From 9e42ab3e45c060ceb91a552a045aa66a571bf163 Mon Sep 17 00:00:00 2001 From: Roman Zippel Date: Fri, 3 Sep 2004 04:12:12 +0000 Subject: [PATCH] combine.c (try_combine): Delay modifying of insns which cannot be easily undone. * combine.c (try_combine): Delay modifying of insns which cannot be easily undone. From-SVN: r87025 --- gcc/ChangeLog | 5 ++++ gcc/combine.c | 73 +++++++++++++++++++++++++++------------------------ 2 files changed, 44 insertions(+), 34 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index b6b81f8f731..9fff478e8e1 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2004-09-02 Roman Zippel + + * combine.c (try_combine): Delay modifying of insns which cannot + be easily undone. + 2004-09-02 Daniel Berlin * gcc/common.opt: Rename ivcanon to tree-loop-ivcanon, tree-lim to diff --git a/gcc/combine.c b/gcc/combine.c index be1a08c2d66..44d8b292b5d 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -1602,6 +1602,7 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p) int i3_subst_into_i2 = 0; /* Notes that I1, I2 or I3 is a MULT operation. */ int have_mult = 0; + int swap_i2i3 = 0; int maxreg; rtx temp; @@ -2468,40 +2469,7 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p) insn_code_number = recog_for_combine (&newpat, i3, &new_i3_notes); if (insn_code_number >= 0) - { - rtx insn; - rtx link; - - /* If we will be able to accept this, we have made a change to the - destination of I3. This requires us to do a few adjustments. */ - PATTERN (i3) = newpat; - adjust_for_new_dest (i3); - - /* I3 now uses what used to be its destination and which is - now I2's destination. That means we need a LOG_LINK from - I3 to I2. But we used to have one, so we still will. - - However, some later insn might be using I2's dest and have - a LOG_LINK pointing at I3. We must remove this link. - The simplest way to remove the link is to point it at I1, - which we know will be a NOTE. */ - - for (insn = NEXT_INSN (i3); - insn && (this_basic_block->next_bb == EXIT_BLOCK_PTR - || insn != BB_HEAD (this_basic_block->next_bb)); - insn = NEXT_INSN (insn)) - { - if (INSN_P (insn) && reg_referenced_p (ni2dest, PATTERN (insn))) - { - for (link = LOG_LINKS (insn); link; - link = XEXP (link, 1)) - if (XEXP (link, 0) == i3) - XEXP (link, 0) = i1; - - break; - } - } - } + swap_i2i3 = 1; } /* Similarly, check for a case where we have a PARALLEL of two independent @@ -2631,6 +2599,43 @@ try_combine (rtx i3, rtx i2, rtx i1, int *new_direct_jump_p) /* We now know that we can do this combination. Merge the insns and update the status of registers and LOG_LINKS. */ + if (swap_i2i3) + { + rtx insn; + rtx link; + rtx ni2dest; + + /* I3 now uses what used to be its destination and which is now + I2's destination. This requires us to do a few adjustments. */ + PATTERN (i3) = newpat; + adjust_for_new_dest (i3); + + /* We need a LOG_LINK from I3 to I2. But we used to have one, + so we still will. + + However, some later insn might be using I2's dest and have + a LOG_LINK pointing at I3. We must remove this link. + The simplest way to remove the link is to point it at I1, + which we know will be a NOTE. */ + + ni2dest = SET_DEST (newi2pat); + for (insn = NEXT_INSN (i3); + insn && (this_basic_block->next_bb == EXIT_BLOCK_PTR + || insn != BB_HEAD (this_basic_block->next_bb)); + insn = NEXT_INSN (insn)) + { + if (INSN_P (insn) && reg_referenced_p (ni2dest, PATTERN (insn))) + { + for (link = LOG_LINKS (insn); link; + link = XEXP (link, 1)) + if (XEXP (link, 0) == i3) + XEXP (link, 0) = i1; + + break; + } + } + } + { rtx i3notes, i2notes, i1notes = 0; rtx i3links, i2links, i1links = 0; -- 2.30.2