[Python-checkins] bpo-47172: Compiler enhancements (GH-32200)
markshannon
webhook-mailer at python.org
Fri Apr 1 10:50:28 EDT 2022
https://github.com/python/cpython/commit/997ba5d126f5040d5b7536f73bc89049e9f9421d
commit: 997ba5d126f5040d5b7536f73bc89049e9f9421d
branch: main
author: Irit Katriel <1055913+iritkatriel at users.noreply.github.com>
committer: markshannon <mark at hotpy.org>
date: 2022-04-01T15:50:15+01:00
summary:
bpo-47172: Compiler enhancements (GH-32200)
* Make virtual opcodes negative.
* Make is_jump detect only actual jumps.
* Use is_block_push for the exception block setup opcodes.
files:
M Python/compile.c
diff --git a/Python/compile.c b/Python/compile.c
index bdf886bf42352..c3773a4f48929 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -72,18 +72,26 @@
/* Pseudo-instructions used in the compiler,
* but turned into NOPs by the assembler. */
-#define SETUP_FINALLY 255
-#define SETUP_CLEANUP 254
-#define SETUP_WITH 253
-#define POP_BLOCK 252
-#define JUMP 251
+#define SETUP_FINALLY -1
+#define SETUP_CLEANUP -2
+#define SETUP_WITH -3
+#define POP_BLOCK -4
+#define JUMP -5
+
+#define MIN_VIRTUAL_OPCODE -5
+#define MAX_ALLOWED_OPCODE 254
+
+#define IS_WITHIN_OPCODE_RANGE(opcode) \
+ ((opcode) >= MIN_VIRTUAL_OPCODE && (opcode) <= MAX_ALLOWED_OPCODE)
+
+#define IS_VIRTUAL_OPCODE(opcode) ((opcode) < 0)
#define IS_TOP_LEVEL_AWAIT(c) ( \
(c->c_flags->cf_flags & PyCF_ALLOW_TOP_LEVEL_AWAIT) \
&& (c->u->u_ste->ste_type == ModuleBlock))
struct instr {
- unsigned char i_opcode;
+ int i_opcode;
int i_oparg;
/* target block (if jump instruction) */
struct basicblock_ *i_target;
@@ -115,8 +123,13 @@ is_bit_set_in_table(const uint32_t *table, int bitindex) {
* Word is indexed by (bitindex>>ln(size of int in bits)).
* Bit within word is the low bits of bitindex.
*/
- uint32_t word = table[bitindex >> LOG_BITS_PER_INT];
- return (word >> (bitindex & MASK_LOW_LOG_BITS)) & 1;
+ if (bitindex >= 0 && bitindex < 256) {
+ uint32_t word = table[bitindex >> LOG_BITS_PER_INT];
+ return (word >> (bitindex & MASK_LOW_LOG_BITS)) & 1;
+ }
+ else {
+ return 0;
+ }
}
static inline int
@@ -125,11 +138,17 @@ is_relative_jump(struct instr *i)
return is_bit_set_in_table(_PyOpcode_RelativeJump, i->i_opcode);
}
+static inline int
+is_block_push(struct instr *instr)
+{
+ int opcode = instr->i_opcode;
+ return opcode == SETUP_FINALLY || opcode == SETUP_WITH || opcode == SETUP_CLEANUP;
+}
+
static inline int
is_jump(struct instr *i)
{
- return i->i_opcode >= SETUP_WITH ||
- i->i_opcode == JUMP ||
+ return i->i_opcode == JUMP ||
is_bit_set_in_table(_PyOpcode_Jump, i->i_opcode);
}
@@ -137,6 +156,7 @@ static int
instr_size(struct instr *instruction)
{
int opcode = instruction->i_opcode;
+ assert(!IS_VIRTUAL_OPCODE(opcode));
int oparg = HAS_ARG(opcode) ? instruction->i_oparg : 0;
int extended_args = (0xFFFFFF < oparg) + (0xFFFF < oparg) + (0xFF < oparg);
int caches = _PyOpcode_Caches[opcode];
@@ -147,6 +167,7 @@ static void
write_instr(_Py_CODEUNIT *codestr, struct instr *instruction, int ilen)
{
int opcode = instruction->i_opcode;
+ assert(!IS_VIRTUAL_OPCODE(opcode));
int oparg = HAS_ARG(opcode) ? instruction->i_oparg : 0;
int caches = _PyOpcode_Caches[opcode];
switch (ilen - caches) {
@@ -1177,6 +1198,7 @@ static int
compiler_addop_line(struct compiler *c, int opcode, int line,
int end_line, int col_offset, int end_col_offset)
{
+ assert(IS_WITHIN_OPCODE_RANGE(opcode));
assert(!HAS_ARG(opcode) || IS_ARTIFICIAL(opcode));
if (compiler_use_new_implicit_block_if_needed(c) < 0) {
@@ -1419,6 +1441,7 @@ compiler_addop_i_line(struct compiler *c, int opcode, Py_ssize_t oparg,
The argument of a concrete bytecode instruction is limited to 8-bit.
