1 //=- SystemZCallingConv.td - Calling conventions for SystemZ -*- tablegen -*-=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
9 // This describes the calling conventions for the SystemZ ABI.
10 //===----------------------------------------------------------------------===//
12 class CCIfExtend<CCAction A>
13 : CCIf<"ArgFlags.isSExt() || ArgFlags.isZExt()", A>;
15 //===----------------------------------------------------------------------===//
16 // SVR4 return value calling convention
17 //===----------------------------------------------------------------------===//
18 def RetCC_SystemZ : CallingConv<[
19 // Promote i32 to i64 if it has an explicit extension type.
20 CCIfType<[i32], CCIfExtend<CCPromoteToType<i64>>>,
22 // ABI-compliant code returns 64-bit integers in R2. Make the other
23 // call-clobbered argument registers available for code that doesn't
24 // care about the ABI. (R6 is an argument register too, but is
25 // call-saved and therefore not suitable for return values.)
26 CCIfType<[i32], CCAssignToReg<[R2L, R3L, R4L, R5L]>>,
27 CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D]>>,
29 // ABI-complaint code returns float and double in F0. Make the
30 // other floating-point argument registers available for code that
31 // doesn't care about the ABI. All floating-point argument registers
32 // are call-clobbered, so we can use all of them here.
33 CCIfType<[f32], CCAssignToReg<[F0S, F2S, F4S, F6S]>>,
34 CCIfType<[f64], CCAssignToReg<[F0D, F2D, F4D, F6D]>>
36 // ABI-compliant code returns long double by reference, but that conversion
37 // is left to higher-level code. Perhaps we could add an f128 definition
38 // here for code that doesn't care about the ABI?
41 //===----------------------------------------------------------------------===//
42 // SVR4 argument calling conventions
43 //===----------------------------------------------------------------------===//
44 def CC_SystemZ : CallingConv<[
45 // Promote i32 to i64 if it has an explicit extension type.
46 // The convention is that true integer arguments that are smaller
47 // than 64 bits should be marked as extended, but structures that
48 // are smaller than 64 bits shouldn't.
49 CCIfType<[i32], CCIfExtend<CCPromoteToType<i64>>>,
51 // Force long double values to the stack and pass i64 pointers to them.
52 CCIfType<[f128], CCPassIndirect<i64>>,
54 // The first 5 integer arguments are passed in R2-R6. Note that R6
56 CCIfType<[i32], CCAssignToReg<[R2L, R3L, R4L, R5L, R6L]>>,
57 CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D, R6D]>>,
59 // The first 4 float and double arguments are passed in even registers F0-F6.
60 CCIfType<[f32], CCAssignToReg<[F0S, F2S, F4S, F6S]>>,
61 CCIfType<[f64], CCAssignToReg<[F0D, F2D, F4D, F6D]>>,
63 // Other arguments are passed in 8-byte-aligned 8-byte stack slots.
64 CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>