Compiler processing system for generating assembly program codes for a computer comprising a plurality of arithmetic units

• US 20010039654A1
• Filed: 12/05/2000
• Published: 11/08/2001
• Est. Priority Date: 12/06/1999
• Status: Abandoned Application

• Current Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Original Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Inventors: Miyamoto, Takashi
• Application Number:
  US09/730,213
• Publication Number:
  US 20010039654A1
• Time in Patent Office: Days
• US Class Current: 717/160
• CPC Class Codes: G06F 8/4441 Reducing the execution time required by the program code
• CPC Class Codes: G06F 8/445 Exploiting fine grain parallelism, i.e. parallelism at instruction level run-time instruction scheduling G06F9/3836

Abstract

Provided is a compiler processing system for generating assembly program codes from a source program for a computer comprising a plurality of arithmetic units, the system comprising: a front end; a machine-independent optimization portion; a code generating portion; and a machine-dependent optimization portion; wherein the machine-dependent optimization portion comprises: a non-instruction scheduling portion; and an instruction scheduling portion comprising: means for determining if an arithmetic unit is available for an inspected instruction at an execution clock concerned; means for determining if there is a substitutional instruction which performs the equivalent function as the inspected instruction if an arithmetic unit is not available for the inspected instruction; means for determining if an arithmetic unit is available at the execution clock for the substitutional instruction, if any; and means for changing the inspected instruction to the substitutional instruction if an arithmetic unit is available for the substitutional instruction.

Claims

1. A compiler processing system for generating assembly program codes from a source program for a computer comprising a plurality of arithmetic units, said system comprising:

a front end which analyzes syntax and semantics of said source program;

a machine-independent optimization portion which performs machine-independent optimization for said source program;

a code generating portion which generates said assembly program codes from said source program which has been optimized in said machine-independent optimization portion; and

a machine-dependent optimization portion which performs machine-dependent optimization for said assembly program codes which have been generated by said code generating portion;

wherein said machine-dependent optimization portion comprises;

a non-instruction scheduling portion which performs optimization other than instruction scheduling;

an instruction scheduling portion which performs optimization including said instruction scheduling, said instruction scheduling portion comprising;

means for determining whether or not an arithmetic unit is available for an inspected instruction at an execution clock concerned;

means for determining whether or not there is a substitutional instruction which performs the equivalent function as said inspected instruction if an arithmetic unit is not available for said inspected instruction;

means for determining whether or not an arithmetic unit is available at said execution clock concerned for said substitutional instruction, if any; and

means for changing said inspected instruction to said substitutional instruction if an arithmetic unit is available for said substitutional instruction.

2. A compiler processing system for generating assembly program codes from a source program for a computer comprising a plurality of arithmetic units, said system comprising:

a front end which analyzes syntax and semantics of said source program;

a machine-independent optimization portion which performs machine-independent optimization for said source program;

a machine-dependent optimization portion which performs machine-dependent optimization for intermediate language codes obtained from said source program; and

a code generating portion which generates said assembly program codes from said intermediate language codes which have been optimized in said machine-dependent optimization portion;

wherein said machine-dependent optimization portion comprises;

a non-instruction scheduling portion which performs optimization other than instruction scheduling;

an instruction scheduling portion which performs optimization including said instruction scheduling, said instruction scheduling portion comprising;

means for determining whether or not an arithmetic unit is available for an inspected instruction at an execution clock concerned;

means for determining whether or not there is a substitutional instruction which performs the equivalent function as said inspected instruction if an arithmetic unit is not available for said inspected instruction;

means for determining whether or not an arithmetic unit is available at said execution clock concerned for said substitutional instruction, if any; and

means for changing said inspected instruction to said substitutional instruction if an arithmetic unit is available for said substitutional instruction.

3. A method for generating assembly program codes from a source program for a computer comprising a plurality of arithmetic units, said method comprising the steps of:

analyzing syntax of said source program;

analyzing semantics of said source program;

performing machine-independent optimization for said source program;

generating said assembly program codes from said source program which has been optimized; and

performsing machine-dependent optimization for said assembly program codes;

wherein said machine-dependent optimization comprises the steps of;

performing optimization other than instruction scheduling;

performing optimization including said instruction scheduling, said instruction scheduling comprising the steps of;

determining whether or not an arithmetic unit is available for an inspected instruction at an execution clock concerned;

determining whether or not there is a substitutional instruction which performs the equivalent function as said inspected instruction if an arithmetic unit is not available for said inspected instruction;

determining whether or not an arithmetic unit is available at said execution clock concerned for said substitutional instruction, if any; and

changing said inspected instruction to said substitutional instruction if an arithmetic unit is available for said substitutional instruction.

