comparison decoders/libmpg123/getcpuflags.S @ 562:7e08477b0fc1

MP3 decoder upgrade work. Ripped out SMPEG and mpglib support, replaced it with "mpg123.c" and libmpg123. libmpg123 is a much better version of mpglib, so it should solve all the problems about MP3's not seeking, or most modern MP3's not playing at all, etc. Since you no longer have to make a tradeoff with SMPEG for features, and SMPEG is basically rotting, I removed it from the project. There is still work to be done with libmpg123...there are MMX, 3DNow, SSE, Altivec, etc decoders which we don't have enabled at the moment, and the build system could use some work to make this compile more cleanly, etc. Still: huge win.
author Ryan C. Gordon <icculus@icculus.org>
date Fri, 30 Jan 2009 02:44:47 -0500
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561:f2985e08589c 562:7e08477b0fc1
1 /*
2 getcpucpuflags: get cpuflags for ia32
3
4 copyright ?-2006 by the mpg123 project - free software under the terms of the LGPL 2.1
5 see COPYING and AUTHORS files in distribution or http:#mpg123.org
6 initially written by KIMURA Takuhiro (for 3DNow!)
7 extended for general use by Thomas Orgis
8
9 extern int getcpuid(struct cpuflags*)
10 or just
11 extern int getcpuid(unsigned int*)
12 where there is memory for 4 ints
13 -> the first set of idflags (basic cpu family info)
14 and the idflags, stdflags, std2flags, extflags written to the parameter
15 -> 0x00000000 (CPUID instruction not supported)
16 */
17
18 #include "mangle.h"
19
20 .text
21 ALIGN4
22
23 .globl ASM_NAME(getcpuflags)
24 /* .type ASM_NAME(getcpuflags),@function */
25 ASM_NAME(getcpuflags):
26 pushl %ebp
27 movl %esp,%ebp
28 pushl %edx
29 pushl %ecx
30 pushl %ebx
31 pushl %esi
32 /* get the int pointer for storing the flags */
33 movl 8(%ebp), %esi
34 /* does that one make sense? */
35 movl $0x80000000,%eax
36 /* now save the flags and do a check for cpuid availability */
37 pushfl
38 pushfl
39 popl %eax
40 movl %eax,%ebx
41 /* set that bit... */
42 xorl $0x00200000,%eax
43 pushl %eax
44 popfl
45 /* ...and read back the flags to see if it is understood */
46 pushfl
47 popl %eax
48 popfl
49 cmpl %ebx,%eax
50 je .Lnocpuid
51 /* In principle, I would have to check the CPU's identify first to be sure how to interpret the extended flags. */
52 /* now get the info, first extended */
53 movl $0x0, 12(%esi) /* clear value */
54 /* only if supported... */
55 movl $0x80000000, %eax
56 cpuid
57 /* IDT CPUs should not change EAX, generally I hope that non-3DNow cpus do not set a bogus support level here. */
58 cmpl $0x80000001, %eax
59 jb .Lnoextended /* Skip ext check without minimal support level. */
60 /* is supported, get flags value */
61 movl $0x80000001,%eax
62 cpuid
63 movl %edx,12(%esi)
64 .Lnoextended:
65 /* then the other ones, called last to get the id flags in %eax for ret */
66 movl $0x00000001,%eax
67 cpuid
68 movl %eax, (%esi)
69 movl %ecx, 4(%esi)
70 movl %edx, 8(%esi)
71 jmp .Lend
72 ALIGN4
73 .Lnocpuid:
74 /* error: set everything to zero */
75 movl $0, %eax
76 movl $0, (%esi)
77 movl $0, 4(%esi)
78 movl $0, 8(%esi)
79 movl $0, 12(%esi)
80 ALIGN4
81 .Lend:
82 /* return value are the id flags, still stored in %eax */
83 popl %esi
84 popl %ebx
85 popl %ecx
86 popl %edx
87 movl %ebp,%esp
88 popl %ebp
89 ret
90
91 /* Mark non-executable stack. */
92 #if defined(__linux__) && defined(__ELF__)
93 .section .note.GNU-stack,"",%progbits
94 #endif