summaryrefslogtreecommitdiff
path: root/tests/float/float_format_ints.py
diff options
context:
space:
mode:
Diffstat (limited to 'tests/float/float_format_ints.py')
-rw-r--r--tests/float/float_format_ints.py32
1 files changed, 30 insertions, 2 deletions
diff --git a/tests/float/float_format_ints.py b/tests/float/float_format_ints.py
index df4444166..7b7b30c4b 100644
--- a/tests/float/float_format_ints.py
+++ b/tests/float/float_format_ints.py
@@ -12,14 +12,42 @@ for b in [13, 123, 457, 23456]:
print(title, "with format", f_fmt, "gives", f_fmt.format(f))
print(title, "with format", g_fmt, "gives", g_fmt.format(f))
+# The tests below check border cases involving all mantissa bits.
+# In case of REPR_C, where the mantissa is missing two bits, the
+# the string representation for such numbers might not always be exactly
+# the same but nevertheless be correct, so we must allow a few exceptions.
+is_REPR_C = float("1.0000001") == float("1.0")
+
# 16777215 is 2^24 - 1, the largest integer that can be completely held
# in a float32.
-print("{:f}".format(16777215))
+val_str = "{:f}".format(16777215)
+
+# When using REPR_C, 16777215.0 is the same as 16777212.0 or 16777214.4
+# (depending on the implementation of pow() function, the result may differ)
+if is_REPR_C and (val_str == "16777212.000000" or val_str == "16777214.400000"):
+ val_str = "16777215.000000"
+
+print(val_str)
+
# 4294967040 = 16777215 * 128 is the largest integer that is exactly
# represented by a float32 and that will also fit within a (signed) int32.
# The upper bound of our integer-handling code is actually double this,
# but that constant might cause trouble on systems using 32 bit ints.
-print("{:f}".format(2147483520))
+val_str = "{:f}".format(2147483520)
+
+# When using FLOAT_IMPL_FLOAT, 2147483520.0 == 2147483500.0
+# Both representations are valid, the second being "simpler"
+is_float32 = float("1e300") == float("inf")
+if is_float32 and val_str == "2147483500.000000":
+ val_str = "2147483520.000000"
+
+# When using REPR_C, 2147483520.0 is the same as 2147483200.0
+# Both representations are valid, the second being "simpler"
+if is_REPR_C and val_str == "2147483200.000000":
+ val_str = "2147483520.000000"
+
+print(val_str)
+
# Very large positive integers can be a test for precision and resolution.
# This is a weird way to represent 1e38 (largest power of 10 for float32).
print("{:.6e}".format(float("9" * 30 + "e8")))