diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c index 09abd46..68a1f96 100644 --- a/src/backend/executor/execExprInterp.c +++ b/src/backend/executor/execExprInterp.c @@ -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, on architectures without many registers. */ 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)