[libpng16] Added ARMv8 support (James Yu <james.yu at linaro.org>). Added file

arm/filter_neon_intrinsics.c; enable with configuration flag
PNG_ARM_NEON_INTRINSICS.

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.6.7beta03 - October 13, 2013
+Libpng 1.6.7beta03 - October 14, 2013
 
 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.
@@ -72,7 +72,10 @@ Version 1.6.7beta02 [October 12, 2013]
   Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
     removing the 1.14 'compile' script but never checking for it.
 
-Version 1.6.7beta03 [October 13, 2013]
+Version 1.6.7beta03 [October 14, 2013]
+  Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
+    arm/filter_neon_intrinsics.c; enable with configuration flag
+    PNG_ARM_NEON_INTRINSICS.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -4686,7 +4686,10 @@ Version 1.6.7beta02 [October 12, 2013]
   Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
     removing the 1.14 'compile' script but never checking for it.
 
-Version 1.6.7beta03 [October 13, 2013]
+Version 1.6.7beta03 [October 14, 2013]
+  Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
+    arm/filter_neon_intrinsics.c; enable with configuration flag
+    PNG_ARM_NEON_INTRINSICS.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

Makefile.am

@@ -81,9 +81,13 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c\
 	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa
 
 if PNG_ARM_NEON
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
+if PNG_ARM_NEON_INTRINSICS
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/filter_neon_intrinsics.c
+else
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
 	arm/filter_neon.S
 endif
+endif
 
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
 

arm/filter_neon_intrinsics.c

@@ -0,0 +1,310 @@
+
+/* filter_neon.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2013 Glenn Randers-Pehrson
+ * Written by James Yu <james.yu@linaro.org>. Oct.2013.
+ * Based on filter_neon.S, written by Mans Rullgard, 2011.
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include <arm_neon.h>
+#include "pngpriv.h"
+
+void
+png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint8x16_t qrp, qpp;
+
+   for (; rp != rp_stop; rp += 16, pp += 16)
+   {
+      qrp = vld1q_u8(rp);
+      qpp = vld1q_u8(pp);
+      qrp = vaddq_u8(qrp, qpp);
+      vst1q_u8(rp, qrp);
+   }
+}
+
+void inline
+png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   PNG_UNUSED(prev_row)
+
+   uint8x8_t vtmp1, vtmp2;
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   uint8x16_t vtmp = vld1q_u8(rp);
+   uint8x8x2_t vrp = *((uint8x8x2_t *)(&vtmp));
+
+   for (; rp != rp_stop;)
+   {
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vadd_u8(vdest.val[0], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vdest.val[2] = vadd_u8(vdest.val[1], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrp = *((uint8x8x2_t *)(&vtmp));
+
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[0])), 0);
+      rp += 3;
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[1])), 0);
+      rp += 3;
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[2])), 0);
+      rp += 3;
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[3])), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   PNG_UNUSED(prev_row)
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp != rp_stop; rp += 16)
+   {
+      uint32x2x4_t vtmp = vld4_u32((uint32_t *)rp);
+      uint8x8x4_t vrp = *((uint8x8x4_t *)(&vtmp));
+
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]);
+      vst4_lane_u32((uint32_t *)rp, *((uint32x2x4_t *)(&vdest)), 0);
+   }
+}
+
+void
+png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t vrp, vpp;
+   uint8x8_t vtmp1, vtmp2, vtmp3;
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrp = *((uint8x8x2_t *)(&vtmp));
+
+   for (; rp != rp_stop; pp += 12)
+   {
+      vtmp = vld1q_u8(pp);
+      vpp = *((uint8x8x2_t *)(&vtmp));
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrp = *((uint8x8x2_t *)(&vtmp));
+
+      vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp3);
+
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[0])), 0);
+      rp += 3;
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[1])), 0);
+      rp += 3;
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[2])), 0);
+      rp += 3;
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[3])), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint32x2x4_t vtmp;
+   uint8x8x4_t vrp, vpp;
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp != rp_stop; rp += 16, pp += 16)
+   {
+      vtmp = vld4_u32((uint32_t *)rp);
+      vrp = *((uint8x8x4_t *)(&vtmp));
+      vtmp = vld4_u32((uint32_t *)pp);
+      vpp = *((uint8x8x4_t *)(&vtmp));
+
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vst4_lane_u32((uint32_t *)rp, *((uint32x2x4_t *)(&vdest)), 0);
+   }
+}
+
+uint8x8_t
+paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c)
+{
+   uint8x8_t d, e;
+   uint16x8_t p1, pa, pb, pc;
+
+   p1 = vaddl_u8(a, b); /* a + b */
+   pc = vaddl_u8(c, c); /* c * 2 */
+   pa = vabdl_u8(b, c); /* pa */
+   pb = vabdl_u8(a, c); /* pb */
+   pc = vabdq_u16(p1, pc); /* pc */
+
+   p1 = vcleq_u16(pa, pb); /* pa <= pb */
+   pa = vcleq_u16(pa, pc); /* pa <= pc */
+   pb = vcleq_u16(pb, pc); /* pb <= pc */
+
+   p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */
+
+   d = vmovn_u16(pb);
+   e = vmovn_u16(p1);
+
+   d = vbsl_u8(d, b, c);
+   e = vbsl_u8(e, a, d);
+
+   return e;
+}
+
+void
+png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t vrp, vpp;
+   uint8x8_t vtmp1, vtmp2, vtmp3;
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrp = *((uint8x8x2_t *)(&vtmp));
+
+   for (; rp != rp_stop; pp += 12)
+   {
+      vtmp = vld1q_u8(pp);
+      vpp = *((uint8x8x2_t *)(&vtmp));
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrp = *((uint8x8x2_t *)(&vtmp));
+
+      vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vlast = vtmp2;
+
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[0])), 0);
+      rp += 3;
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[1])), 0);
+      rp += 3;
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[2])), 0);
+      rp += 3;
+      vst1_lane_u32((uint32_t *)rp, *((uint32x2_t *)(&vdest.val[3])), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint32x2x4_t vtmp;
+   uint8x8x4_t vrp, vpp;
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp != rp_stop; rp += 16, pp += 16)
+   {
+      vtmp = vld4_u32((uint32_t *)rp);
+      vrp = *((uint8x8x4_t *)(&vtmp));
+      vtmp = vld4_u32((uint32_t *)pp);
+      vpp = *((uint8x8x4_t *)(&vtmp));
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vlast = vpp.val[3];
+
+      vst4_lane_u32((uint32_t *)rp, *((uint32x2x4_t *)(&vdest)), 0);
+   }
+}
+

