Add sanity checking for invalid register encodings for saturating instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129096 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp b/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
index f4fa3de268456b30e693244a5eda4b5ab293b729..4933a60ee58fb22d35a2ac2d4190db90859fcbcd 100644 (file)
--- a/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
@@ -1546,6 +1546,11 @@ static bool DisassembleArithMiscFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
 static bool DisassembleSatFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
     unsigned short NumOps, unsigned &NumOpsAdded, BO B) {
 
+  // A8.6.183 SSAT
+  // if d == 15 || n == 15 then UNPREDICTABLE;
+  if (decodeRd(insn) == 15 || decodeRm(insn) == 15)
+    return false;
+
   const TargetInstrDesc &TID = ARMInsts[Opcode];
   NumOpsAdded = TID.getNumOperands() - 2; // ignore predicate operands
 

diff --git a/test/MC/Disassembler/ARM/invalid-SSAT-arm.txt b/test/MC/Disassembler/ARM/invalid-SSAT-arm.txt
new file mode 100644 (file)
index 0000000..9cc8351
--- /dev/null
+++ b/test/MC/Disassembler/ARM/invalid-SSAT-arm.txt
@@ -0,0 +1,11 @@
+# RUN: llvm-mc --disassemble %s -triple=arm-apple-darwin9 |& grep {invalid instruction encoding}
+
+# Opcode=322 Name=SSAT Format=ARM_FORMAT_SATFRM(13)
+#  31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0 
+# -------------------------------------------------------------------------------------------------
+# | 1: 1: 1: 0| 0: 1: 1: 0| 1: 0: 1: 0| 0: 0: 0: 0| 1: 1: 1: 1| 0: 1: 0: 0| 0: 0: 0: 1| 1: 0: 1: 0|
+# -------------------------------------------------------------------------------------------------
+#
+# A8.6.183 SSAT
+# if d == 15 || n == 15 then UNPREDICTABLE;
+0x1a 0xf4 0xa0 0xe6