add commentHEADmaster

1 files changed, 11 insertions, 0 deletions

diff --git a/calc_pi.c b/calc_pi.c
index c3aa4da..5277d33 100644
--- a/calc_pi.c
+++ b/calc_pi.c
@@ -6,6 +6,17 @@
 #include <stdlib.h>
 #include <math.h>
 
+/* This file is C99. Here is some information about compiling this file:
+ * $ (source /etc/os-release; echo $PRETTY_NAME); uname -a
+ * Debian GNU/Linux trixie/sid
+ * Linux redacted 6.11.6-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.11.6-1 (2024-11-04) x86_64 GNU/Linux
+ * $ gcc -ocalc_pi_real calc_pi.c -Wall -Wextra -pedantic -lm -std=c99 -mavx2 -DPOPCOUNT=real_pc -O3
+ * $ gcc -ocalc_pi_fake calc_pi.c -Wall -Wextra -pedantic -lm -std=c99 -O3
+ * $ diff -s <(./calc_pi_real 1000) <(./calc_pi_fake 1000)
+ * Files /dev/fd/63 and /dev/fd/62 are identical
+ * $
+ */
+
 #ifdef __GNUC__
 #define GCC_ALWAYS_INLINE inline __attribute__((always_inline))
 #else