JPH0773049A - Program simulator device - Google Patents

Abstract

PURPOSE:To find unnecessary register save/restore instructions at the time of simulator execution. CONSTITUTION:This device is provided with a register part 131 which detects an accessed register to generate state control data C1, an interrupt generation part 161 which detects the start and the end of interrupt handling, an instruction discriminating part 143, an interupt level management part 162 which discriminates the interrupt level to generate state control data C4, instruction discriminating parts 141 and 142 which discriminates register save and restore instructions respectively to generate state control data C1 and C2, and a register state detection part 17 which detects save and restore instructions for registers, which are not used in the interrupt processing, and registers, which don't require save and restore because thier contents are not changed when being used in the interrupt processing, out of detected save and restore instructions in response to supply of state control data C1 to C4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a program simulator device, and more particularly to a program simulator device such as a microcomputer including interrupt processing.

[0002]

2. Description of the Related Art A simulator device of this type is used as a development tool for efficiently developing software such as a microcomputer. By debugging the software when the hardware is incomplete,
Software development can proceed in parallel with hardware.

Generally, in information processing by a microcomputer or the like, when a processing request of a program B having a higher priority occurs while the processing of a certain program A is in progress, the program B interrupts the program A to process the interrupt program A. It is often necessary to interrupt the process and shift to the processing of program B. In this case, when the processing of the interrupted program B is completed, the processing returns to the processing of the program A, but this program A is restarted from the place where it was interrupted.

In order to efficiently perform such an interrupt process, generally, as information indicating the state at the time of interruption of the program A, the contents of various registers as well as the contents of the program status word and the program counter are stored in a memory. Save to the save area.

At the time of this saving, there are the following two problems. The first problem is that when the number of various registers is large, the time required to save them cannot be ignored. The second problem is that it is meaningless to save the registers that are not used by the interrupt program B and the registers that do not change the contents even if they are used, and cannot be ignored in an information processing system that places emphasis on processing efficiency. is there.

A conventional technique for improving the first problem is to provide a so-called register bank having all registers in double or quadruple. This is a method of eliminating the need to save the register by selectively switching the register bank and using the register during interrupt processing.

[0007] To solve the second problem, Japanese Patent Laid-Open No. Sho 5
The first conventional technique disclosed in Japanese Patent Publication No. 7-10960 is provided with a hardware mechanism for saving only the registers to be saved, and the hardware mechanism is controlled by a dedicated instruction or a field of an interrupt vector. This is a method of saving only the registers.

A second conventional technique for the second problem described in Japanese Patent Laid-Open No. 64-62735 is to issue a save register range specification instruction for specifying a range of registers that need to be saved in advance when an interrupt occurs. This is a method in which the registers are included in the microparogram and only the registers in the specified range are saved based on the save register range specification instruction when an interrupt occurs.

As described above, there is a method of saving registers mainly by hardware, but since dedicated hardware is required for that purpose, new problems such as complication and cost increase of a microcomputer are created. Is occurring.

Therefore, generally, in the microcomputer to be simulated by the simulator device, the contents of the program status word and the program counter are saved by hardware in order to execute the interrupt processing at high speed, but the saving of various registers is performed. Uses a register save instruction of software for each register.

[0011]

The above-described conventional simulator device for a program uses a method of saving registers in a program of a microcomputer to be simulated by a register saving instruction of software. There is a drawback in that it is very difficult to develop a program having a register saving instruction that saves a minimum necessary number of registers, because the contents of use of the registers are not always clear.

[0012]

According to another aspect of the present invention, there is provided a simulator device for a program of the information processing device, wherein the saving and restoring operations of the register are performed by an interrupt process of the information processing device having a register. An interrupt process start detecting means for detecting the start of the interrupt process, an interrupt process end detecting means for detecting the end of the interrupt process, and the accessed register;
Access register detecting means for detecting the first register and generating the first state control data, and a save instruction for determining the save instruction and the restore instruction of the first register and generating the second and third state control data, respectively. And a return instruction determination means, an interrupt level management means for determining the level of the interrupt processing and generating fourth state control data, and the first to fourth state control data in response to the supply of the first to fourth state control data. 1
Second register that is not used in the interrupt process and third register that has no change in contents even if used in the interrupt process
And register state detecting means for detecting the save instruction and the restore instruction for the second and third registers among the save instruction and the restore instruction.

