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/srotm.f b/blas/srotm.f
new file mode 100644
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--- /dev/null
+++ b/blas/srotm.f
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+ SUBROUTINE SROTM(N,SX,INCX,SY,INCY,SPARAM)
+* .. Scalar Arguments ..
+ INTEGER INCX,INCY,N
+* ..
+* .. Array Arguments ..
+ REAL SPARAM(5),SX(*),SY(*)
+* ..
+*
+* Purpose
+* =======
+*
+* APPLY THE MODIFIED GIVENS TRANSFORMATION, H, TO THE 2 BY N MATRIX
+*
+* (SX**T) , WHERE **T INDICATES TRANSPOSE. THE ELEMENTS OF SX ARE IN
+* (DX**T)
+*
+* SX(LX+I*INCX), I = 0 TO N-1, WHERE LX = 1 IF INCX .GE. 0, ELSE
+* LX = (-INCX)*N, AND SIMILARLY FOR SY USING USING LY AND INCY.
+* 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).
+* SEE SROTMG FOR A DESCRIPTION OF DATA STORAGE IN SPARAM.
+*
+*
+* Arguments
+* =========
+*
+* N (input) INTEGER
+* number of elements in input vector(s)
+*
+* SX (input/output) REAL array, dimension N
+* double precision vector with N elements
+*
+* INCX (input) INTEGER
+* storage spacing between elements of SX
+*
+* SY (input/output) REAL array, dimension N
+* double precision vector with N elements
+*
+* INCY (input) INTEGER
+* storage spacing between elements of SY
+*
+* 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 SFLAG,SH11,SH12,SH21,SH22,TWO,W,Z,ZERO
+ INTEGER I,KX,KY,NSTEPS
+* ..
+* .. Data statements ..
+ DATA ZERO,TWO/0.E0,2.E0/
+* ..
+*
+ SFLAG = SPARAM(1)
+ IF (N.LE.0 .OR. (SFLAG+TWO.EQ.ZERO)) GO TO 140
+ IF (.NOT. (INCX.EQ.INCY.AND.INCX.GT.0)) GO TO 70
+*
+ NSTEPS = N*INCX
+ IF (SFLAG) 50,10,30
+ 10 CONTINUE
+ SH12 = SPARAM(4)
+ SH21 = SPARAM(3)
+ DO 20 I = 1,NSTEPS,INCX
+ W = SX(I)
+ Z = SY(I)
+ SX(I) = W + Z*SH12
+ SY(I) = W*SH21 + Z
+ 20 CONTINUE
+ GO TO 140
+ 30 CONTINUE
+ SH11 = SPARAM(2)
+ SH22 = SPARAM(5)
+ DO 40 I = 1,NSTEPS,INCX
+ W = SX(I)
+ Z = SY(I)
+ SX(I) = W*SH11 + Z
+ SY(I) = -W + SH22*Z
+ 40 CONTINUE
+ GO TO 140
+ 50 CONTINUE
+ SH11 = SPARAM(2)
+ SH12 = SPARAM(4)
+ SH21 = SPARAM(3)
+ SH22 = SPARAM(5)
+ DO 60 I = 1,NSTEPS,INCX
+ W = SX(I)
+ Z = SY(I)
+ SX(I) = W*SH11 + Z*SH12
+ SY(I) = W*SH21 + Z*SH22
+ 60 CONTINUE
+ GO TO 140
+ 70 CONTINUE
+ KX = 1
+ KY = 1
+ IF (INCX.LT.0) KX = 1 + (1-N)*INCX
+ IF (INCY.LT.0) KY = 1 + (1-N)*INCY
+*
+ IF (SFLAG) 120,80,100
+ 80 CONTINUE
+ SH12 = SPARAM(4)
+ SH21 = SPARAM(3)
+ DO 90 I = 1,N
+ W = SX(KX)
+ Z = SY(KY)
+ SX(KX) = W + Z*SH12
+ SY(KY) = W*SH21 + Z
+ KX = KX + INCX
+ KY = KY + INCY
+ 90 CONTINUE
+ GO TO 140
+ 100 CONTINUE
+ SH11 = SPARAM(2)
+ SH22 = SPARAM(5)
+ DO 110 I = 1,N
+ W = SX(KX)
+ Z = SY(KY)
+ SX(KX) = W*SH11 + Z
+ SY(KY) = -W + SH22*Z
+ KX = KX + INCX
+ KY = KY + INCY
+ 110 CONTINUE
+ GO TO 140
+ 120 CONTINUE
+ SH11 = SPARAM(2)
+ SH12 = SPARAM(4)
+ SH21 = SPARAM(3)
+ SH22 = SPARAM(5)
+ DO 130 I = 1,N
+ W = SX(KX)
+ Z = SY(KY)
+ SX(KX) = W*SH11 + Z*SH12
+ SY(KY) = W*SH21 + Z*SH22
+ KX = KX + INCX
+ KY = KY + INCY
+ 130 CONTINUE
+ 140 CONTINUE
+ RETURN
+ END