add WebPMemToInt32

and use it with calls to _mm_cvtsi32_si128 and _mm_set_epi32; this calls
WebPMemToUint32, but corrects the type to avoid runtime warnings with
clang -fsanitize=integer of the form:

implicit conversion from type 'uint32_t' (aka 'unsigned int') of value
2155905152 (32-bit, unsigned) to type 'int' changed the value to
-2139062144 (32-bit, signed)

Bug: b/229626362
Change-Id: I50101ba2b46dfaa852f02d46830f3511c80b02d9

src/dsp/dec_sse2.c

@@ -158,10 +158,10 @@ static void Transform_SSE2(const int16_t* in, uint8_t* dst, int do_two) {
       dst3 = _mm_loadl_epi64((__m128i*)(dst + 3 * BPS));
     } else {
       // Load four bytes/pixels per line.
-      dst0 = _mm_cvtsi32_si128(WebPMemToUint32(dst + 0 * BPS));
-      dst1 = _mm_cvtsi32_si128(WebPMemToUint32(dst + 1 * BPS));
-      dst2 = _mm_cvtsi32_si128(WebPMemToUint32(dst + 2 * BPS));
-      dst3 = _mm_cvtsi32_si128(WebPMemToUint32(dst + 3 * BPS));
+      dst0 = _mm_cvtsi32_si128(WebPMemToInt32(dst + 0 * BPS));
+      dst1 = _mm_cvtsi32_si128(WebPMemToInt32(dst + 1 * BPS));
+      dst2 = _mm_cvtsi32_si128(WebPMemToInt32(dst + 2 * BPS));
+      dst3 = _mm_cvtsi32_si128(WebPMemToInt32(dst + 3 * BPS));
     }
     // Convert to 16b.
     dst0 = _mm_unpacklo_epi8(dst0, zero);
@@ -213,10 +213,10 @@ static void TransformAC3(const int16_t* in, uint8_t* dst) {
   const __m128i m3 = _mm_subs_epi16(B, d4);
   const __m128i zero = _mm_setzero_si128();
   // Load the source pixels.
-  __m128i dst0 = _mm_cvtsi32_si128(WebPMemToUint32(dst + 0 * BPS));
-  __m128i dst1 = _mm_cvtsi32_si128(WebPMemToUint32(dst + 1 * BPS));
-  __m128i dst2 = _mm_cvtsi32_si128(WebPMemToUint32(dst + 2 * BPS));
-  __m128i dst3 = _mm_cvtsi32_si128(WebPMemToUint32(dst + 3 * BPS));
+  __m128i dst0 = _mm_cvtsi32_si128(WebPMemToInt32(dst + 0 * BPS));
+  __m128i dst1 = _mm_cvtsi32_si128(WebPMemToInt32(dst + 1 * BPS));
+  __m128i dst2 = _mm_cvtsi32_si128(WebPMemToInt32(dst + 2 * BPS));
+  __m128i dst3 = _mm_cvtsi32_si128(WebPMemToInt32(dst + 3 * BPS));
   // Convert to 16b.
   dst0 = _mm_unpacklo_epi8(dst0, zero);
   dst1 = _mm_unpacklo_epi8(dst1, zero);
@@ -477,11 +477,11 @@ static WEBP_INLINE void Load8x4_SSE2(const uint8_t* const b, int stride,
   // A0 = 63 62 61 60 23 22 21 20 43 42 41 40 03 02 01 00
   // A1 = 73 72 71 70 33 32 31 30 53 52 51 50 13 12 11 10
   const __m128i A0 = _mm_set_epi32(
-      WebPMemToUint32(&b[6 * stride]), WebPMemToUint32(&b[2 * stride]),
-      WebPMemToUint32(&b[4 * stride]), WebPMemToUint32(&b[0 * stride]));
+      WebPMemToInt32(&b[6 * stride]), WebPMemToInt32(&b[2 * stride]),
+      WebPMemToInt32(&b[4 * stride]), WebPMemToInt32(&b[0 * stride]));
   const __m128i A1 = _mm_set_epi32(
-      WebPMemToUint32(&b[7 * stride]), WebPMemToUint32(&b[3 * stride]),
-      WebPMemToUint32(&b[5 * stride]), WebPMemToUint32(&b[1 * stride]));
+      WebPMemToInt32(&b[7 * stride]), WebPMemToInt32(&b[3 * stride]),
+      WebPMemToInt32(&b[5 * stride]), WebPMemToInt32(&b[1 * stride]));
 