[0013]

Embodiments of the present invention will now be described with reference to the drawings.

Referring to FIG. 1, which is a block diagram showing the configuration of an embodiment of the present invention, a simulator device for a program of the present embodiment shown in the drawing is a simulator 1 which is a main body portion, and a console which controls the simulator 1. 2, an input file 3 storing the program information of the simulation target, and an output file 4 storing the processing result of the simulator 1 as output information.

The simulator 1 is provided with an activation unit 11 which activates the simulator 1 by receiving an activation command from the console 2.
And an input unit 12 for supplying the program information from the file 3 to the memory unit 13, and a memory unit 13 for storing the program information supplied from the input unit 12.
An instruction analysis unit 14 that analyzes the program information stored in the memory unit 13, an instruction execution unit 15 that executes the analyzed instruction, an interrupt control unit 16 that manages an interrupt, and access contents and interrupts of registers. From the contents of the interrupt process, registers that are not used in the interrupt process or registers whose contents do not change even if they are used are detected, and unnecessary save / restore commands for these registers in the save / restore instructions are detected.
A state control unit 17 that detects a return instruction, and a state control unit 17
The output unit 18 outputs the processing result of 1 to the file 4 as the processing result of the simulator 1.

The memory unit 13 includes a register unit 131 that stores information about registers of the microcomputer to be simulated.

The instruction analysis section 14 includes an instruction determination section 141 for determining a register save instruction, an instruction determination section 142 for determining a register restore instruction, an instruction determination section 143 for determining a return instruction upon completion of an interrupt, and a soft assignment. An instruction determination unit 144 that determines an embedded instruction.

The interrupt control unit 16 includes an interrupt generation unit 161 that generates an interrupt and an interrupt level management unit 1 that manages an interrupt level.
And 62.

Of these constituent elements, the instruction determination unit 14
4 and the interrupt generation unit 161 constitute an interrupt process start detecting means for detecting that the interrupt process is started. The instruction determination unit 143 constitutes an interrupt processing end detecting means for detecting the end of the interrupt processing. The register unit 131 constitutes an access register detecting means for detecting the accessed register. The instruction determination unit 141 and the instruction determination unit 142 constitute a register save / restore instruction detection unit that detects each register save / restore instruction. State detector 1
Reference numeral 7 constitutes unnecessary register save / restore instruction detecting means for detecting a register save / restore instruction for a register which does not require save and restore.

Next, the operation of this embodiment will be described. First, the start-up unit 1 is controlled by the start-up control from the console 2.
Start 1. The starting unit 11 changes the input from the file 3 to the input unit 12.
The program information is supplied to the memory unit 13 via the. Further, the activation unit 11 supplies the first instruction M1 of the program information to the instruction analysis unit 14. The instruction analysis unit 14 uses the instruction determination units 141 to 144 to identify whether the instruction M1 received by the instruction is a register save instruction, a register restore instruction, an interrupt end return instruction, or a soft interrupt instruction. The identified instruction M1 is supplied to the instruction execution unit 15,
Here, the simulation of the process corresponding to the instruction M1 is executed. At this time, access to the register (hereinafter referred to as target register) of the simulation target microcomputer and memory is performed by the memory unit 13, and among these, access to the target register is performed by the register unit 131 and the register unit 131. Supplies the content of the target register to the state control unit 17 as state control data C1. When the instruction M1 is an instruction to generate an interrupt during execution of the simulation, the interrupt generation unit 161 supplies the interrupt generation signal B to the interrupt level management unit 162. In this way, the instruction to be executed next is determined based on the execution result of the instruction execution unit 15, and the instruction M2 is supplied to the instruction analysis unit 14 again. When this instruction M2 is determined to be a register save instruction by the instruction determination unit 141, an access operation is performed with the register unit 131 as in the case of the above-described instruction M1, and the content of this instruction M2 is It is supplied to the state control unit 17 as state control data C2.
When the instruction determination unit 142 determines that the instruction M2 is a register restore instruction, the instruction M2 performs an access operation with the register unit 131, and the content of the instruction M2 is sent to the state control unit 17 as state control data. Supplied as C3. When the instruction determination unit 143 determines that the instruction M2 is an interrupt end return instruction, the content of the instruction M2 is supplied to the interrupt level management unit 162 as data R. Further, when the instruction determination unit 144 determines that the instruction M2 is a soft interrupt instruction, the content of the instruction M2 is supplied to the interrupt generation unit 161 as the data SB. When the level of the interrupt level management unit 162 changes, this change is supplied to the state control unit 17 as the state control data C4. In response to the supply of the state control data C1 to C4, the state control unit 17 does not use or use the register to be accessed in the interrupt process when the instruction M2 is a register save / restore instruction by the operation described later. Even if it is a register whose contents are not changed, it is detected, and from this result, output information O of a detection result as to whether this instruction M2 is an unnecessary save / restore instruction for the register is generated, and the output unit 18 outputs The output information O is supplied to the file 4.

