lib/Target/X86/X86CallingConv.td - platform/external/llvm - Gitiles

 //===- X86CallingConv.td - Calling Conventions X86 32/64 ---*- tablegen -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This describes the calling conventions for the X86-32 and X86-64
 // architectures.
 //
 //===----------------------------------------------------------------------===//

 /// CCIfSubtarget - Match if the current subtarget has a feature F.
 class CCIfSubtarget<string F, CCAction A>
  : CCIf<!strconcat("State.getTarget().getSubtarget<X86Subtarget>().", F), A>;

 //===----------------------------------------------------------------------===//
 // Return Value Calling Conventions
 //===----------------------------------------------------------------------===//

 // Return-value conventions common to all X86 CC's.
 def RetCC_X86Common : CallingConv<[
   // Scalar values are returned in AX first, then DX.  For i8, the ABI
   // requires the values to be in AL and AH, however this code uses AL and DL
   // instead. This is because using AH for the second register conflicts with
   // the way LLVM does multiple return values -- a return of {i16,i8} would end
   // up in AX and AH, which overlap. Front-ends wishing to conform to the ABI
   // for functions that return two i8 values are currently expected to pack the
   // values into an i16 (which uses AX, and thus AL:AH).
   CCIfType<[i8] , CCAssignToReg<[AL, DL]>>,
   CCIfType<[i16], CCAssignToReg<[AX, DX]>>,
   CCIfType<[i32], CCAssignToReg<[EAX, EDX]>>,
   CCIfType<[i64], CCAssignToReg<[RAX, RDX]>>,

   // Vector types are returned in XMM0 and XMM1, when they fit.  XMMM2 and XMM3
   // can only be used by ABI non-compliant code. If the target doesn't have XMM
   // registers, it won't have vector types.
   CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
             CCAssignToReg<[XMM0,XMM1,XMM2,XMM3]>>,

   // MMX vector types are always returned in MM0. If the target doesn't have
   // MM0, it doesn't support these vector types.
   CCIfType<[v8i8, v4i16, v2i32, v1i64, v2f32], CCAssignToReg<[MM0]>>,

   // Long double types are always returned in ST0 (even with SSE).
   CCIfType<[f80], CCAssignToReg<[ST0, ST1]>>
 ]>;

 // X86-32 C return-value convention.
 def RetCC_X86_32_C : CallingConv<[
   // The X86-32 calling convention returns FP values in ST0, unless marked
   // with "inreg" (used here to distinguish one kind of reg from another,
   // weirdly; this is really the sse-regparm calling convention) in which
   // case they use XMM0, otherwise it is the same as the common X86 calling
   // conv.
   CCIfInReg<CCIfSubtarget<"hasSSE2()",
     CCIfType<[f32, f64], CCAssignToReg<[XMM0,XMM1,XMM2]>>>>,
   CCIfType<[f32,f64], CCAssignToReg<[ST0, ST1]>>,
   CCDelegateTo<RetCC_X86Common>
 ]>;

 // X86-32 FastCC return-value convention.
 def RetCC_X86_32_Fast : CallingConv<[
   // The X86-32 fastcc returns 1, 2, or 3 FP values in XMM0-2 if the target has
   // SSE2.
   // This can happen when a float, 2 x float, or 3 x float vector is split by
   // target lowering, and is returned in 1-3 sse regs.
   CCIfType<[f32], CCIfSubtarget<"hasSSE2()", CCAssignToReg<[XMM0,XMM1,XMM2]>>>,
   CCIfType<[f64], CCIfSubtarget<"hasSSE2()", CCAssignToReg<[XMM0,XMM1,XMM2]>>>,

   // For integers, ECX can be used as an extra return register
   CCIfType<[i8],  CCAssignToReg<[AL, DL, CL]>>,
   CCIfType<[i16], CCAssignToReg<[AX, DX, CX]>>,
   CCIfType<[i32], CCAssignToReg<[EAX, EDX, ECX]>>,

   // Otherwise, it is the same as the common X86 calling convention.
   CCDelegateTo<RetCC_X86Common>
 ]>;

 // X86-64 C return-value convention.
 def RetCC_X86_64_C : CallingConv<[
   // The X86-64 calling convention always returns FP values in XMM0.
   CCIfType<[f32], CCAssignToReg<[XMM0, XMM1]>>,
   CCIfType<[f64], CCAssignToReg<[XMM0, XMM1]>>,

