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
diff --git a/llvm/test/CodeGen/ARM/undefined.ll b/llvm/test/CodeGen/ARM/undefined.ll
new file mode 100644
index 0000000..86422fb
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/undefined.ll
@@ -0,0 +1,14 @@
+; RUN: llc -mtriple armv7-eabi -o - %s | FileCheck %s
+; RUN: llc -mtriple thumbv6m-eabi -o - %s | FileCheck %s
+; RUN: llc -mtriple thumbv7-eabi -o - %s | FileCheck %s
+
+declare void @llvm.arm.undefined(i32) nounwind
+
+define void @undefined_trap() {
+entry:
+ tail call void @llvm.arm.undefined(i32 254)
+ ret void
+}
+
+; CHECK-LABEL: undefined_trap
+; CHECK: udf #254