Use word_mode to push/pop register for x86

Use word_mode to push/pop register for x86

2012-03-08  H.J. Lu  <hongjiu.lu@intel.com>

	* config/i386/i386.c (setup_incoming_varargs_64): Use word_mode
	with integer parameters in registers.
	(gen_push): Push register in word_mode instead of Pmode.
	(ix86_emit_save_regs): Likewise.
	(ix86_emit_save_regs_using_mov): Save integer registers in
	word_mode.
	(gen_pop): Pop register in word_mode instead of Pmode.
	(ix86_emit_restore_regs_using_pop): Likewise.
	(ix86_expand_prologue): Replace Pmode with word_mode for push
	immediate.  Use ix86_gen_pro_epilogue_adjust_stack.  Save and
	restore RAX and R10 in word_mode.
	(ix86_emit_restore_regs_using_mov): Restore integer registers
	in word_mode.
	(ix86_expand_split_stack_prologue): Save R10_REG and restore in
	word_mode.
	(ix86_split_to_parts): Use word_mode with PUT_MODE for push.
	(ix86_split_long_move): Likewise.

	* config/i386/i386.md (W): New.
	(*push<mode>2_prologue): Replace :P with :W.
	(*pop<mode>1): Likewise.
	(*pop<mode>1_epilogue): Likewise.
	(push/pop peephole2): Use word_mode scratch registers.

From-SVN: r185123