// -*- Mode: Asm -*-
//
// 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/.

.set r0,0; .set sp,1; .set RTOC,2; .set r3,3; .set r4,4
.set r5,5; .set r6,6; .set r7,7; .set r8,8; .set r9,9
.set r10,10; .set r11,11; .set r12,12; .set r13,13; .set r14,14
.set r15,15; .set r16,16; .set r17,17; .set r18,18; .set r19,19
.set r20,20; .set r21,21; .set r22,22; .set r23,23; .set r24,24
.set r25,25; .set r26,26; .set r27,27; .set r28,28; .set r29,29
.set r30,30; .set r31,31
.set f0,0; .set f1,1; .set f2,2; .set f3,3; .set f4,4
.set f5,5; .set f6,6; .set f7,7; .set f8,8; .set f9,9
.set f10,10; .set f11,11; .set f12,12; .set f13,13; .set f14,14
.set f15,15; .set f16,16; .set f17,17; .set f18,18; .set f19,19
.set f20,20; .set f21,21; .set f22,22; .set f23,23; .set f24,24
.set f25,25; .set f26,26; .set f27,27; .set f28,28; .set f29,29
.set f30,30; .set f31,31

	.section ".text"
	.align 2
	.globl NS_InvokeByIndex
	.type  NS_InvokeByIndex,@function

//
// NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex,
//                    uint32_t paramCount, nsXPTCVariant* params)
//

NS_InvokeByIndex:
	stwu	sp,-32(sp)			// setup standard stack frame
	mflr	r0				// save LR
	stw	r3,8(sp)			// r3 <= that
	stw	r4,12(sp)			// r4 <= methodIndex
	stw	r30,16(sp)
	stw	r31,20(sp)

	stw	r0,36(sp)			// store LR backchain
	mr	r31,sp

	rlwinm	r10,r5,3,0,27			// r10 = (ParamCount * 2 * 4) & ~0x0f
	addi	r0,r10,96			// reserve stack for GPR and FPR register save area r0 = r10 + 96
	lwz	r9,0(sp)			// r9 = backchain
	neg	r0,r0
	stwux	r9,sp,r0			// reserve stack space and save SP backchain

	addi	r3,sp,8				// r3 <= args
	mr	r4,r5				// r4 <= paramCount
	mr	r5,r6				// r5 <= params
	add	r6,r3,r10			// r6 <= gpregs ( == args + r10 )
	mr	r30,r6				// store in r30 for use later...
	addi	r7,r6,32			// r7 <= fpregs ( == gpregs + 32 )

	bl	invoke_copy_to_stack@local	// (args, paramCount, params, gpregs, fpregs)

	lfd	f1,32(r30)			// load FP registers with method parameters
	lfd	f2,40(r30)
	lfd	f3,48(r30)
	lfd	f4,56(r30)
	lfd	f5,64(r30)
	lfd	f6,72(r30)
	lfd	f7,80(r30)
	lfd	f8,88(r30)

	lwz	r3,8(r31)			// r3 <= that
	lwz	r4,12(r31)			// r4 <= methodIndex
	lwz	r5,0(r3)			// r5 <= vtable ( == *that )
	slwi	r4,r4,2				// convert to offset ( *= 4 )
	lwzx	r0,r5,r4			// r0 <= methodpointer ( == vtable + offset )

	lwz	r4,4(r30)			// load GP regs with method parameters
	lwz	r5,8(r30)
	lwz	r6,12(r30)
	lwz	r7,16(r30)
	lwz	r8,20(r30)
	lwz	r9,24(r30)
	lwz	r10,28(r30)

	mtlr	r0				// copy methodpointer to LR
	blrl					// call method

	lwz	r30,16(r31)			// restore r30 & r31
	lwz	r31,20(r31)

	lwz	r11,0(sp)			// clean up the stack
	lwz	r0,4(r11)
	mtlr	r0
	mr	sp,r11
	blr

	// Magic indicating no need for an executable stack
	.section .note.GNU-stack, "", @progbits