diff options
Diffstat (limited to 'gcc/lower-subreg.c')
| -rw-r--r-- | gcc/lower-subreg.c | 49 |
1 files changed, 47 insertions, 2 deletions
diff --git a/gcc/lower-subreg.c b/gcc/lower-subreg.c index 22a40e629b1..e911205f460 100644 --- a/gcc/lower-subreg.c +++ b/gcc/lower-subreg.c @@ -35,6 +35,7 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA #include "recog.h" #include "bitmap.h" #include "expr.h" +#include "except.h" #include "regs.h" #include "tree-pass.h" @@ -1051,6 +1052,8 @@ decompose_multiword_subregs (bool update_life) int max_regno = max_reg_num (); sbitmap life_blocks; sbitmap sub_blocks; + unsigned int i; + sbitmap_iterator sbi; bitmap_iterator iter; unsigned int regno; @@ -1105,6 +1108,21 @@ decompose_multiword_subregs (bool update_life) rtx orig_insn = insn; bool cfi = control_flow_insn_p (insn); + /* We can end up splitting loads to multi-word pseudos + into separate loads to machine word size pseudos. + When this happens, we first had one load that can + throw, and after resolve_simple_move we'll have a + bunch of loads (at least two). All those loads may + trap if we can have non-call exceptions, so they + all will end the current basic block. We split the + block after the outer loop over all insns, but we + make sure here that we will be able to split the + basic block and still produce the correct control + flow graph for it. */ + gcc_assert (!cfi + || (flag_non_call_exceptions + && can_throw_internal (insn))); + insn = resolve_simple_move (set, insn); if (insn != orig_insn) { @@ -1157,8 +1175,35 @@ decompose_multiword_subregs (bool update_life) update_life_info (life_blocks, UPDATE_LIFE_GLOBAL_RM_NOTES, PROP_DEATH_NOTES); - if (sbitmap_first_set_bit (sub_blocks) >= 0) - find_many_sub_basic_blocks (sub_blocks); + /* If we had insns to split that caused control flow insns in the middle + of a basic block, split those blocks now. Note that we only handle + the case where splitting a load has caused multiple possibly trapping + loads to appear. */ + EXECUTE_IF_SET_IN_SBITMAP (sub_blocks, 0, i, sbi) + { + rtx insn, end; + edge fallthru; + + bb = BASIC_BLOCK (i); + insn = BB_HEAD (bb); + end = BB_END (bb); + + while (insn != end) + { + if (control_flow_insn_p (insn)) + { + /* Split the block after insn. There will be a fallthru + edge, which is OK so we keep it. We have to create the + exception edges ourselves. */ + fallthru = split_block (bb, insn); + rtl_make_eh_edge (NULL, bb, BB_END (bb)); + bb = fallthru->dest; + insn = BB_HEAD (bb); + } + else + insn = NEXT_INSN (insn); + } + } sbitmap_free (life_blocks); sbitmap_free (sub_blocks); |