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| author | Segher Boessenkool <segher@kernel.crashing.org> | 2017-11-29 23:51:16 +0100 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2017-11-29 23:51:16 +0100 |
| commit | 3d985316b89f2551a8fb39687bf4972b372ffdd7 (patch) | |
| tree | 18c98170abdf7bfb6a805c7fba55b1797cfbd691 /gcc | |
| parent | 4a01617886c1833f456948048e5167dac784ef19 (diff) | |
| download | gcc-3d985316b89f2551a8fb39687bf4972b372ffdd7.zip gcc-3d985316b89f2551a8fb39687bf4972b372ffdd7.tar.gz gcc-3d985316b89f2551a8fb39687bf4972b372ffdd7.tar.bz2 | |
combine: Print to dump if some insn cannot be combined into i3
Eventually we should print the reason that any combination fails.
This is a good start (these happen often).
* combine.c (try_combine): Print a message to dump file whenever
I0, I1, or I2 cannot be combined into I3.
From-SVN: r255261
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/combine.c | 24 |
2 files changed, 23 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index c13f67e..d1838f1 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2017-11-29 Segher Boessenkool <segher@kernel.crashing.org> + * combine.c (try_combine): Print a message to dump file whenever + I0, I1, or I2 cannot be combined into I3. + +2017-11-29 Segher Boessenkool <segher@kernel.crashing.org> + PR rtl-optimization/83156 PR rtl-optimization/82621 * combine.c (try_combine): Don't split an I2 if one of the dests is diff --git a/gcc/combine.c b/gcc/combine.c index cfe24f4..863abd7 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -3035,13 +3035,25 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, SUBST (PATTERN (i2), XVECEXP (PATTERN (i2), 0, 1)); } - /* Verify that I2 and I1 are valid for combining. */ - if (! can_combine_p (i2, i3, i0, i1, NULL, NULL, &i2dest, &i2src) - || (i1 && ! can_combine_p (i1, i3, i0, NULL, i2, NULL, - &i1dest, &i1src)) - || (i0 && ! can_combine_p (i0, i3, NULL, NULL, i1, i2, - &i0dest, &i0src))) + /* Verify that I2 and maybe I1 and I0 can be combined into I3. */ + if (!can_combine_p (i2, i3, i0, i1, NULL, NULL, &i2dest, &i2src)) { + if (dump_file) + fprintf (dump_file, "Can't combine i2 into i3\n"); + undo_all (); + return 0; + } + if (i1 && !can_combine_p (i1, i3, i0, NULL, i2, NULL, &i1dest, &i1src)) + { + if (dump_file) + fprintf (dump_file, "Can't combine i1 into i3\n"); + undo_all (); + return 0; + } + if (i0 && !can_combine_p (i0, i3, NULL, NULL, i1, i2, &i0dest, &i0src)) + { + if (dump_file) + fprintf (dump_file, "Can't combine i0 into i3\n"); undo_all (); return 0; } |