On Sat, Aug 12, 2017 at 3:32 AM, H.J. Lu <[email protected]> wrote:
> When we eliminate frame pointer, we should also replace frame pointer
> with stack pointer - UNITS_PER_WORD in debug insns. This patch fixed:
>
> FAIL: gcc.dg/guality/pr58791-5.c -Os line pr58791-5.c:20 b1 == 9
> FAIL: gcc.dg/guality/pr58791-5.c -Os line pr58791-5.c:20 b2 == 73
> FAIL: gcc.dg/guality/pr58791-5.c -Os line pr58791-5.c:20 b3 == 585
> FAIL: gcc.dg/guality/pr58791-5.c -Os line pr58791-5.c:20 b4 == 4681
> FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:17 s1.f == 5.0
> FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:17 s1.g == 6.0
> FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:17 s2.g == 6.0
> FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:20 s1.f == 5.0
> FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:20 s1.g == 6.0
> FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:20 s2.f == 5.0
> FAIL: gcc.dg/guality/pr59776.c -Os line pr59776.c:20 s2.g == 6.0
>
> on Linux/i386.
>
> Tested on i686 and x86-64. OK for trunk?
>
> H.J.
> ---
>
> PR target/81820
> * config/i386/i386.c (ix86_finalize_stack_frame_flags): Replace
> frame pointer with stack pointer - UNITS_PER_WORD in debug insns.
> ---
> gcc/config/i386/i386.c | 36 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index b04321a8d40..0094f2c4441 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -14281,6 +14281,42 @@ ix86_finalize_stack_frame_flags (void)
> df_scan_blocks ();
> df_compute_regs_ever_live (true);
> df_analyze ();
> +
> + if (flag_var_tracking)
> + {
> + /* Since frame pointer is no longer needed, replace it with
> + stack pointer - UNITS_PER_WORD in debug insns. */
> + df_ref ref, next;
> + for (ref = DF_REG_USE_CHAIN (HARD_FRAME_POINTER_REGNUM);
> + ref; ref = next)
> + {
> + rtx_insn *insn = DF_REF_INSN (ref);
> + /* Make sure the next ref is for a different instruction,
> + so that we're not affected by the rescan. */
> + next = DF_REF_NEXT_REG (ref);
> + while (next && DF_REF_INSN (next) == insn)
> + next = DF_REF_NEXT_REG (next);
Can you please explain why the above loop is needed?
Thanks,
Uros.
> + if (DEBUG_INSN_P (insn))
> + {
> + bool changed = false;
> + for (; ref != next; ref = DF_REF_NEXT_REG (ref))
> + {
> + rtx *loc = DF_REF_LOC (ref);
> + if (*loc == hard_frame_pointer_rtx)
> + {
> + *loc = plus_constant (Pmode,
> + stack_pointer_rtx,
> + -UNITS_PER_WORD);
> + changed = true;
> + }
> + }
> + if (changed)
> + df_insn_rescan (insn);
> + }
> + }
> + }
> +
> recompute_frame_layout_p = true;
> }
>
> --
> 2.13.4
>
