diff options
Diffstat (limited to 'Python/ceval_macros.h')
| -rw-r--r-- | Python/ceval_macros.h | 33 |
1 files changed, 1 insertions, 32 deletions
diff --git a/Python/ceval_macros.h b/Python/ceval_macros.h index feaac07fe43..62c80c96e42 100644 --- a/Python/ceval_macros.h +++ b/Python/ceval_macros.h @@ -166,35 +166,6 @@ GETITEM(PyObject *v, Py_ssize_t i) { #define JUMPBY(x) (next_instr += (x)) #define SKIP_OVER(x) (next_instr += (x)) -/* OpCode prediction macros - Some opcodes tend to come in pairs thus making it possible to - predict the second code when the first is run. For example, - COMPARE_OP is often followed by POP_JUMP_IF_FALSE or POP_JUMP_IF_TRUE. - - Verifying the prediction costs a single high-speed test of a register - variable against a constant. If the pairing was good, then the - processor's own internal branch predication has a high likelihood of - success, resulting in a nearly zero-overhead transition to the - next opcode. A successful prediction saves a trip through the eval-loop - including its unpredictable switch-case branch. Combined with the - processor's internal branch prediction, a successful PREDICT has the - effect of making the two opcodes run as if they were a single new opcode - with the bodies combined. - - If collecting opcode statistics, your choices are to either keep the - predictions turned-on and interpret the results as if some opcodes - had been combined or turn-off predictions so that the opcode frequency - counter updates for both opcodes. - - Opcode prediction is disabled with threaded code, since the latter allows - the CPU to record separate branch prediction information for each - opcode. - -*/ - -#define PREDICT_ID(op) PRED_##op -#define PREDICTED(op) PREDICT_ID(op): - /* Stack manipulation macros */ @@ -260,8 +231,6 @@ GETITEM(PyObject *v, Py_ssize_t i) { GETLOCAL(i) = value; \ PyStackRef_XCLOSE(tmp); } while (0) -#define GO_TO_INSTRUCTION(op) goto PREDICT_ID(op) - #ifdef Py_STATS #define UPDATE_MISS_STATS(INSTNAME) \ do { \ @@ -281,7 +250,7 @@ GETITEM(PyObject *v, Py_ssize_t i) { /* This is only a single jump on release builds! */ \ UPDATE_MISS_STATS((INSTNAME)); \ assert(_PyOpcode_Deopt[opcode] == (INSTNAME)); \ - GO_TO_INSTRUCTION(INSTNAME); \ + goto PREDICTED_##INSTNAME; \ } |