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| author | Peter Collingbourne <peter@pcc.me.uk> | 2011-10-27 19:19:14 +0000 |
|---|---|---|
| committer | Peter Collingbourne <peter@pcc.me.uk> | 2011-10-27 19:19:14 +0000 |
| commit | 999f90bedf94e7d55508f0797802b75064f1de09 (patch) | |
| tree | 75288530684cb01a05ecfcef75c747900943458c /docs | |
| parent | 249d953ed7b850446fdfc600992ffb221da2f9d3 (diff) | |
| download | llvm-999f90bedf94e7d55508f0797802b75064f1de09.tar.gz llvm-999f90bedf94e7d55508f0797802b75064f1de09.tar.bz2 llvm-999f90bedf94e7d55508f0797802b75064f1de09.tar.xz | |
Add a pinned metadata name for fpaccuracy, and document it
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143135 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/LangRef.html | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/docs/LangRef.html b/docs/LangRef.html index 8dca415172..a12a42b39d 100644 --- a/docs/LangRef.html +++ b/docs/LangRef.html @@ -103,6 +103,7 @@ <li><a href="#metadata">Metadata Nodes and Metadata Strings</a> <ol> <li><a href="#tbaa">'<tt>tbaa</tt>' Metadata</a></li> + <li><a href="#fpaccuracy">'<tt>fpaccuracy</tt>' Metadata</a></li> </ol> </li> </ol> @@ -2966,6 +2967,35 @@ call void @llvm.dbg.value(metadata !24, i64 0, metadata !25) </div> +<h4> + <a name="fpaccuracy">'<tt>fpaccuracy</tt>' Metadata</a> +</h4> + +<div> + +<p><tt>fpaccuracy</tt> metadata may be attached to any instruction of floating + point type. It expresses the maximum relative error of the result of + that instruction, in ULPs. ULP is defined as follows:</p> + +<blockquote><p> +If x is a real number that lies between two finite consecutive floating-point +numbers a and b, without being equal to one of them, then ulp(x) = |b - a|, +otherwise ulp(x) is the distance between the two non-equal finite +floating-point numbers nearest x. Moreover, ulp(NaN) is NaN. +</p></blockquote> + +<p>The maximum relative error may be any rational number. The metadata node + shall consist of a pair of unsigned integers respectively representing + the numerator and denominator. For example, 2.5 ULP:</p> + +<div class="doc_code"> +<pre> +!0 = metadata !{ i32 5, i32 2 } +</pre> +</div> + +</div> + </div> </div> |