SIMD 8-bit Miscellaneous Instructions

__STATIC_FORCEINLINE unsigned long __RV_CLRS8 (unsigned long a)

__STATIC_FORCEINLINE unsigned long __RV_CLO8 (unsigned long a)

__STATIC_FORCEINLINE unsigned long __RV_CLZ8 (unsigned long a)

__STATIC_FORCEINLINE unsigned long __RV_KABS8 (unsigned long a)

__STATIC_FORCEINLINE unsigned long __RV_SMAX8 (unsigned long a, unsigned long b)

__STATIC_FORCEINLINE unsigned long __RV_SMIN8 (unsigned long a, unsigned long b)

__STATIC_FORCEINLINE unsigned long __RV_UMAX8 (unsigned long a, unsigned long b)

__STATIC_FORCEINLINE unsigned long __RV_UMIN8 (unsigned long a, unsigned long b)

__RV_SCLIP8(a, b)

__RV_UCLIP8(a, b)

group NMSIS_Core_DSP_Intrinsic_SIMD_8B_MISC

SIMD 8-bit Miscellaneous Instructions.

there are 10 SIMD 8-bit Miscellaneous instructions.

Defines

__RV_SCLIP8(a, b)

SCLIP8 (SIMD 8-bit Signed Clip Value)

Type: SIMD

Syntax:

SCLIP8 Rd, Rs1, imm3u[2:0]

Purpose

:

Limit the 8-bit signed integer elements of a register into a signed range simultaneously.

Description

:

This instruction limits the 8-bit signed integer elements stored in Rs1 into a signed integer range between 2^imm3u-1 and -2^imm3u, and writes the limited results to Rd. For example, if imm3u is 3, the 8-bit input values should be saturated between 7 and -8. If saturation is performed, set OV bit to 1.

Operations:

src = Rs1.B[x];
if (src > (2^imm3u)-1) {
  src = (2^imm3u)-1;
  OV = 1;
} else if (src < -2^imm3u) {
  src = -2^imm3u;
  OV = 1;
}
Rd.B[x] = src
for RV32: x=3...0,
for RV64: x=7...0

Parameters

a – [in] unsigned long type of value stored in a
b – [in] unsigned int type of value stored in b

Returns

value stored in unsigned long type

__RV_UCLIP8(a, b)

UCLIP8 (SIMD 8-bit Unsigned Clip Value)

Type: SIMD

Syntax:

UCLIP8 Rt, Ra, imm3u

Purpose

:

Limit the 8-bit signed elements of a register into an unsigned range simultaneously.

Description

:

This instruction limits the 8-bit signed elements stored in Rs1 into an unsigned integer range between 2^imm3u-1 and 0, and writes the limited results to Rd. For example, if imm3u is 3, the 8- bit input values should be saturated between 7 and 0. If saturation is performed, set OV bit to 1.

Operations:

src = Rs1.H[x];
if (src > (2^imm3u)-1) {
  src = (2^imm3u)-1;
  OV = 1;
} else if (src < 0) {
  src = 0;
  OV = 1;
}
Rd.H[x] = src;
for RV32: x=3...0,
for RV64: x=7...0

Parameters

a – [in] unsigned long type of value stored in a
b – [in] unsigned int type of value stored in b

Returns

value stored in unsigned long type

Functions

__STATIC_FORCEINLINE unsigned long __RV_CLRS8 (unsigned long a)

CLRS8 (SIMD 8-bit Count Leading Redundant Sign)

Type: SIMD

Syntax:

CLRS8 Rd, Rs1

Purpose

:

Count the number of redundant sign bits of the 8-bit elements of a general register.

Description

:

Starting from the bits next to the sign bits of the 8-bit elements of Rs1, this instruction counts the number of redundant sign bits and writes the result to the corresponding 8-bit elements of Rd.

Operations:

snum[x] = Rs1.B[x];
cnt[x] = 0;
for (i = 6 to 0) {
  if (snum[x](i) == snum[x](7)) {
    cnt[x] = cnt[x] + 1;
  } else {
    break;
  }
}
Rd.B[x] = cnt[x];
for RV32: x=3...0
for RV64: x=7...0

Parameters: a – [in] unsigned long type of value stored in a
Returns: value stored in unsigned long type

__STATIC_FORCEINLINE unsigned long __RV_CLO8 (unsigned long a)

CLO8 (SIMD 8-bit Count Leading One)

Type: SIMD

Syntax:

CLO8 Rd, Rs1

Purpose

:

Count the number of leading one bits of the 8-bit elements of a general register.

Description

:

Starting from the most significant bits of the 8-bit elements of Rs1, this instruction counts the number of leading one bits and writes the results to the corresponding 8-bit elements of Rd.

Operations:

snum[x] = Rs1.B[x];
cnt[x] = 0;
  for (i = 7 to 0) {
  if (snum[x](i) == 1) {
    cnt[x] = cnt[x] + 1;
  } else {
    break;
  }
}
Rd.B[x] = cnt[x];
for RV32: x=3...0
for RV64: x=7...0

Parameters: a – [in] unsigned long type of value stored in a
Returns: value stored in unsigned long type

__STATIC_FORCEINLINE unsigned long __RV_CLZ8 (unsigned long a)

CLZ8 (SIMD 8-bit Count Leading Zero)

Type: SIMD

Syntax:

CLZ8 Rd, Rs1

Purpose

:

Count the number of leading zero bits of the 8-bit elements of a general register.

