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Comments and small improvements in the manual.
This commit is contained in:
Roberto Ierusalimschy
2021-03-29 11:47:12 -03:00
parent ba81adaad9
commit bef250eb8d
5 changed files with 32 additions and 16 deletions
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21
lopcodes.h
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@@ -190,7 +190,8 @@ enum OpMode {iABC, iABx, iAsBx, iAx, isJ}; /* basic instruction formats */
/*
** grep "ORDER OP" if you change these enums
** Grep "ORDER OP" if you change these enums. Opcodes marked with a (*)
** has extra descriptions in the notes after the enumeration.
*/
typedef enum {
@@ -203,7 +204,7 @@ OP_LOADF,/* A sBx R[A] := (lua_Number)sBx */
OP_LOADK,/* A Bx R[A] := K[Bx] */
OP_LOADKX,/* A R[A] := K[extra arg] */
OP_LOADFALSE,/* A R[A] := false */
OP_LFALSESKIP,/*A R[A] := false; pc++ */
OP_LFALSESKIP,/*A R[A] := false; pc++ (*) */
OP_LOADTRUE,/* A R[A] := true */
OP_LOADNIL,/* A B R[A], R[A+1], ..., R[A+B] := nil */
OP_GETUPVAL,/* A B R[A] := UpValue[B] */
@@ -254,7 +255,7 @@ OP_BXOR,/* A B C R[A] := R[B] ~ R[C] */
OP_SHL,/* A B C R[A] := R[B] << R[C] */
OP_SHR,/* A B C R[A] := R[B] >> R[C] */
OP_MMBIN,/* A B C call C metamethod over R[A] and R[B] */
OP_MMBIN,/* A B C call C metamethod over R[A] and R[B] (*) */
OP_MMBINI,/* A sB C k call C metamethod over R[A] and sB */
OP_MMBINK,/* A B C k call C metamethod over R[A] and K[B] */
@@ -280,7 +281,7 @@ OP_GTI,/* A sB k if ((R[A] > sB) ~= k) then pc++ */
OP_GEI,/* A sB k if ((R[A] >= sB) ~= k) then pc++ */
OP_TEST,/* A k if (not R[A] == k) then pc++ */
OP_TESTSET,/* A B k if (not R[B] == k) then pc++ else R[A] := R[B] */
OP_TESTSET,/* A B k if (not R[B] == k) then pc++ else R[A] := R[B] (*) */
OP_CALL,/* A B C R[A], ... ,R[A+C-2] := R[A](R[A+1], ... ,R[A+B-1]) */
OP_TAILCALL,/* A B C k return R[A](R[A+1], ... ,R[A+B-1]) */
@@ -315,6 +316,18 @@ OP_EXTRAARG/* Ax extra (larger) argument for previous opcode */
/*===========================================================================
Notes:
(*) Opcode OP_LFALSESKIP is used to convert a condition to a boolean
value, in a code equivalent to (not cond ? false : true). (It
produces false and skips the next instruction producing true.)
(*) Opcodes OP_MMBIN and variants follow each arithmetic and
bitwise opcode. If the operation succeeds, it skips this next
opcode. Otherwise, this opcode calls the corresponding metamethod.
(*) Opcode OP_TESTSET is used in short-circuit expressions that need
both to jump and to produce a value, such as (a = b or c).
(*) In OP_CALL, if (B == 0) then B = top - A. If (C == 0), then
'top' is set to last_result+1, so next open instruction (OP_CALL,
OP_RETURN*, OP_SETLIST) may use 'top'.