AE_NSA64 — compute left shift amount to normalize AE_DR register, write to AR register

Instruction Word

Slot
ae2_slot0
6
3
6
2
6
1
6
0
5
9
5
8
5
7
5
6
5
5
5
4
5
3
5
2
5
1
5
0
4
9
4
8
4
7
4
6
4
5
4
4
4
3
4
2
4
1
4
0
3
9
3
8
3
7
3
6
3
5
3
4
3
3
3
2
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9876543210
Format ae_format2 - 64 bit(s)0000 1110
AE_NSA64 1000000000011010 0100 1111
r 3210
ae_fld_dr_to_ar_v0 3210

Slot
ae_slot0
6
3
6
2
6
1
6
0
5
9
5
8
5
7
5
6
5
5
5
4
5
3
5
2
5
1
5
0
4
9
4
8
4
7
4
6
4
5
4
4
4
3
4
2
4
1
4
0
3
9
3
8
3
7
3
6
3
5
3
4
3
3
3
2
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9876543210
Format ae_format - 64 bit(s) 1111
AE_NSA64 11001000 1010
r 3210
ae_fld_dr_to_ar_v0 3210

Slot
Inst
6
3
6
2
6
1
6
0
5
9
5
8
5
7
5
6
5
5
5
4
5
3
5
2
5
1
5
0
4
9
4
8
4
7
4
6
4
5
4
4
4
3
4
2
4
1
4
0
3
9
3
8
3
7
3
6
3
5
3
4
3
3
3
2
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9876543210
Format x24 - 24 bit(s) 0
AE_NSA64 00100101 11010100
r 3210
ae_fld_dr_to_ar_v0 3210

Slot
ae_slot0
6
3
6
2
6
1
6
0
5
9
5
8
5
7
5
6
5
5
5
4
5
3
5
2
5
1
5
0
4
9
4
8
4
7
4
6
4
5
4
4
4
3
4
2
4
1
4
0
3
9
3
8
3
7
3
6
3
5
3
4
3
3
3
2
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9876543210
Format ae_format1 - 64 bit(s)1 1110
AE_NSA64 11001000 1010
r 3210
ae_fld_dr_to_ar_v0 3210

Assembler Syntax

AE_NSA64 a0..15(arr), aed0..15(ae_dr_to_ar_v0)

C Syntax

#include <xtensa/tie/xt_hifi2.h>

extern int AE_NSA64(ae_int64 d0);

Description

AE_NSA64 calculates the left shift amount that will normalize the two's complement contents of an AE_DR register and writes the amount (in the range of 0 to 63) to AR register a. If d0 contains 0 or -1, return 63. To calculate the normalization exponent for a 9.55 fraction, subtract 8 from the result. If the result is negative, a right shift is required for normalization.

Implementation Pipeline

In Out
ae_dr_to_ar_v0 Mstage arr Mstage

Protos that use AE_NSA64

proto AE_NSA64 { out int32 a, in ae_int64 d0 }{}{
AE_NSA64 a, d0;
}
proto AE_NSAQ56S { out int32 a, in ae_q56s d0 }{int32 t}{
AE_NSA64 t, d0;
ADDI a, t, -8;
}