From 47779d46c81495705c542a5284d5a183f1cc1ae7 Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Thu, 3 Jul 2014 11:21:24 -0700
Subject: [PATCH] endian_inl.h: add BSwap32

Change-Id: I96e3ae49659307024415d64587e6312888a0070f
---
 src/dsp/lossless.c         | 18 ++++--------------
 src/utils/bit_reader_inl.h | 21 +--------------------
 src/utils/endian_inl.h     | 23 +++++++++++++++++++++++
 3 files changed, 28 insertions(+), 34 deletions(-)

diff --git a/src/dsp/lossless.c b/src/dsp/lossless.c
index f7101ce6..d0d605d8 100644
--- a/src/dsp/lossless.c
+++ b/src/dsp/lossless.c
@@ -17,8 +17,9 @@
 
 #include <math.h>
 #include <stdlib.h>
-#include "./lossless.h"
 #include "../dec/vp8li.h"
+#include "../utils/endian_inl.h"
+#include "./lossless.h"
 #include "./yuv.h"
 
 #define MAX_DIFF_COST (1e30f)
@@ -1357,22 +1358,11 @@ static void CopyOrSwap(const uint32_t* src, int num_pixels, uint8_t* dst,
   if (is_big_endian() == swap_on_big_endian) {
     const uint32_t* const src_end = src + num_pixels;
     while (src < src_end) {
-      uint32_t argb = *src++;
+      const uint32_t argb = *src++;
 
 #if !defined(__BIG_ENDIAN__)
 #if !defined(WEBP_REFERENCE_IMPLEMENTATION)
-#if defined(__i386__) || defined(__x86_64__)
-      __asm__ volatile("bswap %0" : "=r"(argb) : "0"(argb));
-      *(uint32_t*)dst = argb;
-#elif defined(_MSC_VER)
-      argb = _byteswap_ulong(argb);
-      *(uint32_t*)dst = argb;
-#else
-      dst[0] = (argb >> 24) & 0xff;
-      dst[1] = (argb >> 16) & 0xff;
-      dst[2] = (argb >>  8) & 0xff;
-      dst[3] = (argb >>  0) & 0xff;
-#endif
+      *(uint32_t*)dst = BSwap32(argb);
 #else  // WEBP_REFERENCE_IMPLEMENTATION
       dst[0] = (argb >> 24) & 0xff;
       dst[1] = (argb >> 16) & 0xff;
diff --git a/src/utils/bit_reader_inl.h b/src/utils/bit_reader_inl.h
index 56d33d80..92cc94cd 100644
--- a/src/utils/bit_reader_inl.h
+++ b/src/utils/bit_reader_inl.h
@@ -36,12 +36,6 @@ typedef uint16_t lbit_t;
 typedef uint8_t lbit_t;
 #endif
 
-// gcc 4.3 has builtin functions for swap32/swap64
-#if defined(__GNUC__) && \
-           (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
-#define HAVE_BUILTIN_BSWAP
-#endif
-
 extern const uint8_t kVP8Log2Range[128];
 extern const range_t kVP8NewRange[128];
 
@@ -95,20 +89,7 @@ static WEBP_INLINE void VP8LoadNewBytes(VP8BitReader* const br) {
 #endif
     bits >>= 64 - BITS;
 #elif (BITS >= 24)
-#if defined(HAVE_BUILTIN_BSWAP)
-    bits = (bit_t)__builtin_bswap32(in_bits);
-#elif defined(__i386__) || defined(__x86_64__)
-    {
-      lbit_t swapped_in_bits;
-      __asm__ volatile("bswap %k0" : "=r"(swapped_in_bits) : "0"(in_bits));
-      bits = (bit_t)swapped_in_bits;   // 24b/32b -> 32b/64b zero-extension
-    }
-#elif defined(_MSC_VER)
-    bits = (bit_t)_byteswap_ulong(in_bits);
-#else
-    bits = (bit_t)(in_bits >> 24) | ((in_bits >> 8) & 0xff00)
-         | ((in_bits << 8) & 0xff0000)  | (in_bits << 24);
-#endif  // x86
+    bits = BSwap32(in_bits);
     bits >>= (32 - BITS);
 #elif (BITS == 16)
     // gcc will recognize a 'rorw $8, ...' here:
diff --git a/src/utils/endian_inl.h b/src/utils/endian_inl.h
index ef68fb1d..a9e2aff9 100644
--- a/src/utils/endian_inl.h
+++ b/src/utils/endian_inl.h
@@ -12,6 +12,8 @@
 #ifndef WEBP_UTILS_ENDIAN_INL_H_
 #define WEBP_UTILS_ENDIAN_INL_H_
 
+#include "../webp/types.h"
+
 // some endian fix (e.g.: mips-gcc doesn't define __BIG_ENDIAN__)
 #if !defined(__BIG_ENDIAN__) && defined(__BYTE_ORDER__) && \
     (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
@@ -47,4 +49,25 @@
 #include <endian.h>
 #endif
 
+// gcc 4.3 has builtin functions for swap32/swap64
+// TODO(jzern): this should have a corresponding autoconf check.
+#if defined(__GNUC__) && \
+           (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
+#define HAVE_BUILTIN_BSWAP
+#endif
+
+static WEBP_INLINE uint32_t BSwap32(uint32_t x) {
+#if defined(HAVE_BUILTIN_BSWAP)
+  return __builtin_bswap32(x);
+#elif defined(__i386__) || defined(__x86_64__)
+  uint32_t swapped_bytes;
+  __asm__ volatile("bswap %0" : "=r"(swapped_bytes) : "0"(x));
+  return swapped_bytes;
+#elif defined(_MSC_VER)
+  return (uint32_t)_byteswap_ulong(x);
+#else
+  return (x >> 24) | ((x >> 8) & 0xff00) | ((x << 8) & 0xff0000) | (x << 24);
+#endif  // HAVE_BUILTIN_BSWAP
+}
+
 #endif  // WEBP_UTILS_ENDIAN_INL_H_