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| author | Richard Henderson <rth@cygnus.com> | 2000-04-30 23:55:44 -0700 |
|---|---|---|
| committer | Richard Henderson <rth@gcc.gnu.org> | 2000-04-30 23:55:44 -0700 |
| commit | c4686982aaf87c31ecb76bb361ec3a6685913e4b (patch) | |
| tree | 39852d20e67e689559350a4521e3abf6099689cc /gcc/ifcvt.c | |
| parent | 5724a0e6410d5f68761acc1ba338cce11d3677c8 (diff) | |
| download | gcc-c4686982aaf87c31ecb76bb361ec3a6685913e4b.tar.gz | |
ifcvt.c (noce_process_if_block): Fail the conversion if X is referenced bewteen the condition and the jump.
* ifcvt.c (noce_process_if_block): Fail the conversion if X is
referenced bewteen the condition and the jump. Don't delete
anything but the jump.
From-SVN: r33563
Diffstat (limited to 'gcc/ifcvt.c')
| -rw-r--r-- | gcc/ifcvt.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index b831b3e14d2..ba310da9d84 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -1024,7 +1024,7 @@ noce_process_if_block (test_bb, then_bb, else_bb, join_bb) rtx insn_a, insn_b; rtx set_a, set_b; rtx orig_x, x, a, b; - rtx jump, cond; + rtx jump, cond, insn; /* If this is not a standard conditional jump, we can't parse it. */ jump = test_bb->end; @@ -1046,6 +1046,11 @@ 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 @@ -1165,10 +1170,10 @@ noce_process_if_block (test_bb, then_bb, else_bb, join_bb) } /* The new insns will have been inserted before cond_earliest. We should - be able to remove cond_earliest through the jump with impunity. */ - insn_a = prev_nonnote_insn (if_info.cond_earliest); - flow_delete_insn_chain (if_info.cond_earliest, test_bb->end); - test_bb->end = insn_a; + be able to remove the jump with impunity, but the condition itself may + have been modified by gcse to be shared across basic blocks. */ + test_bb->end = PREV_INSN (jump); + flow_delete_insn (jump); /* If we used a temporary, fix it up now. */ if (orig_x != x) @@ -1178,7 +1183,7 @@ noce_process_if_block (test_bb, then_bb, else_bb, join_bb) insn_b = gen_sequence (); end_sequence (); - test_bb->end = emit_insn_after (insn_b, insn_a); + test_bb->end = emit_insn_after (insn_b, test_bb->end); } /* Merge the blocks! */ |