diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/gcc/cse.c b/gcc/cse.c index fd5e21ac2ee..4d6f76d9328 100644 --- a/gcc/cse.c +++ b/gcc/cse.c @@ -1234,7 +1234,24 @@ insert_regs (rtx x, struct table_elt *classp, int modified) if (REG_P (classp->exp) && GET_MODE (classp->exp) == GET_MODE (x)) { - make_regs_eqv (regno, REGNO (classp->exp)); + unsigned c_regno = REGNO (classp->exp); + + gcc_assert (REGNO_QTY_VALID_P (c_regno)); + + /* Suppose that 5 is hard reg and 100 and 101 are + pseudos. Consider + + (set (reg:si 100) (reg:si 5)) + (set (reg:si 5) (reg:si 100)) + (set (reg:di 101) (reg:di 5)) + + We would now set REG_QTY (101) = REG_QTY (5), but the + entry for 5 is in SImode. When we use this later in + copy propagation, we get the register in wrong mode. */ + if (qty_table[REG_QTY (c_regno)].mode != GET_MODE (x)) + continue; + + make_regs_eqv (regno, c_regno); return 1; } |