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opcode size increased to 7 bits

This commit is contained in:
Roberto Ierusalimschy 2017-10-02 19:51:32 -03:00
parent f3b3d9b5c2
commit 940472c75c
1 changed files with 8 additions and 8 deletions
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16
lopcodes.h
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@ -1,5 +1,5 @@
/*
** $Id: lopcodes.h,v 1.162 2017/09/28 16:53:29 roberto Exp roberto $
** $Id: lopcodes.h,v 1.163 2017/10/01 19:13:43 roberto Exp roberto $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -12,15 +12,15 @@
/*===========================================================================
We assume that instructions are unsigned 32-bit integers.
All instructions have an opcode in the first 6 bits.
All instructions have an opcode in the first 7 bits.
Instructions can have the following formats:
3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0
1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
iABC | C(9) | | B(9) | | A(8) | | Op(6) |
iABx | Bx(18) | | A(8) | | Op(6) |
iAsBx | sBx (signed)(18) | | A(8) | | Op(6) |
iAx | Ax(26) | | Op(6) |
iABC | C(9) | | B(8) | | A(8) | | Op(7) |
iABx | Bx(17) | | A(8) | | Op(7) |
iAsBx | sBx (signed)(17) | | A(8) | | Op(7) |
iAx | Ax(25) | | Op(7) |
A signed argument is represented in excess K: the represented value is
the written unsigned value minus K, where K is half the maximum for the
@ -35,12 +35,12 @@ enum OpMode {iABC, iABx, iAsBx, iAx}; /* basic instruction format */
** size and position of opcode arguments.
*/
#define SIZE_C 9
#define SIZE_B 9
#define SIZE_B 8
#define SIZE_Bx (SIZE_C + SIZE_B)
#define SIZE_A 8
#define SIZE_Ax (SIZE_C + SIZE_B + SIZE_A)
#define SIZE_OP 6
#define SIZE_OP 7
#define POS_OP 0
#define POS_A (POS_OP + SIZE_OP)