postgresql/src/backend/jit/llvm/llvmjit_types.c

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/*-------------------------------------------------------------------------
*
* llvmjit_types.c
* List of types needed by JIT emitting code.
*
* JIT emitting code often needs to access struct elements, create functions
* with the correct signature etc. To allow synchronizing these types with a
* low chance of definitions getting out of sync, this file lists types and
* functions that directly need to be accessed from LLVM.
*
* When LLVM is first used in a backend, a bitcode version of this file will
* be loaded. The needed types and signatures will be stored into Struct*,
* Type*, Func* variables.
*
* NB: This file will not be linked into the server, it's just converted to
* bitcode.
*
*
* Copyright (c) 2016-2020, PostgreSQL Global Development Group
*
* IDENTIFICATION
* src/backend/jit/llvm/llvmjit_types.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/htup.h"
#include "access/htup_details.h"
#include "access/tupdesc.h"
#include "catalog/pg_attribute.h"
#include "executor/execExpr.h"
#include "executor/nodeAgg.h"
#include "executor/tuptable.h"
#include "fmgr.h"
#include "nodes/execnodes.h"
#include "nodes/memnodes.h"
#include "utils/expandeddatum.h"
#include "utils/palloc.h"
/*
* List of types needed for JITing. These have to be non-static, otherwise
* clang/LLVM will omit them. As this file will never be linked into
* anything, that's harmless.
*/
PGFunction TypePGFunction;
size_t TypeSizeT;
bool TypeStorageBool;
Change function call information to be variable length. Before this change FunctionCallInfoData, the struct arguments etc for V1 function calls are stored in, always had space for FUNC_MAX_ARGS/100 arguments, storing datums and their nullness in two arrays. For nearly every function call 100 arguments is far more than needed, therefore wasting memory. Arg and argnull being two separate arrays also guarantees that to access a single argument, two cachelines have to be touched. Change the layout so there's a single variable-length array with pairs of value / isnull. That drastically reduces memory consumption for most function calls (on x86-64 a two argument function now uses 64bytes, previously 936 bytes), and makes it very likely that argument value and its nullness are on the same cacheline. Arguments are stored in a new NullableDatum struct, which, due to padding, needs more memory per argument than before. But as usually far fewer arguments are stored, and individual arguments are cheaper to access, that's still a clear win. It's likely that there's other places where conversion to NullableDatum arrays would make sense, e.g. TupleTableSlots, but that's for another commit. Because the function call information is now variable-length allocations have to take the number of arguments into account. For heap allocations that can be done with SizeForFunctionCallInfoData(), for on-stack allocations there's a new LOCAL_FCINFO(name, nargs) macro that helps to allocate an appropriately sized and aligned variable. Some places with stack allocation function call information don't know the number of arguments at compile time, and currently variably sized stack allocations aren't allowed in postgres. Therefore allow for FUNC_MAX_ARGS space in these cases. They're not that common, so for now that seems acceptable. Because of the need to allocate FunctionCallInfo of the appropriate size, older extensions may need to update their code. To avoid subtle breakages, the FunctionCallInfoData struct has been renamed to FunctionCallInfoBaseData. Most code only references FunctionCallInfo, so that shouldn't cause much collateral damage. This change is also a prerequisite for more efficient expression JIT compilation (by allocating the function call information on the stack, allowing LLVM to optimize it away); previously the size of the call information caused problems inside LLVM's optimizer. Author: Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/20180605172952.x34m5uz6ju6enaem@alap3.anarazel.de
2019-01-26 23:17:52 +01:00
NullableDatum StructNullableDatum;
AggState StructAggState;
AggStatePerGroupData StructAggStatePerGroupData;
AggStatePerTransData StructAggStatePerTransData;
ExprContext StructExprContext;
ExprEvalStep StructExprEvalStep;
ExprState StructExprState;
