Propagation of the stack pointer in cprop_hardreg is currenty forbidden in all cases, due to maybe_mode_change returning NULL. Relax this restriction and allow propagation when no mode change is requested.
gcc/ChangeLog: * regcprop.cc (maybe_mode_change): Enable stack pointer propagation. Signed-off-by: Manolis Tsamis <manolis.tsa...@vrull.eu> --- gcc/regcprop.cc | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/gcc/regcprop.cc b/gcc/regcprop.cc index f426f4fedcd..6cbfadb181f 100644 --- a/gcc/regcprop.cc +++ b/gcc/regcprop.cc @@ -422,7 +422,12 @@ maybe_mode_change (machine_mode orig_mode, machine_mode copy_mode, 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 stack_pointer_rtx; + else + return NULL_RTX; + } if (orig_mode == new_mode) return gen_raw_REG (new_mode, regno); -- 2.34.1