NonSIMD Q31 saturation ALU Instructions
 __STATIC_FORCEINLINE unsigned long __RV_KABSW (signed long a)
 __STATIC_FORCEINLINE long __RV_KADDW (int a, int b)
 __STATIC_FORCEINLINE long __RV_KDMBB (unsigned int a, unsigned int b)
 __STATIC_FORCEINLINE long __RV_KDMBT (unsigned int a, unsigned int b)
 __STATIC_FORCEINLINE long __RV_KDMTT (unsigned int a, unsigned int b)
 __STATIC_FORCEINLINE long __RV_KDMABB (long t, unsigned int a, unsigned int b)
 __STATIC_FORCEINLINE long __RV_KDMABT (long t, unsigned int a, unsigned int b)
 __STATIC_FORCEINLINE long __RV_KDMATT (long t, unsigned int a, unsigned int b)
 __STATIC_FORCEINLINE long __RV_KSLLW (long a, unsigned int b)
 __STATIC_FORCEINLINE long __RV_KSLRAW (int a, int b)
 __STATIC_FORCEINLINE long __RV_KSLRAW_U (int a, int b)
 __STATIC_FORCEINLINE long __RV_KSUBW (int a, int b)
 __STATIC_FORCEINLINE unsigned long __RV_UKADDW (unsigned int a, unsigned int b)
 __STATIC_FORCEINLINE unsigned long __RV_UKSUBW (unsigned int a, unsigned int b)

__RV_KSLLIW(a, b)
 group NMSIS_Core_DSP_Intrinsic_NON_SIMD_Q31_SAT_ALU
NonSIMD Q31 saturation ALU Instructions.
there are NonSIMD Q31 saturation ALU Instructions
Defines

__RV_KSLLIW(a, b)
KSLLIW (Saturating Shift Left Logical Immediate for Word)
Type: DSP
Syntax:
KSLLIW Rd, Rs1, imm5u
Purpose
:
Do logical left shift operation with saturation on a 32bit word. The shift amount is an immediate value.
Description
:
The first word data in Rs1 is leftshifted logically. The shifted out bits are filled with zero and the shift amount is specified by the imm5u constant. Any shifted value greater than 2^311 is saturated to 2^311. Any shifted value smaller than 2^31 is saturated to 2^31. And the saturated result is signextended and written to Rd. If any saturation is performed, set OV bit to 1.
Operations:
sa = imm5u; res[(31+sa):0] = Rs1.W[0] << sa; if (res > (2^31)1) { res = 0x7fffffff; OV = 1; } else if (res < 2^31) { res = 0x80000000; OV = 1; } Rd[31:0] = res[31:0]; // RV32 Rd[63:0] = SE(res[31:0]); // RV64
 Parameters
a – [in] long type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in long type
Functions
 __STATIC_FORCEINLINE unsigned long __RV_KABSW (signed long a)
KABSW (Scalar 32bit Absolute Value with Saturation)
Type: DSP
Syntax:
KABSW Rd, Rs1
Purpose
:
Get the absolute value of a signed 32bit integer in a general register.
Description
:
This instruction calculates the absolute value of a signed 32bit integer stored in Rs1. The result is signextended (for RV64) and written to Rd. This instruction with the minimum negative integer input of 0x80000000 will produce a saturated output of maximum positive integer of 0x7fffffff and the OV flag will be set to 1.
Operations:
if (Rs1.W[0] >= 0) { res = Rs1.W[0]; } else { If (Rs1.W[0] == 0x80000000) { res = 0x7fffffff; OV = 1; } else { res = Rs1.W[0]; } } Rd = SE32(res);
 Parameters
a – [in] signed long type of value stored in a
 Returns
value stored in unsigned long type
 __STATIC_FORCEINLINE long __RV_KADDW (int a, int b)
KADDW (Signed Addition with Q31 Saturation)
Type: DSP
Syntax:
KADDW Rd, Rs1, Rs2
Purpose
:
Add the lower 32bit signed content of two registers with Q31 saturation.
Description
:
The lower 32bit signed content of Rs1 is added with the lower 32bit signed content of Rs2. And the result is saturated to the 32bit signed integer range of [2^31, 2^311] and then sign extended and written to Rd. If saturation happens, this instruction sets the OV flag.
