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authorBjörn Gustavsson <[email protected]>2017-09-19 11:56:45 +0200
committerBjörn Gustavsson <[email protected]>2017-10-05 12:37:57 +0200
commitf88bd45a2c76f84a16b004922945579898cc35ac (patch)
tree22ffd02d93cd1d0f7b03780e84f3c5ada3a86139 /erts/emulator/utils/beam_makeops
parent22d2a00aebf0eef878af95d8b7598adbfca06e7e (diff)
downloadotp-f88bd45a2c76f84a16b004922945579898cc35ac.tar.gz
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Pack operands into the instruction word
On 64-bit machines where the C code is always at address below 4Gb, pack one or more operands into the instruction word.
Diffstat (limited to 'erts/emulator/utils/beam_makeops')
-rwxr-xr-xerts/emulator/utils/beam_makeops304
1 files changed, 215 insertions, 89 deletions
diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops
index 64a9a49ac8..388e3d164d 100755
--- a/erts/emulator/utils/beam_makeops
+++ b/erts/emulator/utils/beam_makeops
@@ -24,6 +24,16 @@ use constant COLD => 0;
use constant WARM => 1;
use constant HOT => 2;
+# Instructions for packing
+use constant PACK_JUMP => 1;
+use constant PACK_IN_INSTR_WORD => 2;
+
+# Packing commands
+use constant PACK_CMD_TIGHTEST => '1';
+use constant PACK_CMD_TIGHT => '2';
+use constant PACK_CMD_LOOSE => '3';
+use constant PACK_CMD_WIDE => '4';
+
$BEAM_FORMAT_NUMBER = undef;
my $target = \&emulator_output;
@@ -32,30 +42,15 @@ my $verbose = 0;
my $hotness = 1;
my $num_file_opcodes = 0;
my $wordsize = 32;
-my %defs; # Defines (from command line).
+my $code_pointers_are_short = 0; # Whether code pointers (to C code) are short.
+my $code_model = 'unknown';
+my %defs; # Defines (from command line).
# This is shift counts and mask for the packer.
my $WHOLE_WORD = '';
-my @pack_instr;
-my @pack_shift;
-my @pack_mask;
-
-$pack_instr[2] = ['6', 'i'];
-$pack_instr[3] = ['0', '0', 'i'];
-$pack_instr[4] = ['6', '6', '6', 'i']; # Only for 64 bit wordsize
-
-$pack_shift[2] = ['0', 'BEAM_LOOSE_SHIFT'];
-$pack_shift[3] = ['0', 'BEAM_TIGHT_SHIFT', '(2*BEAM_TIGHT_SHIFT)'];
-$pack_shift[4] = ['0', 'BEAM_LOOSE_SHIFT', # Only for 64 bit wordsize
- '(2*BEAM_LOOSE_SHIFT)',
- '(3*BEAM_LOOSE_SHIFT)'];
-
-$pack_mask[2] = ['BEAM_LOOSE_MASK', $WHOLE_WORD];
-$pack_mask[3] = ['BEAM_TIGHT_MASK', 'BEAM_TIGHT_MASK', 'BEAM_TIGHT_MASK'];
-$pack_mask[4] = ['BEAM_LOOSE_MASK', # Only for 64 bit wordsize
- 'BEAM_LOOSE_MASK',
- 'BEAM_LOOSE_MASK',
- $WHOLE_WORD];
+
+my @basic_pack_options = (0);
+my @extended_pack_options = @basic_pack_options;
# There are two types of instructions: generic and specific.
# The generic instructions are those generated by the Beam compiler.
@@ -250,6 +245,7 @@ while (@ARGV && $ARGV[0] =~ /^-(.*)/) {
($target = \&compiler_output), next if /^compiler/;
($outdir = shift), next if /^outdir/;
($wordsize = shift), next if /^wordsize/;
+ ($code_model = shift), next if /^code-model/;
($verbose = 1), next if /^v/;
($defs{$1} = $2), next if /^D(\w+)=(\w+)/;
die "$0: Bad option: -$_\n";
@@ -261,14 +257,21 @@ if ($wordsize == 32) {
} elsif ($wordsize == 64) {
$defs{'ARCH_32'} = 0;
$defs{'ARCH_64'} = 1;
+ $code_pointers_are_short = $code_model eq 'small';
}
#
-# Initialize number of arguments per packed word.
