llvm/lib/Target/SystemZ/SystemZCallingConv.td
Bryan Chan 2c448a07a4 [SystemZ] Support Swift Calling Convention
Summary:
Port rL265480, rL264754, rL265997 and rL266252 to SystemZ, in order to enable the Swift port on the architecture. SwiftSelf and SwiftError are assigned to R10 and R9, respectively, which are normally callee-saved registers. For more information, see:

RFC: Implementing the Swift calling convention in LLVM and Clang
https://groups.google.com/forum/#!topic/llvm-dev/epDd2w93kZ0

Reviewers: kbarton, manmanren, rjmccall, uweigand

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19414

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267823 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-28 00:17:23 +00:00

123 lines
5.4 KiB
TableGen

//=- SystemZCallingConv.td - Calling conventions for SystemZ -*- tablegen -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// This describes the calling conventions for the SystemZ ABI.
//===----------------------------------------------------------------------===//
class CCIfExtend<CCAction A>
: CCIf<"ArgFlags.isSExt() || ArgFlags.isZExt()", A>;
class CCIfSubtarget<string F, CCAction A>
: CCIf<!strconcat("static_cast<const SystemZSubtarget&>"
"(State.getMachineFunction().getSubtarget()).", F),
A>;
// Match if this specific argument is a fixed (i.e. named) argument.
class CCIfFixed<CCAction A>
: CCIf<"static_cast<SystemZCCState *>(&State)->IsFixed(ValNo)", A>;
// Match if this specific argument was widened from a short vector type.
class CCIfShortVector<CCAction A>
: CCIf<"static_cast<SystemZCCState *>(&State)->IsShortVector(ValNo)", A>;
//===----------------------------------------------------------------------===//
// z/Linux return value calling convention
//===----------------------------------------------------------------------===//
def RetCC_SystemZ : CallingConv<[
// Promote i32 to i64 if it has an explicit extension type.
CCIfType<[i32], CCIfExtend<CCPromoteToType<i64>>>,
// A SwiftError is returned in R9.
CCIfSwiftError<CCIfType<[i64], CCAssignToReg<[R9D]>>>,
// ABI-compliant code returns 64-bit integers in R2. Make the other
// call-clobbered argument registers available for code that doesn't
// care about the ABI. (R6 is an argument register too, but is
// call-saved and therefore not suitable for return values.)
CCIfType<[i32], CCAssignToReg<[R2L, R3L, R4L, R5L]>>,
CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D]>>,
// ABI-complaint code returns float and double in F0. Make the
// other floating-point argument registers available for code that
// doesn't care about the ABI. All floating-point argument registers
// are call-clobbered, so we can use all of them here.
CCIfType<[f32], CCAssignToReg<[F0S, F2S, F4S, F6S]>>,
CCIfType<[f64], CCAssignToReg<[F0D, F2D, F4D, F6D]>>,
// Similarly for vectors, with V24 being the ABI-compliant choice.
// Sub-128 vectors are returned in the same way, but they're widened
// to one of these types during type legalization.
CCIfSubtarget<"hasVector()",
CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
CCAssignToReg<[V24, V26, V28, V30, V25, V27, V29, V31]>>>
]>;
//===----------------------------------------------------------------------===//
// z/Linux argument calling conventions
//===----------------------------------------------------------------------===//
def CC_SystemZ : CallingConv<[
// Promote i32 to i64 if it has an explicit extension type.
// The convention is that true integer arguments that are smaller
// than 64 bits should be marked as extended, but structures that
// are smaller than 64 bits shouldn't.
CCIfType<[i32], CCIfExtend<CCPromoteToType<i64>>>,
// A SwiftSelf is passed in callee-saved R10.
CCIfSwiftSelf<CCIfType<[i64], CCAssignToReg<[R10D]>>>,
// A SwiftError is passed in callee-saved R9.
CCIfSwiftError<CCIfType<[i64], CCAssignToReg<[R9D]>>>,
// Force long double values to the stack and pass i64 pointers to them.
CCIfType<[f128], CCPassIndirect<i64>>,
// Same for i128 values. These are already split into two i64 here,
// so we have to use a custom handler.
CCIfType<[i64], CCCustom<"CC_SystemZ_I128Indirect">>,
// The first 5 integer arguments are passed in R2-R6. Note that R6
// is call-saved.
CCIfType<[i32], CCAssignToReg<[R2L, R3L, R4L, R5L, R6L]>>,
CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D, R6D]>>,
// The first 4 float and double arguments are passed in even registers F0-F6.
CCIfType<[f32], CCAssignToReg<[F0S, F2S, F4S, F6S]>>,
CCIfType<[f64], CCAssignToReg<[F0D, F2D, F4D, F6D]>>,
// The first 8 named vector arguments are passed in V24-V31. Sub-128 vectors
// are passed in the same way, but they're widened to one of these types
// during type legalization.
CCIfSubtarget<"hasVector()",
CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
CCIfFixed<CCAssignToReg<[V24, V26, V28, V30,
V25, V27, V29, V31]>>>>,
// However, sub-128 vectors which need to go on the stack occupy just a
// single 8-byte-aligned 8-byte stack slot. Pass as i64.
CCIfSubtarget<"hasVector()",
CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
CCIfShortVector<CCBitConvertToType<i64>>>>,
// Other vector arguments are passed in 8-byte-aligned 16-byte stack slots.
CCIfSubtarget<"hasVector()",
CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
CCAssignToStack<16, 8>>>,
// Other arguments are passed in 8-byte-aligned 8-byte stack slots.
CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>
]>;
//===----------------------------------------------------------------------===//
// z/Linux callee-saved registers
//===----------------------------------------------------------------------===//
def CSR_SystemZ : CalleeSavedRegs<(add (sequence "R%dD", 6, 15),
(sequence "F%dD", 8, 15))>;
// R9 is used to return SwiftError; remove it from CSR.
def CSR_SystemZ_SwiftError : CalleeSavedRegs<(sub CSR_SystemZ, R9D)>;