freebsd-dev/source/compiler/aslfold.c
2015-06-18 17:27:40 +00:00

790 lines
21 KiB
C

/******************************************************************************
*
* Module Name: aslfold - Constant folding
*
*****************************************************************************/
/*
* 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.h"
#include "aslcompiler.y.h"
#include "amlcode.h"
#include "acdispat.h"
#include "acparser.h"
#define _COMPONENT ACPI_COMPILER
ACPI_MODULE_NAME ("aslfold")
/* Local prototypes */
static ACPI_STATUS
OpcAmlEvaluationWalk1 (
ACPI_PARSE_OBJECT *Op,
UINT32 Level,
void *Context);
static ACPI_STATUS
OpcAmlEvaluationWalk2 (
ACPI_PARSE_OBJECT *Op,
UINT32 Level,
void *Context);
static ACPI_STATUS
OpcAmlCheckForConstant (
ACPI_PARSE_OBJECT *Op,
UINT32 Level,
void *Context);
static void
OpcUpdateIntegerNode (
ACPI_PARSE_OBJECT *Op,
UINT64 Value);
static ACPI_STATUS
TrTransformToStoreOp (
ACPI_PARSE_OBJECT *Op,
ACPI_WALK_STATE *WalkState);
static ACPI_STATUS
TrSimpleConstantReduction (
ACPI_PARSE_OBJECT *Op,
ACPI_WALK_STATE *WalkState);
static void
TrInstallReducedConstant (
ACPI_PARSE_OBJECT *Op,
ACPI_OPERAND_OBJECT *ObjDesc);
/*******************************************************************************
*
* FUNCTION: OpcAmlConstantWalk
*
* PARAMETERS: ASL_WALK_CALLBACK
*
* RETURN: Status
*
* DESCRIPTION: Reduce an Op and its subtree to a constant if possible
*
******************************************************************************/
ACPI_STATUS
OpcAmlConstantWalk (
ACPI_PARSE_OBJECT *Op,
UINT32 Level,
void *Context)
{
ACPI_WALK_STATE *WalkState;
ACPI_STATUS Status = AE_OK;
if (Op->Asl.CompileFlags == 0)
{
return (AE_OK);
}
/*
* Only interested in subtrees that could possibly contain
* expressions that can be evaluated at this time
*/
if ((!(Op->Asl.CompileFlags & NODE_COMPILE_TIME_CONST)) ||
(Op->Asl.CompileFlags & NODE_IS_TARGET))
{
return (AE_OK);
}
/* Create a new walk state */
WalkState = AcpiDsCreateWalkState (0, NULL, NULL, NULL);
if (!WalkState)
{
return (AE_NO_MEMORY);
}
WalkState->NextOp = NULL;
WalkState->Params = NULL;
/*
* Examine the entire subtree -- all nodes must be constants
* or type 3/4/5 opcodes
*/
Status = TrWalkParseTree (Op, ASL_WALK_VISIT_DOWNWARD,
OpcAmlCheckForConstant, NULL, WalkState);
/*
* Did we find an entire subtree that contains all constants
* and type 3/4/5 opcodes?
*/
switch (Status)
{
case AE_OK:
/* Simple case, like Add(3,4) -> 7 */
Status = TrSimpleConstantReduction (Op, WalkState);
break;
case AE_CTRL_RETURN_VALUE:
/* More complex case, like Add(3,4,Local0) -> Store(7,Local0) */
Status = TrTransformToStoreOp (Op, WalkState);
break;
case AE_TYPE:
AcpiDsDeleteWalkState (WalkState);
return (AE_OK);
default:
AcpiDsDeleteWalkState (WalkState);
break;
}
if (ACPI_FAILURE (Status))
{
DbgPrint (ASL_PARSE_OUTPUT, "Cannot resolve, %s\n",
AcpiFormatException (Status));
/* We could not resolve the subtree for some reason */
AslError (ASL_ERROR, ASL_MSG_CONSTANT_EVALUATION, Op,
(char *) AcpiFormatException (Status));
/* Set the subtree value to ZERO anyway. Eliminates further errors */
OpcUpdateIntegerNode (Op, 0);
}
/* Abort the walk of this subtree, we are done with it */
return (AE_CTRL_DEPTH);
}
/*******************************************************************************
*
* FUNCTION: OpcAmlCheckForConstant
*
* PARAMETERS: ASL_WALK_CALLBACK
*
* RETURN: Status
*
* DESCRIPTION: Check one Op for a type 3/4/5 AML opcode
*
******************************************************************************/
static ACPI_STATUS
OpcAmlCheckForConstant (
ACPI_PARSE_OBJECT *Op,
UINT32 Level,
void *Context)
{
ACPI_WALK_STATE *WalkState = Context;
ACPI_STATUS Status = AE_OK;
WalkState->Op = Op;
WalkState->Opcode = Op->Common.AmlOpcode;
WalkState->OpInfo = AcpiPsGetOpcodeInfo (Op->Common.AmlOpcode);
DbgPrint (ASL_PARSE_OUTPUT, "[%.4d] Opcode: %12.12s ",
Op->Asl.LogicalLineNumber, Op->Asl.ParseOpName);
/*
* TBD: Ignore buffer constants for now. The problem is that these
* constants have been transformed into RAW_DATA at this point, from
* the parse tree transform process which currently happens before
* the constant folding process. We may need to defer this transform
* for buffer until after the constant folding.