An example of each of the program information of the file 3, the output information supplied to the file 4 of the processing result of the program information, and the information supplied to the state control unit 17 at this time is in the form of an assembler source program. 2 (A), (B), and (C) shown in FIG.
The program information shown in (A) includes instructions I1 to I5 and I11.
Have I17. MOVs of the instructions I1, I2, etc. indicate that these instructions I1, I2, etc. are transfer instructions, and A, DE, and HL indicate registers of the microcomputer to be simulated. [A] indicates the stored contents of the address of the memory unit 13 designated by A. Further, INCW of the instructions I3 and I4 indicates that it is an increment instruction of the contents of the register DE and the like. B of instruction I5
NC indicates a branch instruction. Instructions I11, I12
PUSU, etc., sends a save instruction to instructions P15, I15, I16, etc.
OP indicates a return instruction, respectively. RETI of instruction I17
Indicates an interrupt processing end return instruction. NO-NEED of the output information O1 shown in FIG. 2B indicates that processing of the instruction is unnecessary.

Each of the instructions I1 to I5 stores the stored contents of the address of the memory 13 designated by the register DE in the register A.
To the address of the memory 13 designated by the register HL, to increment the contents of the register DE, to increment the contents of the register HL, and to the LAB if there is no carry after the execution of the previous instruction. Indicates to branch. Also, the instruction I
11 to I17 save the contents of the register HL to the save area, save the contents of the register DE to the save area, set the contents of the register A to 12H, and set the contents of the register A to the address of the memory 13 designated by the register HL. To the register DE, or from the save area to the register DE, or from the save area to the register HL.
Indicates that the interrupt process can be completed and the original process can be returned to.
In this example, since the contents of the register DE are not manipulated during the interrupt processing of the instructions I11 to I17, the instructions I12 and I15 for saving / restoring the register DE are obviously unnecessary.

FIG. 2C shows the state supplied to the state control unit 17 when the interrupt processes I11 to I17 are processed immediately after the simulation of the command I2 during the simulation of the program information of the commands I1 to I3. Information S0
~ S11 is shown. The information S0 indicates the names of the registers A, DE, and HL and the interrupt Intr. Information S1 is command I
1 indicates that the register DE is referenced (R) and written (W) to the register A corresponding to the execution of 1, and the state control data C1 is supplied from the register unit 131. The information S2 corresponds to the execution of the instruction I2 and indicates the information that the register A is referenced and the register HL is also referenced, and the state control data C1 is supplied from the register unit 131 together. The information S3 indicates that an interrupt has occurred, and the state control data C4 is supplied from the interrupt generation unit 161 via the interrupt level management unit 162. The information S4 corresponds to the execution of the instruction I11 and indicates the information that the register HL has been saved, and the save instruction determination unit 141 supplies the state control data C2. The information S5 corresponds to the execution of the instruction I12, indicates the information that the register DE has been saved, and the save instruction determination unit 141 supplies the state control data C2. Information S
Reference numeral 6 corresponds to the execution of the instruction I13 and indicates the information written in the register A, and the state control data C1 is supplied from the register unit 131. The information S7 corresponds to the execution of the instruction I14 and indicates the information that the register A is referenced and the register HL is also referenced, and the state control data C1 is supplied from the register unit 131 together. The information S8 corresponds to the execution of the instruction I15, indicates the information that the register DE has been restored, and the restoration instruction determination unit 142 supplies the state control data C3. The information S9 corresponds to the execution of the instruction I16 and indicates the information that the register HL has been restored, and the restoration instruction determination unit 142 supplies the state control data C3. Information S10 corresponds to the execution of the instruction I17 and indicates the end of the interrupt processing, and the return instruction determination unit 143 to the interrupt level management unit 1
The state control data C4 is supplied via 62. The information S11 corresponds to the execution of the instruction I17, indicates the information that the register DE is referred to and written, and the register unit 131
Is supplied with the state control data C1.

