tenfourfox/dom/base/nsTextFragmentVMX.cpp

94 lines
2.8 KiB
C++

// For TenFourFox AltiVec by Cameron Kaiser and Tobias Netzel
// Modified for M682592 (issue 75, issue 109)
// Remember, PPC is normally big endian! Endian Little Hate We! -- Connectix
#include "nscore.h"
#include "nsAlgorithm.h"
#include <algorithm>
#include "nsTextFragmentImpl.h"
#include <altivec.h>
#warning compiled VMX version
namespace mozilla {
namespace VMX {
int32_t
FirstNon8Bit(const char16_t *str, const char16_t *end)
{
const uint32_t numUnicharsPerVector = 8;
const uint32_t numCharsPerVector = 16;
// Paranoia. If this assertion is wrong, change the vector loop below.
MOZ_ASSERT((numCharsPerVector / numUnicharsPerVector) == sizeof(char16_t));
register vector unsigned short vect;
typedef Non8BitParameters<sizeof(size_t)> p;
const uint32_t alignMask = p::alignMask();
const size_t mask = p::mask();
const uint32_t numUnicharsPerWord = p::numUnicharsPerWord();
const int32_t len = end - str;
int32_t i = 0;
int32_t i2 = 0;
// Align ourselves to a 16-byte boundary, as required by AltiVec loads.
int32_t alignLen =
std::min(len, int32_t(((-NS_PTR_TO_UINT32(str)) & 0xf) / sizeof(char16_t)));
if ((len - alignLen) > (numUnicharsPerVector - 1)) {
for (; i < alignLen; i++) {
if (str[i] > 255)
return i;
}
register const vector unsigned short gtcompare =
vec_mergel( vec_splat_s8( 0 ), vec_splat_s8( -1 ) );
const int32_t vectWalkEnd = ((len - i) / numUnicharsPerVector) * numUnicharsPerVector;
i2 = i * sizeof(char16_t);
while (1) {
// Check one VMX register (8 unichars) at a time. The vec_any_gt
// intrinsic does exactly what we want. This loop is manually unrolled;
// it yields notable performance improvements this way.
#define CheckForASCII \
vect = vec_ld(i2, reinterpret_cast<const unsigned short*>(str)); \
if (vec_any_gt(vect, gtcompare)) return i; \
i += numUnicharsPerVector; \
if (!(i < vectWalkEnd)) break; \
i2 += numCharsPerVector;
CheckForASCII CheckForASCII
#undef CheckForASCII
}
} else {
// Align ourselves to a word boundary.
alignLen =
std::min(len, int32_t(((-NS_PTR_TO_UINT32(str)) & alignMask) / sizeof(char16_t)));
for (; i < alignLen; i++) {
if (str[i] > 255)
return i;
}
}
// Check one word at a time.
const int32_t wordWalkEnd = ((len - i) / numUnicharsPerWord) * numUnicharsPerWord;
for(; i < wordWalkEnd; i += numUnicharsPerWord) {
const size_t word = *reinterpret_cast<const size_t*>(str + i);
if (word & mask)
return i;
}
// Take care of the remainder one character at a time.
for (; i < len; i++) {
if (str[i] > 255) {
return i;
}
}
return -1;
}
} // namespace VMX
} // namespace mozilla