Squashed 'third_party/eigen/' content from commit 61d72f6
Change-Id: Iccc90fa0b55ab44037f018046d2fcffd90d9d025
git-subtree-dir: third_party/eigen
git-subtree-split: 61d72f6383cfa842868c53e30e087b0258177257
diff --git a/blas/srotmg.f b/blas/srotmg.f
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+ SUBROUTINE SROTMG(SD1,SD2,SX1,SY1,SPARAM)
+* .. Scalar Arguments ..
+ REAL SD1,SD2,SX1,SY1
+* ..
+* .. Array Arguments ..
+ REAL SPARAM(5)
+* ..
+*
+* Purpose
+* =======
+*
+* CONSTRUCT THE MODIFIED GIVENS TRANSFORMATION MATRIX H WHICH ZEROS
+* THE SECOND COMPONENT OF THE 2-VECTOR (SQRT(SD1)*SX1,SQRT(SD2)*
+* SY2)**T.
+* WITH SPARAM(1)=SFLAG, H HAS ONE OF THE FOLLOWING FORMS..
+*
+* SFLAG=-1.E0 SFLAG=0.E0 SFLAG=1.E0 SFLAG=-2.E0
+*
+* (SH11 SH12) (1.E0 SH12) (SH11 1.E0) (1.E0 0.E0)
+* H=( ) ( ) ( ) ( )
+* (SH21 SH22), (SH21 1.E0), (-1.E0 SH22), (0.E0 1.E0).
+* LOCATIONS 2-4 OF SPARAM CONTAIN SH11,SH21,SH12, AND SH22
+* RESPECTIVELY. (VALUES OF 1.E0, -1.E0, OR 0.E0 IMPLIED BY THE
+* VALUE OF SPARAM(1) ARE NOT STORED IN SPARAM.)
+*
+* THE VALUES OF GAMSQ AND RGAMSQ SET IN THE DATA STATEMENT MAY BE
+* INEXACT. THIS IS OK AS THEY ARE ONLY USED FOR TESTING THE SIZE
+* OF SD1 AND SD2. ALL ACTUAL SCALING OF DATA IS DONE USING GAM.
+*
+*
+* Arguments
+* =========
+*
+*
+* SD1 (input/output) REAL
+*
+* SD2 (input/output) REAL
+*
+* SX1 (input/output) REAL
+*
+* SY1 (input) REAL
+*
+*
+* SPARAM (input/output) REAL array, dimension 5
+* SPARAM(1)=SFLAG
+* SPARAM(2)=SH11
+* SPARAM(3)=SH21
+* SPARAM(4)=SH12
+* SPARAM(5)=SH22
+*
+* =====================================================================
+*
+* .. Local Scalars ..
+ REAL GAM,GAMSQ,ONE,RGAMSQ,SFLAG,SH11,SH12,SH21,SH22,SP1,SP2,SQ1,
+ + SQ2,STEMP,SU,TWO,ZERO
+ INTEGER IGO
+* ..
+* .. Intrinsic Functions ..
+ INTRINSIC ABS
+* ..
+* .. Data statements ..
+*
+ DATA ZERO,ONE,TWO/0.E0,1.E0,2.E0/
+ DATA GAM,GAMSQ,RGAMSQ/4096.E0,1.67772E7,5.96046E-8/
+* ..
+
+ IF (.NOT.SD1.LT.ZERO) GO TO 10
+* GO ZERO-H-D-AND-SX1..
+ GO TO 60
+ 10 CONTINUE
+* CASE-SD1-NONNEGATIVE
+ SP2 = SD2*SY1
+ IF (.NOT.SP2.EQ.ZERO) GO TO 20
+ SFLAG = -TWO
+ GO TO 260
+* REGULAR-CASE..
+ 20 CONTINUE
+ SP1 = SD1*SX1
+ SQ2 = SP2*SY1
+ SQ1 = SP1*SX1
+*
+ IF (.NOT.ABS(SQ1).GT.ABS(SQ2)) GO TO 40
+ SH21 = -SY1/SX1
+ SH12 = SP2/SP1
+*
+ SU = ONE - SH12*SH21
+*
+ IF (.NOT.SU.LE.ZERO) GO TO 30
+* GO ZERO-H-D-AND-SX1..
