[Stackmap] Materialize the jump address within the patchpoint noop slide.

This patch moves the jump address materialization inside the noop slide. This
enables patching of the materialization itself or its complete removal. This
patch also adds the ability to define scratch registers that can be used safely
by the code called from the patchpoint intrinsic. At least one scratch register
is required, because that one is used for the materialization of the jump
address. This patch depends on D2009.

Differential Revision: http://llvm-reviews.chandlerc.com/D2074

Reviewed by Andy

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194306 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 0 deletions

diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 6944f73..5d6d1d2 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -2056,6 +2056,12 @@ public:
     return VT.bitsLT(MinVT) ? MinVT : VT;
   }
 
+  /// Returns a 0 terminated array of registers that can be safely used as
+  /// scratch registers.
+  virtual const uint16_t *getScratchRegisters(CallingConv::ID CC) const {
+    return NULL;
+  }
+
   /// This callback is invoked by the type legalizer to legalize nodes with an
   /// illegal operand type but legal result types.  It replaces the
   /// LowerOperation callback in the type Legalizer.  The reason we can not do