Operations:
tmp = Rs1.W[0] + Rs2.W[0]; if (tmp > (2^31)1) { res = (2^31)1; OV = 1; } else if (tmp < 2^31) { res = 2^31; OV = 1 } else { res = tmp; } Rd = res[31:0]; // RV32 Rd = SE(res[31:0]) // RV64
 Parameters
a – [in] int type of value stored in a
b – [in] int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KDMBB (unsigned int a, unsigned int b)
KDMBB (Signed Saturating Double Multiply B16 x B16)
Type: DSP
Syntax:
KDMxy Rd, Rs1, Rs2 (xy = BB, BT, TT)
Purpose
:
Multiply the signed Q15 integer contents of two 16bit data in the corresponding portion of the lower 32bit chunk in registers and then double and saturate the Q31 result. The result is written into the destination register for RV32 or signextended to 64bits and written into the destination register for RV64. If saturation happens, an overflow flag OV will be set.
Description
:
Multiply the top or bottom 16bit Q15 content of the lower 32bit portion in Rs1 with the top or bottom 16bit Q15 content of the lower 32bit portion in Rs2. The Q30 result is then doubled and saturated into a Q31 value. The Q31 value is then written into Rd (signextended in RV64). When both the two Q15 inputs are 0x8000, saturation will happen. The result will be saturated to 0x7FFFFFFF and the overflow flag OV will be set.
Operations:
aop = Rs1.H[0]; bop = Rs2.H[0]; // KDMBB aop = Rs1.H[0]; bop = Rs2.H[1]; // KDMBT aop = Rs1.H[1]; bop = Rs2.H[1]; // KDMTT If (0x8000 != aop  0x8000 != bop) { Mresult = aop * bop; resQ31 = Mresult << 1; Rd = resQ31; // RV32 Rd = SE(resQ31); // RV64 } else { resQ31 = 0x7FFFFFFF; Rd = resQ31; // RV32 Rd = SE(resQ31); // RV64 OV = 1; }
 Parameters
a – [in] unsigned int type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KDMBT (unsigned int a, unsigned int b)
KDMBT (Signed Saturating Double Multiply B16 x T16)
Type: DSP
Syntax:
KDMxy Rd, Rs1, Rs2 (xy = BB, BT, TT)
Purpose
:
Multiply the signed Q15 integer contents of two 16bit data in the corresponding portion of the lower 32bit chunk in registers and then double and saturate the Q31 result. The result is written into the destination register for RV32 or signextended to 64bits and written into the destination register for RV64. If saturation happens, an overflow flag OV will be set.
Description
:
Multiply the top or bottom 16bit Q15 content of the lower 32bit portion in Rs1 with the top or bottom 16bit Q15 content of the lower 32bit portion in Rs2. The Q30 result is then doubled and saturated into a Q31 value. The Q31 value is then written into Rd (signextended in RV64). When both the two Q15 inputs are 0x8000, saturation will happen. The result will be saturated to 0x7FFFFFFF and the overflow flag OV will be set.
Operations:
aop = Rs1.H[0]; bop = Rs2.H[0]; // KDMBB aop = Rs1.H[0]; bop = Rs2.H[1]; // KDMBT aop = Rs1.H[1]; bop = Rs2.H[1]; // KDMTT If (0x8000 != aop  0x8000 != bop) { Mresult = aop * bop; resQ31 = Mresult << 1; Rd = resQ31; // RV32 Rd = SE(resQ31); // RV64 } else { resQ31 = 0x7FFFFFFF; Rd = resQ31; // RV32 Rd = SE(resQ31); // RV64 OV = 1; }
 Parameters
a – [in] unsigned int type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KDMTT (unsigned int a, unsigned int b)
KDMTT (Signed Saturating Double Multiply T16 x T16)
Type: DSP
Syntax:
KDMxy Rd, Rs1, Rs2 (xy = BB, BT, TT)
Purpose
:
Multiply the signed Q15 integer contents of two 16bit data in the corresponding portion of the lower 32bit chunk in registers and then double and saturate the Q31 result. The result is written into the destination register for RV32 or signextended to 64bits and written into the destination register for RV64. If saturation happens, an overflow flag OV will be set.
Description
:
Multiply the top or bottom 16bit Q15 content of the lower 32bit portion in Rs1 with the top or bottom 16bit Q15 content of the lower 32bit portion in Rs2. The Q30 result is then doubled and saturated into a Q31 value. The Q31 value is then written into Rd (signextended in RV64). When both the two Q15 inputs are 0x8000, saturation will happen. The result will be saturated to 0x7FFFFFFF and the overflow flag OV will be set.
