On Thu, May 27, 2021 at 01:07:09PM +0800, Hongtao Liu via Gcc-patches wrote:
> + /* Flag used for call_insn indicates it's a fake call. */
> + RTX_FLAG (insn, used) = 1;
> + /* CALL_INSN use "used" flag to indicate it's a fake call. */
> + if (i == STACK_POINTER_REGNUM
> + && !RTX_FLAG (insn_info->insn, used))
> - && ! SIBLING_CALL_P (insn))
> + && ! SIBLING_CALL_P (insn)
> + && !RTX_FLAG (insn, used))
> - /* For all other RTXes clear the used flag on the copy. */
> - RTX_FLAG (copy, used) = 0;
> + /* For all other RTXes clear the used flag on the copy.
> + CALL_INSN use "used" flag to indicate it's a fake call. */
> + if (!INSN_P (orig))
> + RTX_FLAG (copy, used) = 0;
> break;
> }
> return copy;
> @@ -57,7 +57,8 @@ requires_stack_frame_p (rtx_insn *insn, HARD_REG_SET
> prologue_used,
> HARD_REG_SET hardregs;
> unsigned regno;
>
> - if (CALL_P (insn))
> + /* CALL_INSN use "used" flag to indicate it's a fake call. */
> + if (CALL_P (insn) && !RTX_FLAG (insn, used))
> return !SIBLING_CALL_P (insn);
Please define a macro for this in rtl.h (and mention it above used;
member too in a comment, see all the other comments in there), like:
/* 1 if RTX is a call_insn for a fake call. */
#define FAKE_CALL_P(RTX) \
(RTL_FLAG_CHECK1 ("FAKE_CALL_P", (RTX), CALL_INSN)->used)
Though, I'm also not sure if used can be actually used for this,
because it is used e.g. in emit-rtl.c for verification of RTL sharing.
Though, it seems no other rtl flag is free for CALL_INSN.
Could this fake call flag sit on the CALL rtx instead?
Jakub
