From 65a3598032fbe78b39af80ab950497b7a1fe2015 Mon Sep 17 00:00:00 2001
From: Andrew Heather <>
Date: Fri, 9 Nov 2018 09:20:50 +0000
Subject: [PATCH] ENH: fft - use fftw_malloc to create in/out arrays. Fixes
#1095
---
src/randomProcesses/fft/fft.C | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/src/randomProcesses/fft/fft.C b/src/randomProcesses/fft/fft.C
index 21e7fd85c4..6e5a74beef 100644
--- a/src/randomProcesses/fft/fft.C
+++ b/src/randomProcesses/fft/fft.C
@@ -180,10 +180,12 @@ void Foam::fft::transform
)
{
// Copy field into fftw containers
- // NB: this is not fully compliant, since array sizing is non-constexpr.
- // However, cannot instantiate List with fftw_complex
const label N = field.size();
- fftw_complex in[N], out[N];
+
+ fftw_complex* inPtr =
+ static_cast<fftw_complex*>(fftw_malloc(sizeof(fftw_complex)*N));
+ fftw_complex* outPtr =
+ static_cast<fftw_complex*>(fftw_malloc(sizeof(fftw_complex)*N));
// If reverse transform : renumber before transform
if (dir == REVERSE_TRANSFORM)
@@ -193,8 +195,8 @@ void Foam::fft::transform
forAll(field, i)
{
- in[i][0] = field[i].Re();
- in[i][1] = field[i].Im();
+ inPtr[i][0] = field[i].Re();
+ inPtr[i][1] = field[i].Im();
}
// Create the plan
@@ -208,19 +210,22 @@ void Foam::fft::transform
// Generic 1..3-D plan
const label rank = nn.size();
fftw_plan plan =
- fftw_plan_dft(rank, nn.begin(), in, out, dir, FFTW_ESTIMATE);
+ fftw_plan_dft(rank, nn.begin(), inPtr, outPtr, dir, FFTW_ESTIMATE);
// Compute the FFT
fftw_execute(plan);
forAll(field, i)
{
- field[i].Re() = out[i][0];
- field[i].Im() = out[i][1];
+ field[i].Re() = outPtr[i][0];
+ field[i].Im() = outPtr[i][1];
}
fftw_destroy_plan(plan);
+ fftw_free(inPtr);
+ fftw_free(outPtr);
+
// If forward transform : renumber after transform
if (dir == FORWARD_TRANSFORM)
{
--
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