+# Initialize pack options.
#
if ($wordsize == 64) {
- $pack_mask[3] = ['BEAM_TIGHT_MASK', 'BEAM_TIGHT_MASK', $WHOLE_WORD];
+ @basic_pack_options = (0,PACK_JUMP);
+ @extended_pack_options = @basic_pack_options;
+ if ($code_pointers_are_short) {
+ foreach (@basic_pack_options) {
+ push @extended_pack_options, $_ | PACK_IN_INSTR_WORD;
+ }
+ }
}
#
@@ -732,12 +735,19 @@ sub emulator_output {
print "#if !defined(ARCH_64)\n";
print qq[ #error "64-bit architecture assumed, but ARCH_64 not defined"\n];
print "#endif\n";
+ if ($code_pointers_are_short) {
+ print "#if !defined(CODE_MODEL_SMALL)\n";
+ print qq[ #error "small code model assumed, but CODE_MODEL_SMALL not defined"\n];
+ print "#endif\n";
+ }
print "#define BEAM_WIDE_MASK 0xFFFFFFFFull\n";
print "#define BEAM_LOOSE_MASK 0xFFFFull\n";
print "#define BEAM_TIGHT_MASK 0xFFFFull\n";
+ print "#define BEAM_TIGHTEST_MASK 0x3FFull\n";
print "#define BEAM_WIDE_SHIFT 32\n";
print "#define BEAM_LOOSE_SHIFT 16\n";
print "#define BEAM_TIGHT_SHIFT 16\n";
+ print "#define BEAM_TIGHTEST_SHIFT 10\n";
}
print "\n";
@@ -1138,7 +1148,7 @@ sub combine_instruction_group {
foreach (0..$#c_args) {
push @first, shift @rest;
}
- my $size = cg_combined_size($s, 1, @first);
+ my $size = cg_combined_size($s, @first);
$offsets{$s} = $offset
unless defined $offsets{$s} and $offsets{$s} < $offset;
$offset += $size - 1;
@@ -1229,7 +1239,7 @@ sub combine_instruction_group {
}
my($gen_code,$down,$up) =
- cg_combined_code($s, 1, $flags, $offset,
+ cg_combined_code($s, $flags, $offset,
$group_size-$offset, $inc, @first);
my $spec_label = "$opcase$label";
$down{$spec_label} = $down;
@@ -1280,7 +1290,7 @@ sub micro_label {
sub cg_basic {
my($name,@args) = @_;
- my($size,$code,$pack_spec) = code_gen($name, 1, '', 0, undef, undef, @args);
+ my($size,$code,$pack_spec) = code_gen($name, \@extended_pack_options, '', 0, undef, undef, @args);
$pack_spec = build_pack_spec($pack_spec);
($size,$code,$pack_spec);
}
@@ -1290,8 +1300,8 @@ sub cg_basic {
#
sub cg_combined_size {
- my($name,$pack,@args) = @_;
- my($size) = code_gen($name, $pack, '', 0, undef, undef, @args);
+ my($name,@args) = @_;
+ my($size) = code_gen($name, \@basic_pack_options, '', 0, undef, undef, @args);
$size;
}
@@ -1300,8 +1310,9 @@ sub cg_combined_size {
#
sub cg_combined_code {
- my($name,$pack,$extra_comments,$offset,$comp_size,$inc,@args) = @_;
- my($size,$code,$pack_spec) = code_gen(@_);
+ my($name,$extra,$offset,$comp_size,$inc,@args) = @_;
+ my($size,$code,$pack_spec) =
+ code_gen($name, \@basic_pack_options, $extra, $offset, $comp_size, $inc, @args);
if ($pack_spec eq '') {
($code,'','');
} else {
@@ -1311,7 +1322,7 @@ sub cg_combined_code {
}
sub code_gen {
- my($name,$pack,$extra_comments,$offset,$comp_size,$inc,@args) = @_;
+ my($name,$pack_options,$extra_comments,$offset,$comp_size,$inc,@args) = @_;
