diff options
Diffstat (limited to 'Python/peephole.c')
| -rw-r--r-- | Python/peephole.c | 791 |
1 files changed, 463 insertions, 328 deletions
diff --git a/Python/peephole.c b/Python/peephole.c index 714a452..11f6f88 100644 --- a/Python/peephole.c +++ b/Python/peephole.c @@ -4,179 +4,246 @@ #include "Python-ast.h" #include "node.h" +#include "pyarena.h" #include "ast.h" #include "code.h" +#include "compile.h" #include "symtable.h" #include "opcode.h" -#include "wordcode_helpers.h" +#define GETARG(arr, i) ((int)((arr[i+2]<<8) + arr[i+1])) #define UNCONDITIONAL_JUMP(op) (op==JUMP_ABSOLUTE || op==JUMP_FORWARD) #define CONDITIONAL_JUMP(op) (op==POP_JUMP_IF_FALSE || op==POP_JUMP_IF_TRUE \ || op==JUMP_IF_FALSE_OR_POP || op==JUMP_IF_TRUE_OR_POP) -#define ABSOLUTE_JUMP(op) (op==JUMP_ABSOLUTE \ +#define ABSOLUTE_JUMP(op) (op==JUMP_ABSOLUTE || op==CONTINUE_LOOP \ || op==POP_JUMP_IF_FALSE || op==POP_JUMP_IF_TRUE \ || op==JUMP_IF_FALSE_OR_POP || op==JUMP_IF_TRUE_OR_POP) #define JUMPS_ON_TRUE(op) (op==POP_JUMP_IF_TRUE || op==JUMP_IF_TRUE_OR_POP) -#define GETJUMPTGT(arr, i) (get_arg(arr, i) / sizeof(_Py_CODEUNIT) + \ - (ABSOLUTE_JUMP(_Py_OPCODE(arr[i])) ? 0 : i+1)) -#define ISBASICBLOCK(blocks, start, end) \ - (blocks[start]==blocks[end]) +#define GETJUMPTGT(arr, i) (GETARG(arr,i) + (ABSOLUTE_JUMP(arr[i]) ? 0 : i+3)) +#define SETARG(arr, i, val) arr[i+2] = val>>8; arr[i+1] = val & 255 +#define CODESIZE(op) (HAS_ARG(op) ? 3 : 1) +#define ISBASICBLOCK(blocks, start, bytes) \ + (blocks[start]==blocks[start+bytes-1]) - -/* Scans back N consecutive LOAD_CONST instructions, skipping NOPs, - returns index of the Nth last's LOAD_CONST's EXTENDED_ARG prefix. - Callers are responsible to check CONST_STACK_LEN beforehand. +/* Replace LOAD_CONST c1. LOAD_CONST c2 ... LOAD_CONST cn BUILD_TUPLE n + with LOAD_CONST (c1, c2, ... cn). + The consts table must still be in list form so that the + new constant (c1, c2, ... cn) can be appended. + Called with codestr pointing to the first LOAD_CONST. + Bails out with no change if one or more of the LOAD_CONSTs is missing. + Also works for BUILD_LIST when followed by an "in" or "not in" test. */ -static Py_ssize_t -lastn_const_start(const _Py_CODEUNIT *codestr, Py_ssize_t i, Py_ssize_t n) +static int +tuple_of_constants(unsigned char *codestr, Py_ssize_t n, PyObject *consts) { - assert(n > 0); - for (;;) { - i--; - assert(i >= 0); - if (_Py_OPCODE(codestr[i]) == LOAD_CONST) { - if (!--n) { - while (i > 0 && _Py_OPCODE(codestr[i-1]) == EXTENDED_ARG) { - i--; - } - return i; - } - } - else { - assert(_Py_OPCODE(codestr[i]) == EXTENDED_ARG); - } - } -} + PyObject *newconst, *constant; + Py_ssize_t i, arg, len_consts; -/* Scans through EXTENDED ARGs, seeking the index of the effective opcode */ -static Py_ssize_t -find_op(const _Py_CODEUNIT *codestr, Py_ssize_t codelen, Py_ssize_t i) -{ - while (i < codelen && _Py_OPCODE(codestr[i]) == EXTENDED_ARG) { - i++; - } - return i; -} + /* Pre-conditions */ + assert(PyList_CheckExact(consts)); + assert(codestr[n*3] == BUILD_TUPLE || codestr[n*3] == BUILD_LIST); + assert(GETARG(codestr, (n*3)) == n); + for (i=0 ; i<n ; i++) + assert(codestr[i*3] == LOAD_CONST); -/* Given the index of the effective opcode, - scan back to construct the oparg with EXTENDED_ARG */ -static unsigned int -get_arg(const _Py_CODEUNIT *codestr, Py_ssize_t i) -{ - _Py_CODEUNIT word; - unsigned int oparg = _Py_OPARG(codestr[i]); - if (i >= 1 && _Py_OPCODE(word = codestr[i-1]) == EXTENDED_ARG) { - oparg |= _Py_OPARG(word) << 8; - if (i >= 2 && _Py_OPCODE(word = codestr[i-2]) == EXTENDED_ARG) { - oparg |= _Py_OPARG(word) << 16; - if (i >= 3 && _Py_OPCODE(word = codestr[i-3]) == EXTENDED_ARG) { - oparg |= _Py_OPARG(word) << 24; - } - } + /* Buildup new tuple of constants */ + newconst = PyTuple_New(n); + if (newconst == NULL) + return 0; + len_consts = PyList_GET_SIZE(consts); + for (i=0 ; i<n ; i++) { + arg = GETARG(codestr, (i*3)); + assert(arg < len_consts); + constant = PyList_GET_ITEM(consts, arg); + Py_INCREF(constant); + PyTuple_SET_ITEM(newconst, i, constant); } - return oparg; -} -/* Fill the region with NOPs. */ -static void -fill_nops(_Py_CODEUNIT *codestr, Py_ssize_t start, Py_ssize_t end) -{ - memset(codestr + start, NOP, (end - start) * sizeof(_Py_CODEUNIT)); -} - -/* Given the index of the effective opcode, - attempt to replace the argument, taking into account EXTENDED_ARG. - Returns -1 on failure, or the new op index on success */ -static Py_ssize_t -set_arg(_Py_CODEUNIT *codestr, Py_ssize_t i, unsigned int oparg) -{ - unsigned int curarg = get_arg(codestr, i); - int curilen, newilen; - if (curarg == oparg) - return i; - curilen = instrsize(curarg); - newilen = instrsize(oparg); - if (curilen < newilen) { - return -1; + /* Append folded constant onto consts */ + if (PyList_Append(consts, newconst)) { + Py_DECREF(newconst); + return 0; } + Py_DECREF(newconst); - write_op_arg(codestr + i + 1 - curilen, _Py_OPCODE(codestr[i]), oparg, newilen); - fill_nops(codestr, i + 1 - curilen + newilen, i + 1); - return i-curilen+newilen; + /* Write NOPs over old LOAD_CONSTS and + add a new LOAD_CONST newconst on top of the BUILD_TUPLE n */ + memset(codestr, NOP, n*3); + codestr[n*3] = LOAD_CONST; + SETARG(codestr, (n*3), len_consts); + return 1; } -/* Attempt to write op/arg at end of specified region of memory. - Preceding memory in the region is overwritten with NOPs. - Returns -1 on failure, op index on success */ -static Py_ssize_t -copy_op_arg(_Py_CODEUNIT *codestr, Py_ssize_t i, unsigned char op, - unsigned int oparg, Py_ssize_t maxi) -{ - int ilen = instrsize(oparg); - if (i + ilen > maxi) { - return -1; - } - write_op_arg(codestr + maxi - ilen, op, oparg, ilen); - fill_nops(codestr, i, maxi - ilen); - return maxi - 1; -} - -/* Replace LOAD_CONST c1, LOAD_CONST c2 ... LOAD_CONST cn, BUILD_TUPLE n - with LOAD_CONST (c1, c2, ... cn). +/* Replace LOAD_CONST c1. LOAD_CONST c2 BINOP + with LOAD_CONST binop(c1,c2) The consts table must still be in list form so that the - new constant (c1, c2, ... cn) can be appended. + new constant can be appended. Called with codestr pointing to the first LOAD_CONST. + Abandons the transformation if the folding fails (i.e. 1+'a'). + If the new constant is a sequence, only folds when the size + is below a threshold value. That keeps pyc files from + becoming large in the presence of code like: (None,)*1000. */ -static Py_ssize_t -fold_tuple_on_constants(_Py_CODEUNIT *codestr, Py_ssize_t codelen, - Py_ssize_t c_start, Py_ssize_t opcode_end, - PyObject *consts, int n) +static int +fold_binops_on_constants(unsigned char *codestr, PyObject *consts) { + PyObject *newconst, *v, *w; + Py_ssize_t len_consts, size; + int opcode; + /* Pre-conditions */ assert(PyList_CheckExact(consts)); - - /* Buildup new tuple of constants */ - PyObject *newconst = PyTuple_New(n); + assert(codestr[0] == LOAD_CONST); + assert(codestr[3] == LOAD_CONST); + + /* Create new constant */ + v = PyList_GET_ITEM(consts, GETARG(codestr, 0)); + w = PyList_GET_ITEM(consts, GETARG(codestr, 3)); + opcode = codestr[6]; + switch (opcode) { + case BINARY_POWER: + newconst = PyNumber_Power(v, w, Py_None); + break; + case BINARY_MULTIPLY: + newconst = PyNumber_Multiply(v, w); + break; + case