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Asked: 2026-05-11T12:21:34+00:00

Here’s my attempt. Any tips on a better solution?: // for loop to convert

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Here’s my attempt. Any tips on a better solution?:

// for loop to convert 32 to 16 bits uint32_t i; int32_t * samps32 = (int32_t *)&(inIQbuffer[0]); int16_t * samps16 = (int16_t *)&(outIQbuffer[0]); for( i = 0; i < ( num_samples * 2/* because each sample is two int32 s*/ ); i++ ) {     overflowCount += ( abs(samps32[i]) & 0xFFFF8000 ) ? 1 : 0;      samps16[i] = (int16_t)samps32[i]; }  // Only report error every 4096 accumulated overflows if( ( overflowCount & 0x1FFF ) > 4096 ) {     printf( 'ERROR: Overflow has occured while scaling from 32 '             'bit to 16 bit samples %d times',              overflowCount ); }

Here’s the part that actually checks for overflow:

overflowCount += ( abs(samps32[i]) & 0xFFFF8000 ) ? 1 : 0;
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1 Answer

  1. It seems that you are checking for the overflow of a 16-bit addition. You can avoid branch in the assembler code by just having

    overflowCount += (samps32[i] & 0x8000) >> 15;

    This generates three ALU operations but no branch in the code. It may or may not be faster than a branching version.

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