my $group_size = defined $comp_size ? $comp_size + $inc : undef;
my $size = 0;
my $flags = '';
@@ -1326,8 +1337,8 @@ sub code_gen {
#
my $c_code_ref = $c_code{$name};
- if ($pack and defined $c_code_ref and $name ne 'catch') {
- ($var_decls, $pack_spec, @args) = do_pack($offset, @args);
+ if (defined $c_code_ref and $name ne 'catch') {
+ ($var_decls, $pack_spec, @args) = do_pack($offset, $pack_options, @args);
}
#
@@ -1603,9 +1614,25 @@ sub needs_do_wrapper {
}
sub do_pack {
- my($offset,@args) = @_;
+ my($offset,$pack_options,@args) = @_;
+ my $ret = ['', ':', @args];
+ my $score = 0;
+
+ foreach my $options (@$pack_options) {
+ my($this_score,$this_result) = do_pack_one($options, $offset, @args);
+ if ($this_score > $score) {
+ $ret = $this_result;
+ $score = $this_score;
+ }
+ }
+ return @$ret;
+}
+
+sub do_pack_one {
+ my($options,$offset,@args) = @_;
my($packable_args) = 0;
my @bits_needed; # Bits needed for each argument.
+ my $pack_in_iw = $options & PACK_IN_INSTR_WORD;
#
# Define the minimum number of bits needed for the packable argument types.
@@ -1619,6 +1646,10 @@ sub do_pack {
't' => 16);
if ($wordsize == 64) {
$bits_needed{'I'} = 32;
+ if ($options & PACK_JUMP) {
+ $bits_needed{'f'} = 32;
+ $bits_needed{'j'} = 32;
+ }
}
#
@@ -1631,51 +1662,46 @@ sub do_pack {
} else {
push @bits_needed, 0;
}
- }
-
- #
- # Try to pack 'f' and 'j', but not at expense at worse packing
- # for other operands. For example, given the arguments "f x x", we
- # want the 'x' operands to be packed, not 'f' and 'x' packed and
- # the final 'x' not packed.
- #
-
- if ($wordsize == 64 and $packable_args == 1) {
- for (my $i = 0; $i < @args; $i++) {
- if ($args[$i] =~ /^[fj]$/) {
- $bits_needed[$i] = 32;
- $packable_args++;
- last;
- }
+ if ($arg =~ /^[fj]$/) {
+ # Only pack the first occurrence of 'f' or 'j'.
+ delete $bits_needed{'f'};
+ delete $bits_needed{'j'};
}
}
#
- # Nothing to pack unless there are at least 2 packable arguments.
+ # Return if there is nothing to pack.
#
- return ('', ':', @args) if $packable_args < 2;
+ if ($packable_args == 0) {
+ return (-1);
+ } elsif ($packable_args == 1 and !$pack_in_iw) {
+ return (-1);
+ }
#
# Determine how many arguments we should pack into each word.
#
my @args_per_word;
my @need_wide_mask;
- my $bits = 0;
- my $word = 0;
- $args_per_word[0] = 0;
- $need_wide_mask[0] = 0;
+ my $bits;
+ my $this_wordsize;
+ my $word = -1;
+
+ my $next_word = sub {
+ $word++;
+ $args_per_word[$word] = 0;
+ $need_wide_mask[$word] = 0;
+ $bits = 0;
+ $this_wordsize = $wordsize;
+ };
+
+ $next_word->();
+ $this_wordsize = 32 if $pack_in_iw;
for (my $i = 0; $i < @args; $i++) {
- if ($bits_needed[$i]) {
my $needed = $bits_needed[$i];
+ next unless $needed;
- my $next_word = sub {
- $word++;
- $args_per_word[$word] = 0;
- $need_wide_mask[$word] = 0;
- $bits = 0;
- };
-
- if ($bits+$needed > $wordsize) { # Does not fit.
