[R] prod and F90 product

[Filippo]

Hi,
I'm having strange differences between the R function prod ad the F90 
function product.
Processing the same vector C (see attachment). I get 2 different results:
prod(C) = 1.069678e-307
testProduct(C) = 0

where testProd is the following wrapping function:

testProd <- function(x) {
     return(.Fortran('testProd', as.double(x), as.double(0), 
as.double(0), as.integer(length(x))))
}

subroutine testProd(x, p, q,  n)
     implicit none
     integer, intent (in) :: n
     double precision, intent (in) :: x(n)
     double precision, intent (out) :: p
     double precision, intent (out) :: q
     integer :: i

     p = product(x)
     q=1
     do i = 1, n
         q = q*x(i)
     end do
end subroutine testProd

I check the lowest possible number and seems to be the same for both R 
and F90.
Can anyone help me understanding this behaviour?
Thank you in advance
Regards,
Filippo

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c(0.126667774727727, 0.126778508335206, 0.126889731437094, 0.127001445486345, 
0.127113651944097, 0.127226352279715, 0.127339547970833, 0.127453240503398, 
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0.128029208383447, 0.128145913640589, 0.128263126377241, 0.128380848147438, 
0.128499080513928, 0.128617825048222, 0.128737083330636, 0.128856856950339, 
0.128977147505404, 0.129097956602849, 0.129219285858691, 0.129341136897992, 
0.129463511354905, 0.129586410872726, 0.129709837103945, 0.12983379171029, 
0.129958276362782, 0.130083292741782, 0.130208842537045, 0.130334927447768, 
0.130461549182643, 0.130588709459909, 0.130716410007402, 0.130844652562612, 
0.130973438872731, 0.13110277069471, 0.131232649795309, 0.131363077951156, 
0.131494056948797, 0.131625588584752, 0.131757674665574, 0.131890317007896, 
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1.29535749263372, 1.3045834943698, 1.31390580326946, 1.32332567340966, 
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1.54611202227448, 1.55803659947138, 1.57009336893313, 1.58228412122724, 
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1.8118966257868, 1.82683754899417, 1.84195198668824, 1.85724233669495, 
1.87271103126437, 1.88836053744482, 1.90419335745236, 1.92021202903522, 
1.93641912583231, 1.95281725772524, 1.96940907118308, 1.9861972495989, 
2.00318451361754, 2.02037362145344, 2.03776736919778, 2.0553685911138, 
2.07318015991939, 2.09120498705573, 2.10944602294091, 2.12790625720719, 
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2.30442524081398, 2.32525064591489, 2.34633077080554, 2.36766908628253, 
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2.57192487382806, 2.59604469854048, 2.62046348096394, 2.64518515148636, 
2.67021367508358, 2.69555305041579, 2.72120730883764, 2.74718051331758, 
2.77347675726154, 2.80010016323613, 2.82705488158604, 2.85434508894054, 
2.88197498660324, 2.90994879881949, 2.93827077091539, 2.96694516730204, 
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5.5281594275631, 5.58441843573103, 5.64107035761498, 5.69810378890798, 
5.75550653621385, 5.81326559350816, 5.87136711887098, 5.92979641158084, 
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6.22628196633371, 6.28631830626767, 6.34655366090301, 6.40696571226526, 
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8.98436125304979, 8.99119651415869, 8.99608521283661, 8.99902098391393
)