skia2/include/core/SkUtils.h
mtklein 9ff378b01b Rewrite memset benches, then use results to add a small-N optimization.
The benches for N <= 10 get around 2x faster on my N7 and N9.  I believe this
is because of the reduced function-call-then-function-pointer-call overhead on
the N7, and additionally because it seems autovectorization beats our NEON code
for small N on the N9.

My desktop is unchanged, though that's probably because N=10 lies well within a
region where memset's performance is essentially constant: N=100 takes only
about 2x as long as N=1 and N=10, which perform nearly identically.

BUG=skia:

Review URL: https://codereview.chromium.org/1073863002
2015-04-09 14:05:17 -07:00

150 lines
5.1 KiB
C++

/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkUtils_DEFINED
#define SkUtils_DEFINED
#include "SkTypes.h"
///////////////////////////////////////////////////////////////////////////////
// Determined empirically using bench/MemsetBench.cpp on a Nexus 7, Nexus 9, and desktop.
#if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2 || defined(SK_ARM_HAS_NEON)
// Platforms where we can assume an autovectorizer will give us a good inline memset.
#define SK_SMALL_MEMSET 1000
#else
// Platforms like Chrome on ARMv7 that don't typically compile with NEON globally.
#define SK_SMALL_MEMSET 10
#endif
/** Similar to memset(), but it assigns a 16bit value into the buffer.
@param buffer The memory to have value copied into it
@param value The 16bit value to be copied into buffer
@param count The number of times value should be copied into the buffer.
*/
void sk_memset16_large(uint16_t dst[], uint16_t value, int count);
inline void sk_memset16(uint16_t dst[], uint16_t value, int count) {
if (count <= SK_SMALL_MEMSET) {
for (int i = 0; i < count; i++) {
dst[i] = value;
}
} else {
sk_memset16_large(dst, value, count);
}
}
typedef void (*SkMemset16Proc)(uint16_t dst[], uint16_t value, int count);
SkMemset16Proc SkMemset16GetPlatformProc();
/** Similar to memset(), but it assigns a 32bit value into the buffer.
@param buffer The memory to have value copied into it
@param value The 32bit value to be copied into buffer
@param count The number of times value should be copied into the buffer.
*/
void sk_memset32_large(uint32_t dst[], uint32_t value, int count);
inline void sk_memset32(uint32_t dst[], uint32_t value, int count) {
if (count <= SK_SMALL_MEMSET) {
for (int i = 0; i < count; i++) {
dst[i] = value;
}
} else {
sk_memset32_large(dst, value, count);
}
}
typedef void (*SkMemset32Proc)(uint32_t dst[], uint32_t value, int count);
SkMemset32Proc SkMemset32GetPlatformProc();
#undef SK_SMALL_MEMSET
/** Similar to memcpy(), but it copies count 32bit values from src to dst.
@param dst The memory to have value copied into it
@param src The memory to have value copied from it
@param count The number of values should be copied.
*/
void sk_memcpy32(uint32_t dst[], const uint32_t src[], int count);
typedef void (*SkMemcpy32Proc)(uint32_t dst[], const uint32_t src[], int count);
SkMemcpy32Proc SkMemcpy32GetPlatformProc();
///////////////////////////////////////////////////////////////////////////////
#define kMaxBytesInUTF8Sequence 4
#ifdef SK_DEBUG
int SkUTF8_LeadByteToCount(unsigned c);
#else
#define SkUTF8_LeadByteToCount(c) ((((0xE5 << 24) >> ((unsigned)c >> 4 << 1)) & 3) + 1)
#endif
inline int SkUTF8_CountUTF8Bytes(const char utf8[]) {
SkASSERT(utf8);
return SkUTF8_LeadByteToCount(*(const uint8_t*)utf8);
}
int SkUTF8_CountUnichars(const char utf8[]);
int SkUTF8_CountUnichars(const char utf8[], size_t byteLength);
SkUnichar SkUTF8_ToUnichar(const char utf8[]);
SkUnichar SkUTF8_NextUnichar(const char**);
SkUnichar SkUTF8_PrevUnichar(const char**);
/** Return the number of bytes need to convert a unichar
into a utf8 sequence. Will be 1..kMaxBytesInUTF8Sequence,
or 0 if uni is illegal.
*/
size_t SkUTF8_FromUnichar(SkUnichar uni, char utf8[] = NULL);
///////////////////////////////////////////////////////////////////////////////
#define SkUTF16_IsHighSurrogate(c) (((c) & 0xFC00) == 0xD800)
#define SkUTF16_IsLowSurrogate(c) (((c) & 0xFC00) == 0xDC00)
int SkUTF16_CountUnichars(const uint16_t utf16[]);
int SkUTF16_CountUnichars(const uint16_t utf16[], int numberOf16BitValues);
// returns the current unichar and then moves past it (*p++)
SkUnichar SkUTF16_NextUnichar(const uint16_t**);
// this guy backs up to the previus unichar value, and returns it (*--p)
SkUnichar SkUTF16_PrevUnichar(const uint16_t**);
size_t SkUTF16_FromUnichar(SkUnichar uni, uint16_t utf16[] = NULL);
size_t SkUTF16_ToUTF8(const uint16_t utf16[], int numberOf16BitValues,
char utf8[] = NULL);
inline bool SkUnichar_IsVariationSelector(SkUnichar uni) {
/* The 'true' ranges are:
* 0x180B <= uni <= 0x180D
* 0xFE00 <= uni <= 0xFE0F
* 0xE0100 <= uni <= 0xE01EF
*/
if (uni < 0x180B || uni > 0xE01EF) {
return false;
}
if ((uni > 0x180D && uni < 0xFE00) || (uni > 0xFE0F && uni < 0xE0100)) {
return false;
}
return true;
}
///////////////////////////////////////////////////////////////////////////////
class SkAutoTrace {
public:
/** NOTE: label contents are not copied, just the ptr is
retained, so DON'T DELETE IT.
*/
SkAutoTrace(const char label[]) : fLabel(label) {
SkDebugf("--- trace: %s Enter\n", fLabel);
}
~SkAutoTrace() {
SkDebugf("--- trace: %s Leave\n", fLabel);
}
private:
const char* fLabel;
};
#define SkAutoTrace(...) SK_REQUIRE_LOCAL_VAR(SkAutoTrace)
#endif