AArch64: allow constant expressions for shifted reg literals
e.g., add w1, w2, w3, lsl #(2 - 1)
This sort of thing comes up in pre-processed assembly playing macro games.
Still validate that it's an assembly time constant. The early exit error check
was just a bit overzealous and disallowed a left paren.
rdar://18430542
llvm-svn: 218336
diff --git a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
index c4f5449..1c92c8c 100644
--- a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
+++ b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
@@ -2299,10 +2299,11 @@
if (Hash)
Parser.Lex(); // Eat the '#'.
- // Make sure we do actually have a number
- if (!Parser.getTok().is(AsmToken::Integer)) {
- Error(Parser.getTok().getLoc(),
- "expected integer shift amount");
+ // Make sure we do actually have a number or a parenthesized expression.
+ SMLoc E = Parser.getTok().getLoc();
+ if (!Parser.getTok().is(AsmToken::Integer) &&
+ !Parser.getTok().is(AsmToken::LParen)) {
+ Error(E, "expected integer shift amount");
return MatchOperand_ParseFail;
}
@@ -2312,11 +2313,11 @@
const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(ImmVal);
if (!MCE) {
- TokError("expected #imm after shift specifier");
+ Error(E, "expected constant '#imm' after shift specifier");
return MatchOperand_ParseFail;
}
- SMLoc E = SMLoc::getFromPointer(getLoc().getPointer() - 1);
+ E = SMLoc::getFromPointer(getLoc().getPointer() - 1);
Operands.push_back(AArch64Operand::CreateShiftExtend(
ShOp, MCE->getValue(), true, S, E, getContext()));
return MatchOperand_Success;