Encoding:

Format:

CMPGU.cond.QB 

CMPGU.EQ.QB  rd, rs, rt

CMPGU.LT.QB  rd, rs, rt

CMPGU.LE.QB  rd, rs, rt

Purpose:

Compare Vectors of Unsigned Byte Values and Write Results to a GPR

Perform an element-wise comparison of two vectors of unsigned bytes, recording the results of the comparison in condition code bits that are written to the specified GPR.

Description:

rd = (rs31..24 cond rt31..24) || (rs23..16 cond rt23..16) || (rs15..8 condrt15..8) 
|| (rs7..0 cond rt7..0)

Each of the unsigned byte elements in register rs are compared with the corresponding unsigned byte elements in register rt. The four 1-bit boolean comparison results are written to the four least-significant bits of destination register

rd. The remaining bits in rd are set to zero.

Restrictions:

No data-dependent exceptions are possible.

The operands must be values in the specified format. If they are not, the results are UNPREDICTABLE and the values of the operand vectors become UNPREDICTABLE.

Operation:

CMPGU.EQ.QB
   ValidateAccessToDSPResources()
   ccD = GPR[rs]31..24 EQ GPR[rt]31..24 
   ccC = GPR[rs]23..16 EQ GPR[rt]23..16 
   ccB = GPR[rs]15..8 EQ GPR[rt]15..8 
   ccA = GPR[rs]7..0 EQ GPR[rt]7..0 
   GPR[rd]31..0 = 0(GPRLEN-4) || ccD || ccC || ccB || ccA
CMPGU.LT.QB
   ValidateAccessToDSPResources()
   ccD = GPR[rs]31..24 LT GPR[rt]31..24 
   ccC = GPR[rs]23..16 LT GPR[rt]23..16 
   ccB = GPR[rs]15..8 LT GPR[rt]15..8 
   ccA = GPR[rs]7..0 LT GPR[rt]7..0 
   GPR[rd]31..0 = 0(GPRLEN-4) || ccD || ccC || ccB || ccA
CMPGU.LE.QB
   ValidateAccessToDSPResources()
   ccB = GPR[rs]15..8 LE GPR[rt]15..8 
   ccA = GPR[rs]7..0 LE GPR[rt]7..0 
   GPR[rd]31..0 = 0(GPRLEN-4) || ccD || ccC || ccB || ccA

Exceptions:

Reserved Instruction, DSP Disabled