implement a trivial binary expression parser, we can now parse all of 176.gcc.llc.s
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73950 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-mc/AsmParser.cpp b/tools/llvm-mc/AsmParser.cpp
index 715ff39..9e8b3cf 100644
--- a/tools/llvm-mc/AsmParser.cpp
+++ b/tools/llvm-mc/AsmParser.cpp
@@ -168,7 +168,9 @@
// memory operand consumed.
} else {
// It must be an parenthesized expression, parse it now.
- if (ParseParenExpr(Disp)) return true;
+ if (ParseParenExpr(Disp) ||
+ ParseBinOpRHS(1, Disp))
+ return true;
// After parsing the base expression we could either have a parenthesized
// memory address or not. If not, return now. If so, eat the (.
@@ -274,9 +276,61 @@
/// expr ::= primaryexpr
///
bool AsmParser::ParseExpression(int64_t &Res) {
- return ParsePrimaryExpr(Res);
+ return ParsePrimaryExpr(Res) ||
+ ParseBinOpRHS(1, Res);
}
-
+
+static unsigned getBinOpPrecedence(asmtok::TokKind K) {
+ switch (K) {
+ default: return 0; // not a binop.
+ case asmtok::Plus:
+ case asmtok::Minus:
+ return 1;
+ case asmtok::Pipe:
+ case asmtok::Caret:
+ case asmtok::Amp:
+ case asmtok::Exclaim:
+ return 2;
+ case asmtok::Star:
+ case asmtok::Slash:
+ case asmtok::Percent:
+ case asmtok::LessLess:
+ case asmtok::GreaterGreater:
+ return 3;
+ }
+}
+
+
+/// ParseBinOpRHS - Parse all binary operators with precedence >= 'Precedence'.
+/// Res contains the LHS of the expression on input.
+bool AsmParser::ParseBinOpRHS(unsigned Precedence, int64_t &Res) {
+ while (1) {
+ unsigned TokPrec = getBinOpPrecedence(Lexer.getKind());
+
+ // If the next token is lower precedence than we are allowed to eat, return
+ // successfully with what we ate already.
+ if (TokPrec < Precedence)
+ return false;
+
+ //asmtok::TokKind BinOp = Lexer.getKind();
+ Lexer.Lex();
+
+ // Eat the next primary expression.
+ int64_t RHS;
+ if (ParsePrimaryExpr(RHS)) return true;
+
+ // If BinOp binds less tightly with RHS than the operator after RHS, let
+ // the pending operator take RHS as its LHS.
+ unsigned NextTokPrec = getBinOpPrecedence(Lexer.getKind());
+ if (TokPrec < NextTokPrec) {
+ if (ParseBinOpRHS(Precedence+1, RHS)) return true;
+ }
+
+ // Merge LHS/RHS: fixme use the right operator etc.
+ Res += RHS;
+ }
+}
+