+ GO TO 60
+ 30 CONTINUE
+ SFLAG = ZERO
+ SD1 = SD1/SU
+ SD2 = SD2/SU
+ SX1 = SX1*SU
+* GO SCALE-CHECK..
+ GO TO 100
+ 40 CONTINUE
+ IF (.NOT.SQ2.LT.ZERO) GO TO 50
+* GO ZERO-H-D-AND-SX1..
+ GO TO 60
+ 50 CONTINUE
+ SFLAG = ONE
+ SH11 = SP1/SP2
+ SH22 = SX1/SY1
+ SU = ONE + SH11*SH22
+ STEMP = SD2/SU
+ SD2 = SD1/SU
+ SD1 = STEMP
+ SX1 = SY1*SU
+* GO SCALE-CHECK
+ GO TO 100
+* PROCEDURE..ZERO-H-D-AND-SX1..
+ 60 CONTINUE
+ SFLAG = -ONE
+ SH11 = ZERO
+ SH12 = ZERO
+ SH21 = ZERO
+ SH22 = ZERO
+*
+ SD1 = ZERO
+ SD2 = ZERO
+ SX1 = ZERO
+* RETURN..
+ GO TO 220
+* PROCEDURE..FIX-H..
+ 70 CONTINUE
+ IF (.NOT.SFLAG.GE.ZERO) GO TO 90
+*
+ IF (.NOT.SFLAG.EQ.ZERO) GO TO 80
+ SH11 = ONE
+ SH22 = ONE
+ SFLAG = -ONE
+ GO TO 90
+ 80 CONTINUE
+ SH21 = -ONE
+ SH12 = ONE
+ SFLAG = -ONE
+ 90 CONTINUE
+ GO TO IGO(120,150,180,210)
+* PROCEDURE..SCALE-CHECK
+ 100 CONTINUE
+ 110 CONTINUE
+ IF (.NOT.SD1.LE.RGAMSQ) GO TO 130
+ IF (SD1.EQ.ZERO) GO TO 160
+ ASSIGN 120 TO IGO
+* FIX-H..
+ GO TO 70
+ 120 CONTINUE
+ SD1 = SD1*GAM**2
+ SX1 = SX1/GAM
+ SH11 = SH11/GAM
+ SH12 = SH12/GAM
+ GO TO 110
+ 130 CONTINUE
+ 140 CONTINUE
+ IF (.NOT.SD1.GE.GAMSQ) GO TO 160
+ ASSIGN 150 TO IGO
+* FIX-H..
+ GO TO 70
+ 150 CONTINUE
+ SD1 = SD1/GAM**2
+ SX1 = SX1*GAM
+ SH11 = SH11*GAM
+ SH12 = SH12*GAM
+ GO TO 140
+ 160 CONTINUE
+ 170 CONTINUE
+ IF (.NOT.ABS(SD2).LE.RGAMSQ) GO TO 190
+ IF (SD2.EQ.ZERO) GO TO 220
+ ASSIGN 180 TO IGO
+* FIX-H..
+ GO TO 70
+ 180 CONTINUE
+ SD2 = SD2*GAM**2
+ SH21 = SH21/GAM
+ SH22 = SH22/GAM
+ GO TO 170
+ 190 CONTINUE
+ 200 CONTINUE
+ IF (.NOT.ABS(SD2).GE.GAMSQ) GO TO 220
+ ASSIGN 210 TO IGO
+* FIX-H..
+ GO TO 70
+ 210 CONTINUE
+ SD2 = SD2/GAM**2
+ SH21 = SH21*GAM
+ SH22 = SH22*GAM
+ GO TO 200
+ 220 CONTINUE
+ IF (SFLAG) 250,230,240
+ 230 CONTINUE
+ SPARAM(3) = SH21
+ SPARAM(4) = SH12
+ GO TO 260
+ 240 CONTINUE
+ SPARAM(2) = SH11
+ SPARAM(5) = SH22
+ GO TO 260
+ 250 CONTINUE
+ SPARAM(2) = SH11
+ SPARAM(3) = SH21
+ SPARAM(4) = SH12
+ SPARAM(5) = SH22
+ 260 CONTINUE
+ SPARAM(1) = SFLAG
+ RETURN
+ END