From 3884972e3f9ae887e0c16ca342851eff3ae67485 Mon Sep 17 00:00:00 2001
From: Pascal Massimino <pascal.massimino@gmail.com>
Date: Wed, 17 Aug 2016 12:09:53 -0700
Subject: [PATCH] remove WEBP_FORCE_ALIGNED and use memcpy() instead.

BUG=webp:297

Change-Id: I89a08debec7bb1b3f411c897260ab1bb63f77df2
---
 CMakeLists.txt             |  1 -
 cmake/config.h.in          |  3 ---
 configure.ac               | 13 -------------
 src/dsp/dsp.h              |  3 +--
 src/utils/bit_reader_inl.h | 12 ++++--------
 src/utils/utils.h          | 11 -----------
 6 files changed, 5 insertions(+), 38 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ab7e1685..25b085eb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,7 +6,6 @@ project(libwebp C)
 option(WEBP_BUILD_CWEBP "Build the cwebp command line tool." OFF)
 option(WEBP_BUILD_DWEBP "Build the dwebp command line tool." OFF)
 option(WEBP_EXPERIMENTAL_FEATURES "Build with experimental features." OFF)
-option(WEBP_FORCE_ALIGNED "Force aligned memory operations." OFF)
 option(WEBP_ENABLE_SWAP_16BIT_CSP "Enable byte swap for 16 bit colorspaces." OFF)
 
 set(WEBP_DEP_LIBRARIES)
diff --git a/cmake/config.h.in b/cmake/config.h.in
index cb3948ea..52ff857c 100644
--- a/cmake/config.h.in
+++ b/cmake/config.h.in
@@ -103,9 +103,6 @@
 /* Enable experimental code */
 #cmakedefine WEBP_EXPERIMENTAL_FEATURES 1
 
-/* Define to 1 to force aligned memory operations */
-#cmakedefine WEBP_FORCE_ALIGNED 1
-
 /* Set to 1 if AVX2 is supported */
 #cmakedefine WEBP_HAVE_AVX2 1
 
diff --git a/configure.ac b/configure.ac
index df31acc1..4c2f929c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -596,19 +596,6 @@ if test "$enable_wic" = "yes"; then
 fi
 esac
 
-dnl === If --enable-aligned is defined, define WEBP_FORCE_ALIGNED
-
-AC_MSG_CHECKING(if --enable-aligned option is specified)
-AC_ARG_ENABLE([aligned],
-              AS_HELP_STRING([--enable-aligned],
-                             [Force aligned memory operations in non-dsp code
-                              (may be slower)]))
-if test "$enable_aligned" = "yes"; then
-  AC_DEFINE(WEBP_FORCE_ALIGNED, [1],
-            [Define to 1 to force aligned memory operations])
-fi
-AC_MSG_RESULT(${enable_aligned-no})
-
 dnl === If --enable-swap-16bit-csp is defined, add -DWEBP_SWAP_16BIT_CSP
 
 USE_SWAP_16BIT_CSP=""
diff --git a/src/dsp/dsp.h b/src/dsp/dsp.h
index d2e59ed5..ac0ccd78 100644
--- a/src/dsp/dsp.h
+++ b/src/dsp/dsp.h
@@ -111,8 +111,7 @@ extern "C" {
 
 #define WEBP_UBSAN_IGNORE_UNDEF
 #define WEBP_UBSAN_IGNORE_UNSIGNED_OVERFLOW
-#if !defined(WEBP_FORCE_ALIGNED) && defined(__clang__) && \
-    defined(__has_attribute)
+#if defined(__clang__) && defined(__has_attribute)
 #if __has_attribute(no_sanitize)
 // This macro prevents the undefined behavior sanitizer from reporting
 // failures. This is only meant to silence unaligned loads on platforms that
diff --git a/src/utils/bit_reader_inl.h b/src/utils/bit_reader_inl.h
index 36570566..003f6a88 100644
--- a/src/utils/bit_reader_inl.h
+++ b/src/utils/bit_reader_inl.h
@@ -20,9 +20,7 @@
 #include "../webp/config.h"
 #endif
 
-#ifdef WEBP_FORCE_ALIGNED
-#include <string.h>  // memcpy
-#endif
+#include <string.h>  // for memcpy
 
 #include "../dsp/dsp.h"
 #include "./bit_reader.h"
@@ -62,10 +60,7 @@ void VP8LoadNewBytes(VP8BitReader* const br) {
   if (br->buf_ < br->buf_max_) {
     // convert memory type to register type (with some zero'ing!)
     bit_t bits;
-#if defined(WEBP_FORCE_ALIGNED)
-    lbit_t in_bits;
-    memcpy(&in_bits, br->buf_, sizeof(in_bits));
-#elif defined(WEBP_USE_MIPS32)
+#if defined(WEBP_USE_MIPS32)
     // This is needed because of un-aligned read.
     lbit_t in_bits;
     lbit_t* p_buf_ = (lbit_t*)br->buf_;
@@ -80,7 +75,8 @@ void VP8LoadNewBytes(VP8BitReader* const br) {
       : "memory", "at"
     );
 #else
-    const lbit_t in_bits = *(const lbit_t*)br->buf_;
+    lbit_t in_bits;
+    memcpy(&in_bits, br->buf_, sizeof(in_bits));
 #endif
     br->buf_ += BITS >> 3;
 #if !defined(WORDS_BIGENDIAN)
diff --git a/src/utils/utils.h b/src/utils/utils.h
index f2066841..6345424c 100644
--- a/src/utils/utils.h
+++ b/src/utils/utils.h
@@ -54,7 +54,6 @@ WEBP_EXTERN(void) WebPSafeFree(void* const ptr);
 #define WEBP_ALIGN_CST 31
 #define WEBP_ALIGN(PTR) (((uintptr_t)(PTR) + WEBP_ALIGN_CST) & ~WEBP_ALIGN_CST)
 
-#if defined(WEBP_FORCE_ALIGNED)
 #include <string.h>
 // memcpy() is the safe way of moving potentially unaligned 32b memory.
 static WEBP_INLINE uint32_t WebPMemToUint32(const uint8_t* const ptr) {
@@ -65,16 +64,6 @@ static WEBP_INLINE uint32_t WebPMemToUint32(const uint8_t* const ptr) {
 static WEBP_INLINE void WebPUint32ToMem(uint8_t* const ptr, uint32_t val) {
   memcpy(ptr, &val, sizeof(val));
 }
-#else
-static WEBP_UBSAN_IGNORE_UNDEF WEBP_INLINE
-uint32_t WebPMemToUint32(const uint8_t* const ptr) {
-  return *(const uint32_t*)ptr;
-}
-static WEBP_UBSAN_IGNORE_UNDEF WEBP_INLINE
-void WebPUint32ToMem(uint8_t* const ptr, uint32_t val) {
-  *(uint32_t*)ptr = val;
-}
-#endif
 
 //------------------------------------------------------------------------------
 // Reading/writing data.