ref: 7e515c46372e6dee7f47bae3733378756e40783a
parent: 4e04fa6dea716d4dafdb8a1d1dedc15455cddf3b
author: James Zern <[email protected]>
date: Wed Jan 14 17:51:49 EST 2015
fix AVX & AVX2 detection fixes issue #790 which resulted in a SIGILL on OpenBSD code is mostly from libwebp, based on the following: https://software.intel.com/en-us/articles/how-to-detect-new-instruction-support-in-the-4th-generation-intel-core-processor-family Change-Id: Ida7c1a18261e98c05ed9c662068140be407ec107
--- a/vpx_ports/x86.h
+++ b/vpx_ports/x86.h
@@ -13,6 +13,7 @@
#define VPX_PORTS_X86_H_
#include <stdlib.h>
#include "vpx_config.h"
+#include "vpx/vpx_integer.h"
#ifdef __cplusplus
extern "C" {@@ -104,6 +105,37 @@
#endif
#endif /* end others */
+// NaCl has no support for xgetbv or the raw opcode.
+#if !defined(__native_client__) && (defined(__i386__) || defined(__x86_64__))
+static INLINE uint64_t xgetbv(void) {+ const uint32_t ecx = 0;
+ uint32_t eax, edx;
+ // Use the raw opcode for xgetbv for compatibility with older toolchains.
+ __asm__ volatile (
+ ".byte 0x0f, 0x01, 0xd0\n"
+ : "=a"(eax), "=d"(edx) : "c" (ecx));
+ return ((uint64_t)edx << 32) | eax;
+}
+#elif (defined(_M_X64) || defined(_M_IX86)) && \
+ defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 160040219 // >= VS2010 SP1
+#include <immintrin.h>
+#define xgetbv() _xgetbv(0)
+#elif defined(_MSC_VER) && defined(_M_IX86)
+static INLINE uint64_t xgetbv(void) {+ uint32_t eax_, edx_;
+ __asm {+ xor ecx, ecx // ecx = 0
+ // Use the raw opcode for xgetbv for compatibility with older toolchains.
+ __asm _emit 0x0f __asm _emit 0x01 __asm _emit 0xd0
+ mov eax_, eax
+ mov edx_, edx
+ }
+ return ((uint64_t)edx_ << 32) | eax_;
+}
+#else
+#define xgetbv() 0U // no AVX for older x64 or unrecognized toolchains.
+#endif
+
#define HAS_MMX 0x01
#define HAS_SSE 0x02
#define HAS_SSE2 0x04
@@ -156,14 +188,17 @@
if (reg_ecx & BIT(19)) flags |= HAS_SSE4_1;
- if (reg_ecx & BIT(28)) flags |= HAS_AVX;
+ // bits 27 (OSXSAVE) & 28 (256-bit AVX)
+ if (reg_ecx & (BIT(27) | BIT(28))) {+ if ((xgetbv() & 0x6) == 0x6) {+ flags |= HAS_AVX;
- /* Get the leaf 7 feature flags. Needed to check for AVX2 support */
- reg_eax = 7;
- reg_ecx = 0;
- cpuid(7, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
+ /* Get the leaf 7 feature flags. Needed to check for AVX2 support */
+ cpuid(7, 0, reg_eax, reg_ebx, reg_ecx, reg_edx);
- if (reg_ebx & BIT(5)) flags |= HAS_AVX2;
+ if (reg_ebx & BIT(5)) flags |= HAS_AVX2;
+ }
+ }
return flags & mask;
}