Operations:
aop = Rs1.H[0]; bop = Rs2.H[0]; // KDMBB aop = Rs1.H[0]; bop = Rs2.H[1]; // KDMBT aop = Rs1.H[1]; bop = Rs2.H[1]; // KDMTT If (0x8000 != aop  0x8000 != bop) { Mresult = aop * bop; resQ31 = Mresult << 1; Rd = resQ31; // RV32 Rd = SE(resQ31); // RV64 } else { resQ31 = 0x7FFFFFFF; Rd = resQ31; // RV32 Rd = SE(resQ31); // RV64 OV = 1; }
 Parameters
a – [in] unsigned int type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KDMABB (long t, unsigned int a, unsigned int b)
KDMABB (Signed Saturating Double Multiply Addition B16 x B16)
Type: DSP
Syntax:
KDMAxy Rd, Rs1, Rs2 (xy = BB, BT, TT)
Purpose
:
Multiply the signed Q15 integer contents of two 16bit data in the corresponding portion of the lower 32bit chunk in registers and then double and saturate the Q31 result, add the result with the signextended lower 32bit chunk destination register and write the saturated addition result into the destination register. If saturation happens, an overflow flag OV will be set.
Description
:
Multiply the top or bottom 16bit Q15 content of the lower 32bit portion in Rs1 with the top or bottom 16bit Q15 content of the lower 32bit portion in Rs2. The Q30 result is then doubled and saturated into a Q31 value. The Q31 value is then added with the content of Rd. If the addition result is beyond the Q31 number range (2^31 <= Q31 <= 2^311), it is saturated to the range and the OV flag is set to 1. The result after saturation is written to Rd. When both the two Q15 inputs are 0x8000, saturation will happen and the overflow flag OV will be set.
Operations:
aop = Rs1.H[0]; bop = Rs2.H[0]; // KDMABB aop = Rs1.H[0]; bop = Rs2.H[1]; // KDMABT aop = Rs1.H[1]; bop = Rs2.H[1]; // KDMATT If (0x8000 != aop  0x8000 != bop) { Mresult = aop * bop; resQ31 = Mresult << 1; } else { resQ31 = 0x7FFFFFFF; OV = 1; } resadd = Rd + resQ31; // RV32 resadd = Rd.W[0] + resQ31; // RV64 if (resadd > (2^31)1) { resadd = (2^31)1; OV = 1; } else if (resadd < 2^31) { resadd = 2^31; OV = 1; } Rd = resadd; // RV32 Rd = SE(resadd); // RV64
 Parameters
t – [in] long type of value stored in t
a – [in] unsigned int type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KDMABT (long t, unsigned int a, unsigned int b)
KDMABT (Signed Saturating Double Multiply Addition B16 x T16)
Type: DSP
Syntax:
KDMAxy Rd, Rs1, Rs2 (xy = BB, BT, TT)
Purpose
:
Multiply the signed Q15 integer contents of two 16bit data in the corresponding portion of the lower 32bit chunk in registers and then double and saturate the Q31 result, add the result with the signextended lower 32bit chunk destination register and write the saturated addition result into the destination register. If saturation happens, an overflow flag OV will be set.
Description
:
Multiply the top or bottom 16bit Q15 content of the lower 32bit portion in Rs1 with the top or bottom 16bit Q15 content of the lower 32bit portion in Rs2. The Q30 result is then doubled and saturated into a Q31 value. The Q31 value is then added with the content of Rd. If the addition result is beyond the Q31 number range (2^31 <= Q31 <= 2^311), it is saturated to the range and the OV flag is set to 1. The result after saturation is written to Rd. When both the two Q15 inputs are 0x8000, saturation will happen and the overflow flag OV will be set.
Operations:
aop = Rs1.H[0]; bop = Rs2.H[0]; // KDMABB aop = Rs1.H[0]; bop = Rs2.H[1]; // KDMABT aop = Rs1.H[1]; bop = Rs2.H[1]; // KDMATT If (0x8000 != aop  0x8000 != bop) { Mresult = aop * bop; resQ31 = Mresult << 1; } else { resQ31 = 0x7FFFFFFF; OV = 1; } resadd = Rd + resQ31; // RV32 resadd = Rd.W[0] + resQ31; // RV64 if (resadd > (2^31)1) { resadd = (2^31)1; OV = 1; } else if (resadd < 2^31) { resadd = 2^31; OV = 1; } Rd = resadd; // RV32 Rd = SE(resadd); // RV64
 Parameters
t – [in] long type of value stored in t
a – [in] unsigned int type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KDMATT (long t, unsigned int a, unsigned int b)
KDMATT (Signed Saturating Double Multiply Addition T16 x T16)
Type: DSP
Syntax:
KDMAxy Rd, Rs1, Rs2 (xy = BB, BT, TT)
Purpose
:
Multiply the signed Q15 integer contents of two 16bit data in the corresponding portion of the lower 32bit chunk in registers and then double and saturate the Q31 result, add the result with the signextended lower 32bit chunk destination register and write the saturated addition result into the destination register. If saturation happens, an overflow flag OV will be set.
