REAL FUNCTION R1MACH(I) C C SINGLE-PRECISION MACHINE CONSTANTS C C R1MACH(1) = B**(EMIN-1), THE SMALLEST POSITIVE MAGNITUDE. C C R1MACH(2) = B**EMAX*(1 - B**(-T)), THE LARGEST MAGNITUDE. C C R1MACH(3) = B**(-T), THE SMALLEST RELATIVE SPACING. C C R1MACH(4) = B**(1-T), THE LARGEST RELATIVE SPACING. C C R1MACH(5) = LOG10(B) C C TO ALTER THIS FUNCTION FOR A PARTICULAR ENVIRONMENT, C THE DESIRED SET OF DATA STATEMENTS SHOULD BE ACTIVATED BY C REMOVING THE C FROM COLUMN 1. C C FOR IEEE-ARITHMETIC MACHINES (BINARY STANDARD), THE FIRST C SET OF CONSTANTS BELOW SHOULD BE APPROPRIATE. C C WHERE POSSIBLE, DECIMAL, OCTAL OR HEXADECIMAL CONSTANTS ARE USED C TO SPECIFY THE CONSTANTS EXACTLY. SOMETIMES THIS REQUIRES USING C EQUIVALENT INTEGER ARRAYS. IF YOUR COMPILER USES HALF-WORD C INTEGERS BY DEFAULT (SOMETIMES CALLED INTEGER*2), YOU MAY NEED TO C CHANGE INTEGER TO INTEGER*4 OR OTHERWISE INSTRUCT YOUR COMPILER C TO USE FULL-WORD INTEGERS IN THE NEXT 5 DECLARATIONS. C C COMMENTS JUST BEFORE THE END STATEMENT (LINES STARTING WITH *) C GIVE C SOURCE FOR R1MACH. C INTEGER SMALL(2) INTEGER LARGE(2) INTEGER RIGHT(2) INTEGER DIVER(2) INTEGER LOG10(2) INTEGER I C/6S C/7S SAVE SMALL, LARGE, RIGHT, DIVER, LOG10 C/ REAL RMACH(5) C EQUIVALENCE (RMACH(1),SMALL(1)) EQUIVALENCE (RMACH(2),LARGE(1)) EQUIVALENCE (RMACH(3),RIGHT(1)) EQUIVALENCE (RMACH(4),DIVER(1)) EQUIVALENCE (RMACH(5),LOG10(1)) C C MACHINE CONSTANTS FOR IEEE ARITHMETIC MACHINES, SUCH AS THE AT&T C 3B SERIES, MOTOROLA 68000 BASED MACHINES (E.G. SUN 3 AND AT&T C PC 7300), AND 8087 BASED MICROS (E.G. IBM PC AND AT&T 6300). C DATA SMALL(1) / 8388608 / DATA LARGE(1) / 2139095039 / DATA RIGHT(1) / 864026624 / DATA DIVER(1) / 872415232 / DATA LOG10(1) / 1050288283 / C C MACHINE CONSTANTS FOR AMDAHL MACHINES. C C DATA SMALL(1) / 1048576 / C DATA LARGE(1) / 2147483647 / C DATA RIGHT(1) / 990904320 / C DATA DIVER(1) / 1007681536 / C DATA LOG10(1) / 1091781651 /, SC/987/ C C MACHINE CONSTANTS FOR THE BURROUGHS 1700 SYSTEM. C C DATA RMACH(1) / Z400800000 / C DATA RMACH(2) / Z5FFFFFFFF / C DATA RMACH(3) / Z4E9800000 / C DATA RMACH(4) / Z4EA800000 / C DATA RMACH(5) / Z500E730E8 /, SC/987/ C C MACHINE CONSTANTS FOR THE BURROUGHS 5700/6700/7700 SYSTEMS. C C DATA RMACH(1) / O1771000000000000 / C DATA RMACH(2) / O0777777777777777 / C DATA RMACH(3) / O1311000000000000 / C DATA RMACH(4) / O1301000000000000 / C DATA RMACH(5) / O1157163034761675 /, SC/987/ C C MACHINE CONSTANTS FOR FTN4 ON THE CDC 6000/7000 SERIES. C C DATA RMACH(1) / 00564000000000000000B / C DATA RMACH(2) / 37767777777777777776B / C DATA RMACH(3) / 16414000000000000000B / C DATA RMACH(4) / 16424000000000000000B / C DATA RMACH(5) / 17164642023241175720B /, SC/987/ C C MACHINE CONSTANTS FOR FTN5 ON THE CDC 6000/7000 SERIES. C C DATA RMACH(1) / O"00564000000000000000" / C DATA RMACH(2) / O"37767777777777777776" / C DATA RMACH(3) / O"16414000000000000000" / C DATA RMACH(4) / O"16424000000000000000" / C DATA RMACH(5) / O"17164642023241175720" /, SC/987/ C C MACHINE CONSTANTS FOR CONVEX C-1. C C DATA RMACH(1) / '00800000'X / C DATA RMACH(2) / '7FFFFFFF'X / C DATA RMACH(3) / '34800000'X / C DATA RMACH(4) / '35000000'X / C DATA RMACH(5) / '3F9A209B'X /, SC/987/ C C MACHINE CONSTANTS FOR THE CRAY 1, XMP, 2, AND 3. C C DATA RMACH(1) / 200034000000000000000B / C DATA RMACH(2) / 577767777777777777776B / C DATA RMACH(3) / 377224000000000000000B / C DATA RMACH(4) / 377234000000000000000B / C DATA RMACH(5) / 377774642023241175720B /, SC/987/ C C MACHINE CONSTANTS FOR THE DATA GENERAL ECLIPSE S/200. C C NOTE - IT MAY BE APPROPRIATE TO INCLUDE THE FOLLOWING LINE - C STATIC RMACH(5) C C DATA SMALL/20K,0/,LARGE/77777K,177777K/ C DATA RIGHT/35420K,0/,DIVER/36020K,0/ C DATA LOG10/40423K,42023K/, SC/987/ C C MACHINE CONSTANTS FOR THE HARRIS SLASH 6 AND SLASH 7. C C DATA SMALL(1),SMALL(2) / '20000000, '00000201 / C DATA LARGE(1),LARGE(2) / '37777777, '00000177 / C DATA RIGHT(1),RIGHT(2) / '20000000, '00000352 / C DATA DIVER(1),DIVER(2) / '20000000, '00000353 / C DATA LOG10(1),LOG10(2) / '23210115, '00000377 /, SC/987/ C C MACHINE CONSTANTS FOR THE HONEYWELL DPS 8/70 SERIES. C C DATA RMACH(1) / O402400000000 / C DATA RMACH(2) / O376777777777 / C DATA RMACH(3) / O714400000000 / C DATA RMACH(4) / O716400000000 / C DATA RMACH(5) / O776464202324 /, SC/987/ C C MACHINE CONSTANTS FOR THE IBM 360/370 SERIES, C THE XEROX SIGMA 5/7/9 AND THE SEL SYSTEMS 85/86. C C DATA RMACH(1) / Z00100000 / C DATA RMACH(2) / Z7FFFFFFF / C DATA RMACH(3) / Z3B100000 / C DATA RMACH(4) / Z3C100000 / C DATA RMACH(5) / Z41134413 /, SC/987/ C C MACHINE CONSTANTS FOR THE INTERDATA 8/32 C WITH THE UNIX SYSTEM FORTRAN 77 COMPILER. C C FOR THE INTERDATA FORTRAN VII COMPILER REPLACE C THE Z'S SPECIFYING HEX CONSTANTS WITH Y'S. C C DATA RMACH(1) / Z'00100000' / C DATA RMACH(2) / Z'7EFFFFFF' / C DATA RMACH(3) / Z'3B100000' / C DATA RMACH(4) / Z'3C100000' / C DATA RMACH(5) / Z'41134413' /, SC/987/ C C MACHINE CONSTANTS FOR THE PDP-10 (KA OR KI PROCESSOR). C C DATA RMACH(1) / "000400000000 / C DATA RMACH(2) / "377777777777 / C DATA RMACH(3) / "146400000000 / C DATA RMACH(4) / "147400000000 / C DATA RMACH(5) / "177464202324 /, SC/987/ C C MACHINE CONSTANTS FOR PDP-11 FORTRANS