*/
if (WalkState->Opcode == AML_BUFFER_OP)
{
DbgPrint (ASL_PARSE_OUTPUT,
"\nBuffer+Buffer->Buffer constant reduction is not supported yet");
Status = AE_TYPE;
goto CleanupAndExit;
}
/*
* These opcodes do not appear in the OpcodeInfo table, but
* they represent constants, so abort the constant walk now.
*/
if ((WalkState->Opcode == AML_RAW_DATA_BYTE) ||
(WalkState->Opcode == AML_RAW_DATA_WORD) ||
(WalkState->Opcode == AML_RAW_DATA_DWORD) ||
(WalkState->Opcode == AML_RAW_DATA_QWORD))
{
DbgPrint (ASL_PARSE_OUTPUT, "RAW DATA");
Status = AE_TYPE;
goto CleanupAndExit;
}
/* Type 3/4/5 opcodes have the AML_CONSTANT flag set */
if (!(WalkState->OpInfo->Flags & AML_CONSTANT))
{
/* Not 3/4/5 opcode, but maybe can convert to STORE */
if (Op->Asl.CompileFlags & NODE_IS_TARGET)
{
DbgPrint (ASL_PARSE_OUTPUT,
"**** Valid Target, transform to Store ****\n");
return (AE_CTRL_RETURN_VALUE);
}
/* Expression cannot be reduced */
DbgPrint (ASL_PARSE_OUTPUT,
"**** Not a Type 3/4/5 opcode (%s) ****",
Op->Asl.ParseOpName);
Status = AE_TYPE;
goto CleanupAndExit;
}
/* Debug output */
DbgPrint (ASL_PARSE_OUTPUT, "TYPE_345");
if (Op->Asl.CompileFlags & NODE_IS_TARGET)
{
if (Op->Asl.ParseOpcode == PARSEOP_ZERO)
{
DbgPrint (ASL_PARSE_OUTPUT, "%-16s", " NULL TARGET");
}
else
{
DbgPrint (ASL_PARSE_OUTPUT, "%-16s", " VALID TARGET");
}
}
if (Op->Asl.CompileFlags & NODE_IS_TERM_ARG)
{
DbgPrint (ASL_PARSE_OUTPUT, "%-16s", " TERMARG");
}
CleanupAndExit:
/* Dump the node compile flags also */
TrPrintNodeCompileFlags (Op->Asl.CompileFlags);
DbgPrint (ASL_PARSE_OUTPUT, "\n");
return (Status);
}
/*******************************************************************************
*
* FUNCTION: TrSimpleConstantReduction
*
* PARAMETERS: Op - Parent operator to be transformed
* WalkState - Current walk state
*
* RETURN: Status
*
* DESCRIPTION: Reduce an entire AML operation to a single constant. The
* operation must not have a target operand.
