35.3.5.2. INTEGER CONVERTIONS ON ALPHA

Alpha Operate Format
+-------------------------+------------------------+
| 31..26	Opcode	  | 31..26	Opcode	   |
| 25..21	Ra	  | 25..21	Ra	   |
| 20..16	Rb	  | 20..13	LIT        |
| 15..13	SBZ	  | 12		1          |
| 12		0	  | 11..5	Function   |	
| 11..5		Function  | 4..0	Rc         |
| 4..0		Rc        |                        |
+-------------------------+------------------------+



Extract Byte
	EXTxx	Ra.rq,Rb.rq,Rc.wq	!Operate Format
	EXTxx	Ra.rq,#b.ib,Rc.wq	!Operate Format

EXTBL		Extract Byte Low
EXTWL		Extract Word Low
EXTLL		Extract Longword Low
EXTQL		Extract Quadword Low
EXTWH		Extract Word High
EXTLH		Extract Longword High
EXTQH		Extract Quadword High


	case
		extbl: 	byte_mask <- 0000 0001 b
		extwX:  byte_mask <- 0000 0011 b
		extlX:  byte_mask <- 0000 1111 b
		extqX:  byte_mask <- 1111 1111 b
	endcase
	case
		extXl:
			byte_loc <- Rbv<2:0> * 8
			temp <- RIGHT_SHIFT(Rav,byte_loc<5:0>)
			Rc <- BYTE_ZAP(temp,NOT(byte_mask))
		extXh:
			byte_loc <- 64 - Rbv<2:0> * 8
			temp <- LEFT_SHIFT(Rav,byte_loc<5:0>)
			Rc <- BYTE_ZAP(temp,NOT(byte_mask))
	endcase

	
	EXTBL	12.06
	EXTWL	12.16
	EXTLL	12.26
	EXTQL	12.36
	EXTWH	12.5A
	EXTLH	12.6A
	EXTQH	12.7A


	// ----------------------------------------------------------





Byte Insert
	INSxx	Ra.rq,Rb.rq,Rc.wq	!Operate Format
	INSxx	Ra.rq,#b.ib,Rc.wq	!Operate Format

INSBL		Insert Byte Low
INSWL		Insert Word Low
INSLL		Insert Longword Low
INSQL		Insert Quadword Low
INSWH		Insert Word High
INSLH		Insert Longword High
INSQH		Insert Quadword High


	case
		insbl: 	byte_mask <- 0000 0000 0000 0001 b
		inswX:  byte_mask <- 0000 0000 0000 0011 b
		inslX:  byte_mask <- 0000 0000 0000 1111 b
		insqX:  byte_mask <- 0000 0000 1111 1111 b
	endcase
	case
		insXl:
			byte_loc <- Rbv<2:0> * 8
			temp <- LEFT_SHIFT(Rav,byte_loc<5:0>)
			Rc <- BYTE_ZAP(temp,NOT(byte_mask<7:0>))
		insXh:
			byte_loc <- 64 - Rbv<2:0> * 8
			temp <- RIGHT_SHIFT(Rav,byte_loc<5:0>)
			Rc <- BYTE_ZAP(temp,NOT(byte_mask<15:8>))
	endcase

	
	INSBL	12.0B
	INSWL	12.1B
	INSLL	12.2B
	INSQL	12.3B
	INSWH	12.57
	INSLH	12.67
	INSQH	12.77

	// ----------------------------------------------------------



Zero Bytes
	ZAPx	Ra.rq,Rb.rq,Rc.wq	!Operate Format
	ZAPx	Ra.rq,#b.ib,Rc.wq	!Operate Format
	

ZAP		Zero Bytes
ZAPNOT		Zero Bytes Not

	case
		ZAP:
			Rc <- BYTE_ZAP(Rav,Rbv<7:0>)
		ZAPNOT:
			Rc <- BYTE_ZAP(Rav,NOT Rbv<7:0>)
	endscase

	ZAP	12.30
	ZAPNOT	12.31


	// ----------------------------------------------------------



Byte  Mask
	MSKx	Ra.rq,Rb.rq,Rc.wq	!Operate Format
	MSKx	Ra.rq,#b.ib,Rc.wq	!Operate Format



MSKBL		Mask Byte Low
MSKWL		Mask Word Low
MSKLL		Mask Longword Low
MSKQL		Mask Quadword Low
MSKWH		Mask Word High
MSKLH		Mask Longword High
MSKQH		Mask Quadword High


	case
		mskbl: 	byte_mask <- 0000 0000 0000 0001 b
		mskwX:  byte_mask <- 0000 0000 0000 0011 b
		msklX:  byte_mask <- 0000 0000 0000 1111 b
		mskqX:  byte_mask <- 0000 0000 1111 1111 b
	endcase
	case
		mskXl:
			Rc <- BYTE_ZAP(Rav,byte_mask<7:0>)
		mskXh:
			Rc <- BYTE_ZAP(Rav,byte_mask<15:8>)
	endcase

	MSKBL	12.02
	MSKWL	12.12	
	MSKLL	12.22
	MSKQL	12.32
	MSKWH	12.51
	MSKLH	12.62
	MSKQH	12.72

	// ----------------------------------------------------------

Sign Extend


	SEXTx	Rb.rq,Rc.wq	!Operate Format
	SEXTx	#b.ib,Rc.wq	!Operate Format

	case
		SEXTB:	Rc <- SEXT(Rbv<7:0>)
		SEXTW:	Rc <- SEXT(Rbv<15:0>)
	endcase

	SEXTB	1C.00
	SEXTW	1C.01

	(Ra must be R31)


// ----------------------------------------------------------------------