target/mips: Amend MXU ASE overview note

Add prefix, suffix, operation descriptions, and other corrections
and amendments to the comment that describes MXU ASE.

Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
This commit is contained in:
Aleksandar Markovic 2018-10-24 14:12:34 +02:00
parent e5bf8a0829
commit 093ade1217

View File

@ -1410,25 +1410,89 @@ enum {
* MXU unit contains 17 registers called X0-X16. X0 is always zero, and X16 is
* the control register.
*
* The notation used in MXU assembler mnemonics:
* The notation used in MXU assembler mnemonics
* --------------------------------------------
*
* Registers:
*
* XRa, XRb, XRc, XRd - MXU registers
* Rb, Rc, Rd, Rs, Rt - general purpose MIPS registers
* s12 - a subfield of an instruction code
* strd2 - a subfield of an instruction code
* eptn2 - a subfield of an instruction code
* eptn3 - a subfield of an instruction code
* optn2 - a subfield of an instruction code
* optn3 - a subfield of an instruction code
* sft4 - a subfield of an instruction code
*
* Subfields:
*
* aptn1 - 1-bit accumulate add/subtract pattern
* aptn2 - 2-bit accumulate add/subtract pattern
* eptn2 - 2-bit execute add/subtract pattern
* optn2 - 2-bit operand pattern
* optn3 - 3-bit operand pattern
* sft4 - 4-bit shift amount
* strd2 - 2-bit stride amount
*
* Prefixes:
*
* <Operation parallel level><Operand size>
* S 32
* D 16
* Q 8
*
* Suffixes:
*
* E - Expand results
* F - Fixed point multiplication
* L - Low part result
* R - Doing rounding
* V - Variable instead of immediate
* W - Combine above L and V
*
* Operations:
*
* ADD - Add or subtract
* ADDC - Add with carry-in
* ACC - Accumulate
* ASUM - Sum together then accumulate (add or subtract)
* ASUMC - Sum together then accumulate (add or subtract) with carry-in
* AVG - Average between 2 operands
* ABD - Absolute difference
* ALN - Align data
* AND - Logical bitwise 'and' operation
* CPS - Copy sign
* EXTR - Extract bits
* I2M - Move from GPR register to MXU register
* LDD - Load data from memory to XRF
* LDI - Load data from memory to XRF (and increase the address base)
* LUI - Load unsigned immediate
* MUL - Multiply
* MULU - Unsigned multiply
* MADD - 64-bit operand add 32x32 product
* MSUB - 64-bit operand subtract 32x32 product
* MAC - Multiply and accumulate (add or subtract)
* MAD - Multiply and add or subtract
* MAX - Maximum between 2 operands
* MIN - Minimum between 2 operands
* M2I - Move from MXU register to GPR register
* MOVZ - Move if zero
* MOVN - Move if non-zero
* NOR - Logical bitwise 'nor' operation
* OR - Logical bitwise 'or' operation
* STD - Store data from XRF to memory
* SDI - Store data from XRF to memory (and increase the address base)
* SLT - Set of less than comparison
* SAD - Sum of absolute differences
* SLL - Logical shift left
* SLR - Logical shift right
* SAR - Arithmetic shift right
* SAT - Saturation
* SFL - Shuffle
* SCOP - Calculate xs scope (-1, means x<0; 0, means x==0; 1, means x>0)
* XOR - Logical bitwise 'exclusive or' operation
*
* Load/Store instructions Multiplication instructions
* ----------------------- ---------------------------
*
* S32LDD XRa, Rb, s12 S32MADD XRa, XRd, Rs, Rt
* S32STD XRa, Rb, s12 S32MADDU XRa, XRd, Rs, Rt
* S32LDDV XRa, Rb, rc, strd2 S32SUB XRa, XRd, Rs, Rt
* S32STDV XRa, Rb, rc, strd2 S32SUBU XRa, XRd, Rs, Rt
* S32LDDV XRa, Rb, rc, strd2 S32MSUB XRa, XRd, Rs, Rt
* S32STDV XRa, Rb, rc, strd2 S32MSUBU XRa, XRd, Rs, Rt
* S32LDI XRa, Rb, s12 S32MUL XRa, XRd, Rs, Rt
* S32SDI XRa, Rb, s12 S32MULU XRa, XRd, Rs, Rt
* S32LDIV XRa, Rb, rc, strd2 D16MUL XRa, XRb, XRc, XRd, optn2