From the information of the state control data C1 to C4, the result of the output information O1 shown in FIG.
POP DE NO-NEED ", ie register D
Obtain a message that does not require E save / restore instruction processing.

Referring to FIG. 3 which is a flow chart when the state control section 17 obtains the output information O1 from the information of the state control data C1 to C4, the array data shown in this figure,
The variables p1 and p2 are state values stored in the state control unit 17, respectively. The variable p1 indicates the interrupt level, and is initially 0.
Then, it becomes 1 when an interrupt occurs during normal program processing, and becomes 2 when an interrupt occurs further. The variable p1 returns to 1 upon completion of the level 2 interrupt, and returns to 0 upon completion of the level 1 interrupt. The variable p2 indicates a register name, which is 0 in the register A, 1 in the register BC, 2 in the register DE, and 3 in the register HL. These variables P1 and P
The first value of the array data [p1] [p2] shown by 2 is 0.

The value of the variable p2 is determined in steps S1 to S8 from the register name of the data C1 according to the state control data C1 supplied at the time of the access instruction to the register. Next, when data [p1] [p2] is 1 in step S9, the process proceeds to step S10, and data [p]
1] [p2] is set to 2. Where data [p1]
A value of 1 in [p2] indicates that the register save instruction has been executed, and a value of 2 indicates that the register access instruction has been executed after execution of the register save instruction.

The value of the variable p2 is determined in steps S11 to S18 from the register name of the data C2 according to the state control data C2 supplied when the register is saved. Step S
At 19 the data [p1] [p2] is set to 1.

With the state control data C4 supplied when the interrupt level changes, it is determined in step S20 whether or not the level is raised, and when it is raised, the process proceeds to step S21, the value of the variable p1 is incremented, and the variable p2 is set to 0 in step S22.
The data [p1] [p2] for 0 to 3 becomes 0. Further, at the time of down, the process proceeds to step S23, where the variable p2 is 0
When data [p1] [p2] in the case of 3 is 1, the message "PUSH / POP register name NO NEED" shown in FIG. 2B is output to the output unit 18, and the value of the variable p1 is output in step S24. Decrement. Therefore, in this case, it means that the access instruction to the register is never executed even though the save instruction of the register is executed.

Referring to FIG. 4 showing the second embodiment of the present invention, the difference between the flow chart of the state control unit 17 shown in this figure and the flow chart of the first embodiment shown in FIG. When the variable P2 is 0 to 3 for the processing of the state control data C3, data write determination steps S39 to S43 to be described later are added after the step S8 in the processing for C1.
When [p1] [p2] becomes 3, “PU
SH / POP register name NO NEED (READON
That is, step S44 for outputting the message "LY)" is added.

In the first step S39 of steps S39 to S43 added to the processing of the state control data C1, dat
If a [p1] [p2] is not 0, the next step S
At 40, it is determined whether the register access data corresponding to the state control data C1 is a write (write) value, that is, a change in register contents, and if it is a write value, step S4
At 1, the value of data [p1] [p2] becomes 2 indicating that the write instruction for the register has been executed. If it is not a write value, it is only a reference to the above register,
In step S42, it is determined whether or not the values of data [p1] [p2] are 2, and if not 2, in step S43, da
The value of ta [p1] [p2] becomes 3 indicating only the reference of the register.

The other operations described above are the same as in the first embodiment.

This makes it possible to display the save / restore instruction as unnecessary if the register used during the interrupt processing is not changed by merely referring to the content.

[0033]

As described above, the simulator device for a program of the present invention does not change the contents of the save instruction and the restore instruction that are unused in the interrupt processing and that is used in the interrupt processing. It is equipped with a register status detection unit that detects registers and save and restore instructions for those registers that do not need to be saved and restored, and notifies the simulation operator of the location of the save and restore instructions. There is an effect that it is possible to easily develop a highly efficient program having a register saving instruction that saves a limited number of registers.

