mips.c (mips_split_64bit_move): Use gen_rtx_REG_offset rather than gen_lowpart to...

mips.c (mips_split_64bit_move): Use gen_rtx_REG_offset rather than gen_lowpart to change a register from DImode...

gcc/
	* config/mips/mips.c (mips_split_64bit_move): Use gen_rtx_REG_offset
	rather than gen_lowpart to change a register from DImode to DFmode.
	(mips_cannot_change_mode_class): Only allow FPRs to change mode if
	both FROM and TO are integer modes that are no bigger than 4 bytes.
	(mips_mode_ok_for_mov_fmt_p): New function.
	(mips_preferred_reload_class): Use it instead of FLOAT_MODE_P.
	(mips_secondary_reload_class): Tweak formatting and comments.
	Use reg_class_subset_p instead of direct comparisons with
	classes.  Only allow direct FPR<->FPR moves for modes that
	satisfy mips_mode_ok_for_mov_fmt_p.  Only allow loads and stores
	for 4- and 8-byte types.  Handle reloads in which X is an FPR.
	* config/mips/mips.md (*movdi_gp32_fp64): Remove f<-f alternative.
	(*movdi_64bit): Likewise.
	(*movsi_internal): Likewise.
	(*movhi_internal): Likewise.
	(*movqi_internal): Likewise.

From-SVN: r128894