Does GNU ARM GCC not support the 'old' DSP intrinsics like __qadd ? I can't find a header which supports this. Are you expected to using CMIS or write your own ASM macro or am I missing something

[CParr.1]

..

[KnarfB]

#include <arm_neon.h> vqadd_* ?

[CParr.1]

That's for the neon unit, not supported by M series. I'm talking about the qadd 'like' instructions as supported by M4/M7 etc

[Tesla DeLorean]

As i recall those were ARM RealView intrinsics

STM32F4xx_DSP_StdPeriph_Lib_V1.8.0\Libraries\CMSIS\Include\core_cmSimd.h

Later mapped with defines, the wrong way round for your case, but

#define __SMLSLDX             __smlsldx

#define __SEL               __sel

#define __QADD              __qadd

#define __QSUB              __qsub

With GNU/GCC doing this

__attribute__( ( always_inline ) ) __STATIC_INLINE uint32_t __QADD(uint32_t op1, uint32_t op2)

{

 uint32_t result;

 __ASM volatile ("qadd %0, %1, %2" : "=r" (result) : "r" (op1), "r" (op2) );

 return(result);

}

__attribute__( ( always_inline ) ) __STATIC_INLINE uint32_t __QSUB(uint32_t op1, uint32_t op2)

{

 uint32_t result;

 __ASM volatile ("qsub %0, %1, %2" : "=r" (result) : "r" (op1), "r" (op2) );

 return(result);

}

[CParr.1]

OK so you have to add this yourself and its not supported directly by the GNU gcc used in STMCubdeIDE, thanks for the confirmation

[Tesla DeLorean]

Depending on the source/age you could create a similar #define translation, doing the reverse, or do a search-n-replace on the source as it is ported to the CMSIS formats.