FreeCalypso > hg > gsm-codec-lib
view libgsmefr/basic_op.h @ 350:9b05bbc23b8a
libgsmefr inline: make shift count guards 100% robust
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Tue, 23 Apr 2024 05:34:54 +0000 |
| parents | ed8762eea8a1 |
| children |
line wrap: on
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/* * This version of basic_op.h for GSM-EFR codec has been created at * Themyscira Wireless with the aim of performance improvement. * The original version contained only function declarations, * resulting in a function call for every elementary operation; * the present version implements most of these operations as inline * functions. (Further update: for extra speed-up, some inline * function implementations have been lifted from PacketVideo AMR * version, aka libopencore-amrnb.) * * Elimination of Overflow flag: examination of EFR code reveals that * both Carry and Overflow flags are accessed outside of basicop2.c * only in g_pitch.c, as part of a code sequence that uses L_macNs. * Since the Overflow flag is not checked anywhere else, we can eliminate * its setting from all other elementary operation functions, saving * some cycles and code size. * * Non-portability: we assume real target machines, not hypothetical * ones. Specifically, we assume that >> does an arithmetic right shift * (sign bit fill). */ /* for the few functions that still use them */ extern __thread Flag Overflow; extern __thread Flag Carry; #define MAX_32 (Word32)0x7fffffff #define MIN_32 (Word32)0x80000000 #define MAX_16 (Word16)0x7fff #define MIN_16 (Word16)0x8000 /* likely and unlikely conditional paths */ #define likely(x) __builtin_expect(!!(x), 1) #define unlikely(x) __builtin_expect(!!(x), 0) /* Word16 operations */ /*___________________________________________________________________________ | | | Function Name : add | | | | Purpose : | | | | Performs the addition (var1+var2) with overflow control and saturation;| | the 16 bit result is set at +32767 when overflow occurs or at -32768 | | when underflow occurs. | | | | Complexity weight : 1 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 add (Word16 var1, Word16 var2) { Word32 L_sum; L_sum = (Word32) var1 + var2; if (unlikely(L_sum > MAX_16)) return MAX_16; else if (unlikely(L_sum < MIN_16)) return MIN_16; else return L_sum; } /*___________________________________________________________________________ | | | Function Name : sub | | | | Purpose : | | | | Performs the subtraction (var1+var2) with overflow control and satu- | | ration; the 16 bit result is set at +32767 when overflow occurs or at | | -32768 when underflow occurs. | | | | Complexity weight : 1 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 sub (Word16 var1, Word16 var2) { Word32 L_diff; L_diff = (Word32) var1 - var2; if (unlikely(L_diff > MAX_16)) return MAX_16; else if (unlikely(L_diff < MIN_16)) return MIN_16; else return L_diff; } /*___________________________________________________________________________ | | | Function Name : abs_s | | | | Purpose : | | | | Absolute value of var1; abs_s(-32768) = 32767. | | | | Complexity weight : 1 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 0000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 abs_s (Word16 var1) { Word16 y = var1 - (var1 < 0); y = y ^ (y >> 15); return (y); } /*___________________________________________________________________________ | | | Function Name : shl | | | | Purpose : | | | | Arithmetically shift the 16 bit input var1 left var2 positions.Zero fill| | the var2 LSB of the result. If var2 is negative, arithmetically shift | | var1 right by -var2 with sign extension. Saturate the result in case of | | underflows or overflows. | | | | Complexity weight : 1 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 shl (Word16 var1, Word16 var2) { Word16 var_out; if (unlikely(var2 < 0)) { if (unlikely(var2 < -15)) var2 = -15; var2 = -var2; var_out = var1 >> var2; } else { if (unlikely(var2 > 15)) var2 = 15; var_out = var1 << var2; if (unlikely(var_out >> var2 != var1)) { var_out = (var1 >> 15) ^ MAX_16; } } return var_out; } /*___________________________________________________________________________ | | | Function Name : shr | | | | Purpose : | | | | Arithmetically shift the 16 bit input var1 right var2 positions with | | sign extension. If var2 is negative, arithmetically shift var1 left by | | -var2 with sign extension. Saturate the result in case of underflows or | | overflows. | | | | Complexity weight : 1 