From 38d8473fbb1188149c6824a92ddebf34f06a56f2 Mon Sep 17 00:00:00 2001 From: Richard Kenner Date: Wed, 7 Dec 1994 21:57:53 -0500 Subject: [PATCH] (distribute_notes): If can't find place for REG_DEAD note, add an INSN with a USE to hold it. From-SVN: r8625 --- gcc/combine.c | 90 +++++++++++++++++++++++++++++---------------------- 1 file changed, 51 insertions(+), 39 deletions(-) diff --git a/gcc/combine.c b/gcc/combine.c index bd751608409..f7415aea817 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -10515,49 +10515,50 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1) reg_n_refs[REGNO (XEXP (note, 0))] = 3; if (place == 0) - for (tem = prev_nonnote_insn (i3); - tem && (GET_CODE (tem) == INSN - || GET_CODE (tem) == CALL_INSN); - tem = prev_nonnote_insn (tem)) - { - /* If the register is being set at TEM, see if that is all - TEM is doing. If so, delete TEM. Otherwise, make this - into a REG_UNUSED note instead. */ - if (reg_set_p (XEXP (note, 0), PATTERN (tem))) - { - rtx set = single_set (tem); + { + for (tem = prev_nonnote_insn (i3); + place == 0 && tem + && (GET_CODE (tem) == INSN || GET_CODE (tem) == CALL_INSN); + tem = prev_nonnote_insn (tem)) + { + /* If the register is being set at TEM, see if that is all + TEM is doing. If so, delete TEM. Otherwise, make this + into a REG_UNUSED note instead. */ + if (reg_set_p (XEXP (note, 0), PATTERN (tem))) + { + rtx set = single_set (tem); - /* Verify that it was the set, and not a clobber that - modified the register. */ + /* Verify that it was the set, and not a clobber that + modified the register. */ - if (set != 0 && ! side_effects_p (SET_SRC (set)) - && rtx_equal_p (XEXP (note, 0), SET_DEST (set))) - { - /* Move the notes and links of TEM elsewhere. - This might delete other dead insns recursively. - First set the pattern to something that won't use - any register. */ + if (set != 0 && ! side_effects_p (SET_SRC (set)) + && rtx_equal_p (XEXP (note, 0), SET_DEST (set))) + { + /* Move the notes and links of TEM elsewhere. + This might delete other dead insns recursively. + First set the pattern to something that won't use + any register. */ - PATTERN (tem) = pc_rtx; + PATTERN (tem) = pc_rtx; - distribute_notes (REG_NOTES (tem), tem, tem, - NULL_RTX, NULL_RTX, NULL_RTX); - distribute_links (LOG_LINKS (tem)); + distribute_notes (REG_NOTES (tem), tem, tem, + NULL_RTX, NULL_RTX, NULL_RTX); + distribute_links (LOG_LINKS (tem)); - PUT_CODE (tem, NOTE); - NOTE_LINE_NUMBER (tem) = NOTE_INSN_DELETED; - NOTE_SOURCE_FILE (tem) = 0; - } - else - { - PUT_REG_NOTE_KIND (note, REG_UNUSED); - - /* If there isn't already a REG_UNUSED note, put one - here. */ - if (! find_regno_note (tem, REG_UNUSED, - REGNO (XEXP (note, 0)))) - place = tem; - break; + PUT_CODE (tem, NOTE); + NOTE_LINE_NUMBER (tem) = NOTE_INSN_DELETED; + NOTE_SOURCE_FILE (tem) = 0; + } + else + { + PUT_REG_NOTE_KIND (note, REG_UNUSED); + + /* If there isn't already a REG_UNUSED note, put one + here. */ + if (! find_regno_note (tem, REG_UNUSED, + REGNO (XEXP (note, 0)))) + place = tem; + break; } } else if (reg_referenced_p (XEXP (note, 0), PATTERN (tem)) @@ -10567,7 +10568,18 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1) place = tem; break; } - } + } + + /* If we haven't found an insn for the death note and it + is still a REG_DEAD note, but we have hit a CODE_LABEL, + insert a USE insn for the register at that label and + put the death node there. This prevents problems with + call-state tracking in caller-save.c. */ + if (REG_NOTE_KIND (note) == REG_DEAD && place == 0 && tem != 0) + place + = emit_insn_after (gen_rtx (USE, VOIDmode, XEXP (note, 0)), + tem); + } /* If the register is set or already dead at PLACE, we needn't do anything with this note if it is still a REG_DEAD note. -- 2.30.2