/* ** Copyright 2003-2010, VisualOn, Inc. ** ** Licensed under the Apache License, Version 2.0 (the "License"); ** you may not use this file except in compliance with the License. ** You may obtain a copy of the License at ** ** http://www.apache.org/licenses/LICENSE-2.0 ** ** Unless required by applicable law or agreed to in writing, software ** distributed under the License is distributed on an "AS IS" BASIS, ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ** See the License for the specific language governing permissions and ** limitations under the License. */ #ifndef __BASIC_OP_H__ #define __BASIC_OP_H__ #include #include #include "typedef.h" #define MAX_32 (Word32)0x7fffffffL #define MIN_32 (Word32)0x80000000L #define MAX_16 ((Word16)+32767) /* 0x7fff */ #define MIN_16 ((Word16)-32768) /* 0x8000 */ #define static_vo static __inline #define saturate(L_var1) (((L_var1) > 0X00007fffL) ? (MAX_16): (((L_var1) < (Word32) 0xffff8000L) ? (MIN_16): ((L_var1) & 0xffff))) #define abs_s(x) ((Word16)(((x) != MIN_16) ? (((x) >= 0) ? (x) : (-(x))) : MAX_16)) /* Short abs, 1 */ #define L_deposit_h(x) (((Word32)(x)) << 16) /* 16 bit var1 -> MSB, 2 */ #define L_deposit_l(x) ((Word32)(x)) /* 16 bit var1 -> LSB, 2 */ #define L_abs(x) (((x) != MIN_32) ? (((x) >= 0) ? (x) : (-(x))) : MAX_32) /* Long abs, 3*/ #define negate(var1) ((Word16)(((var1) == MIN_16) ? MAX_16 : (-(var1)))) /* Short negate, 1*/ #define L_negate(L_var1) (((L_var1) == (MIN_32)) ? (MAX_32) : (-(L_var1))) /* Long negate, 2*/ #define extract_h(a) ((Word16)((a) >> 16)) #define extract_l(x) (Word16)((x)) #define add1(a,b) ((a) + (b)) #define vo_L_msu(a,b,c) ((a) - (((b) * (c)) << 1)) #define vo_mult32(a, b) ((a) * (b)) #define vo_mult(a,b) (((a) * (b)) >> 15) #define vo_L_mult(a,b) (((a) * (b)) << 1) #define vo_shr_r(var1, var2) (((var1)+((Word16)(1L<<((var2)-1))))>>(var2)) #define vo_sub(a,b) ((a) - (b)) #define vo_L_deposit_h(a) ((Word32)((a) << 16)) #define vo_round(a) ((((a) >> 15) + 1) >> 1) #define vo_extract_l(a) ((Word16)(a)) #define vo_L_add(a,b) ((a) + (b)) #define vo_L_sub(a,b) ((a) - (b)) #define vo_mult_r(a,b) (((( (a) * (b) ) >> 14) + 1 ) >> 1 ) #define vo_negate(a) (-(a)) #define vo_L_shr_r(L_var1, var2) (((L_var1)+((Word32)(1L<<((var2)-1))))>>(var2)) /*___________________________________________________________________________ | | | Prototypes for basic arithmetic operators | |___________________________________________________________________________| */ static_vo Word16 add (Word16 var1, Word16 var2); /* Short add,1 */ static_vo Word16 sub (Word16 var1, Word16 var2); /* Short sub,1 */ static_vo Word16 shl (Word16 var1, Word16 var2); /* Short shift left, 1 */ static_vo Word16 shr (Word16 var1, Word16 var2); /* Short shift right, 1 */ static_vo Word16 mult (Word16 var1, Word16 var2); /* Short mult, 1 */ static_vo Word32 L_mult (Word16 var1, Word16 var2); /* Long mult, 1 */ static_vo Word16 voround (Word32 L_var1); /* Round, 1 */ static_vo Word32 L_mac (Word32 L_var3, Word16 var1, Word16 var2); /* Mac, 1 */ static_vo Word32 L_msu (Word32 L_var3, Word16 var1, Word16 var2); /* Msu, 1 */ static_vo Word32 L_add (Word32 L_var1, Word32 L_var2); /* Long add, 2 */ static_vo Word32 L_sub (Word32 L_var1, Word32 L_var2); /* Long sub, 2 */ static_vo Word16 mult_r (Word16 var1, Word16 var2); /* Mult with round, 2 */ static_vo Word32 L_shl2(Word32 L_var1, Word16 var2); /* var2 > 0*/ static_vo Word32 L_shl (Word32 L_var1, Word16 var2); /* Long shift left, 2 */ static_vo Word32 L_shr (Word32 L_var1, Word16 var2); /* Long shift right, 2*/ static_vo Word32 L_shr_r (Word32 L_var1, Word16 var2); /* Long shift right with round, 3 */ static_vo Word16 norm_s (Word16 var1); /* Short norm, 15 */ static_vo Word16 div_s (Word16 var1, Word16 var2); /* Short division, 18 */ static_vo Word16 norm_l (Word32 L_var1); /* Long norm, 30 */ /*___________________________________________________________________________ | | | Functions | |___________________________________________________________________________| */ /*___________________________________________________________________________ | | | 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_vo Word16 add (Word16 var1, Word16 var2) { Word16 var_out; Word32 L_sum; L_sum = (Word32) var1 + var2; var_out = saturate (L_sum); return (var_out); } /*___________________________________________________________________________ | | | 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_vo Word16 sub (Word16 var1, Word16 var2) { Word16 var_out; Word32 L_diff; L_diff = (Word32) var1 - var2; var_out = saturate (L_diff); return (var_out); } /*___________________________________________________________________________ | | | 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_vo Word16 shl (Word16 var1, Word16 var2) { Word16 var_out; Word32 result; if (var2 < 0) { if (var2 < -16) var2 = -16; var_out = var1 >> ((Word16)-var2); } else { if (var2 > 15 && var1 != 0) { var_out = (Word16)((var1 > 0) ? MAX_16 : MIN_16); } else { result = (Word32) var1 *((Word32) 1 << var2); if ((result != (Word32) ((Word16) result))) { var_out = (Word16)((var1 > 0) ? MAX_16 : MIN_16); } else { var_out = extract_l (result); } } } 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_vo Word16 shr (Word16 var1, Word16 var2) { Word16 var_out; if (var2 < 0) { if (var2 < -16) var2 = -16; var_out = shl(var1, (Word16)-var2); } else { if (var2 >= 15) { var_out = (Word16)((var1 < 0) ? -1 : 0); } else { if (var1 < 0) { var_out = (Word16)(~((~var1) >> var2)); } else { var_out = (Word16)(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_vo Word16 mult (Word16 var1, Word16 var2) { Word16 var_out; Word32 L_product; L_product = (Word32) var1 *(Word32) var2; L_product = (L_product & (Word32) 0xffff8000L) >> 15; if (L_product & (Word32) 0x00010000L) L_product = L_product | (Word32) 0xffff0000L; var_out = saturate (L_product); return (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_vo Word32 L_mult (Word16 var1, Word16 var2) { Word32 L_var_out; L_var_out = (Word32) var1 *(Word32) var2; if (L_var_out != (Word32) 0x40000000L) { L_var_out *= 2; } else { L_var_out = MAX_32; } return (L_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_vo Word16 voround (Word32 L_var1) { Word16 var_out; Word32 L_rounded; L_rounded = L_add (L_var1, (Word32) 0x00008000L); var_out = extract_h (L_rounded); return (var_out); } /*___________________________________________________________________________ | | | 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_vo Word32 L_mac (Word32 L_var3, Word16 var1, Word16 var2) { Word32 L_var_out; Word32 L_product; L_product = ((var1 * var2) << 1); 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_vo Word32 L_msu (Word32 L_var3, Word16 var1, Word16 var2) { Word32 L_var_out; Word32 L_product; L_product = (var1 * var2)<<1; L_var_out = L_sub (L_var3, L_product); return (L_var_out); } /*___________________________________________________________________________ | | | 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. | |___________________________________________________________________________| */ __attribute__((no_sanitize("integer"))) static_vo Word32 L_add (Word32 L_var1, Word32 L_var2) { Word32 L_var_out; if (__builtin_add_overflow(L_var1, L_var2, &L_var_out)) { // saturating... 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. | |___________________________________________________________________________| */ __attribute__((no_sanitize("integer"))) static_vo Word32 L_sub (Word32 L_var1, Word32 L_var2) { Word32 L_var_out; if (__builtin_sub_overflow(L_var1, L_var2, &L_var_out)) { // saturating... L_var_out = (L_var1 < 0L) ? MIN_32 : MAX_32; } return (L_var_out); } /*___________________________________________________________________________ | | | 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_vo 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 (L_product_arr & (Word32) 0x00010000L) /* sign extend when necessary */ { L_product_arr |= (Word32) 0xffff0000L; } var_out = saturate (L_product_arr); return (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_vo Word32 L_shl (Word32 L_var1, Word16 var2) { Word32 L_var_out = 0L; if (var2 <= 0) { if (var2 < -32) var2 = -32; L_var_out = (L_var1 >> (Word16)-var2); } else { for (; var2 > 0; var2--) { if (L_var1 > (Word32) 0X3fffffffL) { L_var_out = MAX_32; break; } else { if (L_var1 < (Word32) 0xc0000000L) { //Overflow = 1; L_var_out = MIN_32; break; } } L_var1 *= 2; L_var_out = L_var1; } } return (L_var_out); } static_vo Word32 L_shl2(Word32 L_var1, Word16 var2) { Word32 L_var_out = 0L; for (; var2 > 0; var2--) { if (L_var1 > (Word32) 0X3fffffffL) { L_var_out = MAX_32; break; } else { if (L_var1 < (Word32) 0xc0000000L) { L_var_out = MIN_32; break; } } L_var1 *= 2 ; L_var_out = L_var1; } 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_vo Word32 L_shr (Word32 L_var1, Word16 var2) { Word32 L_var_out; if (var2 < 0) { if (var2 < -32) var2 = -32; L_var_out = L_shl2(L_var1, (Word16)-var2); } else { if (var2 >= 31) { L_var_out = (L_var1 < 0L) ? -1 : 0; } else { if (L_var1 < 0) { L_var_out = ~((~L_var1) >> var2); } else { L_var_out = L_var1 >> var2; } } } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_shr_r | | | | Purpose : | | | | Same as L_shr(L_var1,var2) but with rounding. Saturate the result in | | case of underflows or overflows : | | - If var2 is greater than zero : | | if (L_sub(L_shl(L_shr(L_var1,var2),1),L_shr(L_var1,sub(var2,1))))| | is equal to zero | | then | | L_shr_r(L_var1,var2) = L_shr(L_var1,var2) | | else | | L_shr_r(L_var1,var2) = L_add(L_shr(L_var1,var2),1) | | - If var2 is less than or equal to zero : | | L_shr_r(L_var1,var2) = L_shr(L_var1,var2). | | | | Complexity weight : 3 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var1 <= 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 <= var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ static_vo Word32 L_shr_r (Word32 L_var1, Word16 var2) { Word32 L_var_out; if (var2 > 31) { L_var_out = 0; } else { L_var_out = L_shr (L_var1, var2); if (var2 > 0) { if ((L_var1 & ((Word32) 1 << (var2 - 1))) != 0) { L_var_out++; } } } return (L_var_out); } /*___________________________________________________________________________ | | | 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_vo Word16 norm_s (Word16 var1) { Word16 var_out = 0; if (var1 == 0) { var_out = 0; } else { if (var1 == -1) { var_out = 15; } else { if (var1 < 0) { var1 = (Word16)~var1; } for (var_out = 0; var1 < 0x4000; var_out++) { var1 <<= 1; } } } return (var_out); } /*___________________________________________________________________________ | | | Function Name : div_s | | | | Purpose : | | | | Produces a result which is the fractional integer division of var1 by | | var2; var1 and var2 must be positive and var2 must be greater or equal | | to var1; the result is positive (leading bit equal to 0) and truncated | | to 16 bits. | | If var1 = var2 then div(var1,var2) = 32767. | | | | Complexity weight : 18 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 0000 <= var1 <= var2 and var2 != 0. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : var1 <= var2 <= 0x0000 7fff and var2 != 0. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 0000 <= var_out <= 0x0000 7fff. | | It's a Q15 value (point between b15 and b14). | |___________________________________________________________________________| */ static_vo Word16 div_s (Word16 var1, Word16 var2) { Word16 var_out = 0; Word16 iteration; Word32 L_num; Word32 L_denom; if ((var1 < 0) || (var2 < 0)) { var_out = MAX_16; return var_out; } if (var2 == 0) { var_out = MAX_16; return var_out; } if (var1 == 0) { var_out = 0; } else { if (var1 == var2) { var_out = MAX_16; } else { L_num = L_deposit_l (var1); L_denom = L_deposit_l(var2); for (iteration = 0; iteration < 15; iteration++) { var_out <<= 1; L_num <<= 1; if (L_num >= L_denom) { L_num -= L_denom; var_out += 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_vo Word16 norm_l (Word32 L_var1) { Word16 var_out = 0; if (L_var1 != 0) { var_out = 31; if (L_var1 != (Word32) 0xffffffffL) { L_var1 ^= (L_var1 >>31); for (var_out = 0; L_var1 < (Word32) 0x40000000L; var_out++) { L_var1 <<= 1; } } } return (var_out); } #endif //__BASIC_OP_H__