1 //===- X86CallingConv.td - Calling Conventions X86 32/64 ---*- tablegen -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Chris Lattner and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This describes the calling conventions for the X86-32 and X86-64
13 //===----------------------------------------------------------------------===//
15 /// CCIfSubtarget - Match if the current subtarget has a feature F.
16 class CCIfSubtarget<string F, CCAction A>
17 : CCIf<!strconcat("State.getTarget().getSubtarget<X86Subtarget>().", F), A>;
19 //===----------------------------------------------------------------------===//
20 // Return Value Calling Conventions
21 //===----------------------------------------------------------------------===//
23 // Return-value conventions common to all X86 CC's.
24 def RetCC_X86Common : CallingConv<[
25 // Scalar values are returned in AX first, then DX.
26 CCIfType<[i8] , CCAssignToReg<[AL]>>,
27 CCIfType<[i16], CCAssignToReg<[AX]>>,
28 CCIfType<[i32], CCAssignToReg<[EAX, EDX]>>,
29 CCIfType<[i64], CCAssignToReg<[RAX, RDX]>>,
31 // Vector types are returned in XMM0 and XMM1, when they fit. If the target
32 // doesn't have XMM registers, it won't have vector types.
33 CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
34 CCAssignToReg<[XMM0,XMM1]>>,
36 // MMX vector types are always returned in MM0. If the target doesn't have
37 // MM0, it doesn't support these vector types.
38 CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToReg<[MM0]>>,
40 // Long double types are always returned in ST0 (even with SSE).
41 CCIfType<[f80], CCAssignToReg<[ST0]>>
44 // X86-32 C return-value convention.
45 def RetCC_X86_32_C : CallingConv<[
46 // The X86-32 calling convention returns FP values in ST0, otherwise it is the
47 // same as the common X86 calling conv.
48 CCIfType<[f32], CCAssignToReg<[ST0]>>,
49 CCIfType<[f64], CCAssignToReg<[ST0]>>,
50 CCDelegateTo<RetCC_X86Common>
53 // X86-32 FastCC return-value convention.
54 def RetCC_X86_32_Fast : CallingConv<[
55 // The X86-32 fastcc returns FP values in XMM0 if the target has SSE2,
56 // otherwise it is the the C calling conventions.
57 CCIfType<[f32], CCIfSubtarget<"hasSSE2()", CCAssignToReg<[XMM0]>>>,
58 CCIfType<[f64], CCIfSubtarget<"hasSSE2()", CCAssignToReg<[XMM0]>>>,
59 CCDelegateTo<RetCC_X86Common>
62 // X86-64 C return-value convention.
63 def RetCC_X86_64_C : CallingConv<[
64 // The X86-64 calling convention always returns FP values in XMM0.
65 CCIfType<[f32], CCAssignToReg<[XMM0]>>,
66 CCIfType<[f64], CCAssignToReg<[XMM0]>>,
67 CCDelegateTo<RetCC_X86Common>
72 // This is the root return-value convention for the X86-32 backend.
73 def RetCC_X86_32 : CallingConv<[
74 // If FastCC, use RetCC_X86_32_Fast.
75 CCIfCC<"CallingConv::Fast", CCDelegateTo<RetCC_X86_32_Fast>>,
76 // Otherwise, use RetCC_X86_32_C.
77 CCDelegateTo<RetCC_X86_32_C>
80 // This is the root return-value convention for the X86-64 backend.
81 def RetCC_X86_64 : CallingConv<[
82 // Always just the same as C calling conv for X86-64.
83 CCDelegateTo<RetCC_X86_64_C>
86 // This is the return-value convention used for the entire X86 backend.
87 def RetCC_X86 : CallingConv<[
88 CCIfSubtarget<"is64Bit()", CCDelegateTo<RetCC_X86_64>>,
89 CCDelegateTo<RetCC_X86_32>
92 //===----------------------------------------------------------------------===//
93 // X86-64 Argument Calling Conventions
94 //===----------------------------------------------------------------------===//
96 def CC_X86_64_C : CallingConv<[
97 // Promote i8/i16 arguments to i32.
98 CCIfType<[i8, i16], CCPromoteToType<i32>>,
100 CCIfStruct<CCStructAssign<[RDI, RSI, RDX, RCX, R8, R9 ]>>,
102 // The first 6 integer arguments are passed in integer registers.
103 CCIfType<[i32], CCAssignToReg<[EDI, ESI, EDX, ECX, R8D, R9D]>>,
104 CCIfType<[i64], CCAssignToReg<[RDI, RSI, RDX, RCX, R8 , R9 ]>>,
106 // The first 8 FP/Vector arguments are passed in XMM registers.
107 CCIfType<[f32, f64, v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
108 CCAssignToReg<[XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7]>>,
110 // The first 8 MMX vector arguments are passed in GPRs.
111 CCIfType<[v8i8, v4i16, v2i32, v1i64],
112 CCAssignToReg<[RDI, RSI, RDX, RCX, R8 , R9 ]>>,
114 // The 'nest' parameter, if any, is passed in R10.
115 CCIfNest<CCAssignToReg<[R10]>>,
117 // Integer/FP values get stored in stack slots that are 8 bytes in size and
118 // 8-byte aligned if there are no more registers to hold them.
