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Get rid of macros for bit syntax construction
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The first implementation of the bit syntax was done in Erlang/OTP R7B
before the SMP emulator (the multi-threaded runtime system).
Therefore, global variables were used to keep track of the binary
being constructed.

When the SMP emulator was introduced, the state of the
binary being constructed needed to be local for each
scheduler thread. To reduce the need for extensive rewrites,
macros were used to automagically pass references
to the binary construction state to the helper functions
in erl_bits.c.

Now bite the bullet and remove these macros. Also take the opportunity
to remove the "new" part from function names. They are not exactly
new.
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@bjorng
bjorng committed Aug 5, 2024
1 parent 539497d commit 03c61a4
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Showing 7 changed files with 209 additions and 207 deletions.
35 changes: 16 additions & 19 deletions erts/emulator/beam/emu/bs_instrs.tab
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Original file line number Diff line number Diff line change
Expand Up @@ -373,7 +373,7 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
const BeamInstr* p;
Uint alloc = $Alloc;
Eterm new_binary;
ERL_BITS_DECLARE_STATEP; /* Has to be last declaration */
ErlBitsState* EBS = ERL_BITS_EBS_FROM_REG(reg);

/* We count the total number of bits in an unsigned integer. To avoid
* having to check for overflow when adding to `num_bits`, we ensure that
Expand Down Expand Up @@ -546,7 +546,6 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
}

/* Allocate binary. */
ERL_BITS_RELOAD_STATEP(c_p);
p = p_start;
if (p[0] == BSC_APPEND) {
Uint live = $Live;
Expand All @@ -565,15 +564,13 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
}
p_start += BSC_NUM_ARGS;
} else if (p[0] == BSC_PRIVATE_APPEND) {
Uint unit;
Eterm Src;

$test_heap(alloc, $Live);

$BS_LOAD_UNIT(p, unit);
$BS_LOAD_SRC(p, Src);

new_binary = erts_bs_private_append_checked(c_p, Src, num_bits, unit);
new_binary = erts_bs_private_append_checked(EBS, c_p, Src, num_bits);

if (is_non_value(new_binary)) {
$BS_FAIL_INFO($Fail, c_p->freason, c_p->fvalue, Src);
Expand All @@ -589,7 +586,7 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
/* num_bits = Number of bits to build
* alloc = Total number of words to allocate on heap
*/
erts_bin_offset = 0;
EBS->erts_bin_offset = 0;
if (num_bits <= ERL_ONHEAP_BITS_LIMIT) {
ErlHeapBits *hb;

Expand All @@ -598,7 +595,7 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
HTOP += heap_bits_size(num_bits);
hb->thing_word = header_heap_bits(num_bits);
hb->size = num_bits;
erts_current_bin = (byte *) hb->data;
EBS->erts_current_bin = (byte *) hb->data;
new_binary = make_bitstring(hb);
} else {
Binary* bptr;
Expand All @@ -608,15 +605,15 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
$Live);

bptr = erts_bin_nrml_alloc(NBYTES(num_bits));
erts_current_bin = (byte *)bptr->orig_bytes;
EBS->erts_current_bin = (byte *)bptr->orig_bytes;

LIGHT_SWAPOUT;

new_binary = erts_wrap_refc_bitstring(&MSO(c_p).first,
&MSO(c_p).overhead,
&HEAP_TOP(c_p),
bptr,
erts_current_bin,
EBS->erts_current_bin,
0,
num_bits);

Expand All @@ -640,7 +637,7 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
byte* string;
$BS_LOAD_STRING_SRC(p, string);
$BS_LOAD_FIXED_SIZE(p, Size);
erts_new_bs_put_string(ERL_BITS_ARGS_2(string, Size));
erts_bs_put_string(EBS, string, Size);
continue;
}

