diff options
Diffstat (limited to 'gcc/lra-constraints.c')
| -rw-r--r-- | gcc/lra-constraints.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c index e4e6c8c47eb..bf08dce2e0a 100644 --- a/gcc/lra-constraints.c +++ b/gcc/lra-constraints.c @@ -2474,14 +2474,27 @@ process_alt_operands (int only_alternative) /* We are trying to spill pseudo into memory. It is usually more costly than moving to a hard register although it might takes the same number of - reloads. */ - if (no_regs_p && REG_P (op) && hard_regno[nop] >= 0) + reloads. + + Non-pseudo spill may happen also. Suppose a target allows both + register and memory in the operand constraint alternatives, + then it's typical that an eliminable register has a substition + of "base + offset" which can either be reloaded by a simple + "new_reg <= base + offset" which will match the register + constraint, or a similar reg addition followed by further spill + to and reload from memory which will match the memory + constraint, but this memory spill will be much more costly + usually. + + Code below increases the reject for both pseudo and non-pseudo + spill. */ + if (no_regs_p && !(REG_P (op) && hard_regno[nop] < 0)) { if (lra_dump_file != NULL) fprintf (lra_dump_file, - " %d Spill pseudo into memory: reject+=3\n", - nop); + " %d Spill %spseudo into memory: reject+=3\n", + nop, REG_P (op) ? "" : "Non-"); reject += 3; if (VECTOR_MODE_P (mode)) { |