Fix thumb2 lifting of REV

Vector35 · Aug 21, 2024 · 183a842 · 183a842
1 parent 63f5f43
commit 183a842
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Showing 2 changed files with 6 additions and 4 deletions.
diff --git a/arch/armv7/test_lift.py b/arch/armv7/test_lift.py
@@ -122,7 +122,9 @@
     ('T', b'\x41\xf3\x41\x00', 'LLIL_SET_REG.d(r0,LLIL_ASR.d(LLIL_LSL.d(LLIL_REG.d(r1),LLIL_CONST.b(0x1D)),LLIL_CONST.b(0x1E)))'),
     # sbfx r0, r1, 20, 30 (starting at b20, width 30... gets clamped, so b31b30...b20
     # just r0 = r1 >> 20, no left shift required
-    ('T', b'\x41\xf3\x1d\x50', 'LLIL_SET_REG.d(r0,LLIL_ASR.d(LLIL_REG.d(r1),LLIL_CONST.b(0x14)))')
+    ('T', b'\x41\xf3\x1d\x50', 'LLIL_SET_REG.d(r0,LLIL_ASR.d(LLIL_REG.d(r1),LLIL_CONST.b(0x14)))'),
+    # rev r1, r1
+    ('T', b'\x09\xba',         'LLIL_SET_REG.d(r1,LLIL_OR.d(LLIL_LSR.d(LLIL_REG.d(r1),LLIL_CONST.d(0x18)),LLIL_OR.d(LLIL_LSL.d(LLIL_AND.d(LLIL_LSR.d(LLIL_REG.d(r1),LLIL_CONST.d(0x10)),LLIL_CONST.d(0xFF)),LLIL_CONST.d(0x8)),LLIL_OR.d(LLIL_LSL.d(LLIL_AND.d(LLIL_LSR.d(LLIL_REG.d(r1),LLIL_CONST.d(0x8)),LLIL_CONST.d(0xFF)),LLIL_CONST.d(0x10)),LLIL_LSL.d(LLIL_AND.d(LLIL_REG.d(r1),LLIL_CONST.d(0xFF)),LLIL_CONST.d(0x18))))))'),
 ]
 
 import re

diff --git a/arch/armv7/thumb2_disasm/il_thumb2.cpp b/arch/armv7/thumb2_disasm/il_thumb2.cpp
@@ -1033,9 +1033,9 @@ bool GetLowLevelILForThumbInstruction(Architecture* arch, LowLevelILFunction& il
 	case armv7::ARMV7_REV:
 		il.AddInstruction(WriteILOperand(il, instr, 0,
 			il.Or(4, il.LogicalShiftRight(4, ReadILOperand(il, instr, 1), il.Const(4, 24)),
-				 il.Or(4, il.And(4, il.LogicalShiftRight(4, ReadILOperand(il, instr, 1), il.Const(4, 16)), il.Const(4, 0xff)),
-					  il.Or(4, il.And(4, il.LogicalShiftRight(4, ReadILOperand(il, instr, 1), il.Const(4, 8)), il.Const(4, 0xff)),
-						   il.And(4, ReadILOperand(il, instr, 1), il.Const(4, 0xff)))))));
+				 il.Or(4, il.ShiftLeft(4, il.And(4, il.LogicalShiftRight(4, ReadILOperand(il, instr, 1), il.Const(4, 16)), il.Const(4, 0xff)), il.Const(1, 8)),
+					  il.Or(4, il.ShiftLeft(4, il.And(4, il.LogicalShiftRight(4, ReadILOperand(il, instr, 1), il.Const(4, 8)), il.Const(4, 0xff)), il.Const(1, 16)),
+						   il.ShiftLeft(4, il.And(4, ReadILOperand(il, instr, 1), il.Const(4, 0xff)), il.Const(1, 24)))))));
 		break;
 	case armv7::ARMV7_REV16:
 		il.AddInstruction(il.SetRegister(2, LLIL_TEMP(0), il.RotateRight(2, il.LowPart(2, ReadILOperand(il, instr, 1)), il.Const(1, 16))));