[Brief description of drawings]

FIG. 1 is a first simulator device of a program according to the present invention.
It is a block diagram showing an example of.

FIG. 2 is a diagram showing an example of program information, output information of a processing result thereof, and information supplied to a state control unit.

FIG. 3 is a flowchart showing an example of the operation of this embodiment.

FIG. 4 is a flowchart showing an example of the operation of the second exemplary embodiment of the present invention.

[Explanation of symbols]

 1 Simulator 2 Console 3,4 File 11 Start-up Section 12 Input Section 13 Memory Section 14 Instruction Analysis Section 15 Instruction Execution Section 16 Interrupt Control Section 17 State Control Section 18 Output Section 131 Register Section 141-144 Instruction Determination Section 161 Interrupt Generation Division 162 Interruption level management section

Claims (3)

[Claims] 1. A simulator device for a program of the information processing device in which the register save and restore operations are performed by the interrupt process of the information processing device having a register, the interrupt process start detecting the start of the interrupt process. Detecting means; interrupt processing end detecting means for detecting the end of the interrupt processing; access register detecting means for detecting the first register which is the accessed register and generating first state control data; A save instruction / restore instruction determining unit that determines a save instruction and a restore instruction of the first register and generates second and third state control data, and a fourth state that determines a level of the interrupt processing. An interrupt level management means for generating control data, and one of the first registers in response to the supply of the first to fourth state control data. Of the save instruction and the restore instruction, the second register not used in the interrupt processing and the third register whose content is not changed even if used in the interrupt processing are detected and the second and third A simulator device for a program, comprising: a register state detecting means for detecting a save instruction and a restore instruction for a register. 2. The register state detecting means comprises a first variable indicating the level of the interrupt processing and a second variable indicating the name of the register in response to the supply of the first state control data. The second variable is detected from the name of the register of the first state control data supplied at the time of access to the register for operating the array data, and the value of the array data has already been executed for the register. When it is other than a predetermined first number indicating that there is a certain value, the processing is terminated, and when it is the first number, the value of this array data indicates that the access instruction has been executed after the instruction for the register is executed. A first step of setting a predetermined second number; and from the name of the register of the second state detection data supplied when the register is saved in response to the supply of the second state control data, A second step of detecting a second variable and setting the value of the array data to the first number; a third step of ending the process in response to the supply of the third state control data; In response to the supply of the state control data of No. 4, it is determined whether the level of the interrupt processing of the third state detection data supplied at the time of the change of the level of the interrupt processing is increased or decreased, and when the level is decreased, A predetermined third of the second variable
In the case where the value of the array data is the first number, the save instruction and the restore instruction for the second and third registers are detected, a corresponding message is output, and the first variable is set. The program simulator device according to claim 1, further comprising a fourth step of decrementing. 3. An array composed of a first variable representing a level of the interrupt processing and a second variable representing a name of the register in response to the supply of the first state control data by the register state detecting means. A fourth predetermined value that detects the second variable from the name of the register of the first state control data supplied when accessing the register for manipulating data and the value of the array data indicates the initial state. When it is the write data, it is judged whether or not the register access data corresponding to the first state control data is write data, and when it is other than the fourth number, The value of the array data is set to a predetermined second number indicating that the access instruction has been executed after the execution of the instruction to the register, and the processing is terminated. Is the first If the number is 2, the process is terminated, and if it is not the second number, the value of the array data is set to a predetermined fifth number indicating that the access instruction is a reference instruction, and the process is terminated. 1A And the value of the array data by detecting the second variable from the register name of the second state detection data supplied when the register is saved in response to the supply of the second state control data. To the first number, and a value of the array data corresponding to a predetermined third number of the second variable in response to the supply of the third state control data. A third step of outputting a message corresponding to the case of the fifth number; and a third state supplied when the level of the interrupt processing changes in response to the supply of the fourth state control data. Increasing or decreasing the level of detection data interrupt processing Second determined in advance of the determined second variable in the case of reduction of the level
Corresponding to the value of the array data is the first value, a save instruction and a restore instruction to the second and third registers are detected, and a corresponding message is output to output the first variable. The program simulator device according to claim 1, further comprising a fourth step of decrementing.