coreasm.h

linux-2.6.15.6

	bnez	\ar, \startlabelref
#endif /* XCHAL_HAVE_LOOPS */
\endlabel:
	.endm	// floopend_

/*----------------------------------------------------------------------
 *  crsil  --  conditional RSIL (read/set interrupt level)
 *
 *  Executes the RSIL instruction if it exists, else just reads PS.
 *  The RSIL instruction does not exist in the new exception architecture
 *  if the interrupt option is not selected.
 */

	.macro	crsil	ar, newlevel
#if XCHAL_HAVE_OLD_EXC_ARCH || XCHAL_HAVE_INTERRUPTS
	rsil	\ar, \newlevel
#else
	rsr	\ar, PS
#endif
	.endm	// crsil

/*----------------------------------------------------------------------
 *  window_spill{4,8,12}
 *
 *  These macros spill callers' register windows to the stack.
 *  They work for both privileged and non-privileged tasks.
 *  Must be called from a windowed ABI context, eg. within
 *  a windowed ABI function (ie. valid stack frame, window
 *  exceptions enabled, not in exception mode, etc).
 *
 *  This macro requires a single invocation of the window_spill_common
 *  macro in the same assembly unit and section.
 *
 *  Note that using window_spill{4,8,12} macros is more efficient
 *  than calling a function implemented using window_spill_function,
 *  because the latter needs extra code to figure out the size of
 *  the call to the spilling function.
 *
 *  Example usage:
 *
 *		.text
 *		.align	4
 *		.global	some_function
 *		.type	some_function,@function
 *	some_function:
 *		entry	a1, 16
 *		:
 *		:
 *
 *		window_spill4	// spill windows of some_function's callers; preserves a0..a3 only;
 *				// to use window_spill{8,12} in this example function we'd have
 *				// to increase space allocated by the entry instruction, because
 *				// 16 bytes only allows call4; 32 or 48 bytes (+locals) are needed
 *				// for call8/window_spill8 or call12/window_spill12 respectively.
 *		:
 *
 *		retw
 *
 *		window_spill_common	// instantiates code used by window_spill4
 *
 *
 *  On entry:
 *	none (if window_spill4)
 *	stack frame has enough space allocated for call8 (if window_spill8)
 *	stack frame has enough space allocated for call12 (if window_spill12)
 *  On exit:
 *	 a4..a15 clobbered (if window_spill4)
 *	 a8..a15 clobbered (if window_spill8)
 *	a12..a15 clobbered (if window_spill12)
 *	no caller windows are in live registers
 */

	.macro	window_spill4
#if XCHAL_HAVE_WINDOWED
# if XCHAL_NUM_AREGS == 16
	movi	a15, 0			// for 16-register files, no need to call to reach the end
# elif XCHAL_NUM_AREGS == 32
	call4	.L__wdwspill_assist28	// call deep enough to clear out any live callers
# elif XCHAL_NUM_AREGS == 64
	call4	.L__wdwspill_assist60	// call deep enough to clear out any live callers
# endif
#endif
	.endm	// window_spill4

	.macro	window_spill8
#if XCHAL_HAVE_WINDOWED
# if XCHAL_NUM_AREGS == 16
	movi	a15, 0			// for 16-register files, no need to call to reach the end
# elif XCHAL_NUM_AREGS == 32
	call8	.L__wdwspill_assist24	// call deep enough to clear out any live callers
# elif XCHAL_NUM_AREGS == 64
	call8	.L__wdwspill_assist56	// call deep enough to clear out any live callers
# endif
#endif
	.endm	// window_spill8

	.macro	window_spill12
#if XCHAL_HAVE_WINDOWED
# if XCHAL_NUM_AREGS == 16
	movi	a15, 0			// for 16-register files, no need to call to reach the end
# elif XCHAL_NUM_AREGS == 32
	call12	.L__wdwspill_assist20	// call deep enough to clear out any live callers
# elif XCHAL_NUM_AREGS == 64
	call12	.L__wdwspill_assist52	// call deep enough to clear out any live callers
# endif
#endif
	.endm	// window_spill12

/*----------------------------------------------------------------------
 *  window_spill_function
 *
 *  This macro outputs a function that will spill its caller's callers'
 *  register windows to the stack.  Eg. it could be used to implement
 *  a version of xthal_window_spill() that works in non-privileged tasks.
 *  This works for both privileged and non-privileged tasks.
 *
 *  Typical usage:
 *
 *		.text
 *		.align	4
 *		.global	my_spill_function
 *		.type	my_spill_function,@function
 *	my_spill_function:
 *		window_spill_function
 *
 *  On entry to resulting function:
 *	none
 *  On exit from resulting function:
 *	none (no caller windows are in live registers)
 */

