[thumb2] add intrinsics for rbit and clz instructions

3 files changed, 69 insertions, 26 deletions

diff --git a/arch/armv7/il.h b/arch/armv7/il.h
index 075c2a2e..e4a57907 100644
--- a/arch/armv7/il.h
+++ b/arch/armv7/il.h
@@ -51,6 +51,8 @@ enum Armv7Intrinsic : uint32_t
 
 	ARMV7_INTRIN_EXCLUSIVE_MONITORS_PASS,
 	ARMV7_INTRIN_SET_EXCLUSIVE_MONITORS,
+	ARMV7_INTRIN_RBIT,
+	ARMV7_INTRIN_CLZ,
 };
 
 enum ArmFakeRegister: uint32_t
diff --git a/arch/armv7/thumb2_disasm/arch_thumb2.cpp b/arch/armv7/thumb2_disasm/arch_thumb2.cpp
index 420dcbbb..a6b8ee0a 100644
--- a/arch/armv7/thumb2_disasm/arch_thumb2.cpp
+++ b/arch/armv7/thumb2_disasm/arch_thumb2.cpp
@@ -1403,6 +1403,10 @@ public:
 			return "__wfi";
 		case ARM_M_INTRIN_SET_BASEPRI:
 			return "__set_BASEPRI";
+		case ARMV7_INTRIN_RBIT:
+			return "__rbit";
+		case ARMV7_INTRIN_CLZ:
+			return "__clz";
 		default:
 			return "";
 		}
diff --git a/arch/armv7/thumb2_disasm/il_thumb2.cpp b/arch/armv7/thumb2_disasm/il_thumb2.cpp
index 39d9d0a0..56443ff1 100644
--- a/arch/armv7/thumb2_disasm/il_thumb2.cpp
+++ b/arch/armv7/thumb2_disasm/il_thumb2.cpp
@@ -205,6 +205,27 @@ static ExprId ReadArithOperand(LowLevelILFunction& il, decomp_result* instr, siz
 	return ReadShiftedOperand(il, instr, 2, size);
 }
 
+static uint32_t GetRegisterOperand(decomp_result* instr, size_t operand)
+{
+	uint32_t reg;
+	switch (instr->format->operands[operand].type)
+	{
+		case OPERAND_FORMAT_REG:
+			reg = instr->fields[instr->format->operands[operand].field0];
+			return GetRegisterByIndex(reg);
+		case OPERAND_FORMAT_REG_FP:
+			reg = instr->fields[instr->format->operands[operand].field0];
+			return GetRegisterByIndex(reg, instr->format->operands[operand].prefix);
+		case OPERAND_FORMAT_SP:
+			return armv7::REG_SP;
+		case OPERAND_FORMAT_LR:
+			return armv7::REG_LR;
+		case OPERAND_FORMAT_PC:
+			return armv7::REG_PC;
+		default:
+			return armv7::REG_INVALID;
+	}
+}
 
