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| author | Richard Sandiford <richard.sandiford@arm.com> | 2024-01-12 12:38:00 +0000 |
|---|---|---|
| committer | Richard Sandiford <richard.sandiford@arm.com> | 2024-01-12 12:38:00 +0000 |
| commit | 0d74ff2d7e6cb0698282c506b6655cc06bcfe3d8 (patch) | |
| tree | 13caafe2d2f368ce3799f4537fc80b901ea7b33b /gcc | |
| parent | 81d309168b2a058d4c8ad5430abb56cfe1f82188 (diff) | |
| download | gcc-0d74ff2d7e6cb0698282c506b6655cc06bcfe3d8.zip gcc-0d74ff2d7e6cb0698282c506b6655cc06bcfe3d8.tar.gz gcc-0d74ff2d7e6cb0698282c506b6655cc06bcfe3d8.tar.bz2 | |
Keep track of the FUNCTION_BEG note
function.cc emits a NOTE_FUNCTION_BEG after all arguments have
been copied to pseudos. It then records this note in parm_birth_insn.
Various other pieces of code use this insn as a convenient place to
insert things at the start of the function.
However, cfgexpand later changes parm_birth_insn as follows:
/* If we emitted any instructions for setting up the variables,
emit them before the FUNCTION_START note. */
if (var_seq)
{
emit_insn_before (var_seq, parm_birth_insn);
/* In expand_function_end we'll insert the alloca save/restore
before parm_birth_insn. We've just insertted an alloca call.
Adjust the pointer to match. */
parm_birth_insn = var_seq;
}
But the FUNCTION_BEG note is still useful for things that aren't
sensitive to stack allocation, and it has the advantage that
(unlike the var_seq above) it is never deleted or combined.
This patch adds a separate variable to track it.
gcc/
* emit-rtl.h (rtl_data::x_function_beg_note): New member variable.
(function_beg_insn): New macro.
* function.cc (expand_function_start): Initialize function_beg_insn.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/emit-rtl.h | 4 | ||||
| -rw-r--r-- | gcc/function.cc | 2 |
2 files changed, 5 insertions, 1 deletions
diff --git a/gcc/emit-rtl.h b/gcc/emit-rtl.h index f749ca9..34f44cb 100644 --- a/gcc/emit-rtl.h +++ b/gcc/emit-rtl.h @@ -141,6 +141,9 @@ struct GTY(()) rtl_data { If stack grows up, this is the address for the next slot. */ poly_int64 x_frame_offset; + /* The function's FUNCTION_BEG note. */ + rtx_insn *x_function_beg_insn; + /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */ rtx_insn *x_parm_birth_insn; @@ -323,6 +326,7 @@ struct GTY(()) rtl_data { #define return_label (crtl->x_return_label) #define naked_return_label (crtl->x_naked_return_label) #define stack_slot_list (crtl->x_stack_slot_list) +#define function_beg_insn (crtl->x_function_beg_insn) #define parm_birth_insn (crtl->x_parm_birth_insn) #define frame_offset (crtl->x_frame_offset) #define stack_check_probe_note (crtl->x_stack_check_probe_note) diff --git a/gcc/function.cc b/gcc/function.cc index de356f7..5ffd438 100644 --- a/gcc/function.cc +++ b/gcc/function.cc @@ -5202,7 +5202,7 @@ expand_function_start (tree subr) gcc_assert (NOTE_P (get_last_insn ())); - parm_birth_insn = get_last_insn (); + function_beg_insn = parm_birth_insn = get_last_insn (); /* If the function receives a non-local goto, then store the bits we need to restore the frame pointer. */ |