From 940b29aa635f6844c5de0cff75526c5994b79a18 Mon Sep 17 00:00:00 2001 From: Jan Hubicka Date: Tue, 31 Jul 2001 15:36:12 +0200 Subject: jump.c (duplicate_loop_exit_test): Better test for jumps entering the loop; create loop pre_header. * jump.c (duplicate_loop_exit_test): Better test for jumps entering the loop; create loop pre_header. From-SVN: r44512 --- gcc/jump.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'gcc/jump.c') diff --git a/gcc/jump.c b/gcc/jump.c index ddef4a1..dd099f2 100644 --- a/gcc/jump.c +++ b/gcc/jump.c @@ -305,6 +305,7 @@ duplicate_loop_exit_test (loop_start) rtx lastexit; int max_reg = max_reg_num (); rtx *reg_map = 0; + rtx loop_pre_header_label; /* Scan the exit code. We do not perform this optimization if any insn: @@ -405,6 +406,7 @@ duplicate_loop_exit_test (loop_start) reg_map[REGNO (reg)] = gen_reg_rtx (GET_MODE (reg)); } } + loop_pre_header_label = gen_label_rtx (); /* Now copy each insn. */ for (insn = exitcode; insn != lastexit; insn = NEXT_INSN (insn)) @@ -475,9 +477,14 @@ duplicate_loop_exit_test (loop_start) /* The jump_insn after loop_start should be followed by barrier and loopback label. */ if (prev_nonnote_insn (label) - && (PREV_INSN (prev_nonnote_insn (label)) - == NEXT_INSN (loop_start))) - predict_insn_def (copy, PRED_LOOP_HEADER, TAKEN); + && (prev_nonnote_insn (prev_nonnote_insn (label)) + == next_nonnote_insn (loop_start))) + { + predict_insn_def (copy, PRED_LOOP_HEADER, TAKEN); + /* To keep pre-header, we need to redirect all loop + entrances before the LOOP_BEG note. */ + redirect_jump (copy, loop_pre_header_label, 0); + } else predict_insn_def (copy, PRED_LOOP_HEADER, NOT_TAKEN); } @@ -512,6 +519,8 @@ duplicate_loop_exit_test (loop_start) emit_barrier_before (loop_start); } + emit_label_before (loop_pre_header_label, loop_start); + /* Now scan from the first insn we copied to the last insn we copied (copy) for new pseudo registers. Do this after the code to jump to the end label since that might create a new pseudo too. */ -- cgit v1.1