BINARY_DIVIDE: + /* Cannot fold this operation statically since + the result can depend on the run-time presence + of the -Qnew flag */ + return 0; + case BINARY_TRUE_DIVIDE: + newconst = PyNumber_TrueDivide(v, w); + break; + case BINARY_FLOOR_DIVIDE: + newconst = PyNumber_FloorDivide(v, w); + break; + case BINARY_MODULO: + newconst = PyNumber_Remainder(v, w); + break; + case BINARY_ADD: + newconst = PyNumber_Add(v, w); + break; + case BINARY_SUBTRACT: + newconst = PyNumber_Subtract(v, w); + break; + case BINARY_SUBSCR: + /* #5057: if v is unicode, there might be differences between + wide and narrow builds in cases like '\U00012345'[0] or + '\U00012345abcdef'[3], so it's better to skip the optimization + in order to produce compatible pycs. + */ + if (PyUnicode_Check(v)) + return 0; + newconst = PyObject_GetItem(v, w); + break; + case BINARY_LSHIFT: + newconst = PyNumber_Lshift(v, w); + break; + case BINARY_RSHIFT: + newconst = PyNumber_Rshift(v, w); + break; + case BINARY_AND: + newconst = PyNumber_And(v, w); + break; + case BINARY_XOR: + newconst = PyNumber_Xor(v, w); + break; + case BINARY_OR: + newconst = PyNumber_Or(v, w); + break; + default: + /* Called with an unknown opcode */ + PyErr_Format(PyExc_SystemError, + "unexpected binary operation %d on a constant", + opcode); + return 0; + } if (newconst == NULL) { - return -1; + PyErr_Clear(); + return 0; } - - for (Py_ssize_t i = 0, pos = c_start; i < n; i++, pos++) { - assert(pos < opcode_end); - pos = find_op(codestr, codelen, pos); - assert(_Py_OPCODE(codestr[pos]) == LOAD_CONST); - - unsigned int arg = get_arg(codestr, pos); - PyObject *constant = PyList_GET_ITEM(consts, arg); - Py_INCREF(constant); - PyTuple_SET_ITEM(newconst, i, constant); + size = PyObject_Size(newconst); + if (size == -1) + PyErr_Clear(); + else if (size > 20) { + Py_DECREF(newconst); + return 0; } - Py_ssize_t index = PyList_GET_SIZE(consts); -#if SIZEOF_SIZE_T > SIZEOF_INT - if ((size_t)index >= UINT_MAX - 1) { + /* Append folded constant into consts table */ + len_consts = PyList_GET_SIZE(consts); + if (PyList_Append(consts, newconst)) { Py_DECREF(newconst); - PyErr_SetString(PyExc_OverflowError, "too many constants"); - return -1; + return 0; } -#endif + Py_DECREF(newconst); - /* Append folded constant onto consts */ + /* Write NOP NOP NOP NOP LOAD_CONST newconst */ + memset(codestr, NOP, 4); + codestr[4] = LOAD_CONST; + SETARG(codestr, 4, len_consts); + return 1; +} + +static int +fold_unaryops_on_constants(unsigned char *codestr, PyObject *consts) +{ + PyObject *newconst=NULL, *v; + Py_ssize_t len_consts; + int opcode; + + /* Pre-conditions */ + assert(PyList_CheckExact(consts)); + assert(codestr[0] == LOAD_CONST); + + /* Create new constant */ + v = PyList_GET_ITEM(consts, GETARG(codestr, 0)); + opcode = codestr[3]; + switch (opcode) { + case UNARY_NEGATIVE: + /* Preserve the sign of -0.0 */ + if (PyObject_IsTrue(v) == 1) + newconst = PyNumber_Negative(v); + break; + case UNARY_CONVERT: + newconst = PyObject_Repr(v); + break; + case UNARY_INVERT: + newconst = PyNumber_Invert(v); + break; + default: + /* Called with an unknown opcode */ + PyErr_Format(PyExc_SystemError, + "unexpected unary operation %d on a constant", + opcode); + return 0; + } + if (newconst == NULL) { + PyErr_Clear(); + return 0; + } + + /* Append folded constant into consts table */ + len_consts = PyList_GET_SIZE(consts); if (PyList_Append(consts, newconst)) { Py_DECREF(newconst); - return -1; + return 0; } Py_DECREF(newconst); - return copy_op_arg(codestr, c_start, LOAD_CONST, - (unsigned int)index, opcode_end); + /* Write NOP LOAD_CONST