revert to a lower complexity likely BE(IVAS and EVS-Mono) version without rounding (fd47d26e) · Commits · IVAS Codec Public Collaboration / IVAS Codec

lib_dec/FEC_HQ_phase_ecu.c

+68 −37

Original line number	Diff line number	Diff line
		@@ -1096,23 +1096,56 @@ static void subst_spec(

		Xph = corr_phase[m];
		#ifdef FIX_1002_DEC_PHASE_ECU_USAN_OF_PHASE
		if ( element_mode != EVS_MONO )
		{
		/* BE , but with maintained dual mult of a constant, bnut mask the 10 bits in Word32, truncation */
		#define WMC_TOOL_SKIP
		Xph_short = ( int16_t )( 0x000003ff & ( int32_t )( ( Xph * 512 ) / EVS_PI ) );
		MULT( 2 ); /* mult with constant, twice due to legacy precedence use */
		LOGIC( 1 ); /* L_and */
		MISC( 1 ); /* extract_l */
		#undef WMC_TOOL_SKIP
		#if 1
		int16_t Xph_short_orig = ( int16_t )( ( ( int32_t )( Xph * 512 / EVS_PI ) ) % 32768 ) & 0x03ff; /* BE: 2 mults, 1 modulo / / bad line(for WMC): WMC-costly modulo % in use, no rounding */
		int16_t Xph_short_1mult_nonbe = ( int16_t )( 0x000003ff & ( int32_t )( ( Xph * ( 512.0 / EVS_PI ) ) ) ); /* nonBE: single mult, mask the 10 bits in Word32 , still no rounding */
		int16_t Xph_short_1mult_rnd_nonbe = ( int16_t )( 0x000003ff & ( ( 1L + ( ( int32_t )( Xph * ( 1024.0 / EVS_PI ) ) ) ) >> 1 ) ); /* nonBE: single mult, add 1(round) shift1, mask the 10 bits in Word32 , i.e. with rounding */

		assert( Xph_short == Xph_short_orig && "Xph_short == Xph_short_orig" );
		#endif

		#ifdef DEBUGGING

		int32_t Xph_long_new = ( int32_t )( Xph * ( 512 / EVS_PI ) ); /* mult by a single constant and float cast to int32_t */
		int32_t Xph_long_old = ( int32_t )( ( Xph * 512 ) / EVS_PI ); /* mult by 2 constants ! and float cast to int32_t , (Xph<<9) / pi */
		int32_t Xph_long = Xph_long_old;

		//assert( Xph_long_new == Xph_long_old && __func__ && " Xph_long_new != Xph_long_old" ); // mat differ due to order of division

		int32_t L_tmp1 = Xph_long % 32768; /* counts as division: 6-25 cycles */
		int32_t L_tmp2 = Xph_long & 0x00007fff; /* L_and mask : 1 cycle */
		// assert( L_tmp1 == L_tmp2 && __func__ && " L_tmp1 != L_tmp2 " );


		Xph_long = ( Xph_long & 0x00007fff ); /* L_and() equivalent to % 32768 */
		int16_t Xph_short_new1 = ( (int16_t) Xph_long ) & 0x03ff;
		int16_t Xph_short_new2 = ( int16_t )( Xph_long_old & 0x000003ff );

		//assert( Xph_short == Xph_short_new1 && __func__ && " Xph_short != Xph_short_new1" );
		//assert( Xph_short == Xph_short_new2 && __func__ && " Xph_short != Xph_short_new2" );

		#if 0
		/* guarantee no wrap around to negative side of 32 bit signed integer value */
		#define WMC_TOOL_SKIP
		tmpf = Xph * ( 1.0f / PI2 ); /* normalize : mult() with a constant */
		tmpf = ( 1024.0f * ( tmpf - floorf( tmpf ) ) ) + 0.5f; /* obtain fraction : floor(), sub(), mult(), rnd(), out: [0...1024.5[ */
		Xph_short = ( (int16_t) tmpf ) & 0x03ff; /* mask to [0..1023]: s_and() , out: [0...1023] */
		int16_t Xph_short_flt_correct = ( (int16_t) tmpf ) & 0x03ff; /* mask to [0..1023]: s_and() , out: [0...1023] */

		MULT( 2 );
		MISC( 1 ); /* floor */
		ADD( 2 ); /* sub, rnd */
		LOGIC( 1 ); /* s_and */
		#undef WMC_TOOL_SKIP
		}
		else
		{
		Xph_short = (int16_t) ( ( (int32_t) ( Xph * 512 / EVS_PI ) ) % 32768 ) & 0x03ff; /* WMC-costly % in use, no rounding */
		}
		#endif
		#endif

		#else
		Xph_short = ( int16_t )( ( ( int32_t )( Xph * 512 / EVS_PI ) ) % 32768 ) & 0x03ff;
		#endif
		@@ -1162,25 +1195,23 @@ static void subst_spec(
		}

		#ifdef FIX_1002_DEC_PHASE_ECU_USAN_OF_PHASE
		if ( element_mode != EVS_MONO )
		{
		/* fractional phase of Xph converted to an integer in the range [0..1023] */
		/* in BASOP this is simply a truncation (through extract_l(Word32)) of a 32bit value at the Q16 bimal point + shifting to a 10 bit index */
		#define WMC_TOOL_SKIP
		tmpf = Xph * ( 1.0f / PI2 ); /* normalize : mult() with a constant */
		tmpf = ( 1024.0f * ( tmpf - floorf( tmpf ) ) ) + 0.5f; /* obtain fraction : floor(), sub(), mult(), rnd(), out: [0...1024.5[ */
		Xph_short = ( (int16_t) tmpf ) & 0x03ff; /* mask to [0..1023]: s_and() , out: [0...1023] */

		MULT( 2 );
		MISC( 1 ); /* floor */
		ADD( 2 ); /* sub, rnd */
		LOGIC( 1 ); /* s_and */
		Xph_short = ( int16_t )( ( ( int32_t )( ( Xph * 512 ) / EVS_PI ) ) & 0x000003ff );
		MULT( 2 ); /* mult with constant, twice due to legacy precedence */
		LOGIC( 1 ); /* L_and */
		MISC( 1 ); /* extract_l */
		#undef WMC_TOOL_SKIP
		}
		else
		{
		Xph_short = (int16_t) ( Xph * 512 / EVS_PI ) & 0x03ff; /* NB! USAN warning for cast from float to int16_t, no rounding */
		}
		#if 1
		int16_t Xph_short_orig_ph_dith = ( int16_t )( Xph * 512 / EVS_PI ) & 0x03ff; /* USAN bad cast, bad dual mults */
		assert( Xph_short == Xph_short_orig_ph_dith );
		#endif

		#ifdef DEBUGGING
		/* NB! USAN undefined behaviour warning for float-> short cast adressed, no rounding required here as phase is scrambled anyway */
		/* applied also EVS_MONO */
		#endif


		#else
		Xph_short = ( int16_t )( Xph * 512 / EVS_PI ) & 0x03ff;
		#endif