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| author | Richard Sandiford <richard.sandiford@arm.com> | 2019-07-01 08:58:35 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2019-07-01 08:58:35 +0000 |
| commit | ae5569fa33c9f3286e0b747f8b6607d21a4b9827 (patch) | |
| tree | e304d56814b85dc09725acc219dd030b3af23839 /gcc | |
| parent | ed680e2cc18c73f90e6bfbd3f346a8820476371b (diff) | |
| download | gcc-ae5569fa33c9f3286e0b747f8b6607d21a4b9827.zip gcc-ae5569fa33c9f3286e0b747f8b6607d21a4b9827.tar.gz gcc-ae5569fa33c9f3286e0b747f8b6607d21a4b9827.tar.bz2 | |
Allow earlyclobbers in ira_get_dup_out_num
ira_get_dup_out_num punted on operands that are matched to
earlyclobber outputs:
/* It is better ignore an alternative with early clobber. */
else if (*str == '&')
goto fail;
But I'm not sure why this is the right thing to do. At this stage
we've established that *all* alternatives of interest require the
input to match the output, so
(a) the earlyclobber can only affect other operands and
(b) not tying the registers is bound to introduce a move
The code was part of the initial commit and so isn't obviously
related to a specific testcase. Also, I can imagine LRA makes
a much better job of this situation than reload did. (Certainly
SVE uses matched earlyclobbers extensively and I haven't seen any
problems.)
In case this turns out to regress something important: the main
case that matters for SVE is the one in which all alternatives
are earlyclobber.
2019-07-01 Richard Sandiford <richard.sandiford@arm.com>
gcc/
* ira.c (ira_get_dup_out_num): Don't punt for earlyclobbers.
Use recog_data to test for an output operand.
From-SVN: r272850
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/ira.c | 22 |
2 files changed, 7 insertions, 20 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8f70d1b..b49bc69 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2019-07-01 Richard Sandiford <richard.sandiford@arm.com> + * ira.c (ira_get_dup_out_num): Don't punt for earlyclobbers. + Use recog_data to test for an output operand. + +2019-07-01 Richard Sandiford <richard.sandiford@arm.com> + * ira.c (ira_setup_alts): If any valid alternatives have zero cost, exclude any others that are disparaged or that are bound to need a reload or spill. @@ -1999,26 +1999,8 @@ ira_get_dup_out_num (int op_num, alternative_mask alts) } if (original == -1) goto fail; - dup = -1; - for (ignore_p = false, str = recog_data.constraints[original - '0']; - *str != 0; - str++) - if (ignore_p) - { - if (*str == ',') - ignore_p = false; - } - else if (*str == '#') - ignore_p = true; - else if (! ignore_p) - { - if (*str == '=') - dup = original - '0'; - /* It is better ignore an alternative with early clobber. */ - else if (*str == '&') - goto fail; - } - if (dup >= 0) + dup = original - '0'; + if (recog_data.operand_type[dup] == OP_OUT) return dup; fail: if (use_commut_op_p) |