119 CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>,
121 // Long doubles get stack slots whose size and alignment depends on the
123 CCIfType<[f80], CCAssignToStack<0, 0>>,
125 // Vectors get 16-byte stack slots that are 16-byte aligned.
126 CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCAssignToStack<16, 16>>,
128 // __m64 vectors get 8-byte stack slots that are 8-byte aligned.
129 CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToStack<8, 8>>
132 // Tail call convention (fast): One register is reserved for target address,
134 def CC_X86_64_TailCall : CallingConv<[
135 // Promote i8/i16 arguments to i32.
136 CCIfType<[i8, i16], CCPromoteToType<i32>>,
138 CCIfStruct<CCStructAssign<[RDI, RSI, RDX, RCX, R8]>>,
140 // The first 6 integer arguments are passed in integer registers.
141 CCIfType<[i32], CCAssignToReg<[EDI, ESI, EDX, ECX, R8D]>>,
142 CCIfType<[i64], CCAssignToReg<[RDI, RSI, RDX, RCX, R8]>>,
144 // The first 8 FP/Vector arguments are passed in XMM registers.
145 CCIfType<[f32, f64, v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
146 CCAssignToReg<[XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7]>>,
148 // The first 8 MMX vector arguments are passed in GPRs.
149 CCIfType<[v8i8, v4i16, v2i32, v1i64],
150 CCAssignToReg<[RDI, RSI, RDX, RCX, R8]>>,
152 // The 'nest' parameter, if any, is passed in R10.
153 CCIfNest<CCAssignToReg<[R10]>>,
155 // Integer/FP values get stored in stack slots that are 8 bytes in size and
156 // 8-byte aligned if there are no more registers to hold them.
157 CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>,
159 // Vectors get 16-byte stack slots that are 16-byte aligned.
160 CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCAssignToStack<16, 16>>,
162 // __m64 vectors get 8-byte stack slots that are 8-byte aligned.
163 CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToStack<8, 8>>
167 //===----------------------------------------------------------------------===//
168 // X86 C Calling Convention
169 //===----------------------------------------------------------------------===//
171 /// CC_X86_32_Common - In all X86-32 calling conventions, extra integers and FP
172 /// values are spilled on the stack, and the first 4 vector values go in XMM
174 def CC_X86_32_Common : CallingConv<[
175 // Integer/Float values get stored in stack slots that are 4 bytes in
176 // size and 4-byte aligned.
177 CCIfType<[i32, f32], CCAssignToStack<4, 4>>,
179 // Doubles get 8-byte slots that are 4-byte aligned.
180 CCIfType<[f64], CCAssignToStack<8, 4>>,
182 // Long doubles get slots whose size and alignment depends on the
184 CCIfType<[f80], CCAssignToStack<0, 0>>,
186 // The first 4 vector arguments are passed in XMM registers.
187 CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
188 CCAssignToReg<[XMM0, XMM1, XMM2, XMM3]>>,
190 // Other vectors get 16-byte stack slots that are 16-byte aligned.
191 CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCAssignToStack<16, 16>>,
193 // __m64 vectors get 8-byte stack slots that are 8-byte aligned. They are
194 // passed in the parameter area.
195 CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToStack<8, 8>>
198 def CC_X86_32_C : CallingConv<[
199 // Promote i8/i16 arguments to i32.
200 CCIfType<[i8, i16], CCPromoteToType<i32>>,
202 // The 'nest' parameter, if any, is passed in ECX.
203 CCIfNest<CCAssignToReg<[ECX]>>,
205 // The first 3 integer arguments, if marked 'inreg' and if the call is not
206 // a vararg call, are passed in integer registers.
207 CCIfNotVarArg<CCIfInReg<CCIfType<[i32], CCAssignToReg<[EAX, EDX, ECX]>>>>,
209 // Otherwise, same as everything else.
210 CCDelegateTo<CC_X86_32_Common>
213 /// Same as C calling convention except for non-free ECX which is used for storing
214 /// a potential pointer to the tail called function.
215 def CC_X86_32_TailCall : CallingConv<[
216 // Promote i8/i16 arguments to i32.
217 CCIfType<[i8, i16], CCPromoteToType<i32>>,
219 // Nested function trampolines are currently not supported by fastcc.
221 // The first 3 integer arguments, if marked 'inreg' and if the call is not
222 // a vararg call, are passed in integer registers.
223 CCIfNotVarArg<CCIfInReg<CCIfType<[i32], CCAssignToReg<[EAX, EDX]>>>>,
225 // Otherwise, same as everything else.
226 CCDelegateTo<CC_X86_32_Common>
229 def CC_X86_32_FastCall : CallingConv<[
230 // Promote i8/i16 arguments to i32.
231 CCIfType<[i8, i16], CCPromoteToType<i32>>,
233 // The 'nest' parameter, if any, is passed in EAX.
234 CCIfNest<CCAssignToReg<[EAX]>>,
236 // The first 2 integer arguments are passed in ECX/EDX
237 CCIfType<[i32], CCAssignToReg<[ECX, EDX]>>,
239 // Otherwise, same as everything else.
240 CCDelegateTo<CC_X86_32_Common>