[patch][rfa] Improve cgen profile modelling for VLIW

Dave Brolley <[email protected]> Tue, 21 Oct 2003 13:49:45 -0400

Newsgroups	gmane.comp.emulators.sid.devel
Organization	Red Hat Canada, Ltd
Message-ID	<[email protected]>

Hi,

This patch expands the recently-added cgen model support for cgen-cpu to 
handle generic VLIW issues.  It accumulates the maximum number of cycles 
used by all insns in a VLIW bundle and then calls a virtual function 
(step_latency) to allow the cpu to account for those cycles.

Tested against our internal port but generally useful for other 
architectures.

ok to commit?

Dave

model.ChangeLog (text/plain, 502 B)

2003-10-07  Dave Brolley  <[email protected]>

	* cgen-model.h (class cgen_model): step_cycles and step_latency
	now public.

2003-10-07  Dave Brolley  <[email protected]>

	* cgen-model.h (sidtypes.h): #include it.
	(model_insn_before): Call step_latency. Initialize vliw_cycles.
	(model_insn_after): Call step_cycles. Update vliw_cycles.
	(step_cycles): New method.
	(step_latency): New method.
	(vliw_cycles): New member of cgen_model.
	* cgen-engine.h (enum sem_status): Add SEM_STATUS_STALLED.

model.patch.txt (text/plain, 4 KB)

Index: sid/component/cgen-cpu/cgen-engine.h
===================================================================
RCS file: /cvs/src/src/sid/component/cgen-cpu/cgen-engine.h,v
retrieving revision 1.4
diff -c -p -r1.4 cgen-engine.h
*** sid/component/cgen-cpu/cgen-engine.h	6 Feb 2003 20:44:34 -0000	1.4
--- sid/component/cgen-cpu/cgen-engine.h	21 Oct 2003 17:21:28 -0000
***************
*** 1,6 ****
  // cgen-engine.h - CGEN engine support.  -*- C++ -*-
  
! // Copyright (C) 1999, 2000 Red Hat.
  // This file is part of SID and is licensed under the GPL.
  // See the file COPYING.SID for conditions for redistribution.
  
--- 1,6 ----
  // cgen-engine.h - CGEN engine support.  -*- C++ -*-
  
! // Copyright (C) 1999, 2000, 2003 Red Hat.
  // This file is part of SID and is licensed under the GPL.
  // See the file COPYING.SID for conditions for redistribution.
  
*************** enum sem_status
*** 15,21 ****
  {
    SEM_STATUS_NORMAL,
    SEM_STATUS_BRANCH_TAKEN,
!   SEM_STATUS_DELAYED_BRANCH_TAKEN
  };
  
  // Exceptions used to exit the cpu's "main loop".
--- 15,22 ----
  {
    SEM_STATUS_NORMAL,
    SEM_STATUS_BRANCH_TAKEN,
!   SEM_STATUS_DELAYED_BRANCH_TAKEN,
!   SEM_STATUS_STALLED
  };
  
  // Exceptions used to exit the cpu's "main loop".
Index: sid/component/cgen-cpu/cgen-model.h
===================================================================
RCS file: /cvs/src/src/sid/component/cgen-cpu/cgen-model.h,v
retrieving revision 1.1
diff -c -p -r1.1 cgen-model.h
*** sid/component/cgen-cpu/cgen-model.h	16 Apr 2003 18:13:51 -0000	1.1
--- sid/component/cgen-cpu/cgen-model.h	21 Oct 2003 17:21:28 -0000
***************
*** 7,12 ****
--- 7,13 ----
  #ifndef CGEN_MODEL_H
  #define CGEN_MODEL_H
  
+ #include <sidtypes.h>
  #include "cgen-cpu.h"
  
  namespace cgen
*************** public:
*** 19,37 ****
  
    // To be overridden as needed. Call before each insn is executed. first_p is
    // true when the insn is the first of a group of parallel insns.
!   virtual void model_insn_before (bool first_p = true) {}
  
    // To be overridden as needed. Call after each insn is executed. last_p is
    // true when the insn is the first of a group of parallel insns. cycles is the
    // number of cycles used by each particular insn.
    virtual void model_insn_after (bool last_p = true, sid::host_int_4 cycles = 1)
      {
!       if (last_p && cycles > 0)
  	cpu->update_total_latency (cycles - 1);
      }
  
  protected:
    cgen_bi_endian_cpu *cpu;
  };
  
  } // namespace cgen
--- 20,69 ----
  
    // To be overridden as needed. Call before each insn is executed. first_p is
    // true when the insn is the first of a group of parallel insns.
!   virtual void model_insn_before (bool first_p = true)
!   {
!     if (first_p)
!       {
! 	// There may be latency from insn fetch.
! 	step_latency ();
! 	this->vliw_cycles = 1;
!       }
!   }
  
    // To be overridden as needed. Call after each insn is executed. last_p is
    // true when the insn is the first of a group of parallel insns. cycles is the
    // number of cycles used by each particular insn.
    virtual void model_insn_after (bool last_p = true, sid::host_int_4 cycles = 1)
      {
!       // Accumulate the max cycles used by any one vliw insn.
!       if (cycles > this->vliw_cycles)
! 	this->vliw_cycles = cycles;
! 
!       // Account for the latency of this group of insns.
!       if (last_p)
! 	step_cycles (vliw_cycles);
!     }
! 
!   // To be overridden as needed. Update any state associated with an
!   // insn using the given number of cycles.
!   virtual void step_cycles (sid::host_int_4 cycles)
!   {
!     if (cycles > 0)
!       {
! 	// The cpu counts cycles as number of insns + total latency.
  	cpu->update_total_latency (cycles - 1);
+ 	step_latency (1);
      }
+   }
+ 
+   // To be overridden as needed. Update any state associated with an
+   // insn having latency. Insn latency is tracked using the cpu's
+   // get_total_latency () method.
+   virtual void step_latency (sid::host_int_4 = 0) {}
  
  protected:
    cgen_bi_endian_cpu *cpu;
+   sid::host_int_4 vliw_cycles;
  };
  
  } // namespace cgen