SUPPORTING C 32-BIT INTEGERS (EXPRESSED IN INTEGER AND OCTAL). C C DATA SMALL(1) / 8388608 / C DATA LARGE(1) / 2147483647 / C DATA RIGHT(1) / 880803840 / C DATA DIVER(1) / 889192448 / C DATA LOG10(1) / 1067065499 /, SC/987/ C C DATA RMACH(1) / O00040000000 / C DATA RMACH(2) / O17777777777 / C DATA RMACH(3) / O06440000000 / C DATA RMACH(4) / O06500000000 / C DATA RMACH(5) / O07746420233 /, SC/987/ C C MACHINE CONSTANTS FOR PDP-11 FORTRANS SUPPORTING C 16-BIT INTEGERS (EXPRESSED IN INTEGER AND OCTAL). C C DATA SMALL(1),SMALL(2) / 128, 0 / C DATA LARGE(1),LARGE(2) / 32767, -1 / C DATA RIGHT(1),RIGHT(2) / 13440, 0 / C DATA DIVER(1),DIVER(2) / 13568, 0 / C DATA LOG10(1),LOG10(2) / 16282, 8347 /, SC/987/ C C DATA SMALL(1),SMALL(2) / O000200, O000000 / C DATA LARGE(1),LARGE(2) / O077777, O177777 / C DATA RIGHT(1),RIGHT(2) / O032200, O000000 / C DATA DIVER(1),DIVER(2) / O032400, O000000 / C DATA LOG10(1),LOG10(2) / O037632, O020233 /, SC/987/ C C MACHINE CONSTANTS FOR THE SEQUENT BALANCE 8000. C C DATA SMALL(1) / $00800000 / C DATA LARGE(1) / $7F7FFFFF / C DATA RIGHT(1) / $33800000 / C DATA DIVER(1) / $34000000 / C DATA LOG10(1) / $3E9A209B /, SC/987/ C C MACHINE CONSTANTS FOR THE UNIVAC 1100 SERIES. C C DATA RMACH(1) / O000400000000 / C DATA RMACH(2) / O377777777777 / C DATA RMACH(3) / O146400000000 / C DATA RMACH(4) / O147400000000 / C DATA RMACH(5) / O177464202324 /, SC/987/ C C MACHINE CONSTANTS FOR THE VAX UNIX F77 COMPILER. C C DATA SMALL(1) / 128 / C DATA LARGE(1) / -32769 / C DATA RIGHT(1) / 13440 / C DATA DIVER(1) / 13568 / C DATA LOG10(1) / 547045274 /, SC/987/ C C MACHINE CONSTANTS FOR THE VAX-11 WITH C FORTRAN IV-PLUS COMPILER. C C DATA RMACH(1) / Z00000080 / C DATA RMACH(2) / ZFFFF7FFF / C DATA RMACH(3) / Z00003480 / C DATA RMACH(4) / Z00003500 / C DATA RMACH(5) / Z209B3F9A /, SC/987/ C C MACHINE CONSTANTS FOR VAX/VMS VERSION 2.2. C C DATA RMACH(1) / '80'X / C DATA RMACH(2) / 'FFFF7FFF'X / C DATA RMACH(3) / '3480'X / C DATA RMACH(4) / '3500'X / C DATA RMACH(5) / '209B3F9A'X /, SC/987/ C C *** ISSUE STOP 777 IF ALL DATA STATEMENTS ARE COMMENTED... C IF (SC .NE. 987) THEN C* *** CHECK FOR AUTODOUBLE *** C SMALL(2) = 0 C RMACH(1) = 1E13 C IF (SMALL(2) .NE. 0) THEN C* *** AUTODOUBLED *** C IF ( SMALL(1) .EQ. 1117925532 C * .AND. SMALL(2) .EQ. -448790528) THEN C* *** IEEE BIG ENDIAN *** C SMALL(1) = 1048576 C SMALL(2) = 0 C LARGE(1) = 2146435071 C LARGE(2) = -1 C RIGHT(1) = 1017118720 C RIGHT(2) = 0 C DIVER(1) = 1018167296 C DIVER(2) = 0 C LOG10(1) = 1070810131 C LOG10(2) = 1352628735 C ELSE IF ( SMALL(2) .EQ. 1117925532 C * .AND. SMALL(1) .EQ. -448790528) THEN