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Diffstat (limited to 'contrib/llvm/lib/Target/Sparc/SparcCallingConv.td')
-rw-r--r-- | contrib/llvm/lib/Target/Sparc/SparcCallingConv.td | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/Sparc/SparcCallingConv.td b/contrib/llvm/lib/Target/Sparc/SparcCallingConv.td new file mode 100644 index 0000000..0aa29d1 --- /dev/null +++ b/contrib/llvm/lib/Target/Sparc/SparcCallingConv.td @@ -0,0 +1,144 @@ +//===-- SparcCallingConv.td - Calling Conventions Sparc ----*- 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 Sparc architectures. +// +//===----------------------------------------------------------------------===// + +//===----------------------------------------------------------------------===// +// SPARC v8 32-bit. +//===----------------------------------------------------------------------===// + +def CC_Sparc32 : CallingConv<[ + // Custom assign SRet to [sp+64]. + CCIfSRet<CCCustom<"CC_Sparc_Assign_SRet">>, + // i32 f32 arguments get passed in integer registers if there is space. + CCIfType<[i32, f32], CCAssignToReg<[I0, I1, I2, I3, I4, I5]>>, + // f64 arguments are split and passed through registers or through stack. + CCIfType<[f64], CCCustom<"CC_Sparc_Assign_Split_64">>, + // As are v2i32 arguments (this would be the default behavior for + // v2i32 if it wasn't allocated to the IntPair register-class) + CCIfType<[v2i32], CCCustom<"CC_Sparc_Assign_Split_64">>, + + + // Alternatively, they are assigned to the stack in 4-byte aligned units. + CCAssignToStack<4, 4> +]>; + +def RetCC_Sparc32 : CallingConv<[ + CCIfType<[i32], CCAssignToReg<[I0, I1, I2, I3, I4, I5]>>, + CCIfType<[f32], CCAssignToReg<[F0, F1, F2, F3]>>, + CCIfType<[f64], CCAssignToReg<[D0, D1]>>, + CCIfType<[v2i32], CCCustom<"CC_Sparc_Assign_Ret_Split_64">> +]>; + + +//===----------------------------------------------------------------------===// +// SPARC v9 64-bit. +//===----------------------------------------------------------------------===// +// +// The 64-bit ABI conceptually assigns all function arguments to a parameter +// array starting at [%fp+BIAS+128] in the callee's stack frame. All arguments +// occupy a multiple of 8 bytes in the array. Integer arguments are extended to +// 64 bits by the caller. Floats are right-aligned in their 8-byte slot, the +// first 4 bytes in the slot are undefined. +// +// The integer registers %i0 to %i5 shadow the first 48 bytes of the parameter +// array at fixed offsets. Integer arguments are promoted to registers when +// possible. +// +// The floating point registers %f0 to %f31 shadow the first 128 bytes of the +// parameter array at fixed offsets. Float and double parameters are promoted +// to these registers when possible. +// +// Structs up to 16 bytes in size are passed by value. They are right-aligned +// in one or two 8-byte slots in the parameter array. Struct members are +// promoted to both floating point and integer registers when possible. A +// struct containing two floats would thus be passed in %f0 and %f1, while two +// float function arguments would occupy 8 bytes each, and be passed in %f1 and +// %f3. +// +// When a struct { int, float } is passed by value, the int goes in the high +// bits of an integer register while the float goes in a floating point +// register. +// +// The difference is encoded in LLVM IR using the inreg atttribute on function +// arguments: +// +// C: void f(float, float); +// IR: declare void f(float %f1, float %f3) +// +// C: void f(struct { float f0, f1; }); +// IR: declare void f(float inreg %f0, float inreg %f1) +// +// C: void f(int, float); +// IR: declare void f(int signext %i0, float %f3) +// +// C: void f(struct { int i0high; float f1; }); +// IR: declare void f(i32 inreg %i0high, float inreg %f1) +// +// Two ints in a struct are simply coerced to i64: +// +// C: void f(struct { int i0high, i0low; }); +// IR: declare void f(i64 %i0.coerced) +// +// The frontend and backend divide the task of producing ABI compliant code for +// C functions. The C frontend will: +// +// - Annotate integer arguments with zeroext or signext attributes. +// +// - Split structs into one or two 64-bit sized chunks, or 32-bit chunks with +// inreg attributes. +// +// - Pass structs larger than 16 bytes indirectly with an explicit pointer +// argument. The byval attribute is not used. +// +// The backend will: +// +// - Assign all arguments to 64-bit aligned stack slots, 32-bits for inreg. +// +// - Promote to integer or floating point registers depending on type. +// +// Function return values are passed exactly like function arguments, except a +// struct up to 32 bytes in size can be returned in registers. + +// Function arguments AND most return values. +def CC_Sparc64 : CallingConv<[ + // The frontend uses the inreg flag to indicate i32 and float arguments from + // structs. These arguments are not promoted to 64 bits, but they can still + // be assigned to integer and float registers. + CCIfInReg<CCIfType<[i32, f32], CCCustom<"CC_Sparc64_Half">>>, + + // All integers are promoted to i64 by the caller. + CCIfType<[i32], CCPromoteToType<i64>>, + + // Custom assignment is required because stack space is reserved for all + // arguments whether they are passed in registers or not. + CCCustom<"CC_Sparc64_Full"> +]>; + +def RetCC_Sparc64 : CallingConv<[ + // A single f32 return value always goes in %f0. The ABI doesn't specify what + // happens to multiple f32 return values outside a struct. + CCIfType<[f32], CCCustom<"CC_Sparc64_Half">>, + + // Otherwise, return values are passed exactly like arguments. + CCDelegateTo<CC_Sparc64> +]>; + +// Callee-saved registers are handled by the register window mechanism. +def CSR : CalleeSavedRegs<(add)> { + let OtherPreserved = (add (sequence "I%u", 0, 7), + (sequence "L%u", 0, 7)); +} + +// Callee-saved registers for calls with ReturnsTwice attribute. +def RTCSR : CalleeSavedRegs<(add)> { + let OtherPreserved = (add I6, I7); +} |