aslopt.c revision 199767f8919635c4928607450d9e0abb932109ce
/******************************************************************************
*
* Module Name: aslopt- Compiler optimizations
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2015, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#include "aslcompiler.y.h"
#define _COMPONENT ACPI_COMPILER
ACPI_MODULE_NAME ("aslopt")
/* Local prototypes */
static ACPI_STATUS
char **NewPath);
static ACPI_STATUS
char **ReturnNewPath);
static ACPI_STATUS
char *AmlNameString,
char **NewPath);
/*******************************************************************************
*
* FUNCTION: OptSearchToRoot
*
* PARAMETERS: Op - Current parser op
* WalkState - Current state
* CurrentNode - Where we are in the namespace
* TargetNode - Node to which we are referring
* TargetPath - External full path to the target node
* NewPath - Where the optimized path is returned
*
* RETURN: Status
*
* DESCRIPTION: Attempt to optimize a reference to a single 4-character ACPI
* name utilizing the search-to-root name resolution algorithm
* that is used by AML interpreters.
*
******************************************************************************/
static ACPI_STATUS
char **NewPath)
{
char *Path;
/*
* Check if search-to-root can be utilized. Use the last NameSeg of
* the NamePath and 1) See if can be found and 2) If found, make
* sure that it is the same node that we want. If there is another
* name in the search path before the one we want, the nodes will
* not match, and we cannot use this optimization.
*/
/* Lookup the NameSeg using SEARCH_PARENT (search-to-root) */
if (ACPI_FAILURE (Status))
{
return (Status);
}
/*
* We found the name, but we must check to make sure that the node
* matches. Otherwise, there is another identical name in the search
* path that precludes the use of this optimization.
*/
if (Node != TargetNode)
{
/*
* This means that another object with the same name was found first,
* and we cannot use this optimization.
*/
return (AE_NOT_FOUND);
}
/* Found the node, we can use this optimization */
"NAMESEG: %-24s", Path));
/* We must allocate a new string for the name (TargetPath gets deleted) */
{
*NewPath);
}
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: OptBuildShortestPath
*
* PARAMETERS: Op - Current parser op
* WalkState - Current state
* CurrentNode - Where we are in the namespace
* TargetNode - Node to which we are referring
* CurrentPath - External full path to the current node
* TargetPath - External full path to the target node
* AmlNameStringLength - Length of the original namepath
* IsDeclaration - TRUE for declaration, FALSE for reference
* ReturnNewPath - Where the optimized path is returned
*
* RETURN: Status
*
* DESCRIPTION: Build an optimal NamePath using carats
*
******************************************************************************/
static ACPI_STATUS
char **ReturnNewPath)
{
UINT32 i;
char *NewPath;
char *NewPathExternal;
/*
* Determine the maximum number of NameSegs that the Target and Current paths
* can possibly have in common. (To optimize, we have to have at least 1)
*
* Note: The external NamePath string lengths are always a multiple of 5
* (ACPI_NAME_SIZE + separator)
*/
{
}
/*
* Determine how many NameSegs the two paths have in common.
* (Starting from the root)
*/
for (NumCommonSegments = 0;
{
/* Compare two single NameSegs */
if (!ACPI_COMPARE_NAME (
&((char *) TargetPath->Pointer)[
&((char *) CurrentPath->Pointer)[
{
/* Mismatch */
break;
}
}
/* There must be at least 1 common NameSeg in order to optimize */
if (NumCommonSegments == 0)
{
return (AE_NOT_FOUND);
}
if (NumCommonSegments == MaxCommonSegments)
{
{
return (AE_NOT_FOUND);
}
else
{
}
}
/* Determine how many prefix Carats are required */
/*
* Construct a new target string
*/
/* Insert the Carats into the Target string */
for (i = 0; i < NumCarats; i++)
{
}
/*
* Copy only the necessary (optimal) segments from the original
* target string
*/
/* Special handling for exact subpath in a name declaration */
{
/*
* The current path is longer than the target, and the target is a
* subpath of the current path. We must include one more NameSeg of
* the target path
*/
/* Special handling for Scope() operator */
{
i++;
}
}
/* Make sure we haven't gone off the end of the target path */
{
}
/*
* Internalize the new target string and check it against the original
* string to make sure that this is in fact an optimization. If the
* original string is already optimal, there is no point in continuing.
*/
if (ACPI_FAILURE (Status))
{
return (Status);
}
{
" NOT SHORTER (New %u old %u)",
return (AE_NOT_FOUND);
}
/*
* Check to make sure that the optimization finds the node we are
* looking for. This is simply a sanity check on the new
* path that has been created.
*/
if (ACPI_SUCCESS (Status))
{
/* Found the namepath, but make sure the node is correct */
if (Node == TargetNode)
{
/* The lookup matched the node, accept this optimization */
*ReturnNewPath = NewPath;
}
else
{
/* Node is not correct, do not use this optimization */
"Not using optimized name - found wrong node");
}
}
else
{
/* The lookup failed, we obviously cannot use this optimization */
"Not using optimized name - did not find node");
}
return (Status);
}
/*******************************************************************************
*
* FUNCTION: OptOptimizeNameDeclaration
*
* PARAMETERS: Op - Current parser op
* WalkState - Current state
* CurrentNode - Where we are in the namespace
* AmlNameString - Unoptimized namepath
* NewPath - Where the optimized path is returned
*
* RETURN: Status. AE_OK If path is optimized
*
* DESCRIPTION: Perform a simple optimization of removing an extraneous
* backslash prefix if we are already at the root scope.