   // MMX vector types are always returned in XMM0 except for v1i64 which is
   // returned in RAX. This disagrees with ABI documentation but is bug
   // compatible with gcc.
   CCIfType<[v1i64], CCAssignToReg<[RAX]>>,
   CCIfType<[v8i8, v4i16, v2i32, v2f32], CCAssignToReg<[XMM0, XMM1]>>,
   CCDelegateTo<RetCC_X86Common>
 ]>;

 // X86-Win64 C return-value convention.
 def RetCC_X86_Win64_C : CallingConv<[
   // The X86-Win64 calling convention always returns __m64 values in RAX.
   CCIfType<[v8i8, v4i16, v2i32, v1i64], CCBitConvertToType<i64>>,

   // And FP in XMM0 only.
   CCIfType<[f32], CCAssignToReg<[XMM0]>>,
   CCIfType<[f64], CCAssignToReg<[XMM0]>>,

   // Otherwise, everything is the same as 'normal' X86-64 C CC.
   CCDelegateTo<RetCC_X86_64_C>
 ]>;


 // This is the root return-value convention for the X86-32 backend.
 def RetCC_X86_32 : CallingConv<[
   // If FastCC, use RetCC_X86_32_Fast.
   CCIfCC<"CallingConv::Fast", CCDelegateTo<RetCC_X86_32_Fast>>,
   // Otherwise, use RetCC_X86_32_C.
   CCDelegateTo<RetCC_X86_32_C>
 ]>;

 // This is the root return-value convention for the X86-64 backend.
 def RetCC_X86_64 : CallingConv<[
   // Mingw64 and native Win64 use Win64 CC
   CCIfSubtarget<"isTargetWin64()", CCDelegateTo<RetCC_X86_Win64_C>>,

   // Otherwise, drop to normal X86-64 CC
   CCDelegateTo<RetCC_X86_64_C>
 ]>;

 // This is the return-value convention used for the entire X86 backend.
 def RetCC_X86 : CallingConv<[
   CCIfSubtarget<"is64Bit()", CCDelegateTo<RetCC_X86_64>>,
   CCDelegateTo<RetCC_X86_32>
 ]>;

 //===----------------------------------------------------------------------===//
 // X86-64 Argument Calling Conventions
 //===----------------------------------------------------------------------===//

 def CC_X86_64_C : CallingConv<[
   // Handles byval parameters.
   CCIfByVal<CCPassByVal<8, 8>>,

   // Promote i8/i16 arguments to i32.
   CCIfType<[i8, i16], CCPromoteToType<i32>>,

   // The 'nest' parameter, if any, is passed in R10.
   CCIfNest<CCAssignToReg<[R10]>>,

   // The first 6 v1i64 vector arguments are passed in GPRs on Darwin.
   CCIfType<[v1i64],
             CCIfSubtarget<"isTargetDarwin()",
             CCBitConvertToType<i64>>>,

   // The first 6 integer arguments are passed in integer registers.
   CCIfType<[i32], CCAssignToReg<[EDI, ESI, EDX, ECX, R8D, R9D]>>,
   CCIfType<[i64], CCAssignToReg<[RDI, RSI, RDX, RCX, R8 , R9 ]>>,

   // The first 8 MMX (except for v1i64) vector arguments are passed in XMM
   // registers on Darwin.
   CCIfType<[v8i8, v4i16, v2i32, v2f32],
             CCIfSubtarget<"isTargetDarwin()",
             CCIfSubtarget<"hasSSE2()",
             CCPromoteToType<v2i64>>>>,

   // The first 8 FP/Vector arguments are passed in XMM registers.
   CCIfType<[f32, f64, v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
             CCIfSubtarget<"hasSSE1()",
             CCAssignToReg<[XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7]>>>,

   // Integer/FP values get stored in stack slots that are 8 bytes in size and
   // 8-byte aligned if there are no more registers to hold them.
   CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>,

   // Long doubles get stack slots whose size and alignment depends on the
   // subtarget.
   CCIfType<[f80], CCAssignToStack<0, 0>>,

   // Vectors get 16-byte stack slots that are 16-byte aligned.
   CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCAssignToStack<16, 16>>,

   // __m64 vectors get 8-byte stack slots that are 8-byte aligned.
   CCIfType<[v8i8, v4i16, v2i32, v1i64, v2f32], CCAssignToStack<8, 8>>
 ]>;

 // Calling convention used on Win64
 def CC_X86_Win64_C : CallingConv<[
   // FIXME: Handle byval stuff.
   // FIXME: Handle varargs.

