diff options
| author | Caleb Spare <cespare@gmail.com> | 2015-10-21 20:35:22 -0700 |
|---|---|---|
| committer | Ian Lance Taylor <iant@golang.org> | 2015-10-23 18:29:10 +0000 |
| commit | 22d4c8bf13d5edf4670dbdaf0854d653d9c2b81a (patch) | |
| tree | 1ed97d97461d9628ac76e0034d3e767bc4b6c80a | |
| parent | 8ee0fd862357aade3f58cdb41467408105c9e865 (diff) | |
| download | go-22d4c8bf13d5edf4670dbdaf0854d653d9c2b81a.tar.xz | |
math: fix normalization bug in pure-Go sqrt
Fixes #13013
Change-Id: I6cf500eacdce76e303fc1cd92dd1c80eef0986bc
Reviewed-on: https://go-review.googlesource.com/16158
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
| -rw-r--r-- | src/math/all_test.go | 4 | ||||
| -rw-r--r-- | src/math/sqrt.go | 2 |
2 files changed, 4 insertions, 2 deletions
diff --git a/src/math/all_test.go b/src/math/all_test.go index 53e84765cb..4838ffc5e1 100644 --- a/src/math/all_test.go +++ b/src/math/all_test.go @@ -1363,7 +1363,7 @@ var vfmodfSC = []float64{ var modfSC = [][2]float64{ {Inf(-1), NaN()}, // [2]float64{Copysign(0, -1), Inf(-1)}, {Copysign(0, -1), Copysign(0, -1)}, - {Inf(1), NaN()}, // [2]float64{0, Inf(1)}, + {Inf(1), NaN()}, // [2]float64{0, Inf(1)}, {NaN(), NaN()}, } @@ -1611,6 +1611,7 @@ var vfsqrtSC = []float64{ 0, Inf(1), NaN(), + Float64frombits(2), // subnormal; see https://golang.org/issue/13013 } var sqrtSC = []float64{ NaN(), @@ -1619,6 +1620,7 @@ var sqrtSC = []float64{ 0, Inf(1), NaN(), + 3.1434555694052576e-162, } var vftanhSC = []float64{ diff --git a/src/math/sqrt.go b/src/math/sqrt.go index 23cf2996c2..96af6e2687 100644 --- a/src/math/sqrt.go +++ b/src/math/sqrt.go @@ -108,7 +108,7 @@ func sqrt(x float64) float64 { // normalize x exp := int((ix >> shift) & mask) if exp == 0 { // subnormal x - for ix&1<<shift == 0 { + for ix&(1<<shift) == 0 { ix <<= 1 exp-- } |