 static ExprId WriteILOperand(LowLevelILFunction& il, decomp_result* instr, size_t operand, ExprId value,
 	size_t size = 4, uint32_t flags = 0)
@@ -675,32 +696,41 @@ bool GetLowLevelILForThumbInstruction(Architecture* arch, LowLevelILFunction& il
 			(instr->pc - 4) + instr->fields[instr->format->operands[1].field0], (instr->pc - 4) + (instr->instrSize / 8));
 		break;
 	case armv7::ARMV7_CLZ:
-	{
-		LowLevelILLabel loopStart,
-				loopBody,
-				loopExit;
-		//Count leading zeros
-		//Based on the non-thumb CLZ lifter
-		//
-		// TEMP0 = 0
-		// TEMP1 = op2.reg
-		// while (TEMP1 != 0)
-		// 		TEMP1 = TEMP1 >> 1
-		// 		TEMP0 = TEMP0 + 1
-		// op1.reg = 32 - TEMP0
-		il.AddInstruction(il.SetRegister(4, LLIL_TEMP(0), il.Const(4, 0)));
-		il.AddInstruction(il.SetRegister(4, LLIL_TEMP(1), ReadILOperand(il, instr, 1)));
-		il.AddInstruction(il.Goto(loopStart));
-		il.MarkLabel(loopStart);
-		il.AddInstruction(il.If(il.CompareNotEqual(4, il.Register(4, LLIL_TEMP(1)), il.Const(4, 0)), loopBody, loopExit));
-		il.MarkLabel(loopBody);
-		il.AddInstruction(il.SetRegister(4, LLIL_TEMP(1), il.LogicalShiftRight(4, il.Register(4, LLIL_TEMP(1)), il.Const(4, 1))));
-		il.AddInstruction(il.SetRegister(4, LLIL_TEMP(0), il.Add(4, il.Register(4, LLIL_TEMP(0)), il.Const(4, 1))));
-		il.AddInstruction(il.Goto(loopStart));
-		il.MarkLabel(loopExit);
-		il.AddInstruction(WriteILOperand(il, instr, 0, il.Sub(4, il.Const(4, 32), il.Register(4, LLIL_TEMP(0)))));
-		break;
-	}
+		if (true) {
+			il.AddInstruction(
+				il.Intrinsic(
+					{RegisterOrFlag::Register(GetRegisterOperand(instr, 0))},
+					ARMV7_INTRIN_CLZ,
+					{ReadILOperand(il, instr, 1)}));
+			break;
+		}
+		else
+		{
+			LowLevelILLabel loopStart,
+					loopBody,
+					loopExit;
+			//Count leading zeros
+			//Based on the non-thumb CLZ lifter
+			//
+			// TEMP0 = 0
+			// TEMP1 = op2.reg
+			// while (TEMP1 != 0)
+			// 		TEMP1 = TEMP1 >> 1
+			// 		TEMP0 = TEMP0 + 1
+			// op1.reg = 32 - TEMP0
+			il.AddInstruction(il.SetRegister(4, LLIL_TEMP(0), il.Const(4, 0)));
+			il.AddInstruction(il.SetRegister(4, LLIL_TEMP(1), ReadILOperand(il, instr, 1)));
+			il.AddInstruction(il.Goto(loopStart));
+			il.MarkLabel(loopStart);
+			il.AddInstruction(il.If(il.CompareNotEqual(4, il.Register(4, LLIL_TEMP(1)), il.Const(4, 0)), loopBody, loopExit));
+			il.MarkLabel(loopBody);
+			il.AddInstruction(il.SetRegister(4, LLIL_TEMP(1), il.LogicalShiftRight(4, il.Register(4, LLIL_TEMP(1)), il.Const(4, 1))));
+			il.AddInstruction(il.SetRegister(4, LLIL_TEMP(0), il.Add(4, il.Register(4, LLIL_TEMP(0)), il.Const(4, 1))));
+			il.AddInstruction(il.Goto(loopStart));
+			il.MarkLabel(loopExit);
+			il.AddInstruction(WriteILOperand(il, instr, 0, il.Sub(4, il.Const(4, 32), il.Register(4, LLIL_TEMP(0)))));
+			break;
+		}
 	case armv7::ARMV7_CMP:
 		il.AddInstruction(il.Sub(4, ReadILOperand(il, instr, 0), ReadArithOperand(il, instr, 1), IL_FLAGWRITE_ALL));
 		break;
@@ -1160,6 +1190,13 @@ bool GetLowLevelILForThumbInstruction(Architecture* arch, LowLevelILFunction& il
 	case armv7::ARMV7_PUSH:
 		Push(il, instr->fields[FIELD_registers]);
 		break;
+	case armv7::ARMV7_RBIT:
+		il.AddInstruction(
+			il.Intrinsic(
+				{RegisterOrFlag::Register(GetRegisterOperand(instr, 0))},
+				ARMV7_INTRIN_RBIT,
+				{ReadILOperand(il, instr, 1)}));
+		break;
 	case armv7::ARMV7_REV:
 		il.AddInstruction(WriteILOperand(il, instr, 0,
 			il.Or(4, il.LogicalShiftRight(4, ReadILOperand(il, instr, 1), il.Const(4, 24)),