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| author | jason <jason@8a072113-8704-0410-8d35-dd094bca7971> | 2008-10-28 01:38:50 +0000 |
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| committer | jason <jason@8a072113-8704-0410-8d35-dd094bca7971> | 2008-10-28 01:38:50 +0000 |
| commit | baba851215b44ac3b60b9248eb02bcce7eb76247 (patch) | |
| tree | 8c0f5c006875532a30d4409f5e94b0f310ff00a7 /SRC/ieeeck.f | |
| download | lapack-baba851215b44ac3b60b9248eb02bcce7eb76247.tar.gz lapack-baba851215b44ac3b60b9248eb02bcce7eb76247.tar.bz2 lapack-baba851215b44ac3b60b9248eb02bcce7eb76247.zip | |
Move LAPACK trunk into position.
Diffstat (limited to 'SRC/ieeeck.f')
| -rw-r--r-- | SRC/ieeeck.f | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/SRC/ieeeck.f b/SRC/ieeeck.f new file mode 100644 index 00000000..ac4aff85 --- /dev/null +++ b/SRC/ieeeck.f @@ -0,0 +1,147 @@ + INTEGER FUNCTION IEEECK( ISPEC, ZERO, ONE ) +* +* -- LAPACK auxiliary routine (version 3.1) -- +* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. +* November 2006 +* +* .. Scalar Arguments .. + INTEGER ISPEC + REAL ONE, ZERO +* .. +* +* Purpose +* ======= +* +* IEEECK is called from the ILAENV to verify that Infinity and +* possibly NaN arithmetic is safe (i.e. will not trap). +* +* Arguments +* ========= +* +* ISPEC (input) INTEGER +* Specifies whether to test just for inifinity arithmetic +* or whether to test for infinity and NaN arithmetic. +* = 0: Verify infinity arithmetic only. +* = 1: Verify infinity and NaN arithmetic. +* +* ZERO (input) REAL +* Must contain the value 0.0 +* This is passed to prevent the compiler from optimizing +* away this code. +* +* ONE (input) REAL +* Must contain the value 1.0 +* This is passed to prevent the compiler from optimizing +* away this code. +* +* RETURN VALUE: INTEGER +* = 0: Arithmetic failed to produce the correct answers +* = 1: Arithmetic produced the correct answers +* +* .. Local Scalars .. + REAL NAN1, NAN2, NAN3, NAN4, NAN5, NAN6, NEGINF, + $ NEGZRO, NEWZRO, POSINF +* .. +* .. Executable Statements .. + IEEECK = 1 +* + POSINF = ONE / ZERO + IF( POSINF.LE.ONE ) THEN + IEEECK = 0 + RETURN + END IF +* + NEGINF = -ONE / ZERO + IF( NEGINF.GE.ZERO ) THEN + IEEECK = 0 + RETURN + END IF +* + NEGZRO = ONE / ( NEGINF+ONE ) + IF( NEGZRO.NE.ZERO ) THEN + IEEECK = 0 + RETURN + END IF +* + NEGINF = ONE / NEGZRO + IF( NEGINF.GE.ZERO ) THEN + IEEECK = 0 + RETURN + END IF +* + NEWZRO = NEGZRO + ZERO + IF( NEWZRO.NE.ZERO ) THEN + IEEECK = 0 + RETURN + END IF +* + POSINF = ONE / NEWZRO + IF( POSINF.LE.ONE ) THEN + IEEECK = 0 + RETURN + END IF +* + NEGINF = NEGINF*POSINF + IF( NEGINF.GE.ZERO ) THEN + IEEECK = 0 + RETURN + END IF +* + POSINF = POSINF*POSINF + IF( POSINF.LE.ONE ) THEN + IEEECK = 0 + RETURN + END IF +* +* +* +* +* Return if we were only asked to check infinity arithmetic +* + IF( ISPEC.EQ.0 ) + $ RETURN +* + NAN1 = POSINF + NEGINF +* + NAN2 = POSINF / NEGINF +* + NAN3 = POSINF / POSINF +* + NAN4 = POSINF*ZERO +* + NAN5 = NEGINF*NEGZRO +* + NAN6 = NAN5*0.0 +* + IF( NAN1.EQ.NAN1 ) THEN + IEEECK = 0 + RETURN + END IF +* + IF( NAN2.EQ.NAN2 ) THEN + IEEECK = 0 + RETURN + END IF +* + IF( NAN3.EQ.NAN3 ) THEN + IEEECK = 0 + RETURN + END IF +* + IF( NAN4.EQ.NAN4 ) THEN + IEEECK = 0 + RETURN + END IF +* + IF( NAN5.EQ.NAN5 ) THEN + IEEECK = 0 + RETURN + END IF +* + IF( NAN6.EQ.NAN6 ) THEN + IEEECK = 0 + RETURN + END IF +* + RETURN + END |