-//=- SystemZCallingConv.td - Calling Conventions for SystemZ -*- tablegen -*-=//
+//=- SystemZCallingConv.td - Calling conventions for SystemZ -*- tablegen -*-=//
//
// The LLVM Compiler Infrastructure
//
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
-// This describes the calling conventions for SystemZ architecture.
+// 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>;
+
+
//===----------------------------------------------------------------------===//
-// SystemZ Return Value Calling Convention
+// z/Linux return value calling convention
//===----------------------------------------------------------------------===//
def RetCC_SystemZ : CallingConv<[
- // Promote i8/i16/i32 arguments to i64.
- CCIfType<[i8, i16, i32], CCPromoteToType<i64>>,
+ // Promote i32 to i64 if it has an explicit extension type.
+ CCIfType<[i32], CCIfExtend<CCPromoteToType<i64>>>,
- // i64 is returned in register R2
+ // 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]>>,
- // f32 / f64 are returned in F0
+ // 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<[F0L, F2L, F4L, F6L]>>
+ 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]>>>
]>;
//===----------------------------------------------------------------------===//
-// SystemZ Argument Calling Conventions
+// z/Linux argument calling conventions
//===----------------------------------------------------------------------===//
def CC_SystemZ : CallingConv<[
- // Promote i8/i16/i32 arguments to i64.
- CCIfType<[i8, i16, i32], CCPromoteToType<i64>>,
+ // 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>>>,
+
+ // Force long double values to the stack and pass i64 pointers to them.
+ CCIfType<[f128], CCPassIndirect<i64>>,
- // The first 5 integer arguments of non-varargs functions are passed in
- // integer registers.
+ // 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 floating point arguments of non-varargs functions are passed
- // in FP registers.
+ // The first 4 float and double arguments are passed in even registers F0-F6.
CCIfType<[f32], CCAssignToReg<[F0S, F2S, F4S, F6S]>>,
- CCIfType<[f64], CCAssignToReg<[F0L, F2L, F4L, F6L]>>,
+ CCIfType<[f64], CCAssignToReg<[F0D, F2D, F4D, F6D]>>,
- // Integer values get stored in stack slots that are 8 bytes in
- // size and 8-byte aligned.
- CCIfType<[i64, f32, f64], CCAssignToStack<8, 8>>
+ // 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))>;
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