projects / apple / libc.git / blame
| Commit | Line | Data |
|---|---|---|
| 1f2f436a A |
1 | /* |
| 2 | * Copyright (c) 2007, 2008, 2009, 2010 Apple Inc. All rights reserved. | |
| 3 | * | |
| 4 | * @APPLE_LICENSE_HEADER_START@ | |
| 5 | * | |
| 6 | * This file contains Original Code and/or Modifications of Original Code | |
| 7 | * as defined in and that are subject to the Apple Public Source License | |
| 8 | * Version 2.0 (the 'License'). You may not use this file except in | |
| 9 | * compliance with the License. Please obtain a copy of the License at | |
| 10 | * http://www.opensource.apple.com/apsl/ and read it before using this | |
| 11 | * file. | |
| 12 | * | |
| 13 | * The Original Code and all software distributed under the License are | |
| 14 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
| 15 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, | |
| 16 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. | |
| 18 | * Please see the License for the specific language governing rights and | |
| 19 | * limitations under the License. | |
| 20 | * | |
| 21 | * @APPLE_LICENSE_HEADER_END@ | |
| 22 | */ | |
| 23 | ||
| 24 | #if defined(__i386__) || defined(__x86_64__) | |
| 25 | ||
| 26 | #include <stdlib.h> | |
| 1f2f436a | 27 | #include <machine/cpu_capabilities.h> |
| ad3c9f2a | 28 | #include "platfunc.h" |
| 1f2f436a A |
29 | |
| 30 | #define PLAT_CAP_MASK (kHasMMX | kHasSSE | kHasSSE2 | kHasSSE3 | kCache32 | kCache64 | kCache128 | kFastThreadLocalStorage | kHasSupplementalSSE3 | k64Bit | kHasSSE4_1 | kHasSSE4_2 | kHasAES | kInOrderPipeline | kSlow | kUP) | |
| 31 | ||
| ad3c9f2a A |
32 | inline static int __get_cpu_capabilities() { |
| 33 | return *((int32_t*)_COMM_PAGE_CPU_CAPABILITIES); | |
| 34 | } | |
| 35 | ||
| 1f2f436a A |
36 | inline static int num_cpus(int capabilities) { |
| 37 | return (capabilities & kNumCPUs) >> kNumCPUsShift; | |
| 38 | } | |
| 39 | ||
| 40 | /* TODO: If 8151810 is fixed (or full support for visibility("internal") is added), change this to visibility("internal") */ | |
| 41 | void __attribute__((visibility("hidden"))) *find_platform_function(const platfunc_descriptor *descriptors[]) { | |
| ad3c9f2a | 42 | int cap = __get_cpu_capabilities(), |
| 1f2f436a A |
43 | have_cpus = num_cpus(cap); |
| 44 | ||
| 45 | for (int i = 0; descriptors[i] != 0; i++) { | |
| 46 | int musthave_cpus = num_cpus(descriptors[i]->musthave), | |
| 47 | canthave_cpus = num_cpus(descriptors[i]->canthave); | |
| 48 | uint32_t musthave = descriptors[i]->musthave & PLAT_CAP_MASK, | |
| 49 | canthave = descriptors[i]->canthave & PLAT_CAP_MASK; | |
| 50 | /* First check that the CPU supports all the features that are in musthave */ | |
| 51 | if ((musthave & cap) != musthave) | |
| 52 | continue; | |
| 53 | /* Now check that the CPU doesn't have any of the features that are in canthave */ | |
| 54 | if ((canthave & cap) != 0) | |
| 55 | continue; | |
| 56 | /* Special case check for the number of CPUs. */ | |
| 57 | /* TODO: Should there be a way to specify < or > num cpus? */ | |
| 58 | if (musthave_cpus != 0 && have_cpus != musthave_cpus) | |
| 59 | continue; | |
| 60 | if (canthave_cpus != 0 && have_cpus == canthave_cpus) | |
| 61 | continue; | |
| 62 | /* otherwise, we have found our preferred implementation */ | |
| 63 | return descriptors[i]->address; | |
| 64 | } | |
| 65 | ||
| 66 | /* We didn't find an acceptable implementation. (bug in data structures!) */ | |
| 67 | return NULL; | |
| 68 | } | |
| 69 | ||
| 70 | #endif |