ref: e1d0249e5aeb76fb0bd5b1b6a6ac71599be871bf
parent: bd28952e23bcd268a623ea5202e1cde4a92defe4
author: Werner Lemberg <[email protected]>
date: Wed Aug 23 04:18:22 EDT 2017
[sfnt] Fix clang compilation (#51788). * src/sfnt/pngshim.c (premultiply_data): Use vectors instead of scalars. (vector_shuffle): New macro to take of a different built-in function name on clang.
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2017-08-23 Werner Lemberg <[email protected]>
+
+ [sfnt] Fix clang compilation (#51788).
+
+ * src/sfnt/pngshim.c (premultiply_data): Use vectors instead of
+ scalars.
+ (vector_shuffle): New macro to take of a different built-in function
+ name on clang.
+
2017-08-22 Werner Lemberg <[email protected]>
[base] Don't zero out allocated memory twice (#51816).
--- a/src/sfnt/pngshim.c
+++ b/src/sfnt/pngshim.c
@@ -69,6 +69,15 @@
defined( __OPTIMIZE__ ) && \
__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#ifdef __clang__
+ /* the clang documentation doesn't cover the two-argument case of */
+ /* `__builtin_shufflevector'; however, it is is implemented since */
+ /* version 2.8 */
+#define vector_shuffle __builtin_shufflevector
+#else
+#define vector_shuffle __builtin_shuffle
+#endif
+
typedef unsigned short v82 __attribute__(( vector_size( 16 ) ));
@@ -79,6 +88,13 @@
unsigned char* base = &data[i];
v82 s, s0, s1, a;
+
+ /* clang <= 3.9 can't apply scalar values to vectors */
+ /* (or rather, it needs a different syntax) */
+ v82 n0x80 = { 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80 };+ v82 n0xFF = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };+ v82 n8 = { 8, 8, 8, 8, 8, 8, 8, 8 };+
v82 ma = { 1, 1, 3, 3, 5, 5, 7, 7 }; v82 o1 = { 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF }; v82 m0 = { 1, 0, 3, 2, 5, 4, 7, 6 };@@ -85,21 +101,21 @@
memcpy( &s, base, 16 ); /* RGBA RGBA RGBA RGBA */
- s0 = s & 0xFF; /* R B R B R B R B */
- s1 = s >> 8; /* G A G A G A G A */
+ s0 = s & n0xFF; /* R B R B R B R B */
+ s1 = s >> n8; /* G A G A G A G A */
- a = __builtin_shuffle( s1, ma ); /* A A A A A A A A */
+ a = vector_shuffle( s1, ma ); /* A A A A A A A A */
s1 |= o1; /* G 1 G 1 G 1 G 1 */
- s0 = __builtin_shuffle( s0, m0 ); /* B R B R B R B R */
+ s0 = vector_shuffle( s0, m0 ); /* B R B R B R B R */
s0 *= a;
s1 *= a;
- s0 += 0x80;
- s1 += 0x80;
- s0 = ( s0 + ( s0 >> 8 ) ) >> 8;
- s1 = ( s1 + ( s1 >> 8 ) ) >> 8;
+ s0 += n0x80;
+ s1 += n0x80;
+ s0 = ( s0 + ( s0 >> n8 ) ) >> n8;
+ s1 = ( s1 + ( s1 >> n8 ) ) >> n8;
- s = s0 | ( s1 << 8 );
+ s = s0 | ( s1 << n8 );
memcpy( base, &s, 16 );
}
#endif /* use `vector_size' */