doc: add Go 1.12 release note for trigonometric reductions in math
Worth mentioning because the results are not bit-for-bit identical.
This causes a test failure in github.com/fogleman/gg.
Updates #6794
Change-Id: I701f34927731fb5c658a1be271c04388e5e7e3f7
Reviewed-on: https://go-review.googlesource.com/c/157417
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/doc/go1.12.html b/doc/go1.12.html
index 568920d..e228d98 100644
--- a/doc/go1.12.html
+++ b/doc/go1.12.html
@@ -553,6 +553,20 @@
</dl><!-- lib/time -->
+<dl id="math"><dt><a href="/pkg/math/">math</a></dt>
+ <dd>
+ <p><!-- CL 153059 -->
+ The functions
+ <a href="/pkg/math/#Sin"><code>Sin</code></a>,
+ <a href="/pkg/math/#Cos"><code>Cos</code></a>,
+ <a href="/pkg/math/#Tan"><code>Tan</code></a>,
+ and <a href="/pkg/math/#Sincos"><code>Sincos</code></a> now
+ apply Payne-Hanek range reduction to huge arguments. This
+ produces more accurate answers, but they will not be bit-for-bit
+ identical with the results in earlier releases.
+ </p>
+</dl><!-- math -->
+
<dl id="math/bits"><dt><a href="/pkg/math/bits/">math/bits</a></dt>
<dd>
<p><!-- CL 123157 -->
