[WebAssembly] Assembler: support special floats: infinity / nan
Summary:
These are emitted as identifiers by the InstPrinter, so we should
parse them as such. These could potentially clash with symbols of
the same name, but that is out of our (the WebAssembly backend) control.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64770
llvm-svn: 366139
diff --git a/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp b/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
index e829235..e9a7f69 100644
--- a/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
+++ b/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
@@ -363,6 +363,28 @@
return false;
}
+ bool parseSpecialFloatMaybe(bool IsNegative, OperandVector &Operands) {
+ if (Lexer.isNot(AsmToken::Identifier))
+ return true;
+ auto &Flt = Lexer.getTok();
+ auto S = Flt.getString();
+ double Val;
+ if (S.compare_lower("infinity") == 0) {
+ Val = std::numeric_limits<double>::infinity();
+ } else if (S.compare_lower("nan") == 0) {
+ Val = std::numeric_limits<double>::quiet_NaN();
+ } else {
+ return true;
+ }
+ if (IsNegative)
+ Val = -Val;
+ Operands.push_back(make_unique<WebAssemblyOperand>(
+ WebAssemblyOperand::Float, Flt.getLoc(), Flt.getEndLoc(),
+ WebAssemblyOperand::FltOp{Val}));
+ Parser.Lex();
+ return false;
+ }
+
bool checkForP2AlignIfLoadStore(OperandVector &Operands, StringRef InstName) {
// FIXME: there is probably a cleaner way to do this.
auto IsLoadStore = InstName.find(".load") != StringRef::npos ||
@@ -476,6 +498,8 @@
auto &Tok = Lexer.getTok();
switch (Tok.getKind()) {
case AsmToken::Identifier: {
+ if (!parseSpecialFloatMaybe(false, Operands))
+ break;
auto &Id = Lexer.getTok();
if (ExpectBlockType) {
// Assume this identifier is a block_type.
@@ -507,6 +531,7 @@
} else if(Lexer.is(AsmToken::Real)) {
if (parseSingleFloat(true, Operands))
return true;
+ } else if (!parseSpecialFloatMaybe(true, Operands)) {
} else {
return error("Expected numeric constant instead got: ",
Lexer.getTok());