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Digital-Research-Source-Code/ASSEMBLY & COMPILE TOOLS/PLM VAX COMPILER/plmvax/regs.for
Sepp J Morris 31738079c4 Upload
Digital Research
2020-11-06 18:50:37 +01:00

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Fortran

C***********************************************************************
C
C REGS.FOR
C
C
C D I S C L A I M E R N O T I C E
C ------------------- -----------
C
C This document and/or portions of the material and data furnished
C herewith, was developed under sponsorship of the U. S. Government.
C Neither the U.S. nor the U.S.D.O.E., nor the Leland Stanford Junior
C University, nor their employees, nor their respective contractors,
C subcontractors, or their employees, makes any warranty, express or
C implied, or assumes any liability or responsibility for accuracy,
C completeness or usefulness of any information, apparatus, product
C or process disclosed, or represents that its use will not infringe
C privately-owned rights. Mention of any product, its manufacturer,
C or suppliers shall not, nor is it intended to, imply approval, dis-
C approval, or fitness for any particular use. The U. S. and the
C University at all times retain the right to use and disseminate same
C for any purpose whatsoever. Such distribution shall be made by the
C National Energy Software Center at the Argonne National Laboratory
C and only subject to the distributee furnishing satisfactory proof
C that he has a valid license from the Intel Corporation in effect.
C
C-----------------------------------------------------------------------
C
C This module of the PL/M-VAX compiler contains routines to manage
C register allocation and preservation.
C
C-----------------------------------------------------------------------
C
C 15OCT81 Alex Hunter 1. Experimental version. (V54.)
C 14NOV81 Alex Hunter 1. If LARGE OVERLAY, then add R12 to
C register pool. (V6.2)
C
C-----------------------------------------------------------------------
INTEGER*2 FUNCTION ALLOCATE_REG_WITH_PREFERENCE(TYPE,POSSIBLE_REG)
INCLUDE 'PLMCOM.FOR/NOLIST'
INTEGER*4 LAST_REG,FIRST_REG,R
LOGICAL*4 AVAILABLE(1:16)
R = POSSIBLE_REG
C------- First try to allocate the preferred register.
IF (REGISTER(R) .AND. AVAILABLE(R) .AND.
# (BYTE_SIZE(TYPE).LE.4 .OR. AVAILABLE(R+1))) GO TO 10
C------- Otherwise, use the normal allocation algorithm.
C---------------------------------------------
ENTRY ALLOCATE_REG(TYPE)
C---------------------------------------------
DO R = LAST_REG-1, FIRST_REG, -1
IF (AVAILABLE(R) .AND.
# (BYTE_SIZE(TYPE).LE.4 .OR. AVAILABLE(R+1))) GO TO 10
ENDDO
CALL ERROR('REGISTER POOL EXHAUSTED')
ALLOCATE_REG = LAST_REG-1 ! Just so we can keep compiling.
NODE_TYPE(ALLOCATE_REG) = TYPE
RETURN
C------- Here when we have an available register.
10 CONTINUE
ALLOCATE_REG = R
CALL PRESERVE_REG(R)
AVAILABLE(R) = .FALSE.
NODE_TYPE(R) = TYPE
IF (BYTE_SIZE(TYPE).GT.4) THEN
CALL PRESERVE_REG(R+1)
AVAILABLE(R+1) = .FALSE.
NODE_TYPE(R+1) = TYPE
ENDIF
RETURN
C--------------------------------------
ENTRY FREE_REGS()
C--------------------------------------
IF (MODEL.EQ.4.AND.OVERLAY_FLAG) THEN
LAST_REG=12
ELSEIF (MODEL.EQ.2 .OR. MODEL.EQ.4) THEN
LAST_REG=11
ELSE
LAST_REG=10
ENDIF
FIRST_REG=PROC_AP(PROC_LEVEL)+1
DO R=1,LAST_REG
AVAILABLE(R) = R.GE.FIRST_REG .AND. R.LT.LAST_REG
ENDDO
RETURN
C--------------------------------------
ENTRY FREE_REG(REG)
C--------------------------------------
AVAILABLE(REG) = .TRUE.
IF (BYTE_SIZE(NODE_TYPE(REG)).GT.4) THEN
AVAILABLE(REG+1) = .TRUE.
ENDIF
RETURN
END
C-------------------------------------------------------
SUBROUTINE PRESERVE_REG(REG)
INCLUDE 'PLMCOM.FOR/NOLIST'
PROC_ENTRY_MASK(PROC_LEVEL)=PROC_ENTRY_MASK(PROC_LEVEL).OR.
# ISHFT(1,REG)
RETURN
END
C--------------------------------------------------------
CHARACTER*40 FUNCTION REGISTER_MASK(MASK)
IMPLICIT INTEGER*2 (A-Z)
CHARACTER*3 REGNAME(0:15)
DATA REGNAME
//'R0','R1','R2','R3','R4','R5','R6','R7','R8','R9'
,,'R10','R11','AP','FP','SP','PC'
//
INTEGER*2 REGLEN(0:15)
DATA REGLEN
//2,2,2,2,2,2,2,2,2,2,3,3,2,2,2,2/
REGISTER_MASK='^M<'
N=4
DO 10 I=0,15
IF ((ISHFT(MASK,-I).AND.1).NE.0) THEN
IF (N.GT.4) THEN
REGISTER_MASK(N:)=','
N=N+1
ENDIF
REGISTER_MASK(N:)=REGNAME(I)
N=N+REGLEN(I)
ENDIF
10 CONTINUE
REGISTER_MASK(N:)='>'
RETURN
END