Description
:
Multiply the top or bottom 16bit Q15 content of the lower 32bit portion in Rs1 with the top or bottom 16bit Q15 content of the lower 32bit portion in Rs2. The Q30 result is then doubled and saturated into a Q31 value. The Q31 value is then added with the content of Rd. If the addition result is beyond the Q31 number range (2^31 <= Q31 <= 2^311), it is saturated to the range and the OV flag is set to 1. The result after saturation is written to Rd. When both the two Q15 inputs are 0x8000, saturation will happen and the overflow flag OV will be set.
Operations:
aop = Rs1.H[0]; bop = Rs2.H[0]; // KDMABB aop = Rs1.H[0]; bop = Rs2.H[1]; // KDMABT aop = Rs1.H[1]; bop = Rs2.H[1]; // KDMATT If (0x8000 != aop  0x8000 != bop) { Mresult = aop * bop; resQ31 = Mresult << 1; } else { resQ31 = 0x7FFFFFFF; OV = 1; } resadd = Rd + resQ31; // RV32 resadd = Rd.W[0] + resQ31; // RV64 if (resadd > (2^31)1) { resadd = (2^31)1; OV = 1; } else if (resadd < 2^31) { resadd = 2^31; OV = 1; } Rd = resadd; // RV32 Rd = SE(resadd); // RV64
 Parameters
t – [in] long type of value stored in t
a – [in] unsigned int type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KSLLW (long a, unsigned int b)
KSLLW (Saturating Shift Left Logical for Word)
Type: DSP
Syntax:
KSLLW Rd, Rs1, Rs2
Purpose
:
Do logical left shift operation with saturation on a 32bit word. The shift amount is a variable from a GPR.
Description
:
The first word data in Rs1 is leftshifted logically. The shifted out bits are filled with zero and the shift amount is specified by the loworder 5bits of the value in the Rs2 register. Any shifted value greater than 2^311 is saturated to 2^311. Any shifted value smaller than 2^31 is saturated to 2^31. And the saturated result is signextended and written to Rd. If any saturation is performed, set OV bit to 1.
Operations:
sa = Rs2[4:0]; res[(31+sa):0] = Rs1.W[0] << sa; if (res > (2^31)1) { res = 0x7fffffff; OV = 1; } else if (res < 2^31) { res = 0x80000000; OV = 1; } Rd[31:0] = res[31:0]; // RV32 Rd[63:0] = SE(res[31:0]); // RV64
 Parameters
a – [in] long type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KSLRAW (int a, int b)
KSLRAW (Shift Left Logical with Q31 Saturation or Shift Right Arithmetic)
Type: DSP
Syntax:
KSLRAW Rd, Rs1, Rs2
Purpose
:
Perform a logical left (positive) or arithmetic right (negative) shift operation with Q31 saturation for the left shift on a 32bit data.
Description
:
The lower 32bit content of Rs1 is leftshifted logically or rightshifted arithmetically based on the value of Rs2[5:0]. Rs2[5:0] is in the signed range of [25, 251]. A positive Rs2[5:0] means logical left shift and a negative Rs2[5:0] means arithmetic right shift. The shift amount is the absolute value of Rs2[5:0] clamped to the actual shift range of [0, 31]. The leftshifted result is saturated to the 32bit signed integer range of [2^31, 2^311]. After the shift operation, the final result is bit31 signextended and written to Rd. If any saturation happens, this instruction sets the OV flag. The value of Rs2[31:6] will not affected the operation of this instruction.
Operations:
if (Rs2[5:0] < 0) { sa = Rs2[5:0]; sa = (sa == 32)? 31 : sa; res[31:0] = Rs1.W[0] >>(arith) sa; } else { sa = Rs2[5:0]; tmp = Rs1.W[0] <<(logic) sa; if (tmp > (2^31)1) { res[31:0] = (2^31)1; OV = 1; } else if (tmp < 2^31) { res[31:0] = 2^31; OV = 1 } else { res[31:0] = tmp[31:0]; } } Rd = res[31:0]; // RV32 Rd = SE64(res[31:0]); // RV64
 Parameters
a – [in] int type of value stored in a
b – [in] int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KSLRAW_U (int a, int b)
KSLRAW.u (Shift Left Logical with Q31 Saturation or Rounding Shift Right Arithmetic)
Type: DSP
Syntax:
KSLRAW.u Rd, Rs1, Rs2
Purpose
:
Perform a logical left (positive) or arithmetic right (negative) shift operation with Q31 saturation for the left shift and a rounding up operation for the right shift on a 32bit data.
