169 lines
4.2 KiB
C
169 lines
4.2 KiB
C
/*
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This program is part of the TACLeBench benchmark suite.
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Version V 2.0
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Name: iir
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Author: Juan Martinez Velarde
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Function:
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The equations of each biquad section filter are:
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w(n) = x(n) - ai1*w(n-1) - ai2*w(n-2)
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y(n) = b0*w(n) + bi1*w(n-1) + bi2*w(n-2)
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Biquads are sequentally positioned. Input sample for biquad i is
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xi-1(n). Output sample for biquad i is xi(n).
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System input sample is x0(n). System output sample is xN(n) = y(n)
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for N biquads.
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Each section performs following filtering (biquad i) :
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wi(n)
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xi-1(n) ---(-)---------->-|->---bi0---(+)-------> xi(n)
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A | A
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| |1/z| |
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| | wi(n-1) |
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| v |
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|-<--ai1----<-|->---bi1-->-|
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| | |
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| |1/z| |
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| | wi(n-2) |
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| v |
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|-<--ai2----<--->---bi2-->-|
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The values wi(n-1) and wi(n-2) are stored in wi1 and wi2
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Source: DSPstone
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http://www.ice.rwth-aachen.de/research/tools-projects/entry/detail/dspstone
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Original name: iir_N_sections_float
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Changes:
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24-03-94 creation fixed-point (Martinez Velarde)
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16-03-95 adaption floating-point (Harald L. Schraut)
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License: may be used, modified, and re-distributed freely
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*/
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/*
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Forward declaration of functions
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*/
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// Wasm loop bounds
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__attribute__((import_module("__pragma"), import_name("loopbound"))) extern void
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__pragma_loopbound(unsigned int min_bound, unsigned int max_bound);
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__attribute__((always_inline)) static inline void iir_init(void);
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__attribute__((always_inline)) static inline int iir_return(void);
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__attribute__((noinline)) __attribute__((export_name("entrypoint")))
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__attribute__((noinline)) __attribute__((export_name("entrypoint"))) void
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iir_main(void);
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__attribute__((noinline)) __attribute__((export_name("main")))
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__attribute__((noinline)) __attribute__((export_name("main"))) int
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main(void);
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/*
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Declaration of global variables
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*/
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volatile float iir_wi[2 * 4];
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volatile float iir_coefficients[5 * 4];
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float iir_x;
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/*
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Initialization- and return-value-related functions
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*/
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__attribute__((always_inline)) static inline void
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iir_init(void) {
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int f;
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unsigned int i;
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unsigned char *p;
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volatile char bitmask = 0;
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__pragma_loopbound(20, 20);
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for (f = 0; f < 5 * 4; f++)
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iir_coefficients[f] = 7;
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__pragma_loopbound(8, 8);
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for (f = 0; f < 2 * 4; f++)
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iir_wi[f] = 0;
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iir_x = (float) 1;
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/*
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Apply volatile XOR-bitmask to entire input array.
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*/
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p = (unsigned char *) &iir_coefficients[0];
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__pragma_loopbound(80, 80);
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for (i = 0; i < sizeof(iir_coefficients); ++i, ++p)
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*p ^= bitmask;
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p = (unsigned char *) &iir_wi[0];
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__pragma_loopbound(32, 32);
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for (i = 0; i < sizeof(iir_wi); ++i, ++p)
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*p ^= bitmask;
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}
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__attribute__((always_inline)) static inline int
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iir_return(void) {
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float checksum = 0.0;
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int f;
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__pragma_loopbound(8, 8);
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for (f = 0; f < 2 * 4; f++)
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checksum += iir_wi[f];
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return ((int) checksum);
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}
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/*
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Main functions
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*/
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__attribute__((noinline)) __attribute__((export_name("entrypoint")))
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__attribute__((noinline)) __attribute__((export_name("entrypoint"))) void
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iir_main(void) {
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register float w;
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int f;
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register volatile float *ptr_coeff, *ptr_wi1, *ptr_wi2;
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register float y;
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ptr_coeff = &iir_coefficients[0];
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ptr_wi1 = &iir_wi[0];
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ptr_wi2 = &iir_wi[1];
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y = iir_x;
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__pragma_loopbound(4, 4);
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for (f = 0; f < 4; f++) {
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w = y - *ptr_coeff++ * *ptr_wi1;
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w -= *ptr_coeff++ * *ptr_wi2;
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y = *ptr_coeff++ * w;
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y += *ptr_coeff++ * *ptr_wi1;
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y += *ptr_coeff++ * *ptr_wi2;
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*ptr_wi2++ = *ptr_wi1;
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*ptr_wi1++ = w;
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ptr_wi2++;
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ptr_wi1++;
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}
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}
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__attribute__((noinline)) __attribute__((export_name("main")))
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__attribute__((noinline)) __attribute__((export_name("main"))) int
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main(void) {
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iir_init();
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iir_main();
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return (iir_return() - 400 != 0);
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}
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