diff options
| -rw-r--r-- | gcc/ext-dce.cc | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/gcc/ext-dce.cc b/gcc/ext-dce.cc index 017e2de..eee9208 100644 --- a/gcc/ext-dce.cc +++ b/gcc/ext-dce.cc @@ -207,7 +207,7 @@ ext_dce_process_sets (rtx_insn *insn, rtx obj, bitmap live_tmp) wider than DImode. */ scalar_int_mode outer_mode; if (!is_a <scalar_int_mode> (GET_MODE (x), &outer_mode) - || GET_MODE_BITSIZE (outer_mode) > 64) + || GET_MODE_BITSIZE (outer_mode) > HOST_BITS_PER_WIDE_INT) { /* Skip the subrtxs of this destination. There is little value in iterating into the subobjects, so @@ -239,7 +239,7 @@ ext_dce_process_sets (rtx_insn *insn, rtx obj, bitmap live_tmp) that case. Remember, we can not just continue to process the inner RTXs due to the STRICT_LOW_PART. */ if (!is_a <scalar_int_mode> (GET_MODE (SUBREG_REG (x)), &outer_mode) - || GET_MODE_BITSIZE (outer_mode) > 64) + || GET_MODE_BITSIZE (outer_mode) > HOST_BITS_PER_WIDE_INT) { /* Skip the subrtxs of the STRICT_LOW_PART. We can't process them because it'll set objects as no longer @@ -293,7 +293,7 @@ ext_dce_process_sets (rtx_insn *insn, rtx obj, bitmap live_tmp) the top of the loop which just complicates the flow even more. */ if (!is_a <scalar_int_mode> (GET_MODE (SUBREG_REG (x)), &outer_mode) - || GET_MODE_BITSIZE (outer_mode) > 64) + || GET_MODE_BITSIZE (outer_mode) > HOST_BITS_PER_WIDE_INT) { skipped_dest = true; iter.skip_subrtxes (); @@ -329,7 +329,7 @@ ext_dce_process_sets (rtx_insn *insn, rtx obj, bitmap live_tmp) } /* BIT >= 64 indicates something went horribly wrong. */ - gcc_assert (bit <= 63); + gcc_assert (bit <= HOST_BITS_PER_WIDE_INT - 1); /* Now handle the actual object that was changed. */ if (REG_P (x)) @@ -483,6 +483,17 @@ carry_backpropagate (unsigned HOST_WIDE_INT mask, enum rtx_code code, rtx x) enum machine_mode mode = GET_MODE_INNER (GET_MODE (x)); unsigned HOST_WIDE_INT mmask = GET_MODE_MASK (mode); + + /* While we don't try to optimize operations on types larger + than 64 bits, we do want to make sure not to invoke undefined + behavior when presented with such operations during use + processing. The safe thing to do is to just return mmask + for that scenario indicating every possible chunk is life. */ + scalar_int_mode smode; + if (!is_a <scalar_int_mode> (mode, &smode) + || GET_MODE_BITSIZE (smode) > HOST_BITS_PER_WIDE_INT) + return mmask; + switch (code) { case PLUS: @@ -733,8 +744,17 @@ ext_dce_process_uses (rtx_insn *insn, rtx obj, && SUBREG_PROMOTED_UNSIGNED_P (y))))) break; - /* The SUBREG's mode determine the live width. */ bit = subreg_lsb (y).to_constant (); + + /* If this is a wide object (more bits than we can fit + in a HOST_WIDE_INT), then just break from the SET + context. That will cause the iterator to walk down + into the subrtx and if we land on a REG we'll mark + the whole think live. */ + if (bit >= HOST_BITS_PER_WIDE_INT) + break; + + /* The SUBREG's mode determines the live width. */ if (dst_mask) { dst_mask <<= bit; |