*
* Add (32,64) --> 96
*
******************************************************************************/
static ACPI_STATUS
TrSimpleConstantReduction (
ACPI_PARSE_OBJECT *Op,
ACPI_WALK_STATE *WalkState)
{
ACPI_PARSE_OBJECT *RootOp;
ACPI_PARSE_OBJECT *OriginalParentOp;
ACPI_OPERAND_OBJECT *ObjDesc;
ACPI_STATUS Status;
DbgPrint (ASL_PARSE_OUTPUT,
"Simple subtree constant reduction, operator to constant\n");
/* Allocate a new temporary root for this subtree */
RootOp = TrAllocateNode (PARSEOP_INTEGER);
if (!RootOp)
{
return (AE_NO_MEMORY);
}
RootOp->Common.AmlOpcode = AML_INT_EVAL_SUBTREE_OP;
OriginalParentOp = Op->Common.Parent;
Op->Common.Parent = RootOp;
/* Hand off the subtree to the AML interpreter */
WalkState->CallerReturnDesc = &ObjDesc;
Status = TrWalkParseTree (Op, ASL_WALK_VISIT_TWICE,
OpcAmlEvaluationWalk1, OpcAmlEvaluationWalk2, WalkState);
/* Restore original parse tree */
Op->Common.Parent = OriginalParentOp;
if (ACPI_FAILURE (Status))
{
DbgPrint (ASL_PARSE_OUTPUT,
"Constant Subtree evaluation(1), %s\n",
AcpiFormatException (Status));
return (Status);
}
/* Get the final result */
Status = AcpiDsResultPop (&ObjDesc, WalkState);
if (ACPI_FAILURE (Status))
{
DbgPrint (ASL_PARSE_OUTPUT,
"Constant Subtree evaluation(2), %s\n",
AcpiFormatException (Status));
return (Status);
}
/* Disconnect any existing children, install new constant */
Op->Asl.Child = NULL;
TrInstallReducedConstant (Op, ObjDesc);
UtSetParseOpName (Op);
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: TrTransformToStoreOp
*
* PARAMETERS: Op - Parent operator to be transformed
* WalkState - Current walk state
*
* RETURN: Status
*
* DESCRIPTION: Transforms a single AML operation with a constant and target
* to a simple store operation:
*
* Add (32,64,DATA) --> Store (96,DATA)
*
******************************************************************************/
static ACPI_STATUS
TrTransformToStoreOp (
ACPI_PARSE_OBJECT *Op,
ACPI_WALK_STATE *WalkState)
{
ACPI_PARSE_OBJECT *OriginalTarget;
ACPI_PARSE_OBJECT *NewTarget;
ACPI_PARSE_OBJECT *Child1;
ACPI_PARSE_OBJECT *Child2;
ACPI_OPERAND_OBJECT *ObjDesc;
ACPI_PARSE_OBJECT *NewParent;
ACPI_PARSE_OBJECT *OriginalParent;
ACPI_STATUS Status;
DbgPrint (ASL_PARSE_OUTPUT,
"Reduction/Transform to StoreOp: Store(Constant, Target)\n");
/* Extract the operands */
Child1 = Op->Asl.Child;
Child2 = Child1->Asl.Next;
/*
* Special case for DIVIDE -- it has two targets. The first
* is for the remainder and if present, we will not attempt
* to reduce the expression.
*/
if (Op->Asl.ParseOpcode == PARSEOP_DIVIDE)
{
Child2 = Child2->Asl.Next;
if (Child2->Asl.ParseOpcode != PARSEOP_ZERO)
{
DbgPrint (ASL_PARSE_OUTPUT,
"Cannot reduce DIVIDE - has two targets\n\n");
return (AE_OK);
}
}
/*
* Create a NULL (zero) target so that we can use the
* interpreter to evaluate the expression.
