diff options
| author | Jeff Law <law@redhat.com> | 2017-04-18 09:00:43 -0600 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2017-04-18 09:00:43 -0600 |
| commit | d1446456c3fcaa7be628726c9de4a877729490ca (patch) | |
| tree | bf42d7f94795c94d38ce7af3875c9809475a0fa8 /gcc/regcprop.c | |
| parent | 8c468e1dcd29c3ca6d0ee2d9099c22b10e24e0ac (diff) | |
regcprop.c (maybe_mode_change): Avoid creating copies of the stack pointer.
* regcprop.c (maybe_mode_change): Avoid creating copies of the
stack pointer.
Revert:
2017-04-13 Jeff Law <law@redhat.com>
* config/mips.mips.md (zero_extendsidi2): Do not allow SP to appear
in operands[1] if it is a MEM and TARGET_MIPS16 is active.
From-SVN: r246970
Diffstat (limited to 'gcc/regcprop.c')
| -rw-r--r-- | gcc/regcprop.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/gcc/regcprop.c b/gcc/regcprop.c index ddc6252f53a..367d85a7e24 100644 --- a/gcc/regcprop.c +++ b/gcc/regcprop.c @@ -396,6 +396,13 @@ maybe_mode_change (machine_mode orig_mode, machine_mode copy_mode, && GET_MODE_SIZE (copy_mode) < GET_MODE_SIZE (new_mode)) return NULL_RTX; + /* Avoid creating multiple copies of the stack pointer. Some ports + assume there is one and only one stack pointer. + + It's unclear if we need to do the same for other special registers. */ + if (regno == STACK_POINTER_REGNUM) + return NULL_RTX; + if (orig_mode == new_mode) return gen_raw_REG (new_mode, regno); else if (mode_change_ok (orig_mode, new_mode, regno)) |