ARM: introduce llvm.arm.undefined intrinsic

This intrinsic permits the emission of platform specific undefined sequences.
ARM has reserved the 0xde opcode which takes a single integer parameter (ignored
by the CPU).  This permits the operating system to implement custom behaviour on
this trap.  The llvm.arm.undefined intrinsic is meant to provide a means for
generating the target specific behaviour from the frontend.  This is
particularly useful for Windows on ARM which has made use of a series of these
special opcodes.

llvm-svn: 209390

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrInfo.td b/llvm/lib/Target/ARM/ARMInstrInfo.td
index f642893161c..718d5da9d05 100644
--- a/llvm/lib/Target/ARM/ARMInstrInfo.td
+++ b/llvm/lib/Target/ARM/ARMInstrInfo.td
@@ -1969,7 +1969,7 @@ def DBG : AI<(outs), (ins imm0_15:$opt), MiscFrm, NoItinerary, "dbg", "\t$opt",
 
 // A8.8.247  UDF - Undefined (Encoding A1)
 def UDF : AInoP<(outs), (ins imm0_65535:$imm16), MiscFrm, NoItinerary,
-                "udf", "\t$imm16", []> {
+                "udf", "\t$imm16", [(int_arm_undefined imm0_65535:$imm16)]> {
   bits<16> imm16;
   let Inst{31-28} = 0b1110; // AL
   let Inst{27-25} = 0b011;