Commit 47e61d02e6efb00d9e3c2b38d7fc3211a7514c7f
2022-11-14T22:53:14
* src/pcf/pcfutil.c ({Two,Four}ByteSwap): Use builtins or shifts. We trust glibc which uses shifts or builtins to swap bytes. This must be more efficient.
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diff --git a/src/pcf/pcfutil.c b/src/pcf/pcfutil.c
index 5d3c007..d634a5a 100644
--- a/src/pcf/pcfutil.c
+++ b/src/pcf/pcfutil.c
@@ -57,6 +57,33 @@ in this Software without prior written authorization from The Open Group.
}
+#if defined( __clang__ ) || ( defined( __GNUC__ ) && \
+ ( __GNUC__ > 4 || ( __GNUC__ == 4 && __GNUC_MINOR__ >= 8 ) ) )
+
+#define BSWAP16( x ) __builtin_bswap16( x )
+#define BSWAP32( x ) __builtin_bswap32( x )
+
+#elif defined( _MSC_VER ) && _MSC_VER >= 1300
+
+#pragma intrinsic( _byteswap_ushort )
+#pragma intrinsic( _byteswap_ulong )
+
+#define BSWAP16( x ) _byteswap_ushort( x )
+#define BSWAP32( x ) _byteswap_ulong( x )
+
+#else
+
+#define BSWAP16( x ) \
+ (FT_UInt16)( ( ( ( x ) >> 8 ) & 0xff ) | \
+ ( ( ( x ) & 0xff ) << 8 ) )
+#define BSWAP32( x ) \
+ (FT_UInt32)( ( ( ( x ) & 0xff000000u ) >> 24 ) | \
+ ( ( ( x ) & 0x00ff0000u ) >> 8 ) | \
+ ( ( ( x ) & 0x0000ff00u ) << 8 ) | \
+ ( ( ( x ) & 0x000000ffu ) << 24 ) )
+
+#endif
+
/*
* Invert byte order within each 16-bits of an array.
*/
@@ -65,15 +92,11 @@ in this Software without prior written authorization from The Open Group.
TwoByteSwap( unsigned char* buf,
size_t nbytes )
{
- for ( ; nbytes >= 2; nbytes -= 2, buf += 2 )
- {
- unsigned char c;
+ FT_UInt16* b = (FT_UInt16*)buf;
- c = buf[0];
- buf[0] = buf[1];
- buf[1] = c;
- }
+ for ( ; nbytes >= 2; nbytes -= 2, b++ )
+ *b = BSWAP16( *b );
}
/*
@@ -84,19 +107,11 @@ in this Software without prior written authorization from The Open Group.
FourByteSwap( unsigned char* buf,
size_t nbytes )
{
- for ( ; nbytes >= 4; nbytes -= 4, buf += 4 )
- {
- unsigned char c;
-
+ FT_UInt32* b = (FT_UInt32*)buf;
- c = buf[0];
- buf[0] = buf[3];
- buf[3] = c;
- c = buf[1];
- buf[1] = buf[2];
- buf[2] = c;
- }
+ for ( ; nbytes >= 4; nbytes -= 4, b++ )
+ *b = BSWAP32( *b );
}