1//=- SystemZCallingConv.td - Calling conventions for SystemZ -*- tablegen -*-=//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9// This describes the calling conventions for the SystemZ ABI.
10//===----------------------------------------------------------------------===//
11
12class CCIfExtend<CCAction A>
13  : CCIf<"ArgFlags.isSExt() || ArgFlags.isZExt()", A>;
14
15class CCIfSubtarget<string F, CCAction A>
16  : CCIf<!strconcat("static_cast<const SystemZSubtarget&>"
17                    "(State.getMachineFunction().getSubtarget()).", F),
18         A>;
19
20// Match if this specific argument is a fixed (i.e. named) argument.
21class CCIfFixed<CCAction A>
22    : CCIf<"static_cast<SystemZCCState *>(&State)->IsFixed(ValNo)", A>;
23
24// Match if this specific argument was widened from a short vector type.
25class CCIfShortVector<CCAction A>
26    : CCIf<"static_cast<SystemZCCState *>(&State)->IsShortVector(ValNo)", A>;
27
28
29//===----------------------------------------------------------------------===//
30// z/Linux return value calling convention
31//===----------------------------------------------------------------------===//
32def RetCC_SystemZ : CallingConv<[
33  // Promote i32 to i64 if it has an explicit extension type.
34  CCIfType<[i32], CCIfExtend<CCPromoteToType<i64>>>,
35
36  // A SwiftError is returned in R9.
37  CCIfSwiftError<CCIfType<[i64], CCAssignToReg<[R9D]>>>,
38
39  // ABI-compliant code returns 64-bit integers in R2.  Make the other
40  // call-clobbered argument registers available for code that doesn't
41  // care about the ABI.  (R6 is an argument register too, but is
42  // call-saved and therefore not suitable for return values.)
43  CCIfType<[i32], CCAssignToReg<[R2L, R3L, R4L, R5L]>>,
44  CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D]>>,
45
46  // ABI-complaint code returns float and double in F0.  Make the
47  // other floating-point argument registers available for code that
48  // doesn't care about the ABI.  All floating-point argument registers
49  // are call-clobbered, so we can use all of them here.
50  CCIfType<[f32], CCAssignToReg<[F0S, F2S, F4S, F6S]>>,
51  CCIfType<[f64], CCAssignToReg<[F0D, F2D, F4D, F6D]>>,
52
53  // Similarly for vectors, with V24 being the ABI-compliant choice.
54  // Sub-128 vectors are returned in the same way, but they're widened
55  // to one of these types during type legalization.
56  CCIfSubtarget<"hasVector()",
57    CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
58             CCAssignToReg<[V24, V26, V28, V30, V25, V27, V29, V31]>>>
59]>;
60
61//===----------------------------------------------------------------------===//
62// z/Linux argument calling conventions
63//===----------------------------------------------------------------------===//
64def CC_SystemZ : CallingConv<[
65  // Promote i32 to i64 if it has an explicit extension type.
66  // The convention is that true integer arguments that are smaller
67  // than 64 bits should be marked as extended, but structures that
68  // are smaller than 64 bits shouldn't.
69  CCIfType<[i32], CCIfExtend<CCPromoteToType<i64>>>,
70
71  // A SwiftSelf is passed in callee-saved R10.
72  CCIfSwiftSelf<CCIfType<[i64], CCAssignToReg<[R10D]>>>,
73
74  // A SwiftError is passed in callee-saved R9.
75  CCIfSwiftError<CCIfType<[i64], CCAssignToReg<[R9D]>>>,
76
77  // Force long double values to the stack and pass i64 pointers to them.
78  CCIfType<[f128], CCPassIndirect<i64>>,
79  // Same for i128 values.  These are already split into two i64 here,
80  // so we have to use a custom handler.
81  CCIfType<[i64], CCCustom<"CC_SystemZ_I128Indirect">>,
82
83  // The first 5 integer arguments are passed in R2-R6.  Note that R6
84  // is call-saved.
85  CCIfType<[i32], CCAssignToReg<[R2L, R3L, R4L, R5L, R6L]>>,
86  CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D, R6D]>>,
87
88  // The first 4 float and double arguments are passed in even registers F0-F6.
89  CCIfType<[f32], CCAssignToReg<[F0S, F2S, F4S, F6S]>>,
90  CCIfType<[f64], CCAssignToReg<[F0D, F2D, F4D, F6D]>>,
91
92  // The first 8 named vector arguments are passed in V24-V31.  Sub-128 vectors
93  // are passed in the same way, but they're widened to one of these types
94  // during type legalization.
95  CCIfSubtarget<"hasVector()",
96    CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
97             CCIfFixed<CCAssignToReg<[V24, V26, V28, V30,
98                                      V25, V27, V29, V31]>>>>,
99
100  // However, sub-128 vectors which need to go on the stack occupy just a
101  // single 8-byte-aligned 8-byte stack slot.  Pass as i64.
102  CCIfSubtarget<"hasVector()",
103    CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
104             CCIfShortVector<CCBitConvertToType<i64>>>>,
105
106  // Other vector arguments are passed in 8-byte-aligned 16-byte stack slots.
107  CCIfSubtarget<"hasVector()",
108    CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
109             CCAssignToStack<16, 8>>>,
110
111  // Other arguments are passed in 8-byte-aligned 8-byte stack slots.
112  CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>
113]>;
114
115//===----------------------------------------------------------------------===//
116// z/Linux callee-saved registers
117//===----------------------------------------------------------------------===//
118def CSR_SystemZ : CalleeSavedRegs<(add (sequence "R%dD", 6, 15),
119                                       (sequence "F%dD", 8, 15))>;
120
121// R9 is used to return SwiftError; remove it from CSR.
122def CSR_SystemZ_SwiftError : CalleeSavedRegs<(sub CSR_SystemZ, R9D)>;
123