File: cpuid.c

package info (click to toggle)
aws-crt-python 0.28.4%2Bdfsg-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 78,428 kB
  • sloc: ansic: 437,955; python: 27,657; makefile: 5,855; sh: 4,289; ruby: 208; java: 82; perl: 73; cpp: 25; xml: 11
file content (40 lines) | stat: -rw-r--r-- 1,259 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
/**
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0.
 */

#include <aws/common/cpuid.h>

void aws_run_cpuid(uint32_t eax, uint32_t ecx, uint32_t *abcd) {
    uint32_t ebx = 0;
    uint32_t edx = 0;

#if defined(__i386__) && defined(__PIC__)
    /* in case of PIC under 32-bit EBX cannot be clobbered */
    __asm__ __volatile__("movl %%ebx, %%edi \n\t "
                         "cpuid \n\t "
                         "xchgl %%ebx, %%edi"
                         : "=D"(ebx),
#else
    __asm__ __volatile__("cpuid"
                         : "+b"(ebx),
#endif
                           "+a"(eax),
                           "+c"(ecx),
                           "=d"(edx));
    abcd[0] = eax;
    abcd[1] = ebx;
    abcd[2] = ecx;
    abcd[3] = edx;
}

uint64_t aws_run_xgetbv(uint32_t xcr) {
    /* NOTE: we could have used the _xgetbv() intrinsic in <immintrin.h>, but it's missing from GCC < 9.0:
     * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71659 */

    /* xgetbv writes high and low of 64bit value to EDX:EAX */
    uint32_t xcrhigh;
    uint32_t xcrlow;
    __asm__ __volatile__("xgetbv" : "=a"(xcrlow), "=d"(xcrhigh) : "c"(xcr));
    return (((uint64_t)xcrhigh) << 32) | xcrlow;
}