sp_instr_jump Class Reference

#include <sp_instr.h>

Inheritance diagram for sp_instr_jump:

List of all members.

Public Member Functions
	sp_instr_jump (uint ip, sp_pcontext *ctx)
	sp_instr_jump (uint ip, sp_pcontext *ctx, uint dest)
virtual void	print (String *str)
virtual bool	execute (THD *thd, uint *nextp)
virtual uint	opt_mark (sp_head *sp, List< sp_instr > *leads)
virtual uint	opt_shortcut_jump (sp_head *sp, sp_instr *start)
virtual void	opt_move (uint dst, List< sp_branch_instr > *ibp)
virtual void	set_destination (uint old_dest, uint new_dest)
virtual void	backpatch (uint dest)
Protected Attributes
uint	m_dest
	Where we will go.
sp_instr *	m_optdest

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Detailed Description

This is base class for all kinds of jump instructions.

Note:

this is the only class, we directly construct instances of, that has subclasses. We also redefine sp_instr_jump behavior in those subclasses.

Todo:

later we will consider introducing a new class, which will be the base for sp_instr_jump, sp_instr_set_case_expr and sp_instr_jump_case_when. Something like sp_regular_branch_instr (similar to sp_lex_branch_instr).

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Member Function Documentation

virtual void sp_instr_jump::backpatch

(

uint

dest

)

[inline, virtual]

Update all instruction with the given label in the backpatch list to the specified instruction pointer.

Parameters:

dest	destination instruction pointer.

Implements sp_branch_instr.

Reimplemented in sp_instr_hpush_jump.

virtual bool sp_instr_jump::execute	(	THD *	thd,
		uint *	nextp
	)		[inline, virtual]

Execute this instruction

Parameters:

	thd	Thread context
[out]	nextp	index of the next instruction to execute. (For most instructions this will be the instruction following this one). Note that this parameter is undefined in case of errors, use get_cont_dest() to find the continuation instruction for CONTINUE error handlers.

Returns:

Error status.

Implements sp_instr.

Reimplemented in sp_instr_hreturn, and sp_instr_hpush_jump.

uint sp_instr_jump::opt_mark	(	sp_head *	sp,
		List< sp_instr > *	leads
	)		[virtual]

Mark this instruction as reachable during optimization and return the index to the next instruction. Jump instruction will add their destination to the leads list.

Reimplemented from sp_instr.

Reimplemented in sp_instr_hreturn, and sp_instr_hpush_jump.

void sp_instr_jump::opt_move	(	uint	dst,
		List< sp_branch_instr > *	ibp
	)		[virtual]

Inform the instruction that it has been moved during optimization. Most instructions will simply update its index, but jump instructions must also take care of their destination pointers. Forward jumps get pushed to the backpatch list 'ibp'.

Reimplemented from sp_instr.

uint sp_instr_jump::opt_shortcut_jump	(	sp_head *	sp,
		sp_instr *	start
	)		[virtual]

Short-cut jumps to jumps during optimization. This is used by the jump instructions' opt_mark() methods. 'start' is the starting point, used to prevent the mark sweep from looping for ever. Return the end destination.

Reimplemented from sp_instr.

Reimplemented in sp_instr_hreturn, and sp_instr_hpush_jump.

virtual void sp_instr_jump::set_destination	(	uint	old_dest,
		uint	new_dest
	)		[inline, virtual]

Update the destination; used by the SP-instruction-optimizer.

Parameters:

old_dest	current (old) destination (instruction pointer).
new_dest	new destination (instruction pointer).

Implements sp_branch_instr.

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The documentation for this class was generated from the following files:

• sp_instr.h
• sp_instr.cc