   // Promote i8/i16 arguments to i32.
   CCIfType<[i8, i16], CCPromoteToType<i32>>,

   // The 'nest' parameter, if any, is passed in R10.
   CCIfNest<CCAssignToReg<[R10]>>,

   // 128 bit vectors are passed by pointer
   CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCPassIndirect<i64>>,

   // The first 4 MMX vector arguments are passed in GPRs.
   CCIfType<[v8i8, v4i16, v2i32, v1i64, v2f32],
            CCBitConvertToType<i64>>,

   // The first 4 integer arguments are passed in integer registers.
   CCIfType<[i32], CCAssignToRegWithShadow<[ECX , EDX , R8D , R9D ],
                                           [XMM0, XMM1, XMM2, XMM3]>>,
   CCIfType<[i64], CCAssignToRegWithShadow<[RCX , RDX , R8  , R9  ],
                                           [XMM0, XMM1, XMM2, XMM3]>>,

   // The first 4 FP/Vector arguments are passed in XMM registers.
   CCIfType<[f32, f64, v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
            CCAssignToRegWithShadow<[XMM0, XMM1, XMM2, XMM3],
                                    [RCX , RDX , R8  , R9  ]>>,

   // Integer/FP values get stored in stack slots that are 8 bytes in size and
   // 8-byte aligned if there are no more registers to hold them.
   CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>,

   // Long doubles get stack slots whose size and alignment depends on the
   // subtarget.
   CCIfType<[f80], CCAssignToStack<0, 0>>,

   // __m64 vectors get 8-byte stack slots that are 8-byte aligned.
   CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToStack<8, 8>>
 ]>;

 //===----------------------------------------------------------------------===//
 // X86 C Calling Convention
 //===----------------------------------------------------------------------===//

 /// CC_X86_32_Common - In all X86-32 calling conventions, extra integers and FP
 /// values are spilled on the stack, and the first 4 vector values go in XMM
 /// regs.
 def CC_X86_32_Common : CallingConv<[
   // Handles byval parameters.
   CCIfByVal<CCPassByVal<4, 4>>,

   // The first 3 float or double arguments, if marked 'inreg' and if the call
   // is not a vararg call and if SSE2 is available, are passed in SSE registers.
   CCIfNotVarArg<CCIfInReg<CCIfType<[f32,f64],
                 CCIfSubtarget<"hasSSE2()",
                 CCAssignToReg<[XMM0,XMM1,XMM2]>>>>>,

   // The first 3 __m64 (except for v1i64) vector arguments are passed in mmx
   // registers if the call is not a vararg call.
   CCIfNotVarArg<CCIfType<[v8i8, v4i16, v2i32, v2f32],
                 CCAssignToReg<[MM0, MM1, MM2]>>>,

   // Integer/Float values get stored in stack slots that are 4 bytes in
   // size and 4-byte aligned.
   CCIfType<[i32, f32], CCAssignToStack<4, 4>>,

   // Doubles get 8-byte slots that are 4-byte aligned.
   CCIfType<[f64], CCAssignToStack<8, 4>>,

   // Long doubles get slots whose size depends on the subtarget.
   CCIfType<[f80], CCAssignToStack<0, 4>>,

   // The first 4 SSE vector arguments are passed in XMM registers.
   CCIfNotVarArg<CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
                 CCAssignToReg<[XMM0, XMM1, XMM2, XMM3]>>>,

   // Other SSE vectors get 16-byte stack slots that are 16-byte aligned.
   CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCAssignToStack<16, 16>>,

   // __m64 vectors get 8-byte stack slots that are 4-byte aligned. They are
   // passed in the parameter area.
   CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToStack<8, 4>>]>;

 def CC_X86_32_C : CallingConv<[
   // Promote i8/i16 arguments to i32.
   CCIfType<[i8, i16], CCPromoteToType<i32>>,

   // The 'nest' parameter, if any, is passed in ECX.
   CCIfNest<CCAssignToReg<[ECX]>>,

