From 0927ce96c9f030dc7676ab4defbcd7e3f0ef61bf Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Thu, 4 May 2000 16:22:26 -0700 Subject: [PATCH] ifcvt.c (noce_process_if_block): Fail if A or B modified between condition and jump. * ifcvt.c (noce_process_if_block): Fail if A or B modified between condition and jump. From-SVN: r33689 --- gcc/ifcvt.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index 7595fcbeb66..79be885fc15 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -1054,11 +1054,6 @@ noce_process_if_block (test_bb, then_bb, else_bb, join_bb) x = SET_DEST (set_a); a = SET_SRC (set_a); - /* X may not be mentioned between cond_earliest and the jump. */ - for (insn = jump; insn != if_info.cond_earliest; insn = PREV_INSN (insn)) - if (INSN_P (insn) && reg_mentioned_p (x, insn)) - return FALSE; - /* Look for the other potential set. Make sure we've got equivalent destinations. */ /* ??? This is overconservative. Storing to two different mems is @@ -1088,6 +1083,17 @@ noce_process_if_block (test_bb, then_bb, else_bb, join_bb) } b = (set_b ? SET_SRC (set_b) : x); + /* X may not be mentioned in the range (cond_earliest, jump]. */ + for (insn = jump; insn != if_info.cond_earliest; insn = PREV_INSN (insn)) + if (INSN_P (insn) && reg_mentioned_p (x, insn)) + return FALSE; + + /* A and B may not be modified in the range [cond_earliest, jump). */ + for (insn = if_info.cond_earliest; insn != jump; insn = NEXT_INSN (insn)) + if (INSN_P (insn) + && (modified_in_p (a, insn) || modified_in_p (b, insn))) + return FALSE; + /* Only operate on register destinations, and even then avoid extending the lifetime of hard registers on small register class machines. */ orig_x = x; -- 2.30.2