"(a_) \
: "r"(b_)); \
a_; \
})
#else
/**
* Computes `(a + b) / 2` assuming unsigned.
*/
#define _midpoint(a, b) (((a) & (b)) + ((a) ^ (b)) / 2)
#endif /* __GNUC__ && !__STRICT_ANSI__ && x86 */
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_BITS_MIDPOINT_H_ */