   // B0 = 53 43 52 42 51 41 50 40 13 03 12 02 11 01 10 00
   // B1 = 73 63 72 62 71 61 70 60 33 23 32 22 31 21 30 20
@@ -1015,7 +1015,7 @@ static WEBP_INLINE void TrueMotion_SSE2(uint8_t* dst, int size) {
   const __m128i zero = _mm_setzero_si128();
   int y;
   if (size == 4) {
-    const __m128i top_values = _mm_cvtsi32_si128(WebPMemToUint32(top));
+    const __m128i top_values = _mm_cvtsi32_si128(WebPMemToInt32(top));
     const __m128i top_base = _mm_unpacklo_epi8(top_values, zero);
     for (y = 0; y < 4; ++y, dst += BPS) {
       const int val = dst[-1] - top[-1];

src/dsp/dec_sse41.c

@@ -23,7 +23,7 @@ static void HE16_SSE41(uint8_t* dst) {     // horizontal
   int j;
   const __m128i kShuffle3 = _mm_set1_epi8(3);
   for (j = 16; j > 0; --j) {
-    const __m128i in = _mm_cvtsi32_si128(WebPMemToUint32(dst - 4));
+    const __m128i in = _mm_cvtsi32_si128(WebPMemToInt32(dst - 4));
     const __m128i values = _mm_shuffle_epi8(in, kShuffle3);
     _mm_storeu_si128((__m128i*)dst, values);
     dst += BPS;

src/dsp/enc_sse2.c

@@ -156,10 +156,10 @@ static void ITransform_SSE2(const uint8_t* ref, const int16_t* in, uint8_t* dst,
       ref3 = _mm_loadl_epi64((const __m128i*)&ref[3 * BPS]);
     } else {
       // Load four bytes/pixels per line.
-      ref0 = _mm_cvtsi32_si128(WebPMemToUint32(&ref[0 * BPS]));
-      ref1 = _mm_cvtsi32_si128(WebPMemToUint32(&ref[1 * BPS]));
-      ref2 = _mm_cvtsi32_si128(WebPMemToUint32(&ref[2 * BPS]));
-      ref3 = _mm_cvtsi32_si128(WebPMemToUint32(&ref[3 * BPS]));
+      ref0 = _mm_cvtsi32_si128(WebPMemToInt32(&ref[0 * BPS]));
+      ref1 = _mm_cvtsi32_si128(WebPMemToInt32(&ref[1 * BPS]));
+      ref2 = _mm_cvtsi32_si128(WebPMemToInt32(&ref[2 * BPS]));
+      ref3 = _mm_cvtsi32_si128(WebPMemToInt32(&ref[3 * BPS]));
     }
     // Convert to 16b.
     ref0 = _mm_unpacklo_epi8(ref0, zero);
@@ -875,7 +875,7 @@ static WEBP_INLINE void HD4_SSE2(uint8_t* dst, const uint8_t* top) {
 
 static WEBP_INLINE void TM4_SSE2(uint8_t* dst, const uint8_t* top) {
   const __m128i zero = _mm_setzero_si128();
-  const __m128i top_values = _mm_cvtsi32_si128(WebPMemToUint32(top));
+  const __m128i top_values = _mm_cvtsi32_si128(WebPMemToInt32(top));
   const __m128i top_base = _mm_unpacklo_epi8(top_values, zero);
   int y;
   for (y = 0; y < 4; ++y, dst += BPS) {

src/dsp/rescaler_sse2.c

@@ -132,7 +132,7 @@ static void RescalerImportRowShrink_SSE2(WebPRescaler* const wrk,
     __m128i base = zero;
     accum += wrk->x_add;
     while (accum > 0) {
-      const __m128i A = _mm_cvtsi32_si128(WebPMemToUint32(src));
+      const __m128i A = _mm_cvtsi32_si128(WebPMemToInt32(src));
       src += 4;
       base = _mm_unpacklo_epi8(A, zero);
       // To avoid overflow, we need: base * x_add / x_sub < 32768

src/utils/utils.h

@@ -73,6 +73,11 @@ static WEBP_INLINE uint32_t WebPMemToUint32(const uint8_t* const ptr) {
   memcpy(&A, ptr, sizeof(A));
   return A;
 }
+
+static WEBP_INLINE int32_t WebPMemToInt32(const uint8_t* const ptr) {
+  return (int32_t)WebPMemToUint32(ptr);
+}
+
 static WEBP_INLINE void WebPUint32ToMem(uint8_t* const ptr, uint32_t val) {
   memcpy(ptr, &val, sizeof(val));
 }