[Stackmap] Add AnyReg calling convention support for patchpoint intrinsic.

The idea of the AnyReg Calling Convention is to provide the call arguments in
registers, but not to force them to be placed in a paticular order into a
specified set of registers. Instead it is up tp the register allocator to assign
any register as it sees fit. The same applies to the return value (if
applicable).

Differential Revision: http://llvm-reviews.chandlerc.com/D2009

Reviewed by Andy

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194293 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 23 insertions, 0 deletions

diff --git a/lib/Target/X86/X86CallingConv.td b/lib/Target/X86/X86CallingConv.td
index f5c8d9f..a78b5c0 100644
--- a/lib/Target/X86/X86CallingConv.td
+++ b/lib/Target/X86/X86CallingConv.td
@@ -160,6 +160,17 @@ def RetCC_X86_64_WebKit_JS : CallingConv<[
   CCIfType<[i64], CCAssignToReg<[RAX]>>
 ]>;
 
+// X86-64 AnyReg return-value convention. No explicit register is specified for
+// the return-value. The register allocator is allowed and expected to choose
+// any free register.
+//
+// This calling convention is currently only supported by the stackmap and
+// patchpoint intrinsics. All other uses will result in an assert on Debug
+// builds. On Release builds we fallback to the X86 C calling convention.
+def RetCC_X86_64_AnyReg : CallingConv<[
+  CCCustom<"CC_X86_AnyReg_Error">
+]>;
+
 // This is the root return-value convention for the X86-32 backend.
 def RetCC_X86_32 : CallingConv<[
   // If FastCC, use RetCC_X86_32_Fast.
@@ -178,6 +189,7 @@ def RetCC_X86_64 : CallingConv<[
 
   // Handle JavaScript calls.
   CCIfCC<"CallingConv::WebKit_JS", CCDelegateTo<RetCC_X86_64_WebKit_JS>>,
+  CCIfCC<"CallingConv::AnyReg", CCDelegateTo<RetCC_X86_64_AnyReg>>,
 
   // Handle explicit CC selection
   CCIfCC<"CallingConv::X86_64_Win64", CCDelegateTo<RetCC_X86_Win64_C>>,
@@ -350,6 +362,16 @@ def CC_X86_64_WebKit_JS : CallingConv<[
   CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>
 ]>;
 
+// No explicit register is specified for the AnyReg calling convention. The
+// register allocator may assign the arguments to any free register.
+//
+// This calling convention is currently only supported by the stackmap and
+// patchpoint intrinsics. All other uses will result in an assert on Debug
+// builds. On Release builds we fallback to the X86 C calling convention.
+def CC_X86_64_AnyReg : CallingConv<[
+  CCCustom<"CC_X86_AnyReg_Error">
+]>;
+
 //===----------------------------------------------------------------------===//
 // X86 C Calling Convention
 //===----------------------------------------------------------------------===//
@@ -542,6 +564,7 @@ def CC_X86_64 : CallingConv<[
   CCIfCC<"CallingConv::GHC", CCDelegateTo<CC_X86_64_GHC>>,
   CCIfCC<"CallingConv::HiPE", CCDelegateTo<CC_X86_64_HiPE>>,
   CCIfCC<"CallingConv::WebKit_JS", CCDelegateTo<CC_X86_64_WebKit_JS>>,
+  CCIfCC<"CallingConv::AnyReg", CCDelegateTo<CC_X86_64_AnyReg>>,
   CCIfCC<"CallingConv::X86_64_Win64", CCDelegateTo<CC_X86_Win64_C>>,
   CCIfCC<"CallingConv::X86_64_SysV", CCDelegateTo<CC_X86_64_C>>,