+ if ($bits+$needed > $this_wordsize) { # Does not fit.
$next_word->();
}
if ($args_per_word[$word] == 4) { # Can't handle more than 4 args.
@@ -1695,15 +1721,16 @@ sub do_pack {
# Can only pack two things in a word where one
# item is 32 bits. Force the next item into
# the next word.
- $bits = $wordsize;
+ $bits = $this_wordsize;
}
- }
}
#
# Try to balance packing between words.
#
- if ($args_per_word[$#args_per_word] == 1) {
+ if (@args_per_word == 1 and $args_per_word[0] == 1 and $pack_in_iw) {
+ # Don't rebalance.
+ } elsif ($args_per_word[$#args_per_word] == 1) {
if ($args_per_word[$#args_per_word-1] < 3) {
pop @args_per_word;
} else {
@@ -1753,43 +1780,51 @@ sub do_pack {
# the packing engine works from right-to-left, but we must generate
# the instructions from left-to-right because we must calculate
# instruction sizes from left-to-right.
-
my $arg_num = 0;
for (my $word = 0; $word < @args_per_word; $word++) {
my $ap = 0; # Argument number within word.
my $packed_var = "tmp_packed" . ($word+1);
my $args_per_word = $args_per_word[$word];
- my @shift;
- my @mask;
- my @instr;
-
- if ($need_wide_mask[$word]) {
- @shift = ('0', 'BEAM_WIDE_SHIFT');
- @mask = ('BEAM_WIDE_MASK', $WHOLE_WORD);
- @instr = ('w', 'w');
- } else {
- @shift = @{$pack_shift[$args_per_word]};
- @mask = @{$pack_mask[$args_per_word]};
- @instr = @{$pack_instr[$args_per_word]};
- }
+ my $pack_word_size = ($pack_in_iw && $word == 0) ? 32 : $wordsize;
+
+ my($shref,$mref,$iref,$unpack_suffix) =
+ get_pack_parameters($args_per_word, $pack_word_size,
+ $need_wide_mask[$word]);
+ my @shift = @$shref;
+ my @mask = @$mref;
+ my @instr = @$iref;
while ($ap < $args_per_word) {
my $reg = $args[$arg_num];
my $this_size = $arg_size{$reg};
+
if ($bits_needed[$arg_num]) {
$this_size = 0;
if ($ap == 0) {
- $pack_prefix .= "Eterm $packed_var = " .
- arg_offset($size+$offset) . ";\n";
- $up .= "p";
- $down = "P$down";
- $this_size = 1;
+ my $packed_data;
+ if ($pack_in_iw and $word == 0) {
+ $packed_data = "BeamExtraData(I[0])";
+ if ($args_per_word == 1) {
+ $packed_var = $packed_data;
+ } else {
+ $pack_prefix .= "Eterm $packed_var = $packed_data;\n";
+ }
+ my $pack = chr(ord('#') + $size);
+ $down = "$pack$down";
+ } else {
+ $packed_data = arg_offset($size + $offset);
+ $pack_prefix .= "Eterm $packed_var = $packed_data;\n";
+ $down = "P$down";
+ $up .= "p";
+ $this_size = 1;
+ }
}
$down = "$instr[$ap]$down";
my $unpack = make_unpack($packed_var, $shift[$ap], $mask[$ap]);
- $args[$arg_num] = "packed:$reg:$this_size:$reg" . "b($unpack)";
+ my $macro = "$reg$unpack_suffix";
+ $args[$arg_num] = "packed:$reg:$this_size:$macro($unpack)";
$ap++;
} else {
@@ -1809,7 +1844,98 @@ sub do_pack {
}
my $pack_spec = "$down:$up";
- return ($pack_prefix, $pack_spec, @args);
+ my $score = pack_score($options, @args);
+
+ return ($score, [$pack_prefix,$pack_spec,@args]);
+}
+
+sub get_pack_parameters {
+ my($args_per_word,$pack_word_size,$wide_mask) = @_;
+ my(@shift,@mask,@instr);
+ my $unpack_suffix = 'b';
+
+ if ($wide_mask and $args_per_word > 1) {
+ @shift = ('0', 'BEAM_WIDE_SHIFT');
+ @mask = ('BEAM_WIDE_MASK', $WHOLE_WORD);
+ @instr = (PACK_CMD_WIDE) x 2;
+ } elsif ($args_per_word == 1) {
+ @shift = ('0');
+ @mask = ($WHOLE_WORD);
+ @instr = (PACK_CMD_WIDE);
+ } elsif ($args_per_word == 2) {
+ if ($pack_word_size != $wordsize) {
+ # 64-bit word size, pack 32 bits into instruction word.
