diff --git a/audio/utils.c b/audio/utils.c
index db58642268..4d7b202592 100644
--- a/audio/utils.c
+++ b/audio/utils.c
@@ -15,9 +15,9 @@
 
 #include "utils.h"
 
-#if __SSE2__
+#if defined(__SSE2__)
 #include <emmintrin.h>
-#elif __ALTIVEC__
+#elif defined(__ALTIVEC__)
 #include <altivec.h>
 #endif
 
@@ -39,7 +39,7 @@ void audio_convert_float_to_s16_C(int16_t *out,
    }
 }
 
-#if __SSE2__
+#if defined(__SSE2__)
 void audio_convert_s16_to_float_SSE2(float *out,
       const int16_t *in, size_t samples, float gain)
 {
@@ -84,7 +84,7 @@ void audio_convert_float_to_s16_SSE2(int16_t *out,
 
    audio_convert_float_to_s16_C(out, in, samples - i);
 }
-#elif __ALTIVEC__
+#elif defined(__ALTIVEC__)
 void audio_convert_s16_to_float_altivec(float *out,
       const int16_t *in, size_t samples, float gain)
 {
@@ -133,14 +133,14 @@ void audio_convert_float_to_s16_altivec(int16_t *out,
    else
       audio_convert_float_to_s16_C(out, in, samples);
 }
-#elif HAVE_NEON
+#elif defined(HAVE_NEON)
 void audio_convert_s16_float_asm(float *out, const int16_t *in, size_t samples);
 void audio_convert_s16_to_float_neon(float *out, const int16_t *in, size_t samples,
       float gain)
 {
    (void)gain; // gain is ignored for now.
 
-   size_t aligned_samples = samples & 7;
+   size_t aligned_samples = samples & ~7;
    audio_convert_s16_float_asm(out, in, aligned_samples);
 
    // Could do all conversion in ASM, but keep it simple for now.
@@ -151,7 +151,7 @@ void audio_convert_s16_to_float_neon(float *out, const int16_t *in, size_t sampl
 void audio_convert_float_s16_asm(int16_t *out, const float *in, size_t samples);
 void audio_convert_float_to_s16_neon(int16_t *out, const float *in, size_t samples)
 {
-   size_t aligned_samples = samples & 7;
+   size_t aligned_samples = samples & ~7;
    audio_convert_float_s16_asm(out, in, aligned_samples);
    audio_convert_float_to_s16_C(out + aligned_samples, in + aligned_samples,
          samples - aligned_samples);
diff --git a/audio/utils.h b/audio/utils.h
index ac7ca65caf..6b5d356926 100644
--- a/audio/utils.h
+++ b/audio/utils.h
@@ -19,7 +19,7 @@
 #include <stdint.h>
 #include <stddef.h>
 
-#if __SSE2__
+#if defined(__SSE2__)
 #define audio_convert_s16_to_float audio_convert_s16_to_float_SSE2
 #define audio_convert_float_to_s16 audio_convert_float_to_s16_SSE2
 
@@ -29,7 +29,7 @@ void audio_convert_s16_to_float_SSE2(float *out,
 void audio_convert_float_to_s16_SSE2(int16_t *out,
       const float *in, size_t samples);
 
-#elif __ALTIVEC__
+#elif defined(__ALTIVEC__)
 #define audio_convert_s16_to_float audio_convert_s16_to_float_altivec
 #define audio_convert_float_to_s16 audio_convert_float_to_s16_altivec