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 shr (Word16 var1, Word16 var2) { Word16 var_out; if (unlikely(var2 < 0)) { if (unlikely(var2 < -15)) var2 = -15; var2 = -var2; var_out = var1 << var2; if (unlikely(var_out >> var2 != var1)) { var_out = (var1 >> 15) ^ MAX_16; } } else { if (unlikely(var2 > 15)) var2 = 15; var_out = var1 >> var2; } return var_out; } /*___________________________________________________________________________ | | | Function Name : mult | | | | Purpose : | | | | Performs the multiplication of var1 by var2 and gives a 16 bit result | | which is scaled i.e.: | | mult(var1,var2) = extract_l(L_shr((var1 times var2),15)) and | | mult(-32768,-32768) = 32767. | | | | Complexity weight : 1 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 mult (Word16 var1, Word16 var2) { register Word32 product; product = ((Word32) var1 * var2) >> 15; /* Saturate result (if necessary). */ /* var1 * var2 >0x00007fff is the only case */ /* that saturation occurs. */ if (unlikely(product > 0x00007fff)) product = (Word32) MAX_16; /* Return the product as a 16 bit value by type casting Word32 to Word16 */ return ((Word16) product); } /*___________________________________________________________________________ | | | Function Name : negate | | | | Purpose : | | | | Negate var1 with saturation, saturate in the case where input is -32768:| | negate(var1) = sub(0,var1). | | | | Complexity weight : 1 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 negate (Word16 var1) { Word16 var_out; var_out = (var1 == MIN_16) ? MAX_16 : -var1; return (var_out); } /*___________________________________________________________________________ | | | Function Name : extract_h | | | | Purpose : | | | | Return the 16 MSB of L_var1. | | | | Complexity weight : 1 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32 ) whose value falls in the | | range : 0x8000 0000 <= L_var1 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 extract_h (Word32 L_var1) { Word16 var_out; var_out = (Word16) (L_var1 >> 16); return (var_out); } /*___________________________________________________________________________ | | | Function Name : extract_l | | | | Purpose : | | | | Return the 16 LSB of L_var1. | | | | Complexity weight : 1 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32 ) whose value falls in the | | range : 0x8000 0000 <= L_var1 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 extract_l (Word32 L_var1) { Word16 var_out; var_out = (Word16) L_var1; return (var_out); } /*___________________________________________________________________________ | | | Function Name : round | | | | Purpose : | | | | Round the lower 16 bits of the 32 bit input number into the MS 16 bits | | with saturation. Shift the resulting bits right by 16 and return the 16 | | bit number: | | round(L_var1) = extract_h(L_add(L_var1,32768)) | | | | Complexity weight : 1 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32 ) whose value falls in the | | range : 0x8000 0000 <= L_var1 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 round (Word32 L_var1) { if (unlikely(L_var1 >= 0x7fff8000)) return MAX_16; else return (L_var1 + 0x8000) >> 16; } /* Word32 operations */ /*___________________________________________________________________________ | | | Function Name : L_add | | | | Purpose : | | | | 32 bits addition of the two 32 bits variables (L_var1+L_var2) with | | overflow control and saturation; the result is set at +2147483647 when | | overflow occurs or at -2147483648 when underflow occurs. | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var1 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | L_var2 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static inline Word32 L_add (Word32 L_var1, Word32 L_var2) { Word32 L_var_out; L_var_out = L_var1 + L_var2; if (((L_var1 ^ L_var2) & MIN_32) == 0) { if ((L_var_out ^ L_var1) & MIN_32) { L_var_out = (L_var1 < 0) ? MIN_32 : MAX_32; } } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_sub | | | | Purpose : | | | | 32 bits subtraction of the two 32 bits variables (L_var1-L_var2) with | | overflow control and saturation; the result is set at +2147483647 when | | overflow occurs or at -2147483648 when underflow occurs. | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var1 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | L_var2 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static inline Word32 L_sub (Word32 L_var1, Word32 L_var2) { Word32 L_var_out; L_var_out = L_var1 - L_var2; if (((L_var1 ^ L_var2) & MIN_32) != 