   // The first 3 integer arguments, if marked 'inreg' and if the call is not
   // a vararg call, are passed in integer registers.
   CCIfNotVarArg<CCIfInReg<CCIfType<[i32], CCAssignToReg<[EAX, EDX, ECX]>>>>,

   // Otherwise, same as everything else.
   CCDelegateTo<CC_X86_32_Common>
 ]>;

 def CC_X86_32_FastCall : CallingConv<[
   // Promote i8/i16 arguments to i32.
   CCIfType<[i8, i16], CCPromoteToType<i32>>,

   // The 'nest' parameter, if any, is passed in EAX.
   CCIfNest<CCAssignToReg<[EAX]>>,

   // The first 2 integer arguments are passed in ECX/EDX
   CCIfType<[i32], CCAssignToReg<[ECX, EDX]>>,

   // Otherwise, same as everything else.
   CCDelegateTo<CC_X86_32_Common>
 ]>;

 def CC_X86_32_FastCC : CallingConv<[
   // Handles byval parameters.  Note that we can't rely on the delegation
   // to CC_X86_32_Common for this because that happens after code that
   // puts arguments in registers.
   CCIfByVal<CCPassByVal<4, 4>>,

   // Promote i8/i16 arguments to i32.
   CCIfType<[i8, i16], CCPromoteToType<i32>>,

   // The 'nest' parameter, if any, is passed in EAX.
   CCIfNest<CCAssignToReg<[EAX]>>,

   // The first 2 integer arguments are passed in ECX/EDX
   CCIfType<[i32], CCAssignToReg<[ECX, EDX]>>,

   // The first 3 float or double arguments, if the call is not a vararg
   // call and if SSE2 is available, are passed in SSE registers.
   CCIfNotVarArg<CCIfType<[f32,f64],
                 CCIfSubtarget<"hasSSE2()",
                 CCAssignToReg<[XMM0,XMM1,XMM2]>>>>,

   // Doubles get 8-byte slots that are 8-byte aligned.
   CCIfType<[f64], CCAssignToStack<8, 8>>,

   // Otherwise, same as everything else.
   CCDelegateTo<CC_X86_32_Common>
 ]>;
	//===- X86CallingConv.td - Calling Conventions X86 32/64 ---- tablegen --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This describes the calling conventions for the X86-32 and X86-64
	// architectures.
	//
	//===----------------------------------------------------------------------===//

	/// CCIfSubtarget - Match if the current subtarget has a feature F.
	class CCIfSubtarget<string F, CCAction A>
	: CCIf<!strconcat("State.getTarget().getSubtarget<X86Subtarget>().", F), A>;

	//===----------------------------------------------------------------------===//
	// Return Value Calling Conventions
	//===----------------------------------------------------------------------===//

	// Return-value conventions common to all X86 CC's.
	def RetCC_X86Common : CallingConv<[
	// Scalar values are returned in AX first, then DX. For i8, the ABI
	// requires the values to be in AL and AH, however this code uses AL and DL
	// instead. This is because using AH for the second register conflicts with
	// the way LLVM does multiple return values -- a return of {i16,i8} would end
	// up in AX and AH, which overlap. Front-ends wishing to conform to the ABI
	// for functions that return two i8 values are currently expected to pack the
	// values into an i16 (which uses AX, and thus AL:AH).
	CCIfType<[i8] , CCAssignToReg<[AL, DL]>>,
	CCIfType<[i16], CCAssignToReg<[AX, DX]>>,
	CCIfType<[i32], CCAssignToReg<[EAX, EDX]>>,
	CCIfType<[i64], CCAssignToReg<[RAX, RDX]>>,

	// Vector types are returned in XMM0 and XMM1, when they fit. XMMM2 and XMM3
	// can only be used by ABI non-compliant code. If the target doesn't have XMM
	// registers, it won't have vector types.
	CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
	CCAssignToReg<[XMM0,XMM1,XMM2,XMM3]>>,

	// MMX vector types are always returned in MM0. If the target doesn't have
	// MM0, it doesn't support these vector types.
	CCIfType<[v8i8, v4i16, v2i32, v1i64, v2f32], CCAssignToReg<[MM0]>>,

