X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;ds=sidebyside;f=src%2Flzx_decompress.c;h=ba923fdd3aeb7e51b0238104f494ed07d7c1e64a;hb=b143910f8f18f0725adaf4af7e0bbe7ac5ab5382;hp=cce98e32a96904f850f5da6d3e10c2f11b9f39b5;hpb=4ee103c6e2a2988e1fb358bfa2dc38dcb621505a;p=wimlib

diff --git a/src/lzx_decompress.c b/src/lzx_decompress.c
index cce98e32..ba923fdd 100644
--- a/src/lzx_decompress.c
+++ b/src/lzx_decompress.c
@@ -18,7 +18,7 @@
  * details.
  *
  * You should have received a copy of the GNU Lesser General Public License
- * along with this file; if not, see http://www.gnu.org/licenses/.
+ * along with this file; if not, see https://www.gnu.org/licenses/.
  */
 
 /*
@@ -115,10 +115,10 @@ struct lzx_decompressor {
 	 * bits of aligned offset blocks */
 	u8 extra_offset_bits_minus_aligned[LZX_MAX_OFFSET_SLOTS];
 
-} _aligned_attribute(DECODE_TABLE_ALIGNMENT);
+} __attribute__((aligned(DECODE_TABLE_ALIGNMENT)));
 
 /* Read a Huffman-encoded symbol using the precode. */
-static inline unsigned
+static forceinline unsigned
 read_presym(const struct lzx_decompressor *d, struct input_bitstream *is)
 {
 	return read_huffsym(is, d->precode_decode_table,
@@ -126,7 +126,7 @@ read_presym(const struct lzx_decompressor *d, struct input_bitstream *is)
 }
 
 /* Read a Huffman-encoded symbol using the main code. */
-static inline unsigned
+static forceinline unsigned
 read_mainsym(const struct lzx_decompressor *d, struct input_bitstream *is)
 {
 	return read_huffsym(is, d->maincode_decode_table,
@@ -134,7 +134,7 @@ read_mainsym(const struct lzx_decompressor *d, struct input_bitstream *is)
 }
 
 /* Read a Huffman-encoded symbol using the length code. */
-static inline unsigned
+static forceinline unsigned
 read_lensym(const struct lzx_decompressor *d, struct input_bitstream *is)
 {
 	return read_huffsym(is, d->lencode_decode_table,
@@ -142,7 +142,7 @@ read_lensym(const struct lzx_decompressor *d, struct input_bitstream *is)
 }
 
 /* Read a Huffman-encoded symbol using the aligned offset code. */
-static inline unsigned
+static forceinline unsigned
 read_alignedsym(const struct lzx_decompressor *d, struct input_bitstream *is)
 {
 	return read_huffsym(is, d->alignedcode_decode_table,
@@ -332,10 +332,19 @@ lzx_read_block_header(struct lzx_decompressor *d, struct input_bitstream *is,
 
 /* Decompress a block of LZX-compressed data. */
 static int
-lzx_decompress_block(struct lzx_decompressor *d, struct input_bitstream *is,
+lzx_decompress_block(struct lzx_decompressor *d, struct input_bitstream *_is,
 		     int block_type, u32 block_size,
 		     u8 * const out_begin, u8 *out_next, u32 recent_offsets[])
 {
+	/*
+	 * Redeclare the input bitstream on the stack.  This shouldn't be
+	 * needed, but it can improve the main loop's performance significantly
+	 * with both gcc and clang, apparently because the compiler otherwise
+	 * gets confused and doesn't properly allocate registers for
+	 * 'is->bitbuf' et al. and/or thinks 'is->next' may point into 'is'.
+	 */
+	struct input_bitstream is_onstack = *_is;
+	struct input_bitstream *is = &is_onstack;
 	u8 * const block_end = out_next + block_size;
 	unsigned min_aligned_offset_slot;
 
@@ -435,6 +444,7 @@ lzx_decompress_block(struct lzx_decompressor *d, struct input_bitstream *is,
 		out_next += length;
 	} while (out_next != block_end);
 
+	*_is = is_onstack;
 	return 0;
 }