diff options
Diffstat (limited to 'gcc/cfgrtl.c')
| -rw-r--r-- | gcc/cfgrtl.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c index 569a604..a08d29f 100644 --- a/gcc/cfgrtl.c +++ b/gcc/cfgrtl.c @@ -56,6 +56,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #include "obstack.h" #include "insn-config.h" #include "cfglayout.h" +#include "expr.h" /* Stubs in case we don't have a return insn. */ #ifndef HAVE_return @@ -88,6 +89,7 @@ static bool rtl_redirect_edge_and_branch (edge, basic_block); static edge rtl_split_block (basic_block, void *); static void rtl_dump_bb (basic_block, FILE *); static int rtl_verify_flow_info_1 (void); +static void mark_killed_regs (rtx, rtx, void *); /* Return true if NOTE is not one of the ones that must be kept paired, so that we may simply delete it. */ @@ -1305,6 +1307,101 @@ insert_insn_on_edge (rtx pattern, edge e) end_sequence (); } +/* Called from safe_insert_insn_on_edge through note_stores, marks live + registers that are killed by the store. */ +static void +mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data) +{ + regset killed = data; + int regno, i; + + if (GET_CODE (reg) == SUBREG) + reg = SUBREG_REG (reg); + if (!REG_P (reg)) + return; + regno = REGNO (reg); + if (regno >= FIRST_PSEUDO_REGISTER) + SET_REGNO_REG_SET (killed, regno); + else + { + for (i = 0; i < HARD_REGNO_NREGS (regno, GET_MODE (reg)); i++) + SET_REGNO_REG_SET (killed, regno + i); + } +} + +/* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally + it checks whether this will not clobber the registers that are live on the + edge (i.e. it requieres liveness information to be up-to-date) and if there + are some, then it tries to save and restore them. Returns true if + succesful. */ +bool +safe_insert_insn_on_edge (rtx insn, edge e) +{ + rtx x; + regset_head killed_head; + regset killed = INITIALIZE_REG_SET (killed_head); + rtx save_regs = NULL_RTX; + int regno, noccmode; + enum machine_mode mode; + +#ifdef AVOID_CCMODE_COPIES + noccmode = true; +#else + noccmode = false; +#endif + + for (x = insn; x; x = NEXT_INSN (x)) + if (INSN_P (x)) + note_stores (PATTERN (x), mark_killed_regs, killed); + bitmap_operation (killed, killed, e->dest->global_live_at_start, + BITMAP_AND); + + EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, + { + mode = regno < FIRST_PSEUDO_REGISTER + ? reg_raw_mode[regno] + : GET_MODE (regno_reg_rtx[regno]); + if (mode == VOIDmode) + return false; + + if (noccmode && mode == CCmode) + return false; + + save_regs = alloc_EXPR_LIST (0, + alloc_EXPR_LIST (0, + gen_reg_rtx (mode), + gen_raw_REG (mode, regno)), + save_regs); + }); + + if (save_regs) + { + rtx from, to; + + start_sequence (); + for (x = save_regs; x; x = XEXP (x, 1)) + { + from = XEXP (XEXP (x, 0), 1); + to = XEXP (XEXP (x, 0), 0); + emit_move_insn (to, from); + } + emit_insn (insn); + for (x = save_regs; x; x = XEXP (x, 1)) + { + from = XEXP (XEXP (x, 0), 0); + to = XEXP (XEXP (x, 0), 1); + emit_move_insn (to, from); + } + insn = get_insns (); + end_sequence (); + free_EXPR_LIST_list (&save_regs); + } + insert_insn_on_edge (insn, e); + + FREE_REG_SET (killed); + return true; +} + /* Update the CFG for the instructions queued on edge E. */ static void |