/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

// Platform specific code to invoke XPCOM methods on native objects

#include "xptcall.h"
#include "xptinfo.h"

// 6 integral parameters are passed in registers, but 1 is |this| which isn't
// considered here.
const uint32_t GPR_COUNT = 5;

// 8 floating point parameters are passed in SSE registers
const uint32_t FPR_COUNT = 8;

extern "C" void
InvokeCopyToStack(uint64_t * gpregs, double * fpregs,
                     uint32_t paramCount, nsXPTCVariant * s,
                     uint64_t* d)
{
    uint32_t nr_gpr = 0u;
    uint32_t nr_fpr = 0u;
    uint64_t value = 0u;

    for (uint32_t i = 0; i < paramCount; i++, s++) {
        if (s->IsIndirect())
            value = (uint64_t) &s->val;
        else {
            switch (s->type) {
            case nsXPTType::T_FLOAT:                                break;
            case nsXPTType::T_DOUBLE:                               break;
            case nsXPTType::T_I8:     value = s->val.i8;            break;
            case nsXPTType::T_I16:    value = s->val.i16;           break;
            case nsXPTType::T_I32:    value = s->val.i32;           break;
            case nsXPTType::T_I64:    value = s->val.i64;           break;
            case nsXPTType::T_U8:     value = s->val.u8;            break;
            case nsXPTType::T_U16:    value = s->val.u16;           break;
            case nsXPTType::T_U32:    value = s->val.u32;           break;
            case nsXPTType::T_U64:    value = s->val.u64;           break;
            case nsXPTType::T_BOOL:   value = s->val.b;             break;
            case nsXPTType::T_CHAR:   value = s->val.c;             break;
            case nsXPTType::T_WCHAR:  value = s->val.wc;            break;
            default:                  value = (uint64_t) s->val.p;  break;
            }
        }

        if (!s->IsIndirect() && s->type == nsXPTType::T_DOUBLE) {
            if (nr_fpr < FPR_COUNT)
                fpregs[nr_fpr++] = s->val.d;
            else {
                *((double *)d) = s->val.d;
                d++;
            }
        }
        else if (!s->IsIndirect() && s->type == nsXPTType::T_FLOAT) {
            if (nr_fpr < FPR_COUNT)
                // The value in %xmm register is already prepared to
                // be retrieved as a float. Therefore, we pass the
                // value verbatim, as a double without conversion.
                fpregs[nr_fpr++] = s->val.d;
            else {
                *((float *)d) = s->val.f;
                d++;
            }
        }
        else {
            if (nr_gpr < GPR_COUNT)
                gpregs[nr_gpr++] = value;
            else
                *d++ = value;
        }
    }
}