Description

:

Starting from the most significant bits of the 8-bit elements of Rs1, this instruction counts the number of leading zero bits and writes the results to the corresponding 8-bit elements of Rd.

Operations:

snum[x] = Rs1.B[x];
cnt[x] = 0;
for (i = 7 to 0) {
  if (snum[x](i) == 0) {
    cnt[x] = cnt[x] + 1;
  } else {
    break;
  }
}
Rd.B[x] = cnt[x];
for RV32: x=3...0
for RV64: x=7...0

Parameters: a – [in] unsigned long type of value stored in a
Returns: value stored in unsigned long type

__STATIC_FORCEINLINE unsigned long __RV_KABS8 (unsigned long a)

KABS8 (SIMD 8-bit Saturating Absolute)

Type: SIMD

Syntax:

KABS8 Rd, Rs1

Purpose

:

Get the absolute value of 8-bit signed integer elements simultaneously.

Description

:

This instruction calculates the absolute value of 8-bit signed integer elements stored in Rs1 and writes the element results to Rd. If the input number is 0x80, this instruction generates 0x7f as the output and sets the OV bit to 1.

Operations:

src = Rs1.B[x];
if (src == 0x80) {
  src = 0x7f;
  OV = 1;
} else if (src[7] == 1)
  src = -src;
}
Rd.B[x] = src;
for RV32: x=3...0,
for RV64: x=7...0

Parameters: a – [in] unsigned long type of value stored in a
Returns: value stored in unsigned long type

__STATIC_FORCEINLINE unsigned long __RV_SMAX8 (unsigned long a, unsigned long b)

SMAX8 (SIMD 8-bit Signed Maximum)

Type: SIMD

Syntax:

SMAX8 Rd, Rs1, Rs2

Purpose

:

Do 8-bit signed integer elements finding maximum operations simultaneously.

Description

:

This instruction compares the 8-bit signed integer elements in Rs1 with the 8-bit signed integer elements in Rs2 and selects the numbers that is greater than the other one. The selected results are written to Rd.

Operations:

Rd.B[x] = (Rs1.B[x] > Rs2.B[x])? Rs1.B[x] : Rs2.B[x];
for RV32: x=3...0,
for RV64: x=7...0

Parameters

a – [in] unsigned long type of value stored in a
b – [in] unsigned long type of value stored in b

Returns

value stored in unsigned long type

__STATIC_FORCEINLINE unsigned long __RV_SMIN8 (unsigned long a, unsigned long b)

SMIN8 (SIMD 8-bit Signed Minimum)

Type: SIMD

Syntax:

SMIN8 Rd, Rs1, Rs2

Purpose

:

Do 8-bit signed integer elements finding minimum operations simultaneously.

Description

:

This instruction compares the 8-bit signed integer elements in Rs1 with the 8-bit signed integer elements in Rs2 and selects the numbers that is less than the other one. The selected results are written to Rd.

Operations:

Rd.B[x] = (Rs1.B[x] < Rs2.B[x])? Rs1.B[x] : Rs2.B[x];
for RV32: x=3...0,
for RV64: x=7...0

Parameters

a – [in] unsigned long type of value stored in a
b – [in] unsigned long type of value stored in b

Returns

value stored in unsigned long type

__STATIC_FORCEINLINE unsigned long __RV_UMAX8 (unsigned long a, unsigned long b)

UMAX8 (SIMD 8-bit Unsigned Maximum)

Type: SIMD

Syntax:

UMAX8 Rd, Rs1, Rs2

Purpose

:

Do 8-bit unsigned integer elements finding maximum operations simultaneously.

Description

:

This instruction compares the 8-bit unsigned integer elements in Rs1 with the four 8- bit unsigned integer elements in Rs2 and selects the numbers that is greater than the other one. The two selected results are written to Rd.

Operations:

Rd.B[x] = (Rs1.B[x] >u Rs2.B[x])? Rs1.B[x] : Rs2.B[x];
for RV32: x=3...0,
for RV64: x=7...0

Parameters

a – [in] unsigned long type of value stored in a
b – [in] unsigned long type of value stored in b

Returns

value stored in unsigned long type

__STATIC_FORCEINLINE unsigned long __RV_UMIN8 (unsigned long a, unsigned long b)

UMIN8 (SIMD 8-bit Unsigned Minimum)

Type: SIMD

Syntax:

UMIN8 Rd, Rs1, Rs2

Purpose

:

Do 8-bit unsigned integer elements finding minimum operations simultaneously.

Description

:

This instruction compares the 8-bit unsigned integer elements in Rs1 with the 8-bit unsigned integer elements in Rs2 and selects the numbers that is less than the other one. The selected results are written to Rd.

Operations:

Rd.B[x] = (Rs1.B[x] <u Rs2.B[x])? Rs1.B[x] : Rs2.B[x];
for RV32: x=3...0,
for RV64: x=7...0

Parameters

a – [in] unsigned long type of value stored in a
b – [in] unsigned long type of value stored in b

Returns

value stored in unsigned long type