disable CombinedShannonEntropy_SSE2 on x86
this function produces different results from the C code due to
use of double/float resulting in output differences when compared to
noasm.
@@ -249,6 +249,7 @@ static void AddVectorEq_SSE2(const uint32_t* a, uint32_t* out, int size) {
} \
} while (0)
+#if !(defined(__i386__) || defined(_M_IX86))
static float CombinedShannonEntropy_SSE2(const int X[256], const int Y[256]) {
int i;
double retval = 0.;
@@ -300,6 +301,8 @@ static float CombinedShannonEntropy_SSE2(const int X[256], const int Y[256]) {
retval += VP8LFastSLog2(sumX) + VP8LFastSLog2(sumXY);
return (float)retval;
}
+#endif // !(defined(__i386__) || defined(_M_IX86))
+
#undef ANALYZE_X_OR_Y
#undef ANALYZE_XY
@@ -659,7 +662,12 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInitSSE2(void) {
VP8LCollectColorRedTransforms = CollectColorRedTransforms_SSE2;
VP8LAddVector = AddVector_SSE2;
VP8LAddVectorEq = AddVectorEq_SSE2;
+ // TODO(https://crbug.com/webp/499): this function produces different results
+ // from the C code due to use of double/float resulting in output differences
+ // when compared to -noasm.
+#if !(defined(__i386__) || defined(_M_IX86))
VP8LCombinedShannonEntropy = CombinedShannonEntropy_SSE2;
+#endif
VP8LVectorMismatch = VectorMismatch_SSE2;
VP8LBundleColorMap = BundleColorMap_SSE2;
