diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 16 |
1 files changed, 14 insertions, 2 deletions
@@ -4715,8 +4715,20 @@ cse_insn (rtx_insn *insn) /* Compute SRC's hash code, and also notice if it should not be recorded at all. In that case, - prevent any further processing of this assignment. */ - do_not_record = 0; + prevent any further processing of this assignment. + + We set DO_NOT_RECORD if the destination has a REG_UNUSED note. + This avoids getting the source register into the tables, where it + may be invalidated later (via REG_QTY), then trigger an ICE upon + re-insertion. + + This is only a problem in multi-set insns. If it were a single + set the dead copy would have been removed. If the RHS were anything + but a simple REG, then we won't call insert_regs and thus there's + no potential for triggering the ICE. */ + do_not_record = (REG_P (dest) + && REG_P (src) + && find_reg_note (insn, REG_UNUSED, dest)); hash_arg_in_memory = 0; sets[i].src = src; |