	// Long double types are always returned in ST0 (even with SSE).
	CCIfType<[f80], CCAssignToReg<[ST0, ST1]>>
	]>;

	// X86-32 C return-value convention.
	def RetCC_X86_32_C : CallingConv<[
	// The X86-32 calling convention returns FP values in ST0, unless marked
	// with "inreg" (used here to distinguish one kind of reg from another,
	// weirdly; this is really the sse-regparm calling convention) in which
	// case they use XMM0, otherwise it is the same as the common X86 calling
	// conv.
	CCIfInReg<CCIfSubtarget<"hasSSE2()",
	CCIfType<[f32, f64], CCAssignToReg<[XMM0,XMM1,XMM2]>>>>,
	CCIfType<[f32,f64], CCAssignToReg<[ST0, ST1]>>,
	CCDelegateTo<RetCC_X86Common>
	]>;

	// X86-32 FastCC return-value convention.
	def RetCC_X86_32_Fast : CallingConv<[
	// The X86-32 fastcc returns 1, 2, or 3 FP values in XMM0-2 if the target has
	// SSE2.
	// This can happen when a float, 2 x float, or 3 x float vector is split by
	// target lowering, and is returned in 1-3 sse regs.
	CCIfType<[f32], CCIfSubtarget<"hasSSE2()", CCAssignToReg<[XMM0,XMM1,XMM2]>>>,
	CCIfType<[f64], CCIfSubtarget<"hasSSE2()", CCAssignToReg<[XMM0,XMM1,XMM2]>>>,

	// For integers, ECX can be used as an extra return register
	CCIfType<[i8], CCAssignToReg<[AL, DL, CL]>>,
	CCIfType<[i16], CCAssignToReg<[AX, DX, CX]>>,
	CCIfType<[i32], CCAssignToReg<[EAX, EDX, ECX]>>,

	// Otherwise, it is the same as the common X86 calling convention.
	CCDelegateTo<RetCC_X86Common>
	]>;

	// X86-64 C return-value convention.
	def RetCC_X86_64_C : CallingConv<[
	// The X86-64 calling convention always returns FP values in XMM0.
	CCIfType<[f32], CCAssignToReg<[XMM0, XMM1]>>,
	CCIfType<[f64], CCAssignToReg<[XMM0, XMM1]>>,

	// MMX vector types are always returned in XMM0 except for v1i64 which is
	// returned in RAX. This disagrees with ABI documentation but is bug
	// compatible with gcc.
	CCIfType<[v1i64], CCAssignToReg<[RAX]>>,
	CCIfType<[v8i8, v4i16, v2i32, v2f32], CCAssignToReg<[XMM0, XMM1]>>,
	CCDelegateTo<RetCC_X86Common>
	]>;

	// X86-Win64 C return-value convention.
	def RetCC_X86_Win64_C : CallingConv<[
	// The X86-Win64 calling convention always returns __m64 values in RAX.
	CCIfType<[v8i8, v4i16, v2i32, v1i64], CCBitConvertToType<i64>>,

	// And FP in XMM0 only.
	CCIfType<[f32], CCAssignToReg<[XMM0]>>,
	CCIfType<[f64], CCAssignToReg<[XMM0]>>,

	// Otherwise, everything is the same as 'normal' X86-64 C CC.
	CCDelegateTo<RetCC_X86_64_C>
	]>;


	// This is the root return-value convention for the X86-32 backend.
	def RetCC_X86_32 : CallingConv<[
	// If FastCC, use RetCC_X86_32_Fast.
	CCIfCC<"CallingConv::Fast", CCDelegateTo<RetCC_X86_32_Fast>>,
	// Otherwise, use RetCC_X86_32_C.
	CCDelegateTo<RetCC_X86_32_C>
	]>;

	// This is the root return-value convention for the X86-64 backend.
	def RetCC_X86_64 : CallingConv<[
	// Mingw64 and native Win64 use Win64 CC
	CCIfSubtarget<"isTargetWin64()", CCDelegateTo<RetCC_X86_Win64_C>>,

	// Otherwise, drop to normal X86-64 CC
	CCDelegateTo<RetCC_X86_64_C>
	]>;

	// This is the return-value convention used for the entire X86 backend.
	def RetCC_X86 : CallingConv<[
	CCIfSubtarget<"is64Bit()", CCDelegateTo<RetCC_X86_64>>,
	CCDelegateTo<RetCC_X86_32>
	]>;