Expand All @@ -649,7 +646,7 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
switch (p[0]) {
case BSC_BINARY_ALL:
$BS_LOAD_UNIT(p, unit);
if (!erts_new_bs_put_binary_all(c_p, Src, unit)) {
if (!erts_bs_put_binary_all(EBS, c_p, Src, unit)) {
$BS_FAIL_INFO($Fail, BADARG, am_unit, Src);
}
break;
Expand All @@ -658,14 +655,14 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
$BS_LOAD_FLAGS(p, flags);
$BS_LOAD_SIZE(p, Size);
$BS_GET_UNCHECKED_FIELD_SIZE(Size, unit, $BADARG($Fail), _size);
if (!erts_new_bs_put_binary(c_p, Src, _size)) {
if (!erts_bs_put_binary(EBS, c_p, Src, _size)) {
Eterm reason = is_bitstring(Src) ? am_short : am_type;
$BS_FAIL_INFO($Fail, BADARG, reason, Src);
}
break;
case BSC_BINARY_FIXED_SIZE:
$BS_LOAD_FIXED_SIZE(p, Size);
if (!erts_new_bs_put_binary(c_p, Src, Size)) {
if (!erts_bs_put_binary(EBS, c_p, Src, Size)) {
Eterm reason = is_bitstring(Src) ? am_short : am_type;
$BS_FAIL_INFO($Fail, BADARG, reason, Src);
}
Expand All @@ -675,15 +672,15 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
$BS_LOAD_FLAGS(p, flags);
$BS_LOAD_SIZE(p, Size);
$BS_GET_UNCHECKED_FIELD_SIZE(Size, unit, $BADARG($Fail), _size);
Src = erts_new_bs_put_float(c_p, Src, _size, flags);
Src = erts_bs_put_float(EBS, c_p, Src, _size, flags);
if (is_value(Src)) {
$BS_FAIL_INFO($Fail, BADARG, c_p->fvalue, Src);
}
break;
case BSC_FLOAT_FIXED_SIZE:
$BS_LOAD_FLAGS(p, flags);
$BS_LOAD_FIXED_SIZE(p, Size);
Src = erts_new_bs_put_float(c_p, Src, Size, flags);
Src = erts_bs_put_float(EBS, c_p, Src, Size, flags);
if (is_value(Src)) {
$BS_FAIL_INFO($Fail, BADARG, c_p->fvalue, Src);
}
Expand All @@ -696,7 +693,7 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
$BS_LOAD_FLAGS(p, flags);
$BS_LOAD_SIZE(p, Size);
$BS_GET_UNCHECKED_FIELD_SIZE(Size, unit, $BADARG($Fail), _size);
if (!erts_new_bs_put_integer(ERL_BITS_ARGS_3(Src, _size, flags))) {
if (!erts_bs_put_integer(EBS, Src, _size, flags)) {
$BS_FAIL_INFO($Fail, BADARG, am_type, Src);
}
}
Expand All @@ -705,19 +702,19 @@ i_bs_create_bin(Fail, Alloc, Live, Dst, N) {
case BSC_UTF32:
$BS_LOAD_FLAGS(p, flags);
$BS_LOAD_FIXED_SIZE(p, Size);
if (!erts_new_bs_put_integer(ERL_BITS_ARGS_3(Src, Size, flags))) {
if (!erts_bs_put_integer(EBS, Src, Size, flags)) {
$BS_FAIL_INFO($Fail, BADARG, am_type, Src);
}
break;
case BSC_UTF8:
if (!erts_bs_put_utf8(ERL_BITS_ARGS_1(Src))) {
if (!erts_bs_put_utf8(EBS, Src)) {
$BS_FAIL_INFO($Fail, BADARG, am_type, Src);
}
break;
case BSC_UTF16:
$BS_LOAD_FLAGS(p, flags);
$BS_LOAD_SRC(p, Src);
if (!erts_bs_put_utf16(ERL_BITS_ARGS_2(Src, flags))) {
if (!erts_bs_put_utf16(EBS, Src, flags)) {
$BS_FAIL_INFO($Fail, BADARG, am_type, Src);
}
break;
Expand Down
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