contrib/gcc/caller-save.c

28 #include "insn-config.h"
65    saved in its widest mode with a simple SET insn as long as the memory
75 /* Set of hard regs currently residing in save area (during insn scan).  */
84    insn.  */
105    simple insn to save and restore the register.  This latter check avoids
147      the validity of an insn operand is dependent on the address offset.
182   /* Next we try to form an insn to save and restore the register.  We
183      see if such an insn is recognized and meets its constraints.
382       rtx insn = chain->insn;
383       enum rtx_code code = GET_CODE (insn);
389       if (INSN_P (insn))
392 	     any of them.  We must restore them before the insn if so.  */
404 		  mark_referenced_regs (PATTERN (insn));
413 	  if (code == CALL_INSN && ! find_reg_note (insn, REG_NORETURN, NULL))
450 	      /* Record all registers set in this call insn.  These don't need
451 		 to be saved.  N.B. the call insn might set a subreg of a
455 	      note_stores (PATTERN (insn), mark_set_regs, &this_insn_sets);
458 	      if (SIBLING_CALL_P (insn) && current_function_return_rtx)
484 	     remain saved.  If the last insn in the block is a JUMP_INSN, put
485 	     the restore before the insn, otherwise, put it after the insn.  */
490 		regno += insert_restore (chain, JUMP_P (insn),
497    an insn stores a value in a register.
527 /* Here from note_stores when an insn stores a value in a register.
628    CHAIN if BEFORE_P is nonzero, behind the insn otherwise.  MAXRESTORE is
634    since the address might not be valid so the insn might not be recognized.
653      expect to save.  That will cause us to write an insn with a (nil)
726      expect to save.  That will cause us to write an insn with a (nil)
782 /* Emit a new caller-save insn and set the code.  */
786   rtx insn = chain->insn;
790   /* If INSN references CC0, put our insns in front of the insn that sets
792      insn that references CC0 is for a restore, and doing a restore earlier
796   if ((NONJUMP_INSN_P (insn) || JUMP_P (insn))
798       && reg_referenced_p (cc0_rtx, PATTERN (insn)))
799     chain = chain->prev, insn = chain->insn;
815       new->insn = emit_insn_before (pat, insn);
819       /* Registers that die in CHAIN->INSN still live in the new insn.  */
820       for (link = REG_NOTES (chain->insn); link; link = XEXP (link, 1))
839       if (chain->insn == BB_HEAD (BASIC_BLOCK (chain->block)))
840 	BB_HEAD (BASIC_BLOCK (chain->block)) = new->insn;
849       new->insn = emit_insn_after (pat, insn);
853       /* Registers that are set in CHAIN->INSN live in the new insn.
856       note_stores (PATTERN (chain->insn), add_stored_regs,
859       if (chain->insn == BB_END (BASIC_BLOCK (chain->block)))
860 	BB_END (BASIC_BLOCK (chain->block)) = new->insn;
865   INSN_CODE (new->insn) = code;