4. A method for generating assembly program codes from a source program for a computer comprising a plurality of arithmetic units, said method comprising the steps of:

analyzing syntax of said source program;

analyzing semantics of said source program;

performing machine-independent optimization for said source program;

performing machine-dependent optimization for intermediate language codes obtained from said source program; and

generating said assembly program codes from said intermediate language codes which have been optimized;

wherein said machine-dependent optimization comprises the steps of;

performing optimization other than instruction scheduling;

performing optimization including said instruction scheduling, said instruction scheduling comprising the steps of;

determining whether or not an arithmetic unit is available for an inspected instruction at an execution clock concerned;

determining whether or not there is a substitutional instruction which performs the equivalent function as said inspected instruction if an arithmetic unit is not available for said inspected instruction;

determining whether or not an arithmetic unit is available at said execution clock concerned for said substitutional instruction, if any; and

changing said inspected instruction to said substitutional instruction if an arithmetic unit is available for said substitutional instruction.

5. A computer program for having a computer execute a method for generating assembly program codes from a source program for a computer comprising a plurality of arithmetic units, said method comprising the steps of:

analyzing syntax of said source program;

analyzing semantics of said source program;

performing machine-independent optimization for said source program;

generating said assembly program codes from said source program which has been optimized; and

performsing machine-dependent optimization for said assembly program codes;

wherein said machine-dependent optimization comprises the steps of;

performing optimization other than instruction scheduling;

performing optimization including said instruction scheduling, said instruction scheduling comprising the steps of;

determining whether or not an arithmetic unit is available for an inspected instruction at an execution clock concerned;

determining whether or not there is a substitutional instruction which performs the equivalent function as said inspected instruction if an arithmetic unit is not available for said inspected instruction;

determining whether or not an arithmetic unit is available at said execution clock concerned for said substitutional instruction, if any; and

changing said inspected instruction to said substitutional instruction if an arithmetic unit is available for said substitutional instruction.

6. A computer program for having a computer execute a method for generating assembly program codes from a source program for a computer comprising a plurality of arithmetic units, said method comprising the steps of:

analyzing syntax of said source program;

analyzing semantics of said source program;

performing machine-independent optimization for said source program;

performing machine-dependent optimization for intermediate language codes obtained from said source program; and

generating said assembly program codes from said intermediate language codes which have been optimized;

wherein said machine-dependent optimization comprises the steps of;

performing optimization other than instruction scheduling;

performing optimization including said instruction scheduling, said instruction scheduling comprising the steps of;

determining whether or not an arithmetic unit is available for an inspected instruction at an execution clock concerned;

determining whether or not there is a substitutional instruction which performs the equivalent function as said inspected instruction if an arithmetic unit is not available for said inspected instruction;

determining whether or not an arithmetic unit is available at said execution clock concerned for said substitutional instruction, if any; and

changing said inspected instruction to said substitutional instruction if an arithmetic unit is available for said substitutional instruction.

7. An instruction scheduler for scheduling instructions for a computer comprising a plurality of arithmetic units, said system scheduler comprising:

means for determining whether or not an arithmetic unit is available for an inspected instruction at an execution clock concerned;

means for determining whether or not there is a substitutional instruction which performs the equivalent function as said inspected instruction if an arithmetic unit is not available for said inspected instruction;

means for determining whether or not an arithmetic unit is available at said execution clock concerned for said substitutional instruction, if any; and

means for changing said inspected instruction to said substitutional instruction if an arithmetic unit is available for said substitutional instruction.

8. A method for scheduling instructions for a computer comprising a plurality of arithmetic units, said method comprising the steps of:

determining whether or not an arithmetic unit is available for an inspected instruction at an execution clock concerned;

whether or not there is a substitutional instruction which performs the equivalent function as said inspected instruction if an arithmetic unit is not available for said inspected instruction;

determining whether or not an arithmetic unit is available at said execution clock concerned for said substitutional instruction, if any; and

changing said inspected instruction to said substitutional instruction if an arithmetic unit is available for said substitutional instruction.

9. A computer program for having a computer execute a method for scheduling instructions for a computer comprising a plurality of arithmetic units, said method comprising the steps of:

determining whether or not an arithmetic unit is available for an inspected instruction at an execution clock concerned;

whether or not there is a substitutional instruction which performs the equivalent function as said inspected instruction if an arithmetic unit is not available for said inspected instruction;

determining whether or not an arithmetic unit is available at said execution clock concerned for said substitutional instruction, if any; and

changing said inspected instruction to said substitutional instruction if an arithmetic unit is available for said substitutional instruction.