#define SkUtils_DEFINED
#include "SkTypes.h"
-#if defined(SK_BUILD_FOR_WIN)
- #include <intrin.h>
-#endif
-
-#if defined(SK_CPU_X86)
- static inline void rep_stosw(uint16_t buffer[], uint16_t value, int count) {
- #if defined(SK_BUILD_FOR_WIN)
- __stosw(buffer, value, count);
- #else
- __asm__ __volatile__ ( "rep stosw" : "+D"(buffer), "+c"(count) : "a"(value) );
- #endif
- }
-
- static inline void rep_stosd(uint32_t buffer[], uint32_t value, int count) {
- #if defined(SK_BUILD_FOR_WIN)
- __stosd((PDWORD)buffer, value, count);
- #else
- __asm__ __volatile__ ( "rep stosl" : "+D"(buffer), "+c"(count) : "a"(value) );
- #endif
- }
-#endif
namespace SkOpts {
extern void (*memset16)(uint16_t[], uint16_t, int);
///////////////////////////////////////////////////////////////////////////////
-// The stosw/d and inlining heuristics below were determined using
-// bench/MemsetBench.cpp and perf.skia.org.
+// The inlining heuristics below were determined using bench/MemsetBench.cpp
+// on a x86 desktop, a Nexus 7 with and without NEON, and a Nexus 9:
+// - on x86, inlining was never faster,
+// - on ARMv7, inlining was faster for N<=10. Putting this check inside the NEON
+// code was not helpful; it's got to be here outside.
+// - NEON code generation for ARMv8 with GCC 4.9 is terrible,
+// making the NEON code ~8x slower that just a serial loop.
/** Similar to memset(), but it assigns a 16bit value into the buffer.
@param buffer The memory to have value copied into it
@param count The number of times value should be copied into the buffer.
*/
static inline void sk_memset16(uint16_t buffer[], uint16_t value, int count) {
-#if defined(SK_CPU_X86)
- if (count > 30) { rep_stosw(buffer, value, count); return; }
-#elif defined(SK_ARM_HAS_NEON)
+#if defined(SK_CPU_ARM64)
while (count --> 0) { *buffer++ = value; } return;
+#elif defined(SK_CPU_ARM32)
+ if (count <= 10) { while (count --> 0) { *buffer++ = value; } return; }
#endif
SkOpts::memset16(buffer, value, count);
}
@param count The number of times value should be copied into the buffer.
*/
static inline void sk_memset32(uint32_t buffer[], uint32_t value, int count) {
-#if defined(SK_CPU_X86)
- if (count > 30) { rep_stosd(buffer, value, count); return; }
-#elif defined(SK_ARM_HAS_NEON)
+#if defined(SK_CPU_ARM64)
while (count --> 0) { *buffer++ = value; } return;
+#elif defined(SK_CPU_ARM32)
+ if (count <= 10) { while (count --> 0) { *buffer++ = value; } return; }
#endif
SkOpts::memset32(buffer, value, count);
}