configure.ac

@@ -251,15 +251,23 @@ AC_ARG_ENABLE([arm-neon],
       check)
          AC_DEFINE([PNG_ARM_NEON_CHECK_SUPPORTED], [],
                    [Check for ARM Neon support at run-time]);;
+      check-intrinsics)
+         AC_DEFINE([PNG_ARM_NEON_CHECK_SUPPORTED], [],
+                   [Check for ARM Neon support at run-time]);;
+         ;;
       api)
          AC_DEFINE([PNG_ARM_NEON_API_SUPPORTED], [],
                    [Turn on ARM Neon optimizations at run-time]);;
+      api-intrinsics)
+         ;;
       yes|on)
          AC_DEFINE([PNG_ARM_NEON_OPT], [2],
                    [Enable ARM Neon optimizations])
          AC_MSG_WARN([--enable-arm-neon: please specify 'check' or 'api', if]
             [you want the optimizations unconditionally pass -mfpu=neon]
             [to the compiler.]);;
+      yes-intrinsics|on-intrinsics)
+         ;;
       *)
          AC_MSG_ERROR([--enable-arm-neon=${enable_arm_neon}: invalid value])
    esac])
@@ -275,6 +283,12 @@ AM_CONDITIONAL([PNG_ARM_NEON],
       *)    test "$enable_arm_neon" != '';;
     esac])
 
+AM_CONDITIONAL([PNG_ARM_NEON_INTRINSICS],
+   [test "$enable_arm_neon" = 'yes-intrinsics' 
+      -o "$enable_arm_neon" = 'on-intrinsics'
+      -o "$enable_arm_neon" = 'check-intrinsics'
+      -o "$enable_arm_neon" = 'api-intrinsics'])
+
 AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])
 
 # Config files, substituting as above