mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-09-27 23:01:55 +02:00
Marginal improvement for generated code in execExprInterp.c.
Avoid the coding pattern "*op->resvalue = f();", as some compilers think that requires them to evaluate "op->resvalue" before the function call. Unless there are lots of free registers, this can lead to a useless register spill and reload across the call. I changed all the cases like this in ExecInterpExpr(), but didn't bother in the out-of-line opcode eval subroutines, since those are presumably not as performance-critical. Discussion: https://postgr.es/m/2508.1506630094@sss.pgh.pa.us
This commit is contained in:
parent
5373bc2a08
commit
136ab7c5a5
@ -501,15 +501,17 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
EEO_CASE(EEOP_INNER_SYSVAR)
|
||||
{
|
||||
int attnum = op->d.var.attnum;
|
||||
Datum d;
|
||||
|
||||
/* these asserts must match defenses in slot_getattr */
|
||||
Assert(innerslot->tts_tuple != NULL);
|
||||
Assert(innerslot->tts_tuple != &(innerslot->tts_minhdr));
|
||||
/* heap_getsysattr has sufficient defenses against bad attnums */
|
||||
|
||||
*op->resvalue = heap_getsysattr(innerslot->tts_tuple, attnum,
|
||||
innerslot->tts_tupleDescriptor,
|
||||
op->resnull);
|
||||
/* heap_getsysattr has sufficient defenses against bad attnums */
|
||||
d = heap_getsysattr(innerslot->tts_tuple, attnum,
|
||||
innerslot->tts_tupleDescriptor,
|
||||
op->resnull);
|
||||
*op->resvalue = d;
|
||||
|
||||
EEO_NEXT();
|
||||
}
|
||||
@ -517,15 +519,17 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
EEO_CASE(EEOP_OUTER_SYSVAR)
|
||||
{
|
||||
int attnum = op->d.var.attnum;
|
||||
Datum d;
|
||||
|
||||
/* these asserts must match defenses in slot_getattr */
|
||||
Assert(outerslot->tts_tuple != NULL);
|
||||
Assert(outerslot->tts_tuple != &(outerslot->tts_minhdr));
|
||||
|
||||
/* heap_getsysattr has sufficient defenses against bad attnums */
|
||||
*op->resvalue = heap_getsysattr(outerslot->tts_tuple, attnum,
|
||||
outerslot->tts_tupleDescriptor,
|
||||
op->resnull);
|
||||
d = heap_getsysattr(outerslot->tts_tuple, attnum,
|
||||
outerslot->tts_tupleDescriptor,
|
||||
op->resnull);
|
||||
*op->resvalue = d;
|
||||
|
||||
EEO_NEXT();
|
||||
}
|
||||
@ -533,15 +537,17 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
EEO_CASE(EEOP_SCAN_SYSVAR)
|
||||
{
|
||||
int attnum = op->d.var.attnum;
|
||||
Datum d;
|
||||
|
||||
/* these asserts must match defenses in slot_getattr */
|
||||
Assert(scanslot->tts_tuple != NULL);
|
||||
Assert(scanslot->tts_tuple != &(scanslot->tts_minhdr));
|
||||
/* heap_getsysattr has sufficient defenses against bad attnums */
|
||||
|
||||
*op->resvalue = heap_getsysattr(scanslot->tts_tuple, attnum,
|
||||
scanslot->tts_tupleDescriptor,
|
||||
op->resnull);
|
||||
/* heap_getsysattr has sufficient defenses against bad attnums */
|
||||
d = heap_getsysattr(scanslot->tts_tuple, attnum,
|
||||
scanslot->tts_tupleDescriptor,
|
||||
op->resnull);
|
||||
*op->resvalue = d;
|
||||
|
||||
EEO_NEXT();
|
||||
}
|
||||
@ -641,13 +647,22 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
* As both STRICT checks and function-usage are noticeable performance
|
||||
* wise, and function calls are a very hot-path (they also back
|
||||
* operators!), it's worth having so many separate opcodes.
|
||||
*
|
||||
* Note: the reason for using a temporary variable "d", here and in
|
||||
* other places, is that some compilers think "*op->resvalue = f();"
|
||||
* requires them to evaluate op->resvalue into a register before
|
||||
* calling f(), just in case f() is able to modify op->resvalue
|
||||
* somehow. The extra line of code can save a useless register spill
|
||||
* and reload across the function call.