Change function call information to be variable length. Before this change FunctionCallInfoData, the struct arguments etc for V1 function calls are stored in, always had space for FUNC_MAX_ARGS/100 arguments, storing datums and their nullness in two arrays. For nearly every function call 100 arguments is far more than needed, therefore wasting memory. Arg and argnull being two separate arrays also guarantees that to access a single argument, two cachelines have to be touched. Change the layout so there's a single variable-length array with pairs of value / isnull. That drastically reduces memory consumption for most function calls (on x86-64 a two argument function now uses 64bytes, previously 936 bytes), and makes it very likely that argument value and its nullness are on the same cacheline. Arguments are stored in a new NullableDatum struct, which, due to padding, needs more memory per argument than before. But as usually far fewer arguments are stored, and individual arguments are cheaper to access, that's still a clear win. It's likely that there's other places where conversion to NullableDatum arrays would make sense, e.g. TupleTableSlots, but that's for another commit. Because the function call information is now variable-length allocations have to take the number of arguments into account. For heap allocations that can be done with SizeForFunctionCallInfoData(), for on-stack allocations there's a new LOCAL_FCINFO(name, nargs) macro that helps to allocate an appropriately sized and aligned variable. Some places with stack allocation function call information don't know the number of arguments at compile time, and currently variably sized stack allocations aren't allowed in postgres. Therefore allow for FUNC_MAX_ARGS space in these cases. They're not that common, so for now that seems acceptable. Because of the need to allocate FunctionCallInfo of the appropriate size, older extensions may need to update their code. To avoid subtle breakages, the FunctionCallInfoData struct has been renamed to FunctionCallInfoBaseData. Most code only references FunctionCallInfo, so that shouldn't cause much collateral damage. This change is also a prerequisite for more efficient expression JIT compilation (by allocating the function call information on the stack, allowing LLVM to optimize it away); previously the size of the call information caused problems inside LLVM's optimizer. Author: Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/20180605172952.x34m5uz6ju6enaem@alap3.anarazel.de
2019-01-26 23:17:52 +01:00
FunctionCallInfoBaseData StructFunctionCallInfoData;
HeapTupleData StructHeapTupleData;
MemoryContextData StructMemoryContextData;
TupleTableSlot StructTupleTableSlot;
Make TupleTableSlots extensible, finish split of existing slot type. This commit completes the work prepared in 1a0586de36, splitting the old TupleTableSlot implementation (which could store buffer, heap, minimal and virtual slots) into four different slot types. As described in the aforementioned commit, this is done with the goal of making tuple table slots extensible, to allow for pluggable table access methods. To achieve runtime extensibility for TupleTableSlots, operations on slots that can differ between types of slots are performed using the TupleTableSlotOps struct provided at slot creation time. That includes information from the size of TupleTableSlot struct to be allocated, initialization, deforming etc. See the struct's definition for more detailed information about callbacks TupleTableSlotOps. I decided to rename TTSOpsBufferTuple to TTSOpsBufferHeapTuple and ExecCopySlotTuple to ExecCopySlotHeapTuple, as that seems more consistent with other naming introduced in recent patches. There's plenty optimization potential in the slot implementation, but according to benchmarking the state after this commit has similar performance characteristics to before this set of changes, which seems sufficient. There's a few changes in execReplication.c that currently need to poke through the slot abstraction, that'll be repaired once the pluggable storage patchset provides the necessary infrastructure. Author: Andres Freund and Ashutosh Bapat, with changes by Amit Khandekar Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de
2018-11-17 01:35:11 +01:00
HeapTupleTableSlot StructHeapTupleTableSlot;
MinimalTupleTableSlot StructMinimalTupleTableSlot;
TupleDescData StructTupleDescData;
/*
* To determine which attributes functions need to have (depends e.g. on
* compiler version and settings) to be compatible for inlining, we simply
* copy the attributes of this function.
*/
extern Datum AttributeTemplate(PG_FUNCTION_ARGS);
Datum
AttributeTemplate(PG_FUNCTION_ARGS)
{
PG_RETURN_NULL();
}
/*
* Clang represents stdbool.h style booleans that are returned by functions
* differently (as i1) than stored ones (as i8). Therefore we do not just need
* TypeBool (above), but also a way to determine the width of a returned
* integer. This allows us to keep compatible with non-stdbool using
* architectures.
*/
extern bool FunctionReturningBool(void);
bool
FunctionReturningBool(void)
{
return false;
}
/*
* To force signatures of functions used during JITing to be present,
* reference the functions required. This again has to be non-static, to avoid
* being removed as unnecessary.
*/
void *referenced_functions[] =
{
strlen,
varsize_any,
slot_getsomeattrs_int,
slot_getmissingattrs,
MakeExpandedObjectReadOnlyInternal,
ExecEvalSubscriptingRef,
ExecEvalSysVar,
ExecAggTransReparent,
ExecAggInitGroup
};