*/
NewTarget = TrCreateNullTarget ();
NewTarget->Common.AmlOpcode = AML_INT_NAMEPATH_OP;
/* Handle one-operand cases (NOT, TOBCD, etc.) */
if (!Child2->Asl.Next)
{
Child2 = Child1;
}
/* Link in new NULL target as the last operand */
OriginalTarget = Child2->Asl.Next;
Child2->Asl.Next = NewTarget;
NewTarget->Asl.Parent = OriginalTarget->Asl.Parent;
NewParent = TrAllocateNode (PARSEOP_INTEGER);
NewParent->Common.AmlOpcode = AML_INT_EVAL_SUBTREE_OP;
OriginalParent = Op->Common.Parent;
Op->Common.Parent = NewParent;
/* Hand off the subtree to the AML interpreter */
WalkState->CallerReturnDesc = &ObjDesc;
Status = TrWalkParseTree (Op, ASL_WALK_VISIT_TWICE,
OpcAmlEvaluationWalk1, OpcAmlEvaluationWalk2, WalkState);
if (ACPI_FAILURE (Status))
{
DbgPrint (ASL_PARSE_OUTPUT,
"Constant Subtree evaluation(3), %s\n",
AcpiFormatException (Status));
goto EvalError;
}
/* Get the final result */
Status = AcpiDsResultPop (&ObjDesc, WalkState);
if (ACPI_FAILURE (Status))
{
DbgPrint (ASL_PARSE_OUTPUT,
"Constant Subtree evaluation(4), %s\n",
AcpiFormatException (Status));
goto EvalError;
}
/* Truncate any subtree expressions, they have been evaluated */
Child1->Asl.Child = NULL;
/* Folded constant is in ObjDesc, store into Child1 */
TrInstallReducedConstant (Child1, ObjDesc);
/* Convert operator to STORE */
Op->Asl.ParseOpcode = PARSEOP_STORE;
Op->Asl.AmlOpcode = AML_STORE_OP;
UtSetParseOpName (Op);
Op->Common.Parent = OriginalParent;
/* First child is the folded constant */
/* Second child will be the target */
Child1->Asl.Next = OriginalTarget;
return (AE_OK);
EvalError:
/* Restore original links */
Op->Common.Parent = OriginalParent;
Child2->Asl.Next = OriginalTarget;
return (Status);
}
/*******************************************************************************
*
* FUNCTION: TrInstallReducedConstant
*
* PARAMETERS: Op - Parent operator to be transformed
* ObjDesc - Reduced constant to be installed
*
* RETURN: None
*
* DESCRIPTION: Transform the original operator to a simple constant.
* Handles Integers, Strings, and Buffers.
*
******************************************************************************/
static void
TrInstallReducedConstant (
ACPI_PARSE_OBJECT *Op,
ACPI_OPERAND_OBJECT *ObjDesc)
{
ACPI_PARSE_OBJECT *LengthOp;
ACPI_PARSE_OBJECT *DataOp;
TotalFolds++;
AslError (ASL_OPTIMIZATION, ASL_MSG_CONSTANT_FOLDED, Op,
Op->Asl.ParseOpName);
/*
* Because we know we executed type 3/4/5 opcodes above, we know that
* the result must be either an Integer, String, or Buffer.
*/
switch (ObjDesc->Common.Type)
{
case ACPI_TYPE_INTEGER:
OpcUpdateIntegerNode (Op, ObjDesc->Integer.Value);
DbgPrint (ASL_PARSE_OUTPUT,
"Constant expression reduced to (%s) %8.8X%8.8X\n\n",
Op->Asl.ParseOpName,
ACPI_FORMAT_UINT64 (Op->Common.Value.Integer));
break;
case ACPI_TYPE_STRING:
Op->Asl.ParseOpcode = PARSEOP_STRING_LITERAL;
Op->Common.AmlOpcode = AML_STRING_OP;
Op->Asl.AmlLength = strlen (ObjDesc->String.Pointer) + 1;
Op->Common.Value.String = ObjDesc->String.Pointer;
DbgPrint (ASL_PARSE_OUTPUT,
"Constant expression reduced to (STRING) %s\n\n",
Op->Common.Value.String);
break;
case ACPI_TYPE_BUFFER:
/*
* Create a new parse subtree of the form:
*
* BUFFER (Buffer AML opcode)
* INTEGER (Buffer length in bytes)
* RAW_DATA (Buffer byte data)
*/
Op->Asl.ParseOpcode = PARSEOP_BUFFER;
Op->Common.AmlOpcode = AML_BUFFER_OP;
Op->Asl.CompileFlags = NODE_AML_PACKAGE;
UtSetParseOpName (Op);
/* Child node is the buffer length */
LengthOp = TrAllocateNode (PARSEOP_INTEGER);
LengthOp->Asl.AmlOpcode = AML_DWORD_OP;
LengthOp->Asl.Value.Integer = ObjDesc->Buffer.Length;
LengthOp->Asl.Parent = Op;