	//===----------------------------------------------------------------------===//
	// X86-64 Argument Calling Conventions
	//===----------------------------------------------------------------------===//

	def CC_X86_64_C : CallingConv<[
	// Handles byval parameters.
	CCIfByVal<CCPassByVal<8, 8>>,

	// Promote i8/i16 arguments to i32.
	CCIfType<[i8, i16], CCPromoteToType<i32>>,

	// The 'nest' parameter, if any, is passed in R10.
	CCIfNest<CCAssignToReg<[R10]>>,

	// The first 6 v1i64 vector arguments are passed in GPRs on Darwin.
	CCIfType<[v1i64],
	CCIfSubtarget<"isTargetDarwin()",
	CCBitConvertToType<i64>>>,

	// The first 6 integer arguments are passed in integer registers.
	CCIfType<[i32], CCAssignToReg<[EDI, ESI, EDX, ECX, R8D, R9D]>>,
	CCIfType<[i64], CCAssignToReg<[RDI, RSI, RDX, RCX, R8 , R9 ]>>,

	// The first 8 MMX (except for v1i64) vector arguments are passed in XMM
	// registers on Darwin.
	CCIfType<[v8i8, v4i16, v2i32, v2f32],
	CCIfSubtarget<"isTargetDarwin()",
	CCIfSubtarget<"hasSSE2()",
	CCPromoteToType<v2i64>>>>,

	// The first 8 FP/Vector arguments are passed in XMM registers.
	CCIfType<[f32, f64, v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
	CCIfSubtarget<"hasSSE1()",
	CCAssignToReg<[XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7]>>>,

	// Integer/FP values get stored in stack slots that are 8 bytes in size and
	// 8-byte aligned if there are no more registers to hold them.
	CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>,

	// Long doubles get stack slots whose size and alignment depends on the
	// subtarget.
	CCIfType<[f80], CCAssignToStack<0, 0>>,

	// Vectors get 16-byte stack slots that are 16-byte aligned.
	CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCAssignToStack<16, 16>>,

	// __m64 vectors get 8-byte stack slots that are 8-byte aligned.
	CCIfType<[v8i8, v4i16, v2i32, v1i64, v2f32], CCAssignToStack<8, 8>>
	]>;

	// Calling convention used on Win64
	def CC_X86_Win64_C : CallingConv<[
	// FIXME: Handle byval stuff.
	// FIXME: Handle varargs.

	// Promote i8/i16 arguments to i32.
	CCIfType<[i8, i16], CCPromoteToType<i32>>,

	// The 'nest' parameter, if any, is passed in R10.
	CCIfNest<CCAssignToReg<[R10]>>,

	// 128 bit vectors are passed by pointer
	CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCPassIndirect<i64>>,

	// The first 4 MMX vector arguments are passed in GPRs.
	CCIfType<[v8i8, v4i16, v2i32, v1i64, v2f32],
	CCBitConvertToType<i64>>,

	// The first 4 integer arguments are passed in integer registers.
	CCIfType<[i32], CCAssignToRegWithShadow<[ECX , EDX , R8D , R9D ],
	[XMM0, XMM1, XMM2, XMM3]>>,
	CCIfType<[i64], CCAssignToRegWithShadow<[RCX , RDX , R8 , R9 ],
	[XMM0, XMM1, XMM2, XMM3]>>,

	// The first 4 FP/Vector arguments are passed in XMM registers.
	CCIfType<[f32, f64, v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
	CCAssignToRegWithShadow<[XMM0, XMM1, XMM2, XMM3],
	[RCX , RDX , R8 , R9 ]>>,

	// Integer/FP values get stored in stack slots that are 8 bytes in size and
	// 8-byte aligned if there are no more registers to hold them.
	CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>,

	// Long doubles get stack slots whose size and alignment depends on the
	// subtarget.
	CCIfType<[f80], CCAssignToStack<0, 0>>,

	// __m64 vectors get 8-byte stack slots that are 8-byte aligned.
	CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToStack<8, 8>>
	]>;

	//===----------------------------------------------------------------------===//
	// X86 C Calling Convention
	//===----------------------------------------------------------------------===//

