https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81312
Bug ID: 81312
Summary: Enable X86_TUNE_ACCUMULATE_OUTGOING_ARGS
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
CC: hubicka at ucw dot cz, ubizjak at gmail dot com
Target Milestone: ---
x86-tune.def has
* X86_TUNE_ACCUMULATE_OUTGOING_ARGS: Allocate stack space for outgoing
arguments in prologue/epilogue instead of separately for each call
by push/pop instructions.
This increase code size by about 5% in 32bit mode, less so in 64bit mode
because parameters are passed in registers. It is considerable
win for targets without stack engine that prevents multple push operations
to happen in parallel.
FIXME: the flags is incorrectly enabled for amdfam10, Bulldozer,
Bobcat and Generic. This is because disabling it causes large
regression on mgrid due to IRA limitation leading to unecessary
use of the frame pointer in 32bit mode. */
DEF_TUNE (X86_TUNE_ACCUMULATE_OUTGOING_ARGS, "accumulate_outgoing_args",
m_PPRO | m_P4_NOCONA | m_BONNELL | m_SILVERMONT | m_KNL | m_INTEL
| m_ATHLON_K8)
Is this still true today for the current AMD processors? If yes, I'd like
to enable it for 64-bit -mtune=generic.
