sanitizer: fix unaligned load/stores

When built with -fsanitizer=address,undefined a number of tests,
such as ByteAlignmentTest.SwitchByteAlignment or
ByteAlignmentTest.SwitchByteAlignment produce runtime errors about
unaligned 4-byte loads/stores. While normally not really a problem,
this does technically violate the language and it is eays to fix in
a standard conforming way using memcpy which does not produce
inferior code.

Signed-off-by: Matthias Räncker <theonetruecamper@gmx.de>
Change-Id: Ie1e97ab25fe874f864df48b473569f00563181ae

diff --git a/vpx_dsp/x86/loopfilter_sse2.c b/vpx_dsp/x86/loopfilter_sse2.c
index 28e6fd65f9279a08898162d35ad2c67647308c9b..1a76d670e6b06a90f3afcfc25c087df21dd70028 100644 (file)
--- a/vpx_dsp/x86/loopfilter_sse2.c
+++ b/vpx_dsp/x86/loopfilter_sse2.c
@@ -13,6 +13,7 @@
 #include "./vpx_dsp_rtcd.h"
 #include "vpx_ports/mem.h"
 #include "vpx_ports/emmintrin_compat.h"
+#include "vpx_dsp/x86/mem_sse2.h"
 
 static INLINE __m128i abs_diff(__m128i a, __m128i b) {
   return _mm_or_si128(_mm_subs_epu8(a, b), _mm_subs_epu8(b, a));
@@ -212,21 +213,21 @@ void vpx_lpf_vertical_4_sse2(uint8_t *s, int p /* pitch */,
   // 00 10 20 30 01 11 21 31  02 12 22 32 03 13 23 33
   ps1ps0 = _mm_unpacklo_epi8(ps1ps0, x0);
 
-  *(int *)(s + 0 * p - 2) = _mm_cvtsi128_si32(ps1ps0);
+  storeu_uint32(s + 0 * p - 2, _mm_cvtsi128_si32(ps1ps0));
   ps1ps0 = _mm_srli_si128(ps1ps0, 4);
-  *(int *)(s + 1 * p - 2) = _mm_cvtsi128_si32(ps1ps0);
+  storeu_uint32(s + 1 * p - 2, _mm_cvtsi128_si32(ps1ps0));
   ps1ps0 = _mm_srli_si128(ps1ps0, 4);
-  *(int *)(s + 2 * p - 2) = _mm_cvtsi128_si32(ps1ps0);
+  storeu_uint32(s + 2 * p - 2, _mm_cvtsi128_si32(ps1ps0));
   ps1ps0 = _mm_srli_si128(ps1ps0, 4);
-  *(int *)(s + 3 * p - 2) = _mm_cvtsi128_si32(ps1ps0);
+  storeu_uint32(s + 3 * p - 2, _mm_cvtsi128_si32(ps1ps0));
 
-  *(int *)(s + 4 * p - 2) = _mm_cvtsi128_si32(qs1qs0);
+  storeu_uint32(s + 4 * p - 2, _mm_cvtsi128_si32(qs1qs0));
   qs1qs0 = _mm_srli_si128(qs1qs0, 4);
-  *(int *)(s + 5 * p - 2) = _mm_cvtsi128_si32(qs1qs0);
+  storeu_uint32(s + 5 * p - 2, _mm_cvtsi128_si32(qs1qs0));
   qs1qs0 = _mm_srli_si128(qs1qs0, 4);
-  *(int *)(s + 6 * p - 2) = _mm_cvtsi128_si32(qs1qs0);
+  storeu_uint32(s + 6 * p - 2, _mm_cvtsi128_si32(qs1qs0));
   qs1qs0 = _mm_srli_si128(qs1qs0, 4);
-  *(int *)(s + 7 * p - 2) = _mm_cvtsi128_si32(qs1qs0);
+  storeu_uint32(s + 7 * p - 2, _mm_cvtsi128_si32(qs1qs0));
 }
 
 void vpx_lpf_horizontal_16_sse2(unsigned char *s, int p,

diff --git a/vpx_dsp/x86/mem_sse2.h b/vpx_dsp/x86/mem_sse2.h
index 943d7d7fe641fe5cfa9459fcf5a5223f749d32af..48dc97970a5997555c6234a53dff7df58988c922 100644 (file)
--- a/vpx_dsp/x86/mem_sse2.h
+++ b/vpx_dsp/x86/mem_sse2.h
@@ -12,9 +12,20 @@
 #define VPX_VPX_DSP_X86_MEM_SSE2_H_
 
 #include <emmintrin.h>  // SSE2
+#include <string.h>
 
 #include "./vpx_config.h"
 
+static INLINE void storeu_uint32(void *dst, uint32_t v) {
+  memcpy(dst, &v, sizeof(v));
+}
+
+static INLINE uint32_t loadu_uint32(const void *src) {
+  uint32_t v;
+  memcpy(&v, src, sizeof(v));
+  return v;
+}
+
 static INLINE __m128i loadh_epi64(const __m128i s, const void *const src) {
   return _mm_castps_si128(
       _mm_loadh_pi(_mm_castsi128_ps(s), (const __m64 *)src));

diff --git a/vpx_dsp/x86/variance_sse2.c b/vpx_dsp/x86/variance_sse2.c
index a2a13a68b670fe4c17382b0131874b615fd71498..0279052556369e3275d41860e3475a449a82167d 100644 (file)
--- a/vpx_dsp/x86/variance_sse2.c
+++ b/vpx_dsp/x86/variance_sse2.c
@@ -14,6 +14,7 @@
 #include "./vpx_config.h"
 #include "./vpx_dsp_rtcd.h"
 #include "vpx_ports/mem.h"
+#include "vpx_dsp/x86/mem_sse2.h"
 
 static INLINE unsigned int add32x4_sse2(__m128i val) {
   val = _mm_add_epi32(val, _mm_srli_si128(val, 8));
@@ -35,8 +36,8 @@ unsigned int vpx_get_mb_ss_sse2(const int16_t *src) {
 }
 
 static INLINE __m128i load4x2_sse2(const uint8_t *const p, const int stride) {
-  const __m128i p0 = _mm_cvtsi32_si128(*(const uint32_t *)(p + 0 * stride));
-  const __m128i p1 = _mm_cvtsi32_si128(*(const uint32_t *)(p + 1 * stride));
+  const __m128i p0 = _mm_cvtsi32_si128(loadu_uint32(p + 0 * stride));
+  const __m128i p1 = _mm_cvtsi32_si128(loadu_uint32(p + 1 * stride));
   const __m128i p01 = _mm_unpacklo_epi32(p0, p1);
   return _mm_unpacklo_epi8(p01, _mm_setzero_si128());
 }