Emit memcmp directly from the StringMatcherEmitter.
There should be no difference in the resulting binary, given a sufficiently
smart compiler. However we already had compiler timeouts on the generated
code in Intrinsics.gen, this hopefully makes the lives of slow buildbots a
little easier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157161 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/TableGen/StringMatcher.cpp b/lib/TableGen/StringMatcher.cpp
index 0ce626d..1668170 100644
--- a/lib/TableGen/StringMatcher.cpp
+++ b/lib/TableGen/StringMatcher.cpp
@@ -87,11 +87,11 @@
<< Matches[0]->first[CharNo] << "')\n";
OS << Indent << " break;\n";
} else {
- // Do the comparison with if (Str.substr(1, 3) != "foo").
+ // Do the comparison with if memcmp(Str.data()+1, "foo", 3).
// FIXME: Need to escape general strings.
- OS << Indent << "if (" << StrVariableName << ".substr(" << CharNo << ", "
- << NumChars << ") != \"";
- OS << Matches[0]->first.substr(CharNo, NumChars) << "\")\n";
+ OS << Indent << "if (memcmp(" << StrVariableName << ".data()+" << CharNo
+ << ", \"" << Matches[0]->first.substr(CharNo, NumChars) << "\", "
+ << NumChars << "))\n";
OS << Indent << " break;\n";
}