From cefd7b59df628eca240af3c136d66137c8e94888 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?IOhannes=20m=20zm=C3=B6lnig?= <zmoelnig@iem.at>
Date: Thu, 8 Sep 2022 10:49:36 +0200
Subject: [PATCH] tests: Use fuzzy comparison in test-suite
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Using exact comparison ("a == b") when comparing expected with computed
test data fails the test-suite on many architectures (including, but not
limited to armhf and arm64).

Instead, use epsilon(for now, FLT_EPSILON and DBL_EPSILON) to compare
floating point numbers for equality.


Closes: https://github.com/libsndfile/libsndfile/issues/866

Signed-off-by: IOhannes m zmölnig <zmoelnig@iem.at>
---
 tests/utils.tpl | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/tests/utils.tpl b/tests/utils.tpl
index c68e3a26e..0d1cd8bb9 100644
--- a/tests/utils.tpl
+++ b/tests/utils.tpl
@@ -193,6 +193,7 @@ sf_count_t		file_length_fd (int fd) ;
 #include <string.h>
 #include <ctype.h>
 #include <math.h>
+#include <float.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 
@@ -215,6 +216,28 @@ sf_count_t		file_length_fd (int fd) ;
 #define O_BINARY 0
 #endif
 
+
+/*
+**      Compare for equality, with epsilon
+*/
+static inline int
+equals_short (const short a, const short b)
+{        return (a == b);
+} /* equals_short */
+static inline int
+equals_int (const int a, const int b)
+{        return (a == b);
+} /* equals_int */
+static inline int
+equals_float (const float a, const float b)
+{        return (fabsf(a - b) <= FLT_EPSILON);
+} /* equals_float */
+static inline int
+equals_double (const double a, const double b)
+{       return (fabs(a - b) <= DBL_EPSILON);
+} /* equals_double */
+
+
 [+ FOR float_type +]
 void
 gen_windowed_sine_[+ (get "name") +] ([+ (get "name") +] *data, int len, double maximum)
@@ -752,8 +775,8 @@ compare_[+ (get "io_element") +]_or_die (const [+ (get "io_element") +] *expecte
 	unsigned k ;
 
 	for (k = 0 ; k < count ; k++)
-		if (expected [k] != actual [k])
-		{	printf ("\n\nLine %d : Error at index %d, got " [+ (get "format_str") +] ", should be " [+ (get "format_str") +] ".\n\n", line_num, k, actual [k], expected [k]) ;
+		if (!equals_[+ (get "io_element") +](expected [k], actual [k]))
+		{	printf ("\n\nLine %d : Error at index %d, got " [+ (get "format_str") +] ", should be " [+ (get "format_str") +] "(delta=" [+ (get "format_str") +] " ).\n\n", line_num, k, actual [k], expected [k], actual [k] - expected [k]) ;
 			exit (1) ;
 			} ;