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remove type_use

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This is broken, and results in poor performance due to the undefined
behaviour in the LLVM IR. LLVM's `mergefunc` is a *much* better way of
doing this since it merges based on the equality of the bytecode.

For example, consider `std::repr`. It generates different code per
type, but is not included in the type bounds of generics.

The `mergefunc` pass works for most of our code but currently hits an
assert on libstd. It is receiving attention upstream so it will be
ready soon, but I don't think removing this broken code should wait any
longer. I've opened #9536 about enabling it by default.

Closes #8651
Closes #3547
Closes #2537
Closes #6971
Closes #9222
This commit is contained in:
Daniel Micay 2013-09-26 16:54:15 -04:00
parent 47f2e80b65
commit c3e4e06841
9 changed files with 21 additions and 626 deletions
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79
src/etc/monodebug.pl
View file

@ -1,79 +0,0 @@
#!/usr/bin/perl
#
# This is a tool that helps with debugging incorrect monomorphic instance collapse.
#
# To use:
# $ RUST_LOG=rustc::middle::trans::monomorphize rustc ARGS 2>&1 >log.txt
# $ ./monodebug.pl log.txt
#
# This will show all generics that got collapsed. You can inspect this list to find the instances
# that were mistakenly combined into one. Fixes will (most likely) be applied to type_use.rs.
#
# Questions about this tool go to pcwalton.
#
use strict;
use warnings;
use Data::Dumper qw(Dumper);
use Text::Balanced qw(extract_bracketed);
my %funcs;
while (<>) {
chomp;
/^rust: ~"monomorphic_fn\((.*)"$/ or next;
my $text = $1;
$text =~ /fn_id=(\{ crate: \d+, node: \d+ \} \([^)]+\)), real_substs=(.*?), substs=(.*?), hash_id = \@\{ (.*) \}$/ or next;
my ($fn_id, $real_substs, $substs, $hash_id) = ($1, $2, $3, $4);
#print "$hash_id\n";
$hash_id =~ /^def: { crate: \d+, node: \d+ }, params: ~\[ (.*) \], impl_did_opt: (?:None|Some\({ crate: \d+, node: \d+ }\))$/ or next;
my $params = $1;
my @real_substs;
@real_substs = $real_substs =~ /\\"(.*?)\\"/g;
my @mono_params;
while (1) {
$params =~ s/^, //;
if ($params =~ s/^mono_precise//) {
extract_bracketed($params, '()');
push @mono_params, 'precise';
next;
}
if ($params =~ s/^mono_repr//) {
my $sub = extract_bracketed($params, '()');
push @mono_params, "repr($sub)";
next;
}
if ($params =~ s/^mono_any//) {
push @mono_params, "any";
next;
}
last;
}
my @key_params;
for (my $i = 0; $i < @mono_params; ++$i) {
if ($mono_params[$i] eq 'precise') {
push @key_params, 'precise(' . $real_substs[$i] . ')';
} else {
push @key_params, $mono_params[$i];
}
}
my $key = "$fn_id with " . (join ', ', @key_params);
$funcs{$key}{$real_substs} = 1;
}
while (my ($key, $substs) = each %funcs) {
my @params = keys %$substs;
next if @params == 1;
print "$key\n";
print(('-' x (length $key)), $/);
for my $param (@params) {
print "$param\n";
}
print "\n";
}

1
src/etc/zsh/_rust
View file

@ -71,7 +71,6 @@ _rustc_opts_debug=(
'count-type-sizes:count the sizes of aggregate types'
'meta-stats:gather metadata statistics'
'no-opt:do not optimize, even if -O is passed'
'no-monomorphic-collapse:do not collapse template instantiations'
'print-link-args:Print the arguments passed to the linker'
'gc:Garbage collect shared data (experimental)'
'jit:Execute using JIT (experimental)'