*
******************************************************************************/
static ACPI_STATUS
char *AmlNameString,
char **NewPath)
{
char *NewPathExternal;
if (((CurrentNode == AcpiGbl_RootNode) ||
(ACPI_IS_ROOT_PREFIX (AmlNameString[0])))
{
/*
* The current scope is the root, and the namepath has a root prefix
* that is therefore extraneous. Remove it.
*/
/* Debug output */
NULL, &NewPathExternal);
if (ACPI_FAILURE (Status))
{
return (Status);
}
/*
* Check to make sure that the optimization finds the node we are
* looking for. This is simply a sanity check on the new
* path that has been created.
*
* We know that we are at the root, so NULL is used for the scope.
*/
if (ACPI_SUCCESS (Status))
{
/* Found the namepath, but make sure the node is correct */
if (Node == TargetNode)
{
/* The lookup matched the node, accept this optimization */
"AT ROOT: %-24s", NewPathExternal));
}
else
{
/* Node is not correct, do not use this optimization */
" ***** WRONG NODE"));
"Not using optimized name - found wrong node");
}
}
else
{
/* The lookup failed, we obviously cannot use this optimization */
" ***** NOT FOUND"));
"Not using optimized name - did not find node");
}
return (Status);
}
/* Could not optimize */
return (AE_NOT_FOUND);
}
/*******************************************************************************
*
* FUNCTION: OptOptimizeNamePath
*
* PARAMETERS: Op - Current parser op
* Flags - Opcode info flags
* WalkState - Current state
* AmlNameString - Unoptimized namepath
* TargetNode - Node to which AmlNameString refers
*
* RETURN: None. If path is optimized, the Op is updated with new path
*
* DESCRIPTION: Optimize a Named Declaration or Reference to the minimal length.
* Must take into account both the current location in the
* namespace and the actual reference path.
*
******************************************************************************/
void
char *AmlNameString,
{
char *ExternalNameString;
/* This is an optional optimization */
{
}
/* Various required items */
{
}
"PATH OPTIMIZE: Line %5d ParentOp [%12.12s] ThisOp [%12.12s] ",
{
{
/* We don't want to fuss with actual name declaration nodes here */
"******* NAME DECLARATION\n"));
}
}
/*
* The original path must be longer than one NameSeg (4 chars) for there
* to be any possibility that it can be optimized to a shorter string
*/
if (AmlNameStringLength <= ACPI_NAME_SIZE)
{
"NAMESEG %4.4s\n", AmlNameString));
}
/*
* We need to obtain the node that represents the current scope -- where
* we are right now in the namespace. We will compare this path
* against the Namepath, looking for commonality.
*/
{
}
{
/* This is the declaration of a new name */
/*
* The node of interest is the parent of this node (the containing
* scope). The actual namespace node may be up more than one level
* of parse op or it may not exist at all (if we traverse back
* up to the root.)
*/
{
}
{
}
else
{
}
}
else
{
/* This is a reference to an existing named object */
}
/*
* Obtain the full paths to the two nodes that we are interested in
* (Target and current namespace location) in external
* format -- something we can easily manipulate
*/
if (ACPI_FAILURE (Status))
{
}
/* CurrentPath is the path to this scope (where we are in the namespace) */
if (ACPI_FAILURE (Status))
{
}
/* Debug output only */
if (ACPI_FAILURE (Status))
{
}
"CURRENT SCOPE: (%2u) %-37s FULL PATH TO NAME: (%2u) %-32s ACTUAL AML:%-32s\n",
/*
* Attempt an optmization depending on the type of namepath
*/
{
/*
* This is a named opcode and the namepath is a name declaration, not
* a reference.
*/
if (ACPI_FAILURE (Status))
{
/*
* 2) now attempt to
* optimize the namestring with carats (up-arrow)
*/
}
}
else
{
/*
* This is a reference to an existing named object
*
* 1) Check if search-to-root can be utilized using the last
* NameSeg of the NamePath
*/
if (ACPI_FAILURE (Status))
{
/*
* 2) Search-to-root could not be used, now attempt to
* optimize the namestring with carats (up-arrow)
*/
AmlNameStringLength, 0, &NewPath);
}
}
/*
* Success from above indicates that the NamePath was successfully
* optimized. We need to update the parse op with the new name
*/
if (ACPI_SUCCESS (Status))
{
" REDUCED BY %2u (TOTAL SAVED %2u)",
{
{
/*
* ALIAS is the only oddball opcode, the name declaration
* (alias name) is the second operand
*/
}
else
{
}
}
else if (Flags & AML_CREATE)
{
/* Name must appear as the last parameter */
{
}
/* Update the parse node with the new NamePath */
}
else
{
/* Update the parse node with the new NamePath */
}
}
else
{
}
/* Cleanup path buffers */
}