diff options
Diffstat (limited to 'gcc/loop.c')
| -rw-r--r-- | gcc/loop.c | 62 |
1 files changed, 39 insertions, 23 deletions
diff --git a/gcc/loop.c b/gcc/loop.c index 89402a547c1..5e3039f18ff 100644 --- a/gcc/loop.c +++ b/gcc/loop.c @@ -262,6 +262,8 @@ struct movable invariant. */ unsigned int move_insn : 1; /* 1 means that we call emit_move_insn to load SRC, rather than copying INSN. */ + unsigned int move_insn_first:1;/* Same as above, if this is necessary for the + first insn of a consecutive sets group. */ unsigned int is_equiv : 1; /* 1 means a REG_EQUIV is present on INSN. */ enum machine_mode savemode; /* Nonzero means it is a mode for a low part that we should avoid changing when clearing @@ -861,6 +863,7 @@ scan_loop (loop_start, end, nregs, unroll_p) m->forces = 0; m->partial = 0; m->move_insn = move_insn; + m->move_insn_first = 0; m->is_equiv = (find_reg_note (p, REG_EQUIV, NULL_RTX) != 0); m->savemode = VOIDmode; m->regno = regno; @@ -885,6 +888,12 @@ scan_loop (loop_start, end, nregs, unroll_p) if (m->consec > 0) { + /* It is possible for the first instruction to have a + REG_EQUAL note but a non-invariant SET_SRC, so we must + remember the status of the first instruction in case + the last instruction doesn't have a REG_EQUAL note. */ + m->move_insn_first = m->move_insn; + /* Skip this insn, not checking REG_LIBCALL notes. */ p = next_nonnote_insn (p); /* Skip the consecutive insns, if there are any. */ @@ -1943,20 +1952,41 @@ move_movables (movables, threshold, insn_count, loop_start, end, nregs) CALL_INSN_FUNCTION_USAGE (i1) = copy_rtx (CALL_INSN_FUNCTION_USAGE (p)); } + else if (count == m->consec && m->move_insn_first) + { + /* The SET_SRC might not be invariant, so we must + use the REG_EQUAL note. */ + start_sequence (); + emit_move_insn (m->set_dest, m->set_src); + temp = get_insns (); + end_sequence (); + + add_label_notes (m->set_src, temp); + + i1 = emit_insns_before (temp, loop_start); + if (! find_reg_note (i1, REG_EQUAL, NULL_RTX)) + REG_NOTES (i1) + = gen_rtx_EXPR_LIST ((m->is_equiv ? REG_EQUIV + : REG_EQUAL), + m->set_src, REG_NOTES (i1)); + } else i1 = emit_insn_before (PATTERN (p), loop_start); - REG_NOTES (i1) = REG_NOTES (p); + if (REG_NOTES (i1) == 0) + { + REG_NOTES (i1) = REG_NOTES (p); - /* If there is a REG_EQUAL note present whose value is - not loop invariant, then delete it, since it may - cause problems with later optimization passes. - It is possible for cse to create such notes - like this as a result of record_jump_cond. */ + /* If there is a REG_EQUAL note present whose value + is not loop invariant, then delete it, since it + may cause problems with later optimization passes. + It is possible for cse to create such notes + like this as a result of record_jump_cond. */ - if ((temp = find_reg_note (i1, REG_EQUAL, NULL_RTX)) - && ! invariant_p (XEXP (temp, 0))) - remove_note (i1, temp); + if ((temp = find_reg_note (i1, REG_EQUAL, NULL_RTX)) + && ! invariant_p (XEXP (temp, 0))) + remove_note (i1, temp); + } if (new_start == 0) new_start = i1; @@ -1965,20 +1995,6 @@ move_movables (movables, threshold, insn_count, loop_start, end, nregs) fprintf (loop_dump_stream, " moved to %d", INSN_UID (i1)); -#if 0 - /* This isn't needed because REG_NOTES is copied - below and is wrong since P might be a PARALLEL. */ - if (REG_NOTES (i1) == 0 - && ! m->partial /* But not if it's a zero-extend clr. */ - && ! m->global /* and not if used outside the loop - (since it might get set outside). */ - && CONSTANT_P (SET_SRC (PATTERN (p)))) - REG_NOTES (i1) - = gen_rtx_EXPR_LIST (REG_EQUAL, - SET_SRC (PATTERN (p)), - REG_NOTES (i1)); -#endif - /* If library call, now fix the REG_NOTES that contain insn pointers, namely REG_LIBCALL on FIRST and REG_RETVAL on I1. */ |