From ee16fc4a6f573a5339ddd7474da5aedb4f7c2d87 Mon Sep 17 00:00:00 2001
From: Glenn Randers-Pehrson <glennrp at users.sourceforge.net>
Date: Sat, 29 Nov 2014 16:27:27 -0600
Subject: [PATCH] [libpng16] Added ".align 2" to arm/filter_neon.S to support
 old GAS assemblers

that don't do alignment correctly.
---
 ANNOUNCE                     |  7 ++++---
 CHANGES                      |  5 +++--
 arm/arm_init.c               |  2 +-
 arm/filter_neon.S            | 21 ++++++++++++++-------
 arm/filter_neon_intrinsics.c |  2 +-
 5 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/ANNOUNCE b/ANNOUNCE
index ab3d44910..5396b1921 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,4 +1,4 @@
-Libpng 1.6.16beta01 - November 21, 2014
+Libpng 1.6.16beta01 - November 29, 2014
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -25,8 +25,9 @@ Other information:
 
 Changes since the last public release (1.6.15):
 
-Version 1.6.16beta01 [November 21, 2014]
-  No changes.
+Version 1.6.16beta01 [November 29, 2014]
+  Added ".align 2" to arm/filter_neon.S to support old GAS assemblers that
+    don't do alignment correctly.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index cf1856f31..7cea4fe61 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5099,8 +5099,9 @@ Version 1.6.15rc03 [November 16, 2014]
 Version 1.6.15 [November 20, 2014]
   No changes.
 
-Version 1.6.16beta01 [November 21, 2014]
-  No changes.
+Version 1.6.16beta01 [November 29, 2014]
+  Added ".align 2" to arm/filter_neon.S to support old GAS assemblers that
+    don't do alignment correctly.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/arm/arm_init.c b/arm/arm_init.c
index b0e929bc1..9a23e1040 100644
--- a/arm/arm_init.c
+++ b/arm/arm_init.c
@@ -130,4 +130,4 @@ png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
    }
 }
 #endif /* PNG_ARM_NEON_OPT > 0 */
-#endif /* PNG_READ_SUPPORTED */
+#endif /* READ */
diff --git a/arm/filter_neon.S b/arm/filter_neon.S
index 40d97775d..b7c0a90b4 100644
--- a/arm/filter_neon.S
+++ b/arm/filter_neon.S
@@ -1,18 +1,17 @@
 
 /* filter_neon.S - NEON optimised filter functions
  *
- * Copyright (c) 2013 Glenn Randers-Pehrson
+ * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.8 [December 19, 2013]
+ * Last changed in libpng 1.6.16 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  */
 
-/* This is required to get the symbol renames, which are #defines, and also
- * includes the definition (or not) of PNG_ARM_NEON_OPT and
- * PNG_ARM_NEON_IMPLEMENTATION.
+/* This is required to get the symbol renames, which are #defines, and the
+ * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION.
  */
 #define PNG_VERSION_INFO_ONLY
 #include "../pngpriv.h"
@@ -21,6 +20,8 @@
 .section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
 #endif
 
+#ifdef PNG_READ_SUPPORTED
+
 /* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for
  * ARM64).  The code in arm/filter_neon_intrinsics.c supports ARM64, however it
  * only works if -mfpu=neon is specified on the GCC command line.  See pngpriv.h
@@ -28,7 +29,6 @@
  */
 #if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */
 
-#ifdef PNG_READ_SUPPORTED
 #if PNG_ARM_NEON_OPT > 0
 
 #ifdef __ELF__
@@ -47,6 +47,13 @@ ELF     .size   \name, . - \name
         .purgem endfunc
     .endm
         .text
+
+        /* Explicitly specifying alignment here because some versions of
+         * GAS don't align code correctly.  This is harmless in correctly
+         * written versions of GAS.
+         */
+        .align 2
+
     .if \export
         .global \name
     .endif
@@ -242,5 +249,5 @@ func    png_read_filter_row_paeth3_neon, export=1
         pop             {r4,pc}
 endfunc
 #endif /* PNG_ARM_NEON_OPT > 0 */
-#endif /* PNG_READ_SUPPORTED */
 #endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */
+#endif /* READ */
diff --git a/arm/filter_neon_intrinsics.c b/arm/filter_neon_intrinsics.c
index e7a09f436..a88674755 100644
--- a/arm/filter_neon_intrinsics.c
+++ b/arm/filter_neon_intrinsics.c
@@ -368,5 +368,5 @@ png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
 }
 
 #endif /* PNG_ARM_NEON_OPT > 0 */
-#endif /* PNG_READ_SUPPORTED */
+#endif /* READ */
 #endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */