Add support for multiple single elements vld1 instructions

[icymanred]

This pr adds support for the multiple single elements variant of the vld1 instruction.
A new struct DoubleWordRegisterList is added to represent register lists and a function ReadRegisterList to read it is added.
A utility function GetDataTypeSize is also added to return the size of a instruction datatype in bits.
A visual comparison of llil before and after.

Before

# After

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✅ icymanred
❌ plafosse
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[Copilot]

Pull Request Overview

This PR adds support for the multiple single elements variant of the VLD1 instruction in ARMv7 architecture. The changes include utility functions for handling register lists and data type size calculations, along with the implementation of VLD1 instruction lifting to LLIL.

Key changes:

• Added GetDataTypeSize function to convert data type enums to bit sizes
• Added ReadRegisterList function to parse register list operands using platform-specific intrinsics
• Implemented VLD1 instruction handling with proper register list iteration and memory load operations

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
arch/armv7/il.cpp	Added utility functions and VLD1 instruction implementation with register list handling and memory operations
arch/armv7/armv7_disasm/armv7.h	Added DoubleWordRegisterList struct definition and formatting cleanup for ieee754_double union

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[Copilot]

The ConditionExecute call has incorrect parameters. Based on the function signature shown in the context, ConditionExecute takes (LowLevelILFunction& il, Condition cond, ExprId trueCase), but this call passes addrSize as the first parameter and uses a lambda that doesn't return an ExprId.

Suggested change

	ConditionExecute(addrSize, instr.cond, instr, il, [&](size_t addrSize, Instruction& instr, LowLevelILFunction& il) {
	switch (op1.cls)
	{
	case OperandClass::REG_LIST_DOUBLE:
	DoubleWordRegisterList reglist = ReadRegisterList(op1);
	uint32_t dregsize = get_register_size(REG_D0);
	uint32_t regsize = get_register_size(op2.reg);
	uint32_t dataSizeInBytes = GetDataTypeSize(instr.dataType) / 8;
	for (unsigned int i = 0; i < reglist.size; i++)
	{
	uint32_t curOffset = i * dataSizeInBytes;
	uint32_t curregind = REG_D0 + reglist.start + i;
	il.AddInstruction(il.SetRegister(dregsize, curregind,
	il.Load(dataSizeInBytes, il.Add(regsize, ILREG(op2), il.Const(regsize, curOffset)))));
	}
	if (op2.flags.wb)
	{
	il.AddInstruction(il.SetRegister(
	regsize, op2.reg, il.Add(regsize, ILREG(op2), il.Const(regsize, dataSizeInBytes * reglist.size))));
	}
	}
	});
	break;
	{
	// Build the IL instructions for the VLD1 operation
	switch (op1.cls)
	{
	case OperandClass::REG_LIST_DOUBLE:
	{
	DoubleWordRegisterList reglist = ReadRegisterList(op1);
	uint32_t dregsize = get_register_size(REG_D0);
	uint32_t regsize = get_register_size(op2.reg);
	uint32_t dataSizeInBytes = GetDataTypeSize(instr.dataType) / 8;
	for (unsigned int i = 0; i < reglist.size; i++)
	{
	uint32_t curOffset = i * dataSizeInBytes;
	uint32_t curregind = REG_D0 + reglist.start + i;
	il.AddInstruction(il.SetRegister(dregsize, curregind,
	il.Load(dataSizeInBytes, il.Add(regsize, ILREG(op2), il.Const(regsize, curOffset)))));
	}
	if (op2.flags.wb)
	{
	il.AddInstruction(il.SetRegister(
	regsize, op2.reg, il.Add(regsize, ILREG(op2), il.Const(regsize, dataSizeInBytes * reglist.size))));
	}
	break;
	}
	default:
	break;
	}
	// Use il.Nop() as the trueCase since the instructions have already been added
	ConditionExecute(il, instr.cond, il.Nop());
	break;
	}

[plafosse]

There are two definitions of ConditionExecute consider this one

void ConditionExecute(size_t addrSize, Condition cond, Instruction& instr, LowLevelILFunction& il,
	std::function<void (size_t addrSize, Instruction& instr, LowLevelILFunction& il)> conditionalCode)
{

[Copilot]

Pull Request Overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.

---

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[Copilot]

The switch statement lacks a default case and doesn't return a value for unhandled DataType values. This will cause undefined behavior if an unsupported DataType is passed. Add a default case that returns 0 or asserts/logs an error.

Suggested change

	return 64;
	return 64;
	default:
	return 0;

[Copilot]

The ConditionExecute call signature doesn't match the function definition shown in the context. The function expects (LowLevelILFunction& il, Condition cond, ExprId trueCase) but is being called with (addrSize, instr.cond, instr, il, lambda). This indicates either the wrong overload is being used or the function signature is incorrect.

[Copilot]

The switch statement has no default case and no break statement after the REG_LIST_DOUBLE case. This will cause fall-through behavior and potential undefined behavior if other operand classes are encountered. Add a break statement after line 5146 and consider adding a default case.

[Copilot]

The switch statement has no default case and no break statement after the REG_LIST_DOUBLE case. This will cause fall-through behavior and potential undefined behavior if other operand classes are encountered. Add a break statement after line 5146 and consider adding a default case.

Suggested change

	}
	}
	break;
	default:
	il.AddInstruction(il.Unimplemented());
	break;