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| author | Vladimir Makarov <vmakarov@redhat.com> | 2017-04-07 16:01:50 +0000 |
|---|---|---|
| committer | Vladimir Makarov <vmakarov@gcc.gnu.org> | 2017-04-07 16:01:50 +0000 |
| commit | 057da7af80d2fca356032c22efefcaf50d04da8b (patch) | |
| tree | 1440f552945d7e20bb953c464d47bae09d44299b /gcc/lra-constraints.c | |
| parent | e3d1043293beed1696e6cb68f19d3bd6fb44c3b0 (diff) | |
| download | gcc-057da7af80d2fca356032c22efefcaf50d04da8b.zip gcc-057da7af80d2fca356032c22efefcaf50d04da8b.tar.gz gcc-057da7af80d2fca356032c22efefcaf50d04da8b.tar.bz2 | |
re PR rtl-optimization/70478 ([LRA] S/390: Performance regression - superfluous stack frame)
2017-04-07 Vladimir Makarov <vmakarov@redhat.com>
PR rtl-optimization/70478
* lra-constraints.c (process_alt_operands): Disfavor alternative
insn memory operands.
2017-04-07 Vladimir Makarov <vmakarov@redhat.com>
PR rtl-optimization/70478
* gcc.target/s390/pr70478.c: New.
From-SVN: r246764
Diffstat (limited to 'gcc/lra-constraints.c')
| -rw-r--r-- | gcc/lra-constraints.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c index 4d98624..9440205 100644 --- a/gcc/lra-constraints.c +++ b/gcc/lra-constraints.c @@ -2685,6 +2685,21 @@ process_alt_operands (int only_alternative) } } + /* When we use memory operand, the insn should read the + value from memory and even if we just wrote a value + into the memory it is costly in comparison with an + insn alternative which does not use memory + (e.g. register or immediate operand). */ + if (no_regs_p && offmemok) + { + if (lra_dump_file != NULL) + fprintf + (lra_dump_file, + " Using memory insn operand %d: reject+=3\n", + nop); + reject += 3; + } + #ifdef SECONDARY_MEMORY_NEEDED /* If reload requires moving value through secondary memory, it will need one more insn at least. */ |