	.macro	window_spill_function
#if XCHAL_HAVE_WINDOWED
# if XCHAL_NUM_AREGS == 32
	entry	sp, 48
	bbci.l	a0, 31, 1f		// branch if called with call4
	bbsi.l	a0, 30, 2f		// branch if called with call12
	call8	.L__wdwspill_assist16	// called with call8, only need another 8
	retw
1:	call12	.L__wdwspill_assist16	// called with call4, only need another 12
	retw
2:	call4	.L__wdwspill_assist16	// called with call12, only need another 4
	retw
# elif XCHAL_NUM_AREGS == 64
	entry	sp, 48
	bbci.l	a0, 31, 1f		// branch if called with call4
	bbsi.l	a0, 30, 2f		// branch if called with call12
	call4	.L__wdwspill_assist52	// called with call8, only need a call4
	retw
1:	call8	.L__wdwspill_assist52	// called with call4, only need a call8
	retw
2:	call12	.L__wdwspill_assist40	// called with call12, can skip a call12
	retw
# elif XCHAL_NUM_AREGS == 16
	entry	sp, 16
	bbci.l	a0, 31, 1f	// branch if called with call4
	bbsi.l	a0, 30, 2f	// branch if called with call12
	movi	a7, 0		// called with call8
	retw
1:	movi	a11, 0		// called with call4
2:	retw			// if called with call12, everything already spilled

//	movi	a15, 0		// trick to spill all but the direct caller
//	j	1f
//	//  The entry instruction is magical in the assembler (gets auto-aligned)
//	//  so we have to jump to it to avoid falling through the padding.
//	//  We need entry/retw to know where to return.
//1:	entry	sp, 16
//	retw
# else
#  error "unrecognized address register file size"
# endif
#endif /* XCHAL_HAVE_WINDOWED */
	window_spill_common
	.endm	// window_spill_function

/*----------------------------------------------------------------------
 *  window_spill_common
 *
 *  Common code used by any number of invocations of the window_spill##
 *  and window_spill_function macros.
 *
 *  Must be instantiated exactly once within a given assembly unit,
 *  within call/j range of and same section as window_spill##
 *  macro invocations for that assembly unit.
 *  (Is automatically instantiated by the window_spill_function macro.)
 */

	.macro	window_spill_common
#if XCHAL_HAVE_WINDOWED && (XCHAL_NUM_AREGS == 32 || XCHAL_NUM_AREGS == 64)
	.ifndef	.L__wdwspill_defined
# if XCHAL_NUM_AREGS >= 64
.L__wdwspill_assist60:
	entry	sp, 32
	call8	.L__wdwspill_assist52
	retw
.L__wdwspill_assist56:
	entry	sp, 16
	call4	.L__wdwspill_assist52
	retw
.L__wdwspill_assist52:
	entry	sp, 48
	call12	.L__wdwspill_assist40
	retw
.L__wdwspill_assist40:
	entry	sp, 48
	call12	.L__wdwspill_assist28
	retw
# endif
.L__wdwspill_assist28:
	entry	sp, 48
	call12	.L__wdwspill_assist16
	retw
.L__wdwspill_assist24:
	entry	sp, 32
	call8	.L__wdwspill_assist16
	retw
.L__wdwspill_assist20:
	entry	sp, 16
	call4	.L__wdwspill_assist16
	retw
.L__wdwspill_assist16:
	entry	sp, 16
	movi	a15, 0
	retw
	.set	.L__wdwspill_defined, 1
	.endif
#endif /* XCHAL_HAVE_WINDOWED with 32 or 64 aregs */
	.endm	// window_spill_common

/*----------------------------------------------------------------------
 *  beqi32
 *
 *  macro implements version of beqi for arbitrary 32-bit immidiate value
 *
 *     beqi32 ax, ay, imm32, label
 *
 *  Compares value in register ax with imm32 value and jumps to label if
 *  equal. Clobberes register ay if needed
 *
 */
   .macro beqi32	ax, ay, imm, label
    .ifeq ((\imm-1) & ~7)	// 1..8 ?
		beqi	\ax, \imm, \label
    .else
      .ifeq (\imm+1)		// -1 ?
		beqi	\ax, \imm, \label
      .else
        .ifeq (\imm)		// 0 ?
		beqz	\ax, \label
        .else
		//  We could also handle immediates 10,12,16,32,64,128,256
		//  but it would be a long macro...
		movi	\ay, \imm
		beq	\ax, \ay, \label
        .endif
      .endif
    .endif
   .endm // beqi32

#endif /*XTENSA_COREASM_H*/