From 1abd8794ca2fe6e371b7d512c8a2ab3876d891d2 Mon Sep 17 00:00:00 2001 From: Erik de Castro Lopo Date: Sun, 4 Dec 2016 17:36:58 +1100 Subject: libFLAC/cpu.c: Remove OS SSE detection Assume that all OSes that are usable today support SSE. Patch-from: lvqcl.mail --- src/libFLAC/cpu.c | 166 ------------------------------------------------------ 1 file changed, 166 deletions(-) diff --git a/src/libFLAC/cpu.c b/src/libFLAC/cpu.c index c0e29ad6..ee484a7f 100644 --- a/src/libFLAC/cpu.c +++ b/src/libFLAC/cpu.c @@ -39,23 +39,7 @@ #include #include -#if defined (__NetBSD__) || defined(__OpenBSD__) -# include -# include -# include -#endif - -#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__) || defined(__APPLE__) -# include -# include -#endif - -#if defined(__linux__) && defined(FLAC__CPU_IA32) && !defined FLAC__NO_ASM && (defined FLAC__HAS_NASM || FLAC__HAS_X86INTRIN) && !FLAC__SSE_OS -# include -#endif - #if defined(_MSC_VER) -# include # include /* for __cpuid() and _xgetbv() */ #endif @@ -77,7 +61,6 @@ /* these are flags in EDX of CPUID AX=00000001 */ static const unsigned FLAC__CPUINFO_IA32_CPUID_CMOV = 0x00008000; static const unsigned FLAC__CPUINFO_IA32_CPUID_MMX = 0x00800000; -static const unsigned FLAC__CPUINFO_IA32_CPUID_FXSR = 0x01000000; static const unsigned FLAC__CPUINFO_IA32_CPUID_SSE = 0x02000000; static const unsigned FLAC__CPUINFO_IA32_CPUID_SSE2 = 0x04000000; #endif @@ -97,43 +80,6 @@ static const unsigned FLAC__CPUINFO_IA32_CPUID_FMA = 0x00001000; static const unsigned FLAC__CPUINFO_IA32_CPUID_AVX2 = 0x00000020; #endif -/* - * Extra stuff needed for detection of OS support for SSE on IA-32 - */ -#if defined(__linux__) && defined(FLAC__CPU_IA32) && !defined FLAC__NO_ASM && (defined FLAC__HAS_NASM || FLAC__HAS_X86INTRIN) && !FLAC__SSE_OS -/* - * If the OS doesn't support SSE, we will get here with a SIGILL. We - * modify the return address to jump over the offending SSE instruction - * and also the operation following it that indicates the instruction - * executed successfully. In this way we use no global variables and - * stay thread-safe. - * - * 3 + 3 + 6: - * 3 bytes for "xorps xmm0,xmm0" - * 3 bytes for estimate of how long the follwing "inc var" instruction is - * 6 bytes extra in case our estimate is wrong - * 12 bytes puts us in the NOP "landing zone" - */ -static void sigill_handler_sse_os(int signal, siginfo_t *si, void *uc) -{ - (void)signal, (void)si; - ((ucontext_t*)uc)->uc_mcontext.gregs[14/*REG_EIP*/] += 3 + 3 + 6; -} -#endif - -#if defined FLAC__CPU_IA32 -static void -ia32_disable_sse(FLAC__CPUInfo *info) -{ - info->ia32.sse = false; - info->ia32.sse2 = false; - info->ia32.sse3 = false; - info->ia32.ssse3 = false; - info->ia32.sse41 = false; - info->ia32.sse42 = false; -} -#endif - #if defined FLAC__CPU_IA32 || defined FLAC__CPU_X86_64 static uint32_t cpu_xgetbv_x86(void) @@ -155,11 +101,7 @@ ia32_cpu_info (FLAC__CPUInfo *info) { #if !defined FLAC__CPU_IA32 (void) info; -#elif defined(__ANDROID__) || defined(ANDROID) - /* no need to check OS SSE support */ - info->use_asm = true; #else - FLAC__bool ia32_fxsr = false; FLAC__bool ia32_osxsave = false; FLAC__uint32 flags_eax, flags_ebx, flags_ecx, flags_edx; @@ -181,7 +123,6 @@ ia32_cpu_info (FLAC__CPUInfo *info) info->ia32.cmov = (flags_edx & FLAC__CPUINFO_IA32_CPUID_CMOV ) ? true : false; info->ia32.mmx = (flags_edx & FLAC__CPUINFO_IA32_CPUID_MMX ) ? true : false; - ia32_fxsr = (flags_edx & FLAC__CPUINFO_IA32_CPUID_FXSR ) ? true : false; info->ia32.sse = (flags_edx & FLAC__CPUINFO_IA32_CPUID_SSE ) ? true : false; info->ia32.sse2 = (flags_edx & FLAC__CPUINFO_IA32_CPUID_SSE2 ) ? true : false; info->ia32.sse3 = (flags_ecx & FLAC__CPUINFO_IA32_CPUID_SSE3 ) ? true : false; @@ -213,110 +154,6 @@ ia32_cpu_info (FLAC__CPUInfo *info) dfprintf(stderr, " AVX2 ....... %c\n", info->ia32.avx2 ? 