Exponentially decrease # of iters in benchmark

Author: smu160

benches/benchmark.sh

@@ -2,26 +2,31 @@
 
 set -Eeuo pipefail
 
-if [[ "$#" -ne 3 ]]
+if [[ "$#" -ne 2 ]]
 then
-  echo "Usage: $0 <n-lower-bound> <n-upper-bound> <iters>"
-  exit 1
+    echo "Usage: $0 <n-lower-bound> <n-upper-bound>"
+    exit 1
 fi
 
 start=$1
 end=$2
-iters=$3
+max_iters=1000  # Set your desired maximum number of iterations
 
 OUTPUT_DIR=benchmark-data.$(date +"%Y.%m.%d.%H-%M-%S")
 mkdir -p "$OUTPUT_DIR"/fftw3 && mkdir "$OUTPUT_DIR"/rustfft && mkdir "$OUTPUT_DIR"/phastft
 
+
 benchmark_fftw3() {
     make clean && make
 
     for n in $(seq "$start" "$end"); do
-        echo "Running FFTW3 benchmark for N = 2^${n}..." && \
+        # clamp to `max_iters`
+        iters=$((2**($end - $n)))
+        iters=$((iters > max_iters ? max_iters : iters))
+        echo "Running FFTW3 benchmark for N = 2^${n} for ${iters} iterations..."
+
         for _ in $(seq 1 "$iters"); do
-            ./bench_fftw "${n}" >> "${OUTPUT_DIR}"/fftw3/size_"${n}"
+            ./bench_fftw "${n}" >> "${OUTPUT_DIR}/fftw3/size_${n}"
         done
     done
 }
@@ -30,7 +35,10 @@ benchmark_phastft() {
     cargo clean && cargo build --release --examples
 
     for n in $(seq "$start" "$end"); do
-        echo "Running PhastFT benchmark for N = 2^${n}..." && \
+        iters=$((2**($end - $n)))
+        iters=$((iters > max_iters ? max_iters : iters))
+        echo "Running PhastFT benchmark for N = 2^${n}..."
+
         for _ in $(seq 1 "$iters"); do
             ../target/release/examples/benchmark "${n}" >> "${OUTPUT_DIR}"/phastft/size_"${n}"
         done
@@ -41,7 +49,10 @@ benchmark_rustfft() {
     cargo clean && cargo build --release --examples
 
     for n in $(seq "$start" "$end"); do
-        echo "Running RustFFT benchmark for N = 2^${n}..." && \
+        iters=$((2**($end - $n)))
+        iters=$((iters > max_iters ? max_iters : iters))
+        echo "Running RustFFT benchmark for N = 2^${n}..."
+
         for _ in $(seq 1 "$iters"); do
             ../target/release/examples/rustfft "${n}" >> "${OUTPUT_DIR}"/rustfft/size_"${n}"
         done