Thumb2 parsing and encoding for LDR(immediate).
The immediate offset of the non-writeback i8 form (encoding T4) allows
negative offsets only. The positive offset form of the encoding is the
LDRT instruction. Immediate offsets in the range [0,255] use encoding T3
instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139254 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index b00bb0c..9efdd42 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -732,6 +732,28 @@
int64_t Val = Mem.OffsetImm->getValue();
return Val > -256 && Val < 256;
}
+ bool isMemNegImm8Offset() const {
+ if (Kind != Memory || Mem.OffsetRegNum != 0)
+ return false;
+ // Immediate offset in range [-255, -1].
+ if (!Mem.OffsetImm) return true;
+ int64_t Val = Mem.OffsetImm->getValue();
+ return Val > -256 && Val < 0;
+ }
+ bool isMemUImm12Offset() const {
+ // If we have an immediate that's not a constant, treat it as a label
+ // reference needing a fixup. If it is a constant, it's something else
+ // and we reject it.
+ if (Kind == Immediate && !isa<MCConstantExpr>(getImm()))
+ return true;
+
+ if (Kind != Memory || Mem.OffsetRegNum != 0)
+ return false;
+ // Immediate offset in range [0, 4095].
+ if (!Mem.OffsetImm) return true;
+ int64_t Val = Mem.OffsetImm->getValue();
+ return (Val >= 0 && Val < 4096);
+ }
bool isMemImm12Offset() const {
// If we have an immediate that's not a constant, treat it as a label
// reference needing a fixup. If it is a constant, it's something else
@@ -1077,6 +1099,28 @@
Inst.addOperand(MCOperand::CreateImm(Val));
}
+ void addMemNegImm8OffsetOperands(MCInst &Inst, unsigned N) const {
+ assert(N == 2 && "Invalid number of operands!");
+ int64_t Val = Mem.OffsetImm ? Mem.OffsetImm->getValue() : 0;
+ Inst.addOperand(MCOperand::CreateReg(Mem.BaseRegNum));
+ Inst.addOperand(MCOperand::CreateImm(Val));
+ }
+
+ void addMemUImm12OffsetOperands(MCInst &Inst, unsigned N) const {
+ assert(N == 2 && "Invalid number of operands!");
+ // If this is an immediate, it's a label reference.
+ if (Kind == Immediate) {
+ addExpr(Inst, getImm());
+ Inst.addOperand(MCOperand::CreateImm(0));
+ return;
+ }
+
+ // Otherwise, it's a normal memory reg+offset.
+ int64_t Val = Mem.OffsetImm ? Mem.OffsetImm->getValue() : 0;
+ Inst.addOperand(MCOperand::CreateReg(Mem.BaseRegNum));
+ Inst.addOperand(MCOperand::CreateImm(Val));
+ }
+
void addMemImm12OffsetOperands(MCInst &Inst, unsigned N) const {
assert(N == 2 && "Invalid number of operands!");
// If this is an immediate, it's a label reference.