C* *** IEEE LITTLE ENDIAN *** C SMALL(2) = 1048576 C SMALL(1) = 0 C LARGE(2) = 2146435071 C LARGE(1) = -1 C RIGHT(2) = 1017118720 C RIGHT(1) = 0 C DIVER(2) = 1018167296 C DIVER(1) = 0 C LOG10(2) = 1070810131 C LOG10(1) = 1352628735 C ELSE IF ( SMALL(1) .EQ. -2065213935 C * .AND. SMALL(2) .EQ. 10752) THEN C* *** VAX WITH D_FLOATING *** C SMALL(1) = 128 C SMALL(2) = 0 C LARGE(1) = -32769 C LARGE(2) = -1 C RIGHT(1) = 9344 C RIGHT(2) = 0 C DIVER(1) = 9472 C DIVER(2) = 0 C LOG10(1) = 546979738 C LOG10(2) = -805796613 C ELSE IF ( SMALL(1) .EQ. 1267827943 C * .AND. SMALL(2) .EQ. 704643072) THEN C* *** IBM MAINFRAME *** C SMALL(1) = 1048576 C SMALL(2) = 0 C LARGE(1) = 2147483647 C LARGE(2) = -1 C RIGHT(1) = 856686592 C RIGHT(2) = 0 C DIVER(1) = 873463808 C DIVER(2) = 0 C LOG10(1) = 1091781651 C LOG10(2) = 1352628735 C ELSE C WRITE(*,*)'Adjust autodoubled R1MACH by uncommenting' C WRITE(*,*)'data statements appropriate for your machine.' C STOP 777 C END IF C ELSE C RMACH(1) = 1234567. C IF (SMALL(1) .EQ. 1234613304) THEN C* *** IEEE *** C SMALL(1) = 8388608 C LARGE(1) = 2139095039 C RIGHT(1) = 864026624 C DIVER(1) = 872415232 C LOG10(1) = 1050288283 C ELSE IF (SMALL(1) .EQ. -1271379306) THEN C* *** VAX *** C SMALL(1) = 128 C LARGE(1) = -32769 C RIGHT(1) = 13440 C DIVER(1) = 13568 C LOG10(1) = 547045274 C ELSE IF (SMALL(1) .EQ. 1175639687) THEN C* *** IBM *** C SMALL(1) = 1048576 C LARGE(1) = 2147483647 C RIGHT(1) = 990904320 C DIVER(1) = 1007681536 C LOG10(1) = 1091781651 C ELSE C WRITE(*,*)'Adjust R1MACH by uncommenting' C WRITE(*,*)'data statements appropriate for your machine.' C STOP 777 C END IF C END IF C SC = 987 C END IF C C *** ISSUE STOP 776 IF ALL DATA STATEMENTS ARE OBVIOUSLY WRONG... C IF (RMACH(4) .GE. 1.0) STOP 776 C*C/6S C*C IF (I .LT. 1 .OR. I .GT. 5) C*C 1 CALL SETERR(24HR1MACH - I OUT OF BOUNDS,24,1,2) C*C/7S C* IF (I .LT. 1 .OR. I .GT. 5) C* 1 CALL SETERR('R1MACH - I OUT OF BOUNDS',24,1,2) C*C/ C C IF (I .LT. 1 .OR. I .GT. 5) THEN C WRITE(*,*) 'R1MACH(I): I =',I,' is out of bounds.' C STOP C END IF IF (I .LT. 1 .OR. I .GT. 5) THEN R1MACH = 0.0 END IF R1MACH = RMACH(I) RETURN C C* /* C source for R1MACH -- remove the * in column 1 */ C*#include C*#include C*#include C* C*float r1mach_(long *i) C*{ C* switch(*i){ C* case 1: return FLT_MIN; C* case 2: return FLT_MAX; C* case 3: return FLT_EPSILON/FLT_RADIX; C* case 4: return FLT_EPSILON; C* case 5: return log10(FLT_RADIX); C* } C* C* fprintf(stderr, "invalid argument: r1mach(%ld)\n", *i); C* exit(1); C* return 0; /* for compilers that complain of missing return values */ C* } END