newconst */ + codestr[0] = NOP; + codestr[1] = LOAD_CONST; + SETARG(codestr, 1, len_consts); + return 1; } static unsigned int * -markblocks(_Py_CODEUNIT *code, Py_ssize_t len) +markblocks(unsigned char *code, Py_ssize_t len) { unsigned int *blocks = PyMem_New(unsigned int, len); - int i, j, opcode, blockcnt = 0; + int i,j, opcode, blockcnt = 0; if (blocks == NULL) { PyErr_NoMemory(); @@ -185,8 +252,8 @@ markblocks(_Py_CODEUNIT *code, Py_ssize_t len) memset(blocks, 0, len*sizeof(int)); /* Mark labels in the first pass */ - for (i = 0; i < len; i++) { - opcode = _Py_OPCODE(code[i]); + for (i=0 ; i<len ; i+=CODESIZE(opcode)) { + opcode = code[i]; switch (opcode) { case FOR_ITER: case JUMP_FORWARD: @@ -195,17 +262,18 @@ markblocks(_Py_CODEUNIT *code, Py_ssize_t len) case POP_JUMP_IF_FALSE: case POP_JUMP_IF_TRUE: case JUMP_ABSOLUTE: + case CONTINUE_LOOP: + case SETUP_LOOP: + case SETUP_EXCEPT: case SETUP_FINALLY: case SETUP_WITH: - case SETUP_ASYNC_WITH: j = GETJUMPTGT(code, i); - assert(j < len); blocks[j] = 1; break; } } /* Build block numbers in the second pass */ - for (i = 0; i < len; i++) { + for (i=0 ; i<len ; i++) { blockcnt += blocks[i]; /* increment blockcnt over labels */ blocks[i] = blockcnt; } @@ -216,136 +284,221 @@ markblocks(_Py_CODEUNIT *code, Py_ssize_t len) The consts object should still be in list form to allow new constants to be appended. - To keep the optimizer simple, it bails when the lineno table has complex - encoding for gaps >= 255. + To keep the optimizer simple, it bails out (does nothing) for code + containing extended arguments or that has a length over 32,700. That + allows us to avoid overflow and sign issues. Likewise, it bails when + the lineno table has complex encoding for gaps >= 255. Optimizations are restricted to simple transformations occurring within a single basic block. All transformations keep the code size the same or smaller. For those that reduce size, the gaps are initially filled with NOPs. Later those NOPs are removed and the jump addresses retargeted in - a single pass. */ + a single pass. Line numbering is adjusted accordingly. */ PyObject * PyCode_Optimize(PyObject *code, PyObject* consts, PyObject *names, - PyObject *lnotab_obj) + PyObject *lineno_obj) { - Py_ssize_t h, i, nexti, op_start, tgt; - unsigned int j, nops; - unsigned char opcode, nextop; - _Py_CODEUNIT *codestr = NULL; - unsigned char *lnotab; - unsigned int cum_orig_offset, last_offset; - Py_ssize_t tabsiz; - // Count runs of consecutive LOAD_CONSTs - unsigned int cumlc = 0, lastlc = 0; + Py_ssize_t i, j, codelen; + int nops, h, adj; + int tgt, tgttgt, opcode; + unsigned char *codestr = NULL; + unsigned char *lineno; + int *addrmap = NULL; + int new_line, cum_orig_line, last_line, tabsiz; + int cumlc=0, lastlc=0; /* Count runs of consecutive LOAD_CONSTs */ unsigned int *blocks = NULL; + char *name; /* Bail out if an exception is set */ if (PyErr_Occurred()) goto exitError; - /* Bypass optimization when the lnotab table is too complex */ - assert(PyBytes_Check(lnotab_obj)); - lnotab = (unsigned char*)PyBytes_AS_STRING(lnotab_obj); - tabsiz = PyBytes_GET_SIZE(lnotab_obj); - assert(tabsiz == 0 || Py_REFCNT(lnotab_obj) == 1); - - /* Don't optimize if lnotab contains instruction pointer delta larger - than +255 (encoded as multiple bytes), just to keep the peephole optimizer - simple. The optimizer leaves line number deltas unchanged. */ - - for (i = 0; i < tabsiz; i += 2) { - if (lnotab[i] == 255) { - goto exitUnchanged; - } - } + /* Bypass optimization when the lineno table is too complex */ + assert(PyString_Check(lineno_obj)); + lineno = (unsigned char*)PyString_AS_STRING(lineno_obj); + tabsiz = PyString_GET_SIZE(lineno_obj); + if (memchr(lineno, 255, tabsiz) != NULL) + goto exitUnchanged; - assert(PyBytes_Check(code)); - Py_ssize_t codesize = PyBytes_GET_SIZE(code); - assert(codesize % sizeof(_Py_CODEUNIT) == 0); - Py_ssize_t codelen = codesize / sizeof(_Py_CODEUNIT); - if (codelen > INT_MAX) { - /* Python assembler is limited to INT_MAX: see assembler.a_offset in - compile.c. */ + /* Avoid situations where jump retargeting could overflow */ + assert(PyString_Check(code)); + codelen = PyString_GET_SIZE(code); + if (codelen > 32700) goto exitUnchanged; - } /* Make a modifiable copy of the code string */ - codestr = (_Py_CODEUNIT *)PyMem_Malloc(codesize); - if (codestr == NULL) { + codestr = (unsigned char *)PyMem_Malloc(codelen); + if (codestr == NULL) + goto exitError; + codestr = (unsigned char *)memcpy(codestr, + PyString_AS_STRING(code), codelen); + + /* Verify that RETURN_VALUE terminates the codestring. This allows + the various transformation patterns to look ahead several + instructions without additional checks to make sure they are not + looking beyond the end of the code string. + */ + if (codestr[codelen-1] != RETURN_VALUE) + goto exitUnchanged; + + /* Mapping to new jump targets after NOPs are removed */ + addrmap = PyMem_New(int, codelen); + if (addrmap == NULL) { PyErr_NoMemory(); goto exitError; } - memcpy(codestr, PyBytes_AS_STRING(code), codesize); blocks = markblocks(codestr, codelen); if (blocks == NULL) goto exitError; assert(PyList_Check(consts)); - for (i=find_op(codestr, codelen, 0) ; i<codelen ; i=nexti) { - opcode = _Py_OPCODE(codestr[i]); - op_start = i; - while (op_start >= 1 && _Py_OPCODE(codestr[op_start-1]) == EXTENDED_ARG) { - op_start--; - } - - nexti = i + 1; - while (nexti < codelen && _Py_OPCODE(codestr[nexti]) == EXTENDED_ARG) - nexti++; - nextop = nexti < codelen ? _Py_OPCODE(codestr[nexti]) : 0; + for (i=0 ; i<codelen ; i += CODESIZE(codestr[i])) { + reoptimize_current: + opcode = codestr[i]; lastlc = cumlc; cumlc = 0; switch (opcode) { + /* Replace UNARY_NOT POP_JUMP_IF_FALSE + with POP_JUMP_IF_TRUE */ + case UNARY_NOT: + if (codestr[i+1] != POP_JUMP_IF_FALSE + || !ISBASICBLOCK(blocks,i,4)) + continue; + j = GETARG(codestr, i+1); + codestr[i] = POP_JUMP_IF_TRUE; + SETARG(codestr, i, j); + codestr[i+3] = NOP; + goto reoptimize_current; + + /* not a is b --> a is not b + not a in b --> a not in b + not a is not b --> a is b + not a not in b --> a in b + */ + case COMPARE_OP: + j = GETARG(codestr, i); + if (j < 6 || j > 9 || + codestr[i+3] != UNARY_NOT || + !ISBASICBLOCK(blocks,i,4)) + continue; + SETARG(codestr, i, (j^1)); + codestr[i+3] = NOP; + break; + + /* Replace LOAD_GLOBAL/LOAD_NAME None + with LOAD_CONST None */ + case LOAD_NAME: + case LOAD_GLOBAL: + j = GETARG(codestr, i); + name = PyString_AsString(PyTuple_GET_ITEM(names, j)); + if (name == NULL || strcmp(name, "None") != 0) + continue; + for (j=0 ; j < PyList_GET_SIZE(consts) ; j++) { + if (PyList_GET_ITEM(consts, j) == Py_None) + break; + } + if (j == PyList_GET_SIZE(consts)) { + if (PyList_Append(consts, Py_None) == -1) + goto exitError; + } + assert(PyList_GET_ITEM(consts, j) == Py_None); + codestr[i] = LOAD_CONST; + SETARG(codestr, i, j); + cumlc = lastlc + 1; + break; + /* Skip over LOAD_CONST trueconst - POP_JUMP_IF_FALSE xx. This improves - "while 1" performance. */ + POP_JUMP_IF_FALSE xx. This improves + "while 1" performance. */ case LOAD_CONST: cumlc = lastlc + 1; - if (nextop != POP_JUMP_IF_FALSE || - !ISBASICBLOCK(blocks, op_start, i + 1)) { - break; - } - PyObject* cnt = PyList_GET_ITEM(consts, get_arg(codestr, i)); - int is_true = PyObject_IsTrue(cnt); - if (is_true == -1) { - goto exitError; - } - if (is_true == 1) { - fill_nops(codestr, op_start, nexti + 1); - cumlc = 0; - } + j = GETARG(codestr, i); + if (codestr[i+3] != POP_JUMP_IF_FALSE || + !ISBASICBLOCK(blocks,i,6) || + !PyObject_IsTrue(PyList_GET_ITEM(consts, j))) + continue; + memset(codestr+i, NOP, 6); + cumlc = 0; break; - /* Try to fold tuples of constants. + /* Try to fold tuples of constants (includes a case for lists + which are only used for "in" and "not in" tests). Skip over BUILD_SEQN 1 UNPACK_SEQN 1. Replace BUILD_SEQN 2 UNPACK_SEQN 2 with ROT2. Replace BUILD_SEQN 3 UNPACK_SEQN 3 with ROT3 ROT2. */ case BUILD_TUPLE: - j = get_arg(codestr, i); - if (j > 0 && lastlc >= j) { - h = lastn_const_start(codestr, op_start, j); - if (ISBASICBLOCK(blocks, h, op_start)) { - h = fold_tuple_on_constants(codestr, codelen, - h, i+1, consts, j); - break; - } - } - if (nextop != UNPACK_SEQUENCE || - !ISBASICBLOCK(blocks, op_start, i + 1) || - j != get_arg(codestr, nexti)) + case BUILD_LIST: + j = GETARG(codestr, i); + h = i - 3 * j; + if (h >= 0 && + j <= lastlc && + ((opcode == BUILD_TUPLE && + ISBASICBLOCK(blocks, h, 3*(j+1))) || + (opcode == BUILD_LIST && + codestr[i+3]==COMPARE_OP && + ISBASICBLOCK(blocks, h, 3*(j+2)) && + (GETARG(codestr,i+3)==6 || + GETARG(codestr,i+3)==7))) && + tuple_of_constants(&codestr[h], j, consts)) { + assert(codestr[i] == LOAD_CONST); + cumlc = 1; break; - if (j < 2) { - fill_nops(codestr, op_start, nexti + 1); + } + if (codestr[i+3] != UNPACK_SEQUENCE || + !ISBASICBLOCK(blocks,i,6) || + j != GETARG(codestr, i+3)) + continue; + if (j == 1) { + memset(codestr+i, NOP, 6); } else if (j == 2) { - codestr[op_start] = PACKOPARG(ROT_TWO, 0); - fill_nops(codestr, op_start + 1, nexti + 1); + codestr[i] = ROT_TWO; + memset(codestr+i+1, NOP, 5); } else if (j == 3) { - codestr[op_start] = PACKOPARG(ROT_THREE, 0); - codestr[op_start + 1] = PACKOPARG(ROT_TWO, 0); - fill_nops(codestr, op_start + 2, nexti + 1); + codestr[i] = ROT_THREE; + codestr[i+1] = ROT_TWO; + memset(codestr+i+2, NOP, 4); + } + break; + + /* Fold binary ops on constants. + LOAD_CONST c1 LOAD_CONST c2 BINOP --> LOAD_CONST binop(c1,c2) */ + case BINARY_POWER: + case BINARY_MULTIPLY: + case BINARY_TRUE_DIVIDE: + case BINARY_FLOOR_DIVIDE: + case BINARY_MODULO: + case BINARY_ADD: + case BINARY_SUBTRACT: + case BINARY_SUBSCR: + case BINARY_LSHIFT: + case BINARY_RSHIFT: + case BINARY_AND: + case BINARY_XOR: + case BINARY_OR: + if (lastlc >= 2 && + ISBASICBLOCK(blocks, i-6, 7) && + fold_binops_on_constants(&codestr[i-6], consts)) { + i -= 2; + assert(codestr[i] == LOAD_CONST); + cumlc = 1; + } + break; + + /* Fold unary ops on constants. + LOAD_CONST c1 UNARY_OP --> LOAD_CONST unary_op(c) */ + case UNARY_NEGATIVE: + case UNARY_CONVERT: + case UNARY_INVERT: + if (lastlc >= 1 && + ISBASICBLOCK(blocks, i-3, 4) && + fold_unaryops_on_constants(&codestr[i-3], consts)) { + i -= 2; + assert(codestr[i] == LOAD_CONST); + cumlc = 1; } break; @@ -353,47 +506,42 @@ PyCode_Optimize(PyObject *code, PyObject* consts, PyObject *names, result of the first test implies the success of a similar test or the failure of the opposite test. Arises in code like: + "if a and b:" + "if a or b:" "a and b or c" "(a and b) and c" - "(a or b) or c" - "(a or b) and c" x:JUMP_IF_FALSE_OR_POP y y:JUMP_IF_FALSE_OR_POP z --> x:JUMP_IF_FALSE_OR_POP z x:JUMP_IF_FALSE_OR_POP y y:JUMP_IF_TRUE_OR_POP z - --> x:POP_JUMP_IF_FALSE y+1 - where y+1 is the instruction following the second test. + --> x:POP_JUMP_IF_FALSE y+3 + where y+3 