0) { if ((L_var_out ^ L_var1) & MIN_32) { L_var_out = (L_var1 < 0) ? MIN_32 : MAX_32; } } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_mult | | | | Purpose : | | | | L_mult is the 32 bit result of the multiplication of var1 times var2 | | with one shift left i.e.: | | L_mult(var1,var2) = L_shl((var1 times var2),1) and | | L_mult(-32768,-32768) = 2147483647. | | | | Complexity weight : 1 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static inline Word32 L_mult (Word16 var1, Word16 var2) { register Word32 L_product; L_product = (Word32) var1 * var2; if (likely(L_product != (Word32) 0x40000000)) { L_product <<= 1; /* Multiply by 2 */ } else { Overflow = 1; L_product = MAX_32; } return (L_product); } /*___________________________________________________________________________ | | | Function Name : L_mac | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Add the 32 bit | | result to L_var3 with saturation, return a 32 bit result: | | L_mac(L_var3,var1,var2) = L_add(L_var3,L_mult(var1,var2)). | | | | Complexity weight : 1 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static inline Word32 L_mac (Word32 L_var3, Word16 var1, Word16 var2) { Word32 L_var_out; Word32 L_product; L_product = L_mult (var1, var2); L_var_out = L_add (L_var3, L_product); return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_msu | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Subtract the 32 | | bit result to L_var3 with saturation, return a 32 bit result: | | L_msu(L_var3,var1,var2) = L_sub(L_var3,L_mult(var1,var2)). | | | | Complexity weight : 1 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static inline Word32 L_msu (Word32 L_var3, Word16 var1, Word16 var2) { Word32 L_var_out; Word32 L_product; L_product = L_mult (var1, var2); L_var_out = L_sub (L_var3, L_product); return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_negate | | | | Purpose : | | | | Negate the 32 bit variable L_var1 with saturation; saturate in the case | | where input is -2147483648 (0x8000 0000). | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var1 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static inline Word32 L_negate (Word32 L_var1) { Word32 L_var_out; L_var_out = (L_var1 == MIN_32) ? MAX_32 : -L_var1; return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_shl | | | | Purpose : | | | | Arithmetically shift the 32 bit input L_var1 left var2 positions. Zero | | fill the var2 LSB of the result. If var2 is negative, arithmetically | | shift L_var1 right by -var2 with sign extension. Saturate the result in | | case of underflows or overflows. | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var1 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static inline Word32 L_shl (Word32 L_var1, Word16 var2) { Word32 L_var_out; if (unlikely(var2 < 0)) { if (unlikely(var2 < -31)) var2 = -31; var2 = -var2; L_var_out = L_var1 >> var2; } else { if (unlikely(var2 > 31)) var2 = 31; L_var_out = L_var1 << var2; if (unlikely(L_var_out >> var2 != L_var1)) L_var_out = (L_var1 >> 31) ^ MAX_32; } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_shr | | | | Purpose : | | | | Arithmetically shift the 32 bit input L_var1 right var2 positions with | | sign extension. If var2 is negative, arithmetically shift L_var1 left | | by -var2 and zero fill the -var2 LSB of the result. Saturate the result | | in case of underflows or overflows. | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var1 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static inline Word32 L_shr (Word32 L_var1, Word16 var2) { Word32 L_var_out; if (unlikely(var2 < 0)) { if (unlikely(var2 < -31)) var2 = -31; var2 = -var2; L_var_out = L_var1 << var2; if (unlikely(L_var_out >> var2 != L_var1)) L_var_out = (L_var1 >> 31) ^ MAX_32; } else { if (unlikely(var2 > 31)) var2 = 31; L_var_out = L_var1 >> var2; } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_deposit_h | | | | Purpose : | | | | Deposit the 16 bit var1 into the 16 MS bits of the 32 bit output. The | | 16 LS bits of the output are zeroed. | | | | Complexity weight : 2 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var_out <= 0x7fff 0000. | |___________________________________________________________________________| */ static inline Word32 L_deposit_h (Word16 var1) { Word32 L_var_out; L_var_out = (Word32) var1 << 16; return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_deposit_l | | | | Purpose : | | | | Deposit the 16 bit var1 into the 16 LS bits of the 32 bit output. The | | 16 MS bits