diff options
Diffstat (limited to 'gcc/df-scan.c')
| -rw-r--r-- | gcc/df-scan.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/gcc/df-scan.c b/gcc/df-scan.c index e9da64f..3dbda7a 100644 --- a/gcc/df-scan.c +++ b/gcc/df-scan.c @@ -2576,9 +2576,21 @@ df_ref_record (enum df_ref_class cl, if (GET_CODE (reg) == SUBREG) { - regno += subreg_regno_offset (regno, GET_MODE (SUBREG_REG (reg)), - SUBREG_BYTE (reg), GET_MODE (reg)); - endregno = regno + subreg_nregs (reg); + int off = subreg_regno_offset (regno, GET_MODE (SUBREG_REG (reg)), + SUBREG_BYTE (reg), GET_MODE (reg)); + unsigned int nregno = regno + off; + endregno = nregno + subreg_nregs (reg); + if (off < 0 && regno < (unsigned) -off) + /* Deal with paradoxical SUBREGs on big endian where + in debug insns the hard reg number might be smaller + than -off, such as (subreg:DI (reg:SI 0 [+4 ]) 0)); + RA decisions shouldn't be affected by debug insns + and so RA can decide to put pseudo into a hard reg + with small REGNO, even when it is referenced in + a paradoxical SUBREG in a debug insn. */ + regno = 0; + else + regno = nregno; } else endregno = END_REGNO (reg); |