ARM LDRD(register) assembly parsing and encoding.
Add support for literal encoding of #-0 along the way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137254 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index fcc8a6a..72ab7ea 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -114,6 +114,7 @@
OperandMatchResultTy parseRotImm(SmallVectorImpl<MCParsedAsmOperand*>&);
OperandMatchResultTy parseBitfield(SmallVectorImpl<MCParsedAsmOperand*>&);
OperandMatchResultTy parsePostIdxReg(SmallVectorImpl<MCParsedAsmOperand*>&);
+ OperandMatchResultTy parseAM3Offset(SmallVectorImpl<MCParsedAsmOperand*>&);
// Asm Match Converter Methods
bool cvtLdWriteBackRegAddrMode2(MCInst &Inst, unsigned Opcode,
@@ -557,7 +558,8 @@
const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
if (!CE) return false;
int64_t Val = CE->getValue();
- return Val > -256 && Val < 256;
+ // Special case, #-0 is INT32_MIN.
+ return (Val > -256 && Val < 256) || Val == INT32_MIN;
}
bool isAddrMode5() const {
if (Kind != Memory)
@@ -865,6 +867,7 @@
ARM_AM::getAM3Opc(PostIdxReg.isAdd ? ARM_AM::add : ARM_AM::sub, 0);
Inst.addOperand(MCOperand::CreateReg(PostIdxReg.RegNum));
Inst.addOperand(MCOperand::CreateImm(Val));
+ return;
}
// Constant offset.
@@ -874,7 +877,7 @@
// Special case for #-0
if (Val == INT32_MIN) Val = 0;
if (Val < 0) Val = -Val;
- Val = ARM_AM::getAM2Opc(AddSub, Val, ARM_AM::no_shift);
+ Val = ARM_AM::getAM3Opc(AddSub, Val);
Inst.addOperand(MCOperand::CreateReg(0));
Inst.addOperand(MCOperand::CreateImm(Val));
}
@@ -2007,6 +2010,76 @@
return MatchOperand_Success;
}
+ARMAsmParser::OperandMatchResultTy ARMAsmParser::
+parseAM3Offset(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
+ // Check for a post-index addressing register operand. Specifically:
+ // am3offset := '+' register
+ // | '-' register
+ // | register
+ // | # imm
+ // | # + imm
+ // | # - imm
+
+ // This method must return MatchOperand_NoMatch without consuming any tokens
+ // in the case where there is no match, as other alternatives take other
+ // parse methods.
+ AsmToken Tok = Parser.getTok();
+ SMLoc S = Tok.getLoc();
+
+ // Do immediates first, as we always parse those if we have a '#'.
+ if (Parser.getTok().is(AsmToken::Hash)) {
+ Parser.Lex(); // Eat the '#'.
+ // Explicitly look for a '-', as we need to encode negative zero
+ // differently.
+ bool isNegative = Parser.getTok().is(AsmToken::Minus);
+ const MCExpr *Offset;
+ if (getParser().ParseExpression(Offset))
+ return MatchOperand_ParseFail;
+ const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Offset);
+ if (!CE) {
+ Error(S, "constant expression expected");
+ return MatchOperand_ParseFail;
+ }
+ SMLoc E = Tok.getLoc();
+ // Negative zero is encoded as the flag value INT32_MIN.
+ int32_t Val = CE->getValue();
+ if (isNegative && Val == 0)
+ Val = INT32_MIN;
+
+ Operands.push_back(
+ ARMOperand::CreateImm(MCConstantExpr::Create(Val, getContext()), S, E));
+
+ return MatchOperand_Success;
+ }
+
+
+ bool haveEaten = false;
+ bool isAdd = true;
+ int Reg = -1;
+ if (Tok.is(AsmToken::Plus)) {
+ Parser.Lex(); // Eat the '+' token.
+ haveEaten = true;
+ } else if (Tok.is(AsmToken::Minus)) {
+ Parser.Lex(); // Eat the '-' token.
+ isAdd = false;
+ haveEaten = true;
+ }
+ if (Parser.getTok().is(AsmToken::Identifier))
+ Reg = tryParseRegister();
+ if (Reg == -1) {
+ if (!haveEaten)
+ return MatchOperand_NoMatch;
+ Error(Parser.getTok().getLoc(), "register expected");
+ return MatchOperand_ParseFail;
+ }
+ SMLoc E = Parser.getTok().getLoc();
+
+ Operands.push_back(ARMOperand::CreatePostIdxReg(Reg, isAdd, ARM_AM::no_shift,
+ 0, S, E));
+
+ return MatchOperand_Success;
+}
+
/// cvtLdWriteBackRegAddrMode2 - Convert parsed operands to MCInst.
/// Needed here because the Asm Gen Matcher can't handle properly tied operands
/// when they refer multiple MIOperands inside a single one.