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| author | Georg-Johann Lay <avr@gjlay.de> | 2024-11-30 14:58:05 +0100 |
|---|---|---|
| committer | Georg-Johann Lay <avr@gjlay.de> | 2024-11-30 15:13:37 +0100 |
| commit | 214985f6b35ea8038c4e96590b435aaef2919769 (patch) | |
| tree | 704454a22a31cac35c48e835c275b9c2f8582ce7 | |
| parent | 6bebb3b0f3fa422d248a1c2075da0598a44c7320 (diff) | |
| download | gcc-214985f6b35ea8038c4e96590b435aaef2919769.zip gcc-214985f6b35ea8038c4e96590b435aaef2919769.tar.gz gcc-214985f6b35ea8038c4e96590b435aaef2919769.tar.bz2 | |
AVR: ad target/84211 - Split MOVW into MOVs in try_split_any.
When splitting multi-byte REG-REG moves in try_split_any(),
it's not clear whether propagating constants will turn
out as profitable. When MOVW is available, split into
REG-REG moves instead of a possible REG-CONST.
gcc/
PR target/84211
* config/avr/avr-passes.cc (try_split_any) [SET, MOVW]: Prefer
reg=reg move over reg=const when splitting a reg=reg insn.
| -rw-r--r-- | gcc/config/avr/avr-passes.cc | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/gcc/config/avr/avr-passes.cc b/gcc/config/avr/avr-passes.cc index 68ebd31..7be5ec2 100644 --- a/gcc/config/avr/avr-passes.cc +++ b/gcc/config/avr/avr-passes.cc @@ -2912,6 +2912,14 @@ optimize_data_t::try_split_any (bbinfo_t *) xsrc = gen_rtx_REG (HImode, r16); i += step; } + // ...or a reg-reg move from a multi-byte move... + else if (r_src + // Prefer a reg-reg move over a (potential) load + // of a constant, because the subsequent RTL + // peephole pass may combine it to a MOVW again. + && AVR_HAVE_MOVW + && REG_P (curr.ii.m_src)) + xsrc = gen_rtx_REG (QImode, r_src); // ...or a cheap constant... else if (val8 >= 0 && AVRasm::constant_cost (SET, r_dest, val8) <= 1) |