From c651fdc0cf2ba7986ce0a0a23b4dbb44b6ecdae3 Mon Sep 17 00:00:00 2001 From: Robert Griesemer Date: Tue, 24 Feb 2015 11:24:27 -0800 Subject: math/big: change Float.SetMantExp to always multiply mant by 2**exp Change-Id: If840e647376a2141f8c17729f7ef251bfff13f5f Reviewed-on: https://go-review.googlesource.com/5810 Reviewed-by: Rob Pike --- src/math/big/float_test.go | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'src/math/big/float_test.go') diff --git a/src/math/big/float_test.go b/src/math/big/float_test.go index 2789cfb9f3..6714a92bf0 100644 --- a/src/math/big/float_test.go +++ b/src/math/big/float_test.go @@ -167,11 +167,17 @@ func TestFloatSetMantExp(t *testing.T) { {"+Inf", -1234, "+Inf"}, {"-Inf", -1234, "-Inf"}, {"0", -MaxExp - 1, "0"}, - {"1", -MaxExp - 1, "+Inf"}, // exponent magnitude too large - {"-1", -MaxExp - 1, "-Inf"}, // exponent magnitude too large + {"0.5", -MaxExp - 1, "+Inf"}, // exponent overflow + {"-0.5", -MaxExp - 1, "-Inf"}, // exponent overflow + {"0.5", MaxExp + 1, "+Inf"}, // exponent overflow + {"-0.5", MaxExp + 1, "-Inf"}, // exponent overflow + {"1", MaxExp, "+Inf"}, // exponent overflow + {"2", MaxExp - 1, "+Inf"}, // exponent overflow {"0.75", 1, "1.5"}, {"0.5", 11, "1024"}, {"-0.5", -2, "-0.125"}, + {"32", 5, "1024"}, + {"1024", -10, "1"}, } { frac := makeFloat(test.frac) want := makeFloat(test.z) @@ -180,6 +186,10 @@ func TestFloatSetMantExp(t *testing.T) { if !feq(&z, want) { t.Errorf("SetMantExp(%s, %d) = %s; want %s", test.frac, test.exp, z.Format('g', 10), test.z) } + // test inverse property + if z.SetMantExp(want.MantExp()).Cmp(want) != 0 { + t.Errorf("Inverse property not satisfied: got %s; want %s", z.Format('g', 10), test.z) + } } } -- cgit v1.3-5-g45d5