+ @shift = ('0', 'BEAM_TIGHT_SHIFT');
+ @mask = ('BEAM_TIGHT_MASK', $WHOLE_WORD);
+ @instr = (PACK_CMD_TIGHT) x 2;
+ } else {
+ # 32/64 bit word size
+ @shift = ('0', 'BEAM_LOOSE_SHIFT');
+ @mask = ('BEAM_LOOSE_MASK', $WHOLE_WORD);
+ @instr = (PACK_CMD_LOOSE) x 2;
+ }
+ } elsif ($args_per_word == 3) {
+ if ($pack_word_size != $wordsize) {
+ # 64-bit word size, pack 3 register numbers into instruction word.
+ @shift = ('0', 'BEAM_TIGHTEST_SHIFT', '(2*BEAM_TIGHTEST_SHIFT)');
+ @mask = ('BEAM_TIGHTEST_MASK', 'BEAM_TIGHTEST_MASK', $WHOLE_WORD);
+ @instr = (PACK_CMD_TIGHTEST) x 3;
+ $unpack_suffix = '';
+ } else {
+ # 32/64 bit word size.
+ @shift = ('0', 'BEAM_TIGHT_SHIFT', '(2*BEAM_TIGHT_SHIFT)');
+ if ($wordsize == 32) {
+ @mask = ('BEAM_TIGHT_MASK') x 3;
+ } elsif ($wordsize == 64) {
+ @mask = ('BEAM_TIGHT_MASK', 'BEAM_TIGHT_MASK', $WHOLE_WORD);
+ }
+ @instr = (PACK_CMD_TIGHT) x 3;
+ }
+ } elsif ($args_per_word == 4) {
+ # 64 bit word size only.
+ @shift = ('0',
+ 'BEAM_LOOSE_SHIFT',
+ '(2*BEAM_LOOSE_SHIFT)',
+ '(3*BEAM_LOOSE_SHIFT)');
+ @mask = ('BEAM_LOOSE_MASK', 'BEAM_LOOSE_MASK',
+ 'BEAM_LOOSE_MASK', $WHOLE_WORD);
+ @instr = (PACK_CMD_LOOSE) x 4;
+ }
+
+ unless (@shift) {
+ error("internal error: args_per_word=$args_per_word, " .
+ "pack_word_size=$pack_word_size");
+ }
+
+ (\@shift,\@mask,\@instr,$unpack_suffix);
+}
+
+sub pack_score {
+ my($options,@args) = @_;
+ my $size = 0;
+
+ # Calculate the number of words.
+ foreach (@args) {
+ if (/^packed:[^:]*:(\d+)/) {
+ $size += $1;
+ } else {
+ $size += $arg_size{$_}
+ }
+ }
+
+ # Less numbers of words give a higher score; for the same number of
+ # words, using PACK_JUMP or PACK_IN_INSTR_WORD gives a lower score.
+ my $score = 1 + $max_spec_operands*($max_spec_operands - $size);
+ if ($options == PACK_IN_INSTR_WORD) {
+ $score += 0;
+ } elsif ($options == PACK_JUMP) {
+ $score += 1;
+ } elsif ($options == (PACK_JUMP|PACK_IN_INSTR_WORD)) {
+ $score += 2;
+ } elsif ($options == 0) {
+ $score += 3;
+ }
+ $score;
}
sub make_unpack {