RPCS3/archived-pugixml
1
0
Fork 0
mirror of https://github.com/RPCS3/pugixml.git synced 2026-01-31 01:25:21 +01:00
Code Issues Packages Projects Releases Wiki Activity

Reorder conditions in compact_string implementation

Browse Source 
Now compact_string matches compact_pointer_parent.

Turns out PUGI__UNLIKELY is good at reordering conditions but usually does not
really affect performance. Since MSVC should treat "if" branches as taken and
does not support branch probabilities, don't use them if we don't need to.
This commit is contained in:
Arseny Kapoulkine
2015-05-02 15:57:46 -07:00
parent f8915c8eab
commit 20e2041f14
1 changed files with 28 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

58
src/pugixml.cpp
View File

@@ -849,7 +849,7 @@ PUGI__NS_BEGIN
{
xml_memory_page* page = compact_get_page(this, header_offset);
if (page->compact_shared_parent == 0)
if (PUGI__UNLIKELY(page->compact_shared_parent == 0))
page->compact_shared_parent = value;
if (page->compact_shared_parent == value)
@@ -872,17 +872,15 @@ PUGI__NS_BEGIN
operator T*() const
{
int data = _data;
if (data)
if (_data)
{
if (data < 65534)
if (_data < 65534)
{
uintptr_t base = reinterpret_cast<uintptr_t>(this) & ~(compact_alignment - 1);
return reinterpret_cast<T*>(base + ((data - 1 - 65533) << compact_alignment_log2));
return reinterpret_cast<T*>(base + ((_data - 1 - 65533) << compact_alignment_log2));
}
else if (data == 65534)
else if (_data == 65534)
return static_cast<T*>(compact_get_page(this, header_offset)->compact_shared_parent);
else
return compact_get_value<header_offset, T>(this);
@@ -923,37 +921,37 @@ PUGI__NS_BEGIN
ptrdiff_t offset = value - page->compact_string_base;
if (PUGI__UNLIKELY(static_cast<uintptr_t>(offset) >= (65535 << 7)))
{
compact_set_value<header_offset>(this, value);
_data = 255;
}
else
if (static_cast<uintptr_t>(offset) < (65535 << 7))
{
uint16_t* base = reinterpret_cast<uint16_t*>(reinterpret_cast<char*>(this) - base_offset);
if (PUGI__UNLIKELY(*base))
if (*base == 0)
{
*base = static_cast<uint16_t>((offset >> 7) + 1);
_data = static_cast<unsigned char>((offset & 127) + 1);
}
else
{
ptrdiff_t remainder = offset - ((*base - 1) << 7);
if (PUGI__UNLIKELY(static_cast<uintptr_t>(remainder) >= 254))
if (static_cast<uintptr_t>(remainder) < 254)
{
_data = static_cast<unsigned char>(remainder + 1);
}
else
{
compact_set_value<header_offset>(this, value);
_data = 255;
}
else
{
_data = static_cast<unsigned char>(remainder + 1);
}
}
else
{
*base = static_cast<uint16_t>((offset >> 7) + 1);
_data = static_cast<unsigned char>((offset & 127) + 1);
}
}
else
{
compact_set_value<header_offset>(this, value);
_data = 255;
}
}
else
{
@@ -965,11 +963,7 @@ PUGI__NS_BEGIN
{
if (_data)
{
if (PUGI__UNLIKELY(_data == 255))
{
return compact_get_value<header_offset, char_t>(this);
}
else
if (_data < 255)
{
xml_memory_page* page = compact_get_page(this, header_offset);
@@ -980,6 +974,10 @@ PUGI__NS_BEGIN
return page->compact_string_base + offset;
}
else
{
return compact_get_value<header_offset, char_t>(this);
}
}
else
return 0;