'Y' : 'n'); } - /* - * now have to check for OS support of SSE instructions - */ - if(info->ia32.sse) { -#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__) || defined(__APPLE__) - int sse = 0; - size_t len = sizeof(sse); - /* at least one of these must work: */ - sse = sse || (sysctlbyname("hw.instruction_sse", &sse, &len, NULL, 0) == 0 && sse); - sse = sse || (sysctlbyname("hw.optional.sse" , &sse, &len, NULL, 0) == 0 && sse); /* __APPLE__ ? */ - if(!sse) - ia32_disable_sse(info); -#elif defined(__NetBSD__) || defined (__OpenBSD__) - int val = 0, mib[2] = { CTL_MACHDEP, CPU_SSE }; - size_t len = sizeof(val); - if(sysctl(mib, 2, &val, &len, NULL, 0) < 0 || !val) - ia32_disable_sse(info); - else { /* double-check SSE2 */ - mib[1] = CPU_SSE2; - len = sizeof(val); - if(sysctl(mib, 2, &val, &len, NULL, 0) < 0 || !val) { - ia32_disable_sse(info); - info->ia32.sse = true; - } - } -#elif defined(__linux__) && !FLAC__SSE_OS - int sse = 0; - struct sigaction sigill_save; - struct sigaction sigill_sse; - sigill_sse.sa_sigaction = sigill_handler_sse_os; - sigemptyset(&sigill_sse.sa_mask); - sigill_sse.sa_flags = SA_SIGINFO | SA_RESETHAND; /* SA_RESETHAND just in case our SIGILL return jump breaks, so we don't get stuck in a loop */ - if(0 == sigaction(SIGILL, &sigill_sse, &sigill_save)) - { - /* http://www.ibiblio.org/gferg/ldp/GCC-Inline-Assembly-HOWTO.html */ - /* see sigill_handler_sse_os() for an explanation of the following: */ - asm volatile ( - "xorps %%xmm0,%%xmm0\n\t" /* will cause SIGILL if unsupported by OS */ - "incl %0\n\t" /* SIGILL handler will jump over this */ - /* landing zone */ - "nop\n\t" /* SIGILL jump lands here if "inc" is 9 bytes */ - "nop\n\t" - "nop\n\t" - "nop\n\t" - "nop\n\t" - "nop\n\t" - "nop\n\t" /* SIGILL jump lands here if "inc" is 3 bytes (expected) */ - "nop\n\t" - "nop" /* SIGILL jump lands here if "inc" is 1 byte */ - : "=r"(sse) - : "0"(sse) - ); - - sigaction(SIGILL, &sigill_save, NULL); - } - - if(!sse) - ia32_disable_sse(info); -#elif defined(_MSC_VER) - __try { - __asm { - xorps xmm0,xmm0 - } - } - __except(EXCEPTION_EXECUTE_HANDLER) { - if (_exception_code() == STATUS_ILLEGAL_INSTRUCTION) - ia32_disable_sse(info); - } -#elif defined(__GNUC__) /* MinGW goes here */ - int sse = 0; - /* Based on the idea described in Agner Fog's manual "Optimizing subroutines in assembly language" */ - /* In theory, not guaranteed to detect lack of OS SSE support on some future Intel CPUs, but in practice works (see the aforementioned manual) */ - if (ia32_fxsr) { - struct { - FLAC__uint32 buff[128]; - } __attribute__((aligned(16))) fxsr; - FLAC__uint32 old_val, new_val; - - memset(fxsr.buff, 0, sizeof (fxsr.buff)); - - asm volatile ("fxsave %0" : "=m" (fxsr) : "m" (fxsr)); - old_val = fxsr.buff[50]; - fxsr.buff[50] ^= 0x0013c0de; /* change value in the buffer */ - asm volatile ("fxrstor %0" : "=m" (fxsr) : "m" (fxsr)); /* try to change SSE register */ - fxsr.buff[50] = old_val; /* restore old value in the buffer */ - asm volatile ("fxsave %0" : "=m" (fxsr) : "m" (fxsr)); /* old value will be overwritten if SSE register was changed */ - new_val = fxsr.buff[50]; /* == old_val if FXRSTOR didn't change SSE register and (old_val ^ 0x0013c0de) otherwise */ - fxsr.buff[50] = old_val; /* again restore old value in the buffer */ - asm volatile ("fxrstor %0" : "=m" (fxsr) : "m" (fxsr)); /* restore old values of registers */ - - if ((old_val^new_val) == 0x0013c0de) - sse = 1; - } - if(!sse) - ia32_disable_sse(info); -#else - /* no way to test, disable to be safe */ - ia32_disable_sse(info); -#endif - dfprintf(stderr, " SSE OS sup . %c\n", info->ia32.sse ? 'Y' : 'n'); - } - else /* info->ia32.sse == false */ - ia32_disable_sse(info); - /* * now have to check for OS support of AVX instructions */ @@ -341,9 +178,6 @@ x86_64_cpu_info (FLAC__CPUInfo *info) { #if !defined FLAC__CPU_X86_64 (void) info; -#elif defined(__ANDROID__) || defined(ANDROID) - /* no need to check OS SSE support */ - info->use_asm = true; #elif !defined FLAC__NO_ASM && FLAC__HAS_X86INTRIN FLAC__bool x86_osxsave = false; FLAC__uint32 flags_eax, flags_ebx, flags_ecx, flags_edx; -- cgit v1.2.1