is the instruction following the second test. */ case JUMP_IF_FALSE_OR_POP: case JUMP_IF_TRUE_OR_POP: - h = get_arg(codestr, i) / sizeof(_Py_CODEUNIT); - tgt = find_op(codestr, codelen, h); - - j = _Py_OPCODE(codestr[tgt]); + tgt = GETJUMPTGT(codestr, i); + j = codestr[tgt]; if (CONDITIONAL_JUMP(j)) { - /* NOTE: all possible jumps here are absolute. */ + /* NOTE: all possible jumps here are absolute! */ if (JUMPS_ON_TRUE(j) == JUMPS_ON_TRUE(opcode)) { - /* The second jump will be taken iff the first is. - The current opcode inherits its target's - stack effect */ - h = set_arg(codestr, i, get_arg(codestr, tgt)); + /* The second jump will be + taken iff the first is. */ + tgttgt = GETJUMPTGT(codestr, tgt); + /* The current opcode inherits + its target's stack behaviour */ + codestr[i] = j; + SETARG(codestr, i, tgttgt); + goto reoptimize_current; } else { /* The second jump is not taken if the first is (so jump past it), and all conditional jumps pop their argument when they're not taken (so change the first jump to pop its argument when it's taken). */ - Py_ssize_t arg = (tgt + 1); - /* cannot overflow: codelen <= INT_MAX */ - assert((size_t)arg <= UINT_MAX / sizeof(_Py_CODEUNIT)); - arg *= sizeof(_Py_CODEUNIT); - h = set_arg(codestr, i, (unsigned int)arg); - j = opcode == JUMP_IF_TRUE_OR_POP ? - POP_JUMP_IF_TRUE : POP_JUMP_IF_FALSE; - } - - if (h >= 0) { - nexti = h; - codestr[nexti] = PACKOPARG(j, _Py_OPARG(codestr[nexti])); - break; + if (JUMPS_ON_TRUE(opcode)) + codestr[i] = POP_JUMP_IF_TRUE; + else + codestr[i] = POP_JUMP_IF_FALSE; + SETARG(codestr, i, (tgt + 3)); + goto reoptimize_current; } } /* Intentional fallthrough */ @@ -401,132 +549,119 @@ PyCode_Optimize(PyObject *code, PyObject* consts, PyObject *names, /* Replace jumps to unconditional jumps */ case POP_JUMP_IF_FALSE: case POP_JUMP_IF_TRUE: + case FOR_ITER: case JUMP_FORWARD: case JUMP_ABSOLUTE: - h = GETJUMPTGT(codestr, i); - tgt = find_op(codestr, codelen, h); + case CONTINUE_LOOP: + case SETUP_LOOP: + case SETUP_EXCEPT: + case SETUP_FINALLY: + case SETUP_WITH: + tgt = GETJUMPTGT(codestr, i); /* Replace JUMP_* to a RETURN into just a RETURN */ if (UNCONDITIONAL_JUMP(opcode) && - _Py_OPCODE(codestr[tgt]) == RETURN_VALUE) { - codestr[op_start] = PACKOPARG(RETURN_VALUE, 0); - fill_nops(codestr, op_start + 1, i + 1); - } else if (UNCONDITIONAL_JUMP(_Py_OPCODE(codestr[tgt]))) { - size_t arg = GETJUMPTGT(codestr, tgt); - if (opcode == JUMP_FORWARD) { /* JMP_ABS can go backwards */ - opcode = JUMP_ABSOLUTE; - } else if (!ABSOLUTE_JUMP(opcode)) { - if (arg < (size_t)(i + 1)) { - break; /* No backward relative jumps */ - } - arg -= i + 1; /* Calc relative jump addr */ - } - /* cannot overflow: codelen <= INT_MAX */ - assert(arg <= (UINT_MAX / sizeof(_Py_CODEUNIT))); - arg *= sizeof(_Py_CODEUNIT); - copy_op_arg(codestr, op_start, opcode, - (unsigned int)arg, i + 1); + codestr[tgt] == RETURN_VALUE) { + codestr[i] = RETURN_VALUE; + memset(codestr+i+1, NOP, 2); + continue; } + if (!UNCONDITIONAL_JUMP(codestr[tgt])) + continue; + tgttgt = GETJUMPTGT(codestr, tgt); + if (opcode == JUMP_FORWARD) /* JMP_ABS can go backwards */ + opcode = JUMP_ABSOLUTE; + if (!ABSOLUTE_JUMP(opcode)) + tgttgt -= i + 3; /* Calc relative jump addr */ + if (tgttgt < 0) /* No backward relative jumps */ + continue; + codestr[i] = opcode; + SETARG(codestr, i, tgttgt); break; - /* Remove unreachable ops after RETURN */ + case EXTENDED_ARG: + goto exitUnchanged; + + /* Replace RETURN LOAD_CONST None RETURN with just RETURN */ + /* Remove unreachable JUMPs after RETURN */ case RETURN_VALUE: - h = i + 1; - while (h < codelen && ISBASICBLOCK(blocks, i, h)) - { - /* Leave SETUP_FINALLY and RERAISE in place to help find block limits. */ - if (_Py_OPCODE(codestr[h]) == SETUP_FINALLY || _Py_OPCODE(codestr[h]) == RERAISE) { - while (h > i + 1 && - _Py_OPCODE(codestr[h - 1]) == EXTENDED_ARG) - { - h--; - } - break; - } - h++; - } - if (h > i + 1) { - fill_nops(codestr, i + 1, h); - nexti = find_op(codestr, codelen, h); - } + if (i+4 >= codelen) + continue; + if (codestr[i+4] == RETURN_VALUE && + ISBASICBLOCK(blocks,i,5)) + memset(codestr+i+1, NOP, 4); + else if (UNCONDITIONAL_JUMP(codestr[i+1]) && + ISBASICBLOCK(blocks,i,4)) + memset(codestr+i+1, NOP, 3); break; } } - /* Fixup lnotab */ - for (i = 0, nops = 0; i < codelen; i++) { - size_t block = (size_t)i - nops; - /* cannot overflow: codelen <= INT_MAX */ - assert(block <= UINT_MAX); - /* original code offset => new code offset */ - blocks[i] = (unsigned int)block; - if (_Py_OPCODE(codestr[i]) == NOP) { + /* Fixup linenotab */ + for (i=0, nops=0 ; i<codelen ; i += CODESIZE(codestr[i])) { + addrmap[i] = i - nops; + if (codestr[i] == NOP) nops++; - } } - cum_orig_offset = 0; - last_offset = 0; + cum_orig_line = 0; + last_line = 0; for (i=0 ; i < tabsiz ; i+=2) { - unsigned int offset_delta, new_offset; - cum_orig_offset += lnotab[i]; - assert(cum_orig_offset % sizeof(_Py_CODEUNIT) == 0); - new_offset = blocks[cum_orig_offset / sizeof(_Py_CODEUNIT)] * - sizeof(_Py_CODEUNIT); - offset_delta = new_offset - last_offset; - assert(offset_delta <= 255); - lnotab[i] = (unsigned char)offset_delta; - last_offset = new_offset; + cum_orig_line += lineno[i]; + new_line = addrmap[cum_orig_line]; + assert (new_line - last_line < 255); + lineno[i] =((unsigned char)(new_line - last_line)); + last_line = new_line; } /* Remove NOPs and fixup jump targets */ - for (op_start = i = h = 0; i < codelen; i++, op_start = i) { - j = _Py_OPARG(codestr[i]); - while (_Py_OPCODE(codestr[i]) == EXTENDED_ARG) { - i++; - j = j<<8 | _Py_OPARG(codestr[i]); - } - opcode = _Py_OPCODE(codestr[i]); + for (i=0, h=0 ; i<codelen ; ) { + opcode = codestr[i]; switch (opcode) { - case NOP:continue; + case NOP: + i++; + continue; case JUMP_ABSOLUTE: + case CONTINUE_LOOP: case POP_JUMP_IF_FALSE: case POP_JUMP_IF_TRUE: case JUMP_IF_FALSE_OR_POP: case JUMP_IF_TRUE_OR_POP: - j = blocks[j / sizeof(_Py_CODEUNIT)] * sizeof(_Py_CODEUNIT); + j = addrmap[GETARG(codestr, i)]; + SETARG(codestr, i, j); break; case FOR_ITER: case JUMP_FORWARD: + case SETUP_LOOP: + case SETUP_EXCEPT: case SETUP_FINALLY: case SETUP_WITH: - case SETUP_ASYNC_WITH: - j = blocks[j / sizeof(_Py_CODEUNIT) + i + 1] - blocks[i] - 1; - j *= sizeof(_Py_CODEUNIT); + j = addrmap[GETARG(codestr, i) + i + 3] - addrmap[i] - 3; + SETARG(codestr, i, j); break; } - Py_ssize_t ilen = i - op_start + 1; - if (instrsize(j) > ilen) { - goto exitUnchanged; - } - assert(ilen <= INT_MAX); - /* If instrsize(j) < ilen, we'll emit EXTENDED_ARG 0 */ - write_op_arg(codestr + h, opcode, j, (int)ilen); - h += ilen; + adj = CODESIZE(opcode); + while (adj--) + codestr[h++] = codestr[i++]; } - assert(h + (Py_ssize_t)nops == codelen); + assert(h + nops == codelen); - PyMem_Free(blocks); - code = PyBytes_FromStringAndSize((char *)codestr, h * sizeof(_Py_CODEUNIT)); + code = PyString_FromStringAndSize((char *)codestr, h); + PyMem_Free(addrmap); PyMem_Free(codestr); + PyMem_Free(blocks); return code; exitError: code = NULL; exitUnchanged: + if (blocks != NULL) + PyMem_Free(blocks); + if (addrmap != NULL) + PyMem_Free(addrmap); + if (codestr != NULL) + PyMem_Free(codestr); Py_XINCREF(code); - PyMem_Free(blocks); - PyMem_Free(codestr); return code; } |