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
diff --git a/docs/LangRef.html b/docs/LangRef.html
index 8dca415..a12a42b 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 @@
</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>
diff --git a/include/llvm/LLVMContext.h b/include/llvm/LLVMContext.h
index 65146c3..1c50630 100644
--- a/include/llvm/LLVMContext.h
+++ b/include/llvm/LLVMContext.h
@@ -40,7 +40,8 @@
enum {
MD_dbg = 0, // "dbg"
MD_tbaa = 1, // "tbaa"
- MD_prof = 2 // "prof"
+ MD_prof = 2, // "prof"
+ MD_fpaccuracy = 3 // "fpaccuracy"
};
/// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
diff --git a/lib/VMCore/LLVMContext.cpp b/lib/VMCore/LLVMContext.cpp
index 3ed2c2c..e1a9b17 100644
--- a/lib/VMCore/LLVMContext.cpp
+++ b/lib/VMCore/LLVMContext.cpp
@@ -43,6 +43,11 @@
// Create the 'prof' metadata kind.
unsigned ProfID = getMDKindID("prof");
assert(ProfID == MD_prof && "prof kind id drifted"); (void)ProfID;
+
+ // Create the 'fpaccuracy' metadata kind.
+ unsigned FPAccuracyID = getMDKindID("fpaccuracy");
+ assert(FPAccuracyID == MD_fpaccuracy && "fpaccuracy kind id drifted");
+ (void)FPAccuracyID;
}
LLVMContext::~LLVMContext() { delete pImpl; }