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author | Rafael Espindola <rafael.espindola@gmail.com> | 2012-03-24 00:14:51 +0000 |
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committer | Rafael Espindola <rafael.espindola@gmail.com> | 2012-03-24 00:14:51 +0000 |
commit | 39dd328ed0892e063d02768336c4b792c925cdc3 (patch) | |
tree | aa22c2c837d8e0dd7d4cc7747d37d37f2235bd73 /docs | |
parent | 1db394921b9635980555cc8d7e0d05b5e885784f (diff) | |
download | external_llvm-39dd328ed0892e063d02768336c4b792c925cdc3.zip external_llvm-39dd328ed0892e063d02768336c4b792c925cdc3.tar.gz external_llvm-39dd328ed0892e063d02768336c4b792c925cdc3.tar.bz2 |
First part of PR12251. Add documentation and verifier support for the range
metadata.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153359 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs')
-rw-r--r-- | docs/LangRef.html | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/docs/LangRef.html b/docs/LangRef.html index 81dabc9..cfe4890 100644 --- a/docs/LangRef.html +++ b/docs/LangRef.html @@ -104,6 +104,7 @@ <ol> <li><a href="#tbaa">'<tt>tbaa</tt>' Metadata</a></li> <li><a href="#fpaccuracy">'<tt>fpaccuracy</tt>' Metadata</a></li> + <li><a href="#range">'<tt>range</tt>' Metadata</a></li> </ol> </li> </ol> @@ -3028,6 +3029,39 @@ call void @llvm.dbg.value(metadata !24, i64 0, metadata !25) </pre> </div> +<!-- _______________________________________________________________________ --> +<h4> + <a name="range">'<tt>range</tt>' Metadata</a> +</h4> + +<div> +<p><tt>range</tt> metadata may be attached only to loads of integer types. It + expresses the possible ranges the loaded value is in. The ranges are + represented with a flattened list of integers. The loaded value is known to + be in the union of the ranges defined by each consecutive pair. Each pair + has the following properties:</p> +<ul> + <li>The type must match the type loaded by the instruction.</li> + <li>The pair <tt>a,b</tt> represents the range <tt>[a,b)</tt>.</li> + <li>Both <tt>a</tt> and <tt>b</tt> are constants.</li> + <li>The range is allowed to wrap.</li> + <li>The range should not represent the full or empty set. That is, + <tt>a!=b</tt>. </li> +</ul> + +<p>Examples:</p> +<div class="doc_code"> +<pre> + %a = load i8* %x, align 1, !range !0 ; Can only be 0 or 1 + %b = load i8* %y, align 1, !range !1 ; Can only be 255 (-1), 0 or 1 + %c = load i8* %z, align 1, !range !2 ; Can only be 0, 1, 3, 4 or 5 +... +!0 = metadata !{ i8 0, i8 2 } +!1 = metadata !{ i8 255, i8 2 } +!2 = metadata !{ i8 0, i8 2, i8 3, i8 6 } +</pre> +</div> +</div> </div> </div> |