diff options
| author | Richard Biener <rguenther@suse.de> | 2020-04-16 09:37:44 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2020-04-16 12:54:38 +0200 |
| commit | eafeba3e5187a53a4c08a3285b4b220e1ab68b60 (patch) | |
| tree | 130e5753d2a1ad6a56f8c33c1c51c2f13e5e7a2d /gcc/expr.c | |
| parent | 437eea66a4b010d8e94aa81c2b40ccf0588e5fab (diff) | |
middle-end/94614 - avoid multiword moves to nothing
This adjusts emit_move_multi_word to handle moves into paradoxical
subregs parts that are not there and adjusts lower-subregs
CLOBBER resolving to deal with those as well.
2020-04-16 Richard Biener <rguenther@suse.de>
PR middle-end/94614
* expr.c (emit_move_multi_word): Do not generate code when
the destination part is undefined_operand_subword_p.
* lower-subreg.c (resolve_clobber): Look through a paradoxica
subreg.
Diffstat (limited to 'gcc/expr.c')
| -rw-r--r-- | gcc/expr.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/gcc/expr.c b/gcc/expr.c index b97c217e86d..dfbeae71518 100644 --- a/gcc/expr.c +++ b/gcc/expr.c @@ -3692,6 +3692,11 @@ emit_move_multi_word (machine_mode mode, rtx x, rtx y) need_clobber = false; for (i = 0; i < CEIL (mode_size, UNITS_PER_WORD); i++) { + /* Do not generate code for a move if it would go entirely + to the non-existing bits of a paradoxical subreg. */ + if (undefined_operand_subword_p (x, i)) + continue; + rtx xpart = operand_subword (x, i, 1, mode); rtx ypart; |