	/// CC_X86_32_Common - In all X86-32 calling conventions, extra integers and FP
	/// values are spilled on the stack, and the first 4 vector values go in XMM
	/// regs.
	def CC_X86_32_Common : CallingConv<[
	// Handles byval parameters.
	CCIfByVal<CCPassByVal<4, 4>>,

	// The first 3 float or double arguments, if marked 'inreg' and if the call
	// is not a vararg call and if SSE2 is available, are passed in SSE registers.
	CCIfNotVarArg<CCIfInReg<CCIfType<[f32,f64],
	CCIfSubtarget<"hasSSE2()",
	CCAssignToReg<[XMM0,XMM1,XMM2]>>>>>,

	// The first 3 __m64 (except for v1i64) vector arguments are passed in mmx
	// registers if the call is not a vararg call.
	CCIfNotVarArg<CCIfType<[v8i8, v4i16, v2i32, v2f32],
	CCAssignToReg<[MM0, MM1, MM2]>>>,

	// Integer/Float values get stored in stack slots that are 4 bytes in
	// size and 4-byte aligned.
	CCIfType<[i32, f32], CCAssignToStack<4, 4>>,

	// Doubles get 8-byte slots that are 4-byte aligned.
	CCIfType<[f64], CCAssignToStack<8, 4>>,

	// Long doubles get slots whose size depends on the subtarget.
	CCIfType<[f80], CCAssignToStack<0, 4>>,

	// The first 4 SSE vector arguments are passed in XMM registers.
	CCIfNotVarArg<CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],
	CCAssignToReg<[XMM0, XMM1, XMM2, XMM3]>>>,

	// Other SSE vectors get 16-byte stack slots that are 16-byte aligned.
	CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCAssignToStack<16, 16>>,

	// __m64 vectors get 8-byte stack slots that are 4-byte aligned. They are
	// passed in the parameter area.
	CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToStack<8, 4>>]>;

	def CC_X86_32_C : CallingConv<[
	// Promote i8/i16 arguments to i32.
	CCIfType<[i8, i16], CCPromoteToType<i32>>,

	// The 'nest' parameter, if any, is passed in ECX.
	CCIfNest<CCAssignToReg<[ECX]>>,

	// The first 3 integer arguments, if marked 'inreg' and if the call is not
	// a vararg call, are passed in integer registers.
	CCIfNotVarArg<CCIfInReg<CCIfType<[i32], CCAssignToReg<[EAX, EDX, ECX]>>>>,

	// Otherwise, same as everything else.
	CCDelegateTo<CC_X86_32_Common>
	]>;

	def CC_X86_32_FastCall : CallingConv<[
	// Promote i8/i16 arguments to i32.
	CCIfType<[i8, i16], CCPromoteToType<i32>>,

	// The 'nest' parameter, if any, is passed in EAX.
	CCIfNest<CCAssignToReg<[EAX]>>,

	// The first 2 integer arguments are passed in ECX/EDX
	CCIfType<[i32], CCAssignToReg<[ECX, EDX]>>,

	// Otherwise, same as everything else.
	CCDelegateTo<CC_X86_32_Common>
	]>;

	def CC_X86_32_FastCC : CallingConv<[
	// Handles byval parameters. Note that we can't rely on the delegation
	// to CC_X86_32_Common for this because that happens after code that
	// puts arguments in registers.
	CCIfByVal<CCPassByVal<4, 4>>,

	// Promote i8/i16 arguments to i32.
	CCIfType<[i8, i16], CCPromoteToType<i32>>,

	// The 'nest' parameter, if any, is passed in EAX.
	CCIfNest<CCAssignToReg<[EAX]>>,

	// The first 2 integer arguments are passed in ECX/EDX
	CCIfType<[i32], CCAssignToReg<[ECX, EDX]>>,

	// The first 3 float or double arguments, if the call is not a vararg
	// call and if SSE2 is available, are passed in SSE registers.
	CCIfNotVarArg<CCIfType<[f32,f64],
	CCIfSubtarget<"hasSSE2()",
	CCAssignToReg<[XMM0,XMM1,XMM2]>>>>,

	// Doubles get 8-byte slots that are 8-byte aligned.
	CCIfType<[f64], CCAssignToStack<8, 8>>,

	// Otherwise, same as everything else.
	CCDelegateTo<CC_X86_32_Common>
	]>;