EXTENDED_ARG is used for 16, 24, and 32-bit arguments. */
+ assert(IS_WITHIN_OPCODE_RANGE(opcode));
assert(HAS_ARG(opcode));
assert(0 <= oparg && oparg <= 2147483647);
@@ -1462,7 +1485,8 @@ static int add_jump_to_block(struct compiler *c, int opcode,
int col_offset, int end_col_offset,
basicblock *target)
{
- assert(HAS_ARG(opcode));
+ assert(IS_WITHIN_OPCODE_RANGE(opcode));
+ assert(HAS_ARG(opcode) || IS_VIRTUAL_OPCODE(opcode));
assert(target != NULL);
if (compiler_use_new_implicit_block_if_needed(c) < 0) {
@@ -7040,7 +7064,7 @@ stackdepth(struct compiler *c)
maxdepth = new_depth;
}
assert(depth >= 0); /* invalid code or bug in stackdepth() */
- if (is_jump(instr)) {
+ if (is_jump(instr) || is_block_push(instr)) {
effect = stack_effect(instr->i_opcode, instr->i_oparg, 1);
assert(effect != PY_INVALID_STACK_EFFECT);
int target_depth = depth + effect;
@@ -7159,13 +7183,6 @@ assemble_emit_table_pair(struct assembler* a, PyObject** table, int* offset,
return 1;
}
-static int
-is_block_push(struct instr *instr)
-{
- int opcode = instr->i_opcode;
- return opcode == SETUP_FINALLY || opcode == SETUP_WITH || opcode == SETUP_CLEANUP;
-}
-
static basicblock *
push_except_block(ExceptStack *stack, struct instr *setup) {
assert(is_block_push(setup));
@@ -8600,6 +8617,7 @@ apply_static_swaps(basicblock *block, int i)
static bool
jump_thread(struct instr *inst, struct instr *target, int opcode)
{
+ assert(!IS_VIRTUAL_OPCODE(opcode) || opcode == JUMP);
assert(is_jump(inst));
assert(is_jump(target));
// bpo-45773: If inst->i_target == target->i_target, then nothing actually
@@ -8629,7 +8647,7 @@ optimize_basic_block(struct compiler *c, basicblock *bb, PyObject *consts)
struct instr *inst = &bb->b_instr[i];
int oparg = inst->i_oparg;
int nextop = i+1 < bb->b_iused ? bb->b_instr[i+1].i_opcode : 0;
- if (is_jump(inst)) {
+ if (is_jump(inst) || is_block_push(inst)) {
/* Skip over empty basic blocks. */
while (inst->i_target->b_iused == 0) {
inst->i_target = inst->i_target->b_next;
@@ -8996,8 +9014,9 @@ mark_reachable(struct assembler *a) {
}
for (int i = 0; i < b->b_iused; i++) {
basicblock *target;
- if (is_jump(&b->b_instr[i])) {
- target = b->b_instr[i].i_target;
+ struct instr *instr = &b->b_instr[i];
+ if (is_jump(instr) || is_block_push(instr)) {
+ target = instr->i_target;
if (target->b_predecessors == 0) {
*sp++ = target;
}
@@ -9073,13 +9092,6 @@ propagate_line_numbers(struct assembler *a) {
}
}
if (is_jump(&b->b_instr[b->b_iused-1])) {
- switch (b->b_instr[b->b_iused-1].i_opcode) {
- /* Note: Only actual jumps, not exception handlers */
- case SETUP_WITH:
- case SETUP_FINALLY:
- case SETUP_CLEANUP:
- continue;
- }
basicblock *target = b->b_instr[b->b_iused-1].i_target;
if (target->b_predecessors == 1) {
if (target->b_instr[0].i_lineno < 0) {
@@ -9205,13 +9217,6 @@ duplicate_exits_without_lineno(struct compiler *c)
*/
for (basicblock *b = c->u->u_blocks; b != NULL; b = b->b_list) {
if (b->b_iused > 0 && is_jump(&b->b_instr[b->b_iused-1])) {
- switch (b->b_instr[b->b_iused-1].i_opcode) {
- /* Note: Only actual jumps, not exception handlers */
- case SETUP_WITH:
- case SETUP_FINALLY:
- case SETUP_CLEANUP:
- continue;
- }
basicblock *target = b->b_instr[b->b_iused-1].i_target;
if (is_exit_without_lineno(target) && target->b_predecessors > 1) {
basicblock *new_target = compiler_copy_block(c, target);
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