[PATCH 1/2] [ARC] Fix and refurbish the interrupts.

[Jeff Law]

On 7/9/19 10:23 AM, claziss@gmail.com wrote:
> Hi Jeff,
> 
> Please find attached the updated patch.
> 
> What is new:
> - mailing list feedback is taken into account.
> - some comments are updated.
> - a new test is added.
> - the ARC AUX registers used by ZOL (hardware loop) and FPX (a custom
> floating point implementation) are saved before fp-register.
> - the millicode optimization is not used by ISR.
> 
> 
> Thank you,
> Claudiu
> 
> 
> 0001-ARC-Fix-and-refurbish-the-interrupts.patch
> 
> From d22368681b7aab4bef4b5c32a9a472808f2c16cd Mon Sep 17 00:00:00 2001
> From: Claudiu Zissulescu <claziss@gmail.com>
> Date: Fri, 17 May 2019 14:48:17 +0300
> Subject: [PATCH] [ARC] Fix and refurbish the interrupts.
> 
> When entering an interrupt, not only the call save registers needs to
> be place on stack but also the call clobbers one. More over, the
> ARC700 return from interrupt instruction needs to be rtie, the same
> like ARCv2 CPUs. While the ARC6xx family uses j.f [ilinkX]
> instruction. Additionally, we need to save the state of the ZOL
> machinery, namely the lp_count, lp_end and lp_start registers. For
> architectures which are using extension registers (i.e., HS48) we need
> to save/restore them as well.
> 
> gcc/
> xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>
> 
> 	* config/arc/arc-protos.h (arc_output_function_epilogue): Delete
> 	declaration.
> 	(arc_compute_frame_size): Millicode is disabled when compiling
> 	ISR.
> 	(arc_return_address_register): Likewise.
> 	(arc_compute_function_type): Likewise.
> 	(arc_compute_frame_size): Likewise.
> 	(secondary_reload_info): Likewise.
> 	(arc_get_unalign): Likewise.
> 	(arc_can_use_return_insn): Declare.
> 	* config/arc/arc.c (AUX_LP_START): Define
> 	(AUX_LP_END): Likewise.
> 	(arc_frame_info): Update gmask member to 64-bit datum.
> 	(GMASK_LEN): Update.
> 	(arc_compute_function_type): Make it static, move it forward.
> 	(arc_must_save_register): Update, consider the extra regs.
> 	(arc_compute_millicode_save_restore_regs): Update to use the 64
> 	bit gmask.
> 	(arc_compute_frame_size): Likewise.
> 	(arc_enter_leave_p): Likewise.
> 	(arc_save_callee_saves): Likewise.
> 	(arc_restore_callee_saves): Likewise.
> 	(arc_save_callee_enter): Likewise.
> 	(arc_restore_callee_leave): Likewise.
> 	(arc_save_callee_milli): Likewise.
> 	(arc_restore_callee_milli): Likewise.
> 	(arc_expand_prologue): Add new interrupt handling.
> 	(arc_return_address_register): Make it static, move it forward.
> 	(arc_expand_epilogue): Add new interrupt handling.
> 	(arc_get_unalign): Delete.
> 	(arc_epilogue_uses): Make sure we do not remove the extra
> 	saved/restored registers when interrupt.
> 	(arc_can_use_return_insn): New function.
> 	(push_reg): Likewise.
> 	(pop_reg): Likewise.
> 	(arc_save_callee_saves): Add ZOL and FPX aux registers saving
> 	procedures.
> 	(arc_restore_callee_saves): Likewise, but restoring.
> 	* config/arc/arc.md (VUNSPEC_ARC_ARC600_RTIE): Define.
> 	(R33_REG): Likewise.
> 	(R34_REG): Likewise.
> 	(R35_REG): Likewise.
> 	(R36_REG): Likewise.
> 	(R37_REG): Likewise.
> 	(R38_REG): Likewise.
> 	(R39_REG): Likewise.
> 	(R45_REG): Likewise.
> 	(R46_REG): Likewise.
> 	(R47_REG): Likewise.
> 	(R48_REG): Likewise.
> 	(R49_REG): Likewise.
> 	(R50_REG): Likewise.
> 	(R51_REG): Likewise.
> 	(R52_REG): Likewise.
> 	(R53_REG): Likewise.
> 	(R54_REG): Likewise.
> 	(R55_REG): Likewise.
> 	(R56_REG): Likewise.
> 	(R58_REG): Likewise.
> 	(type): Add rtie attribute.
> 	(in_call_delay_slot): Use RETURN_ADDR_REGNUM.
> 	(movsi_insn): Accept moves to lp_count.
> 	(rtie): Update pattern.
> 	(simple_return): Simplify it, don't use this pattern as a return
> 	from an interrupt.
> 	(arc600_rtie): New pattern.
> 	(p_return_i): Clean up.
> 	(return): Likewise.
> 	* config/arc/builtins.def (rtie): Only available for non ARC6xx
> 	family CPUs.
> 	* config/arc/predicates.md (move_src_operand): Consider lp_count
> 	as a register.
> 
> gcc/testsuite
> xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>
> 
> 	* gcc.target/arc/arc.exp (check_effective_target_accregs): New
> 	predicate.
> 	* gcc.target/arc/builtin_special.c: Update test/
> 	* gcc.target/arc/interrupt-1.c: Likewise.
> 	* gcc.target/arc/interrupt-10.c: New test.
> 	* gcc.target/arc/interrupt-11.c: Likewise.
> 	* gcc.target/arc/interrupt-12.c: Likewise.
OK

Jeff