Description
:
The lower 32bit content of Rs1 is leftshifted logically or rightshifted arithmetically based on the value of Rs2[5:0]. Rs2[5:0] is in the signed range of [25, 251]. A positive Rs2[5:0] means logical left shift and a negative Rs2[5:0] means arithmetic right shift. The shift amount is the absolute value of Rs2[5:0] clamped to the actual shift range of [0, 31]. The leftshifted result is saturated to the 32bit signed integer range of [2^31, 2^311]. The rightshifted result is added a 1 to the most significant discarded bit position for rounding effect. After the shift, saturation, or rounding, the final result is bit31 signextended and written to Rd. If any saturation happens, this instruction sets the OV flag. The value of Rs2[31:6] will not affect the operation of this instruction.
Operations:
if (Rs2[5:0] < 0) { sa = Rs2[5:0]; sa = (sa == 32)? 31 : sa; res[31:1] = SE33(Rs1[31:(sa1)]) + 1; rst[31:0] = res[31:0]; } else { sa = Rs2[5:0]; tmp = Rs1.W[0] <<(logic) sa; if (tmp > (2^31)1) { rst[31:0] = (2^31)1; OV = 1; } else if (tmp < 2^31) { rst[31:0] = 2^31; OV = 1 } else { rst[31:0] = tmp[31:0]; } } Rd = rst[31:0]; // RV32 Rd = SE64(rst[31:0]); // RV64
 Parameters
a – [in] int type of value stored in a
b – [in] int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE long __RV_KSUBW (int a, int b)
KSUBW (Signed Subtraction with Q31 Saturation)
Type: DSP
Syntax:
KSUBW Rd, Rs1, Rs2
Purpose
:
Subtract the signed lower 32bit content of two registers with Q31 saturation.
Description
:
The signed lower 32bit content of Rs2 is subtracted from the signed lower 32bit content of Rs1. And the result is saturated to the 32bit signed integer range of [2^31, 2^311] and then signextened and written to Rd. If saturation happens, this instruction sets the OV flag.
Operations:
tmp = Rs1.W[0]  Rs2.W[0]; if (tmp > (2^31)1) { res = (2^31)1; OV = 1; } else if (tmp < 2^31) { res = 2^31; OV = 1 } else { res = tmp; } Rd = res[31:0]; // RV32 Rd = SE(res[31:0]); // RV64
 Parameters
a – [in] int type of value stored in a
b – [in] int type of value stored in b
 Returns
value stored in long type
 __STATIC_FORCEINLINE unsigned long __RV_UKADDW (unsigned int a, unsigned int b)
UKADDW (Unsigned Addition with U32 Saturation)
Type: DSP
Syntax:
UKADDW Rd, Rs1, Rs2
Purpose
:
Add the unsigned lower 32bit content of two registers with U32 saturation.
Description
:
The unsigned lower 32bit content of Rs1 is added with the unsigned lower 32bit content of Rs2. And the result is saturated to the 32bit unsigned integer range of [0, 2^321] and then signextended and written to Rd. If saturation happens, this instruction sets the OV flag.
Operations:
tmp = Rs1.W[0] + Rs2.W[0]; if (tmp > (2^32)1) { tmp[31:0] = (2^32)1; OV = 1; } Rd = tmp[31:0]; // RV32 Rd = SE(tmp[31:0]); // RV64
 Parameters
a – [in] unsigned int type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in unsigned long type
 __STATIC_FORCEINLINE unsigned long __RV_UKSUBW (unsigned int a, unsigned int b)
UKSUBW (Unsigned Subtraction with U32 Saturation)
Type: DSP
Syntax:
UKSUBW Rd, Rs1, Rs2
Purpose
:
Subtract the unsigned lower 32bit content of two registers with unsigned 32bit saturation.
Description
:
The unsigned lower 32bit content of Rs2 is subtracted from the unsigned lower 32bit content of Rs1. And the result is saturated to the 32bit unsigned integer range of [0, 2^321] and then signextended and written to Rd. If saturation happens, this instruction sets the OV flag.
Operations:
tmp = Rs1.W[0]  Rs2.W[0]; if (tmp < 0) { tmp[31:0] = 0; OV = 1; } Rd = tmp[31:0]; // RV32 Rd = SE(tmp[31:0]); // RV64
 Parameters
a – [in] unsigned int type of value stored in a
b – [in] unsigned int type of value stored in b
 Returns
value stored in unsigned long type

__RV_KSLLIW(a, b)