(void) OpcSetOptimalIntegerSize (LengthOp);
Op->Asl.Child = LengthOp;
/* Next child is the raw buffer data */
DataOp = TrAllocateNode (PARSEOP_RAW_DATA);
DataOp->Asl.AmlOpcode = AML_RAW_DATA_BUFFER;
DataOp->Asl.AmlLength = ObjDesc->Buffer.Length;
DataOp->Asl.Value.String = (char *) ObjDesc->Buffer.Pointer;
DataOp->Asl.Parent = Op;
LengthOp->Asl.Next = DataOp;
DbgPrint (ASL_PARSE_OUTPUT,
"Constant expression reduced to (BUFFER) length %X\n\n",
ObjDesc->Buffer.Length);
break;
default:
break;
}
}
/*******************************************************************************
*
* FUNCTION: OpcUpdateIntegerNode
*
* PARAMETERS: Op - Current parse object
* Value - Value for the integer op
*
* RETURN: None
*
* DESCRIPTION: Update node to the correct Integer type and value
*
******************************************************************************/
static void
OpcUpdateIntegerNode (
ACPI_PARSE_OBJECT *Op,
UINT64 Value)
{
Op->Common.Value.Integer = Value;
/*
* The AmlLength is used by the parser to indicate a constant,
* (if non-zero). Length is either (1/2/4/8)
*/
switch (Op->Asl.AmlLength)
{
case 1:
TrUpdateNode (PARSEOP_BYTECONST, Op);
Op->Asl.AmlOpcode = AML_RAW_DATA_BYTE;
break;
case 2:
TrUpdateNode (PARSEOP_WORDCONST, Op);
Op->Asl.AmlOpcode = AML_RAW_DATA_WORD;
break;
case 4:
TrUpdateNode (PARSEOP_DWORDCONST, Op);
Op->Asl.AmlOpcode = AML_RAW_DATA_DWORD;
break;
case 8:
TrUpdateNode (PARSEOP_QWORDCONST, Op);
Op->Asl.AmlOpcode = AML_RAW_DATA_QWORD;
break;
case 0:
default:
OpcSetOptimalIntegerSize (Op);
TrUpdateNode (PARSEOP_INTEGER, Op);
break;
}
Op->Asl.AmlLength = 0;
}
/*******************************************************************************
*
* FUNCTION: OpcAmlEvaluationWalk1
*
* PARAMETERS: ASL_WALK_CALLBACK
*
* RETURN: Status
*
* DESCRIPTION: Descending callback for AML execution of constant subtrees
*
******************************************************************************/
static ACPI_STATUS
OpcAmlEvaluationWalk1 (
ACPI_PARSE_OBJECT *Op,
UINT32 Level,
void *Context)
{
ACPI_WALK_STATE *WalkState = Context;
ACPI_STATUS Status;
ACPI_PARSE_OBJECT *OutOp;
WalkState->Op = Op;
WalkState->Opcode = Op->Common.AmlOpcode;
WalkState->OpInfo = AcpiPsGetOpcodeInfo (Op->Common.AmlOpcode);
/* Copy child pointer to Arg for compatibility with Interpreter */
if (Op->Asl.Child)
{
Op->Common.Value.Arg = Op->Asl.Child;
}
/* Call AML dispatcher */
Status = AcpiDsExecBeginOp (WalkState, &OutOp);
if (ACPI_FAILURE (Status))
{
DbgPrint (ASL_PARSE_OUTPUT,
"%s Constant interpretation failed (1) - %s\n",
Op->Asl.ParseOpName, AcpiFormatException (Status));
}
return (Status);
}
/*******************************************************************************
*
* FUNCTION: OpcAmlEvaluationWalk2
*
* PARAMETERS: ASL_WALK_CALLBACK
*
* RETURN: Status
*
* DESCRIPTION: Ascending callback for AML execution of constant subtrees
*
******************************************************************************/
static ACPI_STATUS
OpcAmlEvaluationWalk2 (
ACPI_PARSE_OBJECT *Op,
UINT32 Level,
void *Context)
{
ACPI_WALK_STATE *WalkState = Context;
ACPI_STATUS Status;
WalkState->Op = Op;
WalkState->Opcode = Op->Common.AmlOpcode;
WalkState->OpInfo = AcpiPsGetOpcodeInfo (Op->Common.AmlOpcode);
/* Copy child pointer to Arg for compatibility with Interpreter */
if (Op->Asl.Child)
{
Op->Common.Value.Arg = Op->Asl.Child;
}
/* Call AML dispatcher */
Status = AcpiDsExecEndOp (WalkState);
if (ACPI_FAILURE (Status))
{
DbgPrint (ASL_PARSE_OUTPUT,
"%s: Constant interpretation failed (2) - %s\n",
Op->Asl.ParseOpName, AcpiFormatException (Status));
}
return (Status);
}