macosx-fpsave.asm   [plain text]


/* This file contains the floating-point save and restore routines.

   THE SAVE AND RESTORE ROUTINES CAN HAVE ONLY ONE GLOBALLY VISIBLE ENTRY POINT
   - callers have to jump to "saveFP+60" to save f29..f31, for example.
   For FP reg saves/restores, it takes one instruction (4 bytes) to do the
   operation; for Vector regs, 2 instructions are required (8 bytes.)
   MORAL: DO NOT MESS AROUND WITH THESE FUNCTIONS!  */

.text
	.align 2

/* saveFP saves R0 -- assumed to be the callers LR -- to 8(R1).  */

.private_extern saveFP
saveFP:
	stfd f14,-144(r1)
	stfd f15,-136(r1)
	stfd f16,-128(r1)
	stfd f17,-120(r1)
	stfd f18,-112(r1)
	stfd f19,-104(r1)
	stfd f20,-96(r1)
	stfd f21,-88(r1)
	stfd f22,-80(r1)
	stfd f23,-72(r1)
	stfd f24,-64(r1)
	stfd f25,-56(r1)
	stfd f26,-48(r1)
	stfd f27,-40(r1)
	stfd f28,-32(r1)
	stfd f29,-24(r1)
	stfd f30,-16(r1)
	stfd f31,-8(r1)
	stw  r0,8(r1)
	blr

/* restFP restores the caller`s LR from 8(R1).  Note that the code for this
   starts at the offset of F30 restoration, so calling this routine in an
   attempt to restore only F31 WILL NOT WORK (it would be a stupid thing to
   do, anyway.)  */

.private_extern restFP
restFP:
	lfd f14,-144(r1)
	lfd f15,-136(r1)
	lfd f16,-128(r1)
	lfd f17,-120(r1)
	lfd f18,-112(r1)
	lfd f19,-104(r1)
	lfd f20,-96(r1)
	lfd f21,-88(r1)
	lfd f22,-80(r1)
	lfd f23,-72(r1)
	lfd f24,-64(r1)
	lfd f25,-56(r1)
	lfd f26,-48(r1)
	lfd f27,-40(r1)
	lfd f28,-32(r1)
	lfd f29,-24(r1)
			/* <OFFSET OF F30 RESTORE> restore callers LR  */
	lwz r0,8(r1)
	lfd f30,-16(r1)
			/* and prepare for return to caller  */
	mtlr r0	
	lfd f31,-8(r1)
	blr