diff options
Diffstat (limited to 'Python/optimizer.c')
| -rw-r--r-- | Python/optimizer.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/Python/optimizer.c b/Python/optimizer.c index 7c46bd6..d44e733 100644 --- a/Python/optimizer.c +++ b/Python/optimizer.c @@ -409,6 +409,9 @@ BRANCH_TO_GUARD[4][2] = { #define TRACE_STACK_SIZE 5 +#define CONFIDENCE_RANGE 1000 +#define CONFIDENCE_CUTOFF 333 + /* Returns 1 on success, * 0 if it failed to produce a worthwhile trace, * and -1 on an error. @@ -431,6 +434,7 @@ translate_bytecode_to_trace( _Py_CODEUNIT *instr; } trace_stack[TRACE_STACK_SIZE]; int trace_stack_depth = 0; + int confidence = CONFIDENCE_RANGE; // Adjusted by branch instructions #ifdef Py_DEBUG char *python_lltrace = Py_GETENV("PYTHON_LLTRACE"); @@ -513,7 +517,6 @@ top: // Jump here after _PUSH_FRAME or likely branches uint32_t oparg = instr->op.arg; uint32_t extras = 0; - if (opcode == EXTENDED_ARG) { instr++; extras += 1; @@ -543,11 +546,22 @@ top: // Jump here after _PUSH_FRAME or likely branches int counter = instr[1].cache; int bitcount = _Py_popcount32(counter); int jump_likely = bitcount > 8; + if (jump_likely) { + confidence = confidence * bitcount / 16; + } + else { + confidence = confidence * (16 - bitcount) / 16; + } + if (confidence < CONFIDENCE_CUTOFF) { + DPRINTF(2, "Confidence too low (%d)\n", confidence); + OPT_STAT_INC(low_confidence); + goto done; + } uint32_t uopcode = BRANCH_TO_GUARD[opcode - POP_JUMP_IF_FALSE][jump_likely]; _Py_CODEUNIT *next_instr = instr + 1 + _PyOpcode_Caches[_PyOpcode_Deopt[opcode]]; - DPRINTF(4, "%s(%d): counter=%x, bitcount=%d, likely=%d, uopcode=%s\n", + DPRINTF(2, "%s(%d): counter=%x, bitcount=%d, likely=%d, confidence=%d, uopcode=%s\n", _PyUOpName(opcode), oparg, - counter, bitcount, jump_likely, _PyUOpName(uopcode)); + counter, bitcount, jump_likely, confidence, _PyUOpName(uopcode)); ADD_TO_TRACE(uopcode, max_length, 0, target); if (jump_likely) { _Py_CODEUNIT *target_instr = next_instr + oparg; |