optimized samplebuffer copying

Makefile

@@ -8,7 +8,7 @@ TARGET_PLATFORM = L4
 
 # Compiler options here.
 ifeq ($(USE_OPT),)
-  USE_OPT = -Os -g3 -ggdb -fomit-frame-pointer -falign-functions=16 --specs=nosys.specs
+  USE_OPT = -O0 -g3 -ggdb -fomit-frame-pointer -falign-functions=16 --specs=nosys.specs
 endif
 
 # C specific options here (added to USE_OPT).

source/samplebuffer.cpp

@@ -19,8 +19,8 @@ void SampleBuffer::clear() {
 }
 __attribute__((section(".convcode")))
 void SampleBuffer::modify(Sample *data, unsigned int srcsize) {
-    auto size = std::min(srcsize, m_size);
-    size = (size + 15) & 0xFF0;
+    auto size = srcsize < m_size ? srcsize : m_size;
+    size = (size + 15) & (~15);
 
     m_modified = m_buffer;
     const int *src = reinterpret_cast<const int *>(data);
@@ -49,8 +49,8 @@ void SampleBuffer::modify(Sample *data, unsigned int srcsize) {
 }
 __attribute__((section(".convcode")))
 void SampleBuffer::midmodify(Sample *data, unsigned int srcsize) {
-    auto size = std::min(srcsize, m_size / 2);
-    size = (size + 15) & 0xFF0;
+    auto size = srcsize < m_size / 2 ? srcsize : m_size / 2;
+    size = (size + 15) & (~15);
 
     m_modified = middata();
     const int *src = reinterpret_cast<const int *>(data);