On Thu, Jun 03, 2021 at 02:54:07PM +0800, liuhongt wrote:
> Use "used" flag for CALL_INSN to indicate it's a fake call. If it's a
> fake call, it won't have its own function stack.
>
> gcc/ChangeLog
>
> PR target/82735
> * df-scan.c (df_get_call_refs): When call_insn is a fake call,
> it won't use stack pointer reg.
> * final.c (leaf_function_p): When call_insn is a fake call, it
> won't affect caller as a leaf function.
> * reg-stack.c (callee_clobbers_any_stack_reg): New.
> (subst_stack_regs): When call_insn doesn't clobber any stack
> reg, don't clear the arguments.
> * rtl.c (shallow_copy_rtx): Don't clear flag used when orig is
> a insn.
> * shrink-wrap.c (requires_stack_frame_p): No need for stack
> frame for a fake call.
> * rtl.h (FAKE_CALL_P): New macro.
Ok, thanks.
Jakub