of the output are sign extended. | | | | Complexity weight : 2 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0xFFFF 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word32 L_deposit_l (Word16 var1) { Word32 L_var_out; L_var_out = (Word32) var1; return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_abs | | | | Purpose : | | | | Absolute value of L_var1; Saturate in case where the input is | | -214783648 | | | | Complexity weight : 3 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var1 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x0000 0000 <= var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static inline Word32 L_abs (Word32 L_var1) { Word32 L_var_out; if (L_var1 == MIN_32) { L_var_out = MAX_32; } else { if (L_var1 < 0) { L_var_out = -L_var1; } else { L_var_out = L_var1; } } return (L_var_out); } /* additional ops */ /*___________________________________________________________________________ | | | Function Name : mult_r | | | | Purpose : | | | | Same as mult with rounding, i.e.: | | mult_r(var1,var2) = extract_l(L_shr(((var1 * var2) + 16384),15)) and | | mult_r(-32768,-32768) = 32767. | | | | Complexity weight : 2 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ static inline Word16 mult_r (Word16 var1, Word16 var2) { Word16 var_out; Word32 L_product_arr; L_product_arr = (Word32) var1 *(Word32) var2; /* product */ L_product_arr += (Word32) 0x00004000L; /* round */ L_product_arr &= (Word32) 0xffff8000L; L_product_arr >>= 15; /* shift */ if (unlikely(L_product_arr > MAX_16)) return MAX_16; else if (unlikely(L_product_arr < MIN_16)) return MIN_16; else return L_product_arr; } /*___________________________________________________________________________ | | | Function Name : norm_s | | | | Purpose : | | | | Produces the number of left shift needed to normalize the 16 bit varia- | | ble var1 for positive values on the interval with minimum of 16384 and | | maximum of 32767, and for negative values on the interval with minimum | | of -32768 and maximum of -16384; in order to normalize the result, the | | following operation must be done : | | norm_var1 = shl(var1,norm_s(var1)). | | | | Complexity weight : 15 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 0000 <= var_out <= 0x0000 000f. | |___________________________________________________________________________| */ static inline Word16 norm_s (Word16 var1) { Word16 var_out; if (var1 == 0) { var_out = 0; } else { if (var1 == (Word16) 0xffff) { var_out = 15; } else { if (var1 < 0) { var1 = ~var1; } for (var_out = 0; var1 < 0x4000; var_out++) { var1 <<= 1; } } } return (var_out); } /*___________________________________________________________________________ | | | Function Name : norm_l | | | | Purpose : | | | | Produces the number of left shifts needed to normalize the 32 bit varia-| | ble L_var1 for positive values on the interval with minimum of | | 1073741824 and maximum of 2147483647, and for negative values on the in-| | terval with minimum of -2147483648 and maximum of -1073741824; in order | | to normalize the result, the following operation must be done : | | norm_L_var1 = L_shl(L_var1,norm_l(L_var1)). | | | | Complexity weight : 30 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var1 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 0000 <= var_out <= 0x0000 001f. | |___________________________________________________________________________| */ static inline Word16 norm_l (Word32 L_var1) { Word16 var_out; if (L_var1 == 0) { var_out = 0; } else { if (L_var1 == (Word32) 0xffffffffL) { var_out = 31; } else { if (L_var1 < 0) { L_var1 = ~L_var1; } for (var_out = 0; L_var1 < (Word32) 0x40000000L; var_out++) { L_var1 <<= 1; } } } return (var_out); } /* ETSI functions that aren't inlined */ Word32 L_macNs (Word32 L_var3, Word16 var1, Word16 var2); /* Mac without sat, 1 */ Word32 L_msuNs (Word32 L_var3, Word16 var1, Word16 var2); /* Msu without sat, 1 */ Word32 L_add_c (Word32 L_var1, Word32 L_var2); /* Long add with c, 2 */ Word32 L_sub_c (Word32 L_var1, Word32 L_var2); /* Long sub with c, 2 */ Word16 shr_r (Word16 var1, Word16 var2); /* Shift right with round, 2 */ Word16 mac_r (Word32 L_var3, Word16 var1, Word16 var2); /* Mac with rounding,2 */ Word16 msu_r (Word32 L_var3, Word16 var1, Word16 var2); /* Msu with rounding,2 */ Word32 L_shr_r (Word32 L_var1, Word16 var2); /* Long shift right with round, 3 */ Word32 L_sat (Word32 L_var1); /* Long saturation, 4 */ Word16 div_s (Word16 var1, Word16 var2); /* Short division, 18 */