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TableGen / AsmMatcher: Tweaks to avoid generating completely bogus match

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functions.
 - Fix variant flattening when the variant embeds an operand reference.

 - Ignore instructions which reference an operand multiple times (e.g., "xorb
   $dst, $dst"), and operands which have extra flags (e.g., "$dst:subreg32").


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78099 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Daniel Dunbar 2009-08-04 20:36:45 +00:00
parent 6db0a8b4fd
commit 53a7f16dcc
1 changed files with 74 additions and 16 deletions
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90
utils/TableGen/AsmMatcherEmitter.cpp
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@ -29,23 +29,40 @@ static std::string FlattenVariants(const std::string &AsmString,
std::string Res = "";
for (;;) {
// Add the prefix until the next '{', and split out the contents in the
// braces.
std::pair<StringRef, StringRef> Inner, Split = Cur.split('{');
// Find the start of the next variant string.
size_t VariantsStart = 0;
for (size_t e = Cur.size(); VariantsStart != e; ++VariantsStart)
if (Cur[VariantsStart] == '{' &&
(VariantsStart == 0 || Cur[VariantsStart-1] != '$'))
break;
Res += Split.first;
if (Split.second.empty())
// Add the prefix to the result.
Res += Cur.slice(0, VariantsStart);
if (VariantsStart == Cur.size())
break;
Inner = Split.second.split('}');
++VariantsStart; // Skip the '{'.
// Scan to the end of the variants string.
size_t VariantsEnd = VariantsStart;
unsigned NestedBraces = 1;
for (size_t e = Cur.size(); VariantsEnd != e; ++VariantsEnd) {
if (Cur[VariantsEnd] == '}') {
if (--NestedBraces == 0)
break;
} else if (Cur[VariantsEnd] == '{')
++NestedBraces;
}
// Select the Nth variant (or empty).
StringRef Selection = Inner.first;
StringRef Selection = Cur.slice(VariantsStart, VariantsEnd);
for (unsigned i = 0; i != N; ++i)
Selection = Selection.split('|').second;
Res += Selection.split('|').first;
Cur = Inner.second;
assert(VariantsEnd != Cur.size() &&
"Unterminated variants in assembly string!");
Cur = Cur.substr(VariantsEnd + 1);
}
return Res;
@ -128,6 +145,12 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
if (Form->getValue()->getAsString() == "Pseudo")
continue;
// Ignore "PHI" node.
//
// FIXME: This is also a hack.
if (it->first == "PHI")
continue;
// Ignore instructions with no .s string.
//
// FIXME: What are these?
@ -138,12 +161,6 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
if (StringRef(CGI.AsmString).startswith("lock"))
continue;
// FIXME: Hack.
#if 0
if (1 && it->first != "SUB8mr")
continue;
#endif
std::string Flattened = FlattenVariants(CGI.AsmString, 0);
SmallVector<StringRef, 8> Tokens;
@ -167,9 +184,50 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
}
});
// FIXME: Ignore non-literal tokens.
if (std::find(Tokens[0].begin(), Tokens[0].end(), '$') != Tokens[0].end())
// FIXME: Ignore prefixes with non-literal tokens.
if (std::find(Tokens[0].begin(), Tokens[0].end(), '$') != Tokens[0].end()) {
DEBUG({
errs() << "warning: '" << it->first << "': "
<< "ignoring non-literal token '" << Tokens[0] << "', \n";
});
continue;
}
// Ignore instructions with subreg specifiers, these are always fake
// instructions for simplifying codegen.
//
// FIXME: Is this true?
//
// Also, we ignore instructions which reference the operand multiple times;
// this implies a constraint we would not currently honor. These are
// currently always fake instructions for simplifying codegen.
//
// FIXME: Encode this assumption in the .td, so we can error out here.
std::set<std::string> OperandNames;
unsigned HasSubreg = 0, HasDuplicate = 0;
for (unsigned i = 1, e = Tokens.size(); i < e; ++i) {
if (Tokens[i][0] == '$' &&
std::find(Tokens[i].begin(),
Tokens[i].end(), ':') != Tokens[i].end())
HasSubreg = i;
if (Tokens[i][0] == '$' && !OperandNames.insert(Tokens[i]).second)
HasDuplicate = i;
}
if (HasSubreg) {
DEBUG({
errs() << "warning: '" << it->first << "': "
<< "ignoring instruction; operand with subreg attribute '"
<< Tokens[HasSubreg] << "', \n";
});
continue;
} else if (HasDuplicate) {
DEBUG({
errs() << "warning: '" << it->first << "': "
<< "ignoring instruction; tied operand '"
<< Tokens[HasSubreg] << "', \n";
});
continue;
}
std::string FnName = "Match_" + Target.getName() + "_Inst_" + it->first;
MatchFns.push_back(FnName);