|
||||
*/
|
||||
EEO_CASE(EEOP_FUNCEXPR)
|
||||
{
|
||||
FunctionCallInfo fcinfo = op->d.func.fcinfo_data;
|
||||
Datum d;
|
||||
|
||||
fcinfo->isnull = false;
|
||||
*op->resvalue = op->d.func.fn_addr(fcinfo);
|
||||
d = op->d.func.fn_addr(fcinfo);
|
||||
*op->resvalue = d;
|
||||
*op->resnull = fcinfo->isnull;
|
||||
|
||||
EEO_NEXT();
|
||||
@ -658,6 +673,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
FunctionCallInfo fcinfo = op->d.func.fcinfo_data;
|
||||
bool *argnull = fcinfo->argnull;
|
||||
int argno;
|
||||
Datum d;
|
||||
|
||||
/* strict function, so check for NULL args */
|
||||
for (argno = 0; argno < op->d.func.nargs; argno++)
|
||||
@ -669,7 +685,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
}
|
||||
}
|
||||
fcinfo->isnull = false;
|
||||
*op->resvalue = op->d.func.fn_addr(fcinfo);
|
||||
d = op->d.func.fn_addr(fcinfo);
|
||||
*op->resvalue = d;
|
||||
*op->resnull = fcinfo->isnull;
|
||||
|
||||
strictfail:
|
||||
@ -680,11 +697,13 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
{
|
||||
FunctionCallInfo fcinfo = op->d.func.fcinfo_data;
|
||||
PgStat_FunctionCallUsage fcusage;
|
||||
Datum d;
|
||||
|
||||
pgstat_init_function_usage(fcinfo, &fcusage);
|
||||
|
||||
fcinfo->isnull = false;
|
||||
*op->resvalue = op->d.func.fn_addr(fcinfo);
|
||||
d = op->d.func.fn_addr(fcinfo);
|
||||
*op->resvalue = d;
|
||||
*op->resnull = fcinfo->isnull;
|
||||
|
||||
pgstat_end_function_usage(&fcusage, true);
|
||||
@ -698,6 +717,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
PgStat_FunctionCallUsage fcusage;
|
||||
bool *argnull = fcinfo->argnull;
|
||||
int argno;
|
||||
Datum d;
|
||||
|
||||
/* strict function, so check for NULL args */
|
||||
for (argno = 0; argno < op->d.func.nargs; argno++)
|
||||
@ -712,7 +732,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
pgstat_init_function_usage(fcinfo, &fcusage);
|
||||
|
||||
fcinfo->isnull = false;
|
||||
*op->resvalue = op->d.func.fn_addr(fcinfo);
|
||||
d = op->d.func.fn_addr(fcinfo);
|
||||
*op->resvalue = d;
|
||||
*op->resnull = fcinfo->isnull;
|
||||
|
||||
pgstat_end_function_usage(&fcusage, true);
|
||||
@ -1113,6 +1134,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
if (!op->d.iocoerce.finfo_in->fn_strict || str != NULL)
|
||||
{
|
||||
FunctionCallInfo fcinfo_in;
|
||||
Datum d;
|
||||
|
||||
fcinfo_in = op->d.iocoerce.fcinfo_data_in;
|
||||
fcinfo_in->arg[0] = PointerGetDatum(str);
|
||||
@ -1120,7 +1142,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
/* second and third arguments are already set up */
|
||||
|
||||
fcinfo_in->isnull = false;
|
||||
*op->resvalue = FunctionCallInvoke(fcinfo_in);
|
||||
d = FunctionCallInvoke(fcinfo_in);
|
||||
*op->resvalue = d;
|
||||
|
||||
/* Should get null result if and only if str is NULL */
|
||||
if (str == NULL)
|
||||
@ -1268,6 +1291,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
EEO_CASE(EEOP_ROWCOMPARE_STEP)
|
||||
{
|
||||
FunctionCallInfo fcinfo = op->d.rowcompare_step.fcinfo_data;
|
||||
Datum d;
|
||||
|
||||
/* force NULL result if strict fn and NULL input */
|
||||
if (op->d.rowcompare_step.finfo->fn_strict &&
|
||||
@ -1279,7 +1303,8 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
|
||||
|
||||
/* Apply comparison function */
|
||||
fcinfo->isnull = false;
|
||||
*op->resvalue = op->d.rowcompare_step.fn_addr(fcinfo);
|
||||
d = op->d.rowcompare_step.fn_addr(fcinfo);
|
||||
*op->resvalue = d;
|
||||
|
||||
/* force NULL result if NULL function result */
|
||||
if (fcinfo->isnull)
|
||||
|
Loading…
Reference in New Issue
Block a user