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 12 class CCIfExtend<CCAction A> 13 : CCIf<"ArgFlags.isSExt() || ArgFlags.isZExt()", A>; 14 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>>>, 21 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<[R2W, R3W, R4W, R5W]>>, 27 CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D]>>, 28 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]>> 35 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? 39 ]>; 40 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>>>, 50 51 // Force long double values to the stack and pass i64 pointers to them. 52 CCIfType<[f128], CCPassIndirect<i64>>, 53 54 // The first 5 integer arguments are passed in R2-R6. Note that R6 55 // is call-saved. 56 CCIfType<[i32], CCAssignToReg<[R2W, R3W, R4W, R5W, R6W]>>, 57 CCIfType<[i64], CCAssignToReg<[R2D, R3D, R4D, R5D, R6D]>>, 58 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]>>, 62 63 // Other arguments are passed in 8-byte-aligned 8-byte stack slots. 64 CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>> 65 ]>; 66
