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| author | Vladimir N. Makarov <vmakarov@redhat.com> | 2023-07-20 14:34:26 -0400 |
|---|---|---|
| committer | Vladimir N. Makarov <vmakarov@redhat.com> | 2023-07-20 14:42:58 -0400 |
| commit | 4b8878fbf7b74ea5c3405c9f558df0517036f131 (patch) | |
| tree | 5d854fc253a2dd88ffd1ddb7f29bb4707c6195f1 | |
| parent | bdda084bc4604467587447fbc4be1c8da0a12665 (diff) | |
| download | gcc-4b8878fbf7b74ea5c3405c9f558df0517036f131.zip gcc-4b8878fbf7b74ea5c3405c9f558df0517036f131.tar.gz gcc-4b8878fbf7b74ea5c3405c9f558df0517036f131.tar.bz2 | |
[LRA]: Exclude reloading of frame pointer in subreg for some cases
LRA for avr port reloads frame pointer in subreg although we can just
simplify the subreg. It results in generation of bad performance code. The following
patch fixes this.
gcc/ChangeLog:
* lra-constraints.cc (simplify_operand_subreg): Check frame pointer
simplification.
| -rw-r--r-- | gcc/lra-constraints.cc | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc index 76a155e..f3784cf 100644 --- a/gcc/lra-constraints.cc +++ b/gcc/lra-constraints.cc @@ -1797,6 +1797,16 @@ simplify_operand_subreg (int nop, machine_mode reg_mode) alter_subreg (curr_id->operand_loc[nop], false); return true; } + auto fp_subreg_can_be_simplified_after_reload_p = [] (machine_mode innermode, + poly_uint64 offset, + machine_mode mode) { + reload_completed = 1; + bool res = simplify_subreg_regno (FRAME_POINTER_REGNUM, + innermode, + offset, mode) >= 0; + reload_completed = 0; + return res; + }; /* Force a reload of the SUBREG_REG if this is a constant or PLUS or if there may be a problem accessing OPERAND in the outer mode. */ @@ -1809,6 +1819,12 @@ simplify_operand_subreg (int nop, machine_mode reg_mode) >= hard_regno_nregs (hard_regno, mode)) && simplify_subreg_regno (hard_regno, innermode, SUBREG_BYTE (operand), mode) < 0 + /* Exclude reloading of frame pointer in subreg if frame pointer can not + be simplified here only because the reload is not finished yet. */ + && (hard_regno != FRAME_POINTER_REGNUM + || !fp_subreg_can_be_simplified_after_reload_p (innermode, + SUBREG_BYTE (operand), + mode)) /* Don't reload subreg for matching reload. It is actually valid subreg in LRA. */ && ! LRA_SUBREG_P (operand)) |