Attachment 1477282 Details for Bug 1619354 – reduced standalone test case

reduced standalone test case

file_1619354.txt (text/plain), 1.29 KB, created by Dan Horák on 2018-08-20 15:10:30 UTC

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Creator: Dan Horák

Created: 2018-08-20 15:10:30 UTC

Size: 1.29 KB

patch

obsolete

>// gcc -std=gnu11 -Wall -pipe -g3 -O2 -funroll-loops -o t t.c
>
>#include <stdint.h>
>#include <stdio.h>
>#include <stdlib.h>
>#include <assert.h>
>
>#define JEMALLOC_HAVE_BUILTIN_CLZ 1
>
>static inline uint32_t pow2_ceil_u32(uint32_t x) {
>#if defined(JEMALLOC_HAVE_BUILTIN_CLZ)
>        if (x <= 1) {
>                return x;
>        }
>        size_t msb_on_index;
>        msb_on_index = (31 ^ __builtin_clz(x - 1));
>        assert(msb_on_index < 31);
>        return 1U << (msb_on_index + 1);
>#else
>        x--;
>        x |= x >> 1;
>        x |= x >> 2;
>        x |= x >> 4;
>        x |= x >> 8;
>        x |= x >> 16;
>        x++;
>        return x;
>#endif
>}
>
>
>void test_pow2_ceil_u32(void) {
>	unsigned i;
>
>	for (i = 0; i < sizeof(uint32_t) * 8; i++) {
>		do {
>			uint32_t a_ = (pow2_ceil_u32(((uint32_t)1) << i));
>			uint32_t b_ = (((uint32_t)1) << i);
>			if (!(a_ == b_)) {
>				char prefix[256];
>				char message[256];
>				snprintf(prefix, sizeof(prefix), "Failed assertion: (%s) == (%s) --> %u != %u: ", "pow2_ceil_u32(((uint32_t)1) << i)", "((uint32_t)1) << i", a_, b_);
>				snprintf(message, sizeof(message), "Unexpected result, i=%u", (uint32_t)i);
>				printf("%s%s\n", prefix, message);
>			}
>		} while (0);
>	}
>}
>
>int
>main(void) {
>	test_pow2_ceil_u32();
>	
>	return 0;
>}

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