#include "postgres.h"
#include <llvm-c/Core.h>
#include "access/htup_details.h"
#include "access/tupdesc_details.h"
#include "executor/tuptable.h"
#include "jit/llvmjit.h"
#include "jit/llvmjit_emit.h"
Include dependency graph for llvmjit_deform.c:
Functions
LLVMValueRef	slot_compile_deform (LLVMJitContext context, TupleDesc desc, const TupleTableSlotOps ops, int natts)
Function Documentation

◆ slot_compile_deform()

LLVMValueRef slot_compile_deform	(	LLVMJitContext *	context,
		TupleDesc	desc,
		const TupleTableSlotOps *	ops,
		int	natts
	)
Definition at line 34 of file llvmjit_deform.c.
 {
     char       *funcname;
  
     LLVMModuleRef mod;
     LLVMBuilderRef b;
  
     LLVMTypeRef deform_sig;
     LLVMValueRef v_deform_fn;
  
     LLVMBasicBlockRef b_entry;
     LLVMBasicBlockRef b_adjust_unavail_cols;
     LLVMBasicBlockRef b_find_start;
  
     LLVMBasicBlockRef b_out;
     LLVMBasicBlockRef b_dead;
     LLVMBasicBlockRef *attcheckattnoblocks;
     LLVMBasicBlockRef *attstartblocks;
     LLVMBasicBlockRef *attisnullblocks;
     LLVMBasicBlockRef *attcheckalignblocks;
     LLVMBasicBlockRef *attalignblocks;
     LLVMBasicBlockRef *attstoreblocks;
  
     LLVMValueRef v_offp;
  
     LLVMValueRef v_tupdata_base;
     LLVMValueRef v_tts_values;
     LLVMValueRef v_tts_nulls;
     LLVMValueRef v_slotoffp;
     LLVMValueRef v_flagsp;
     LLVMValueRef v_nvalidp;
     LLVMValueRef v_nvalid;
     LLVMValueRef v_maxatt;
  
     LLVMValueRef v_slot;
  
     LLVMValueRef v_tupleheaderp;
     LLVMValueRef v_tuplep;
     LLVMValueRef v_infomask1;
     LLVMValueRef v_infomask2;
     LLVMValueRef v_bits;
  
     LLVMValueRef v_hoff;
  
     LLVMValueRef v_hasnulls;
  
     /* last column (0 indexed) guaranteed to exist */
     int         guaranteed_column_number = -1;
  
     /* current known alignment */
     int         known_alignment = 0;
  
     /* if true, known_alignment describes definite offset of column */
     bool        attguaranteedalign = true;
  
     int         attnum;
  
     /* virtual tuples never need deforming, so don't generate code */
     if (ops == &TTSOpsVirtual)
         return NULL;
  
     /* decline to JIT for slot types we don't know to handle */
     if (ops != &TTSOpsHeapTuple && ops != &TTSOpsBufferHeapTuple &&
         ops != &TTSOpsMinimalTuple)
         return NULL;
  
     mod = llvm_mutable_module(context);
  
     funcname = llvm_expand_funcname(context, "deform");
  
     /*
      * Check which columns have to exist, so we don't have to check the row's
      * natts unnecessarily.
      */
     for (attnum = 0; attnum < desc->natts; attnum++)
     {
         Form_pg_attribute att = TupleDescAttr(desc, attnum);
  
         /*
          * If the column is declared NOT NULL then it must be present in every
          * tuple, unless there's a "missing" entry that could provide a
          * non-NULL value for it. That in turn guarantees that the NULL bitmap
          * - if there are any NULLable columns - is at least long enough to
          * cover columns up to attnum.
          *
          * Be paranoid and also check !attisdropped, even though the
          * combination of attisdropped && attnotnull combination shouldn't
          * exist.
          */
         if (att->attnotnull &&
             !att->atthasmissing &&
             !att->attisdropped)
             guaranteed_column_number = attnum;
     }
  
     /* Create the signature and function */
     {
         LLVMTypeRef param_types[1];
  
         param_types[0] = l_ptr(StructTupleTableSlot);
  
         deform_sig = LLVMFunctionType(LLVMVoidType(), param_types,
                                       lengthof(param_types), 0);
     }
     v_deform_fn = LLVMAddFunction(mod, funcname, deform_sig);
     LLVMSetLinkage(v_deform_fn, LLVMInternalLinkage);
     LLVMSetParamAlignment(LLVMGetParam(v_deform_fn, 0), MAXIMUM_ALIGNOF);
     llvm_copy_attributes(AttributeTemplate, v_deform_fn);
  
     b_entry =
         LLVMAppendBasicBlock(v_deform_fn, "entry");
     b_adjust_unavail_cols =
         LLVMAppendBasicBlock(v_deform_fn, "adjust_unavail_cols");
     b_find_start =
         LLVMAppendBasicBlock(v_deform_fn, "find_startblock");
     b_out =
         LLVMAppendBasicBlock(v_deform_fn, "outblock");
     b_dead =
         LLVMAppendBasicBlock(v_deform_fn, "deadblock");
  
     b = LLVMCreateBuilder();
  
     attcheckattnoblocks = palloc(sizeof(LLVMBasicBlockRef) * natts);
     attstartblocks = palloc(sizeof(LLVMBasicBlockRef) * natts);
     attisnullblocks = palloc(sizeof(LLVMBasicBlockRef) * natts);
     attcheckalignblocks = palloc(sizeof(LLVMBasicBlockRef) * natts);
     attalignblocks = palloc(sizeof(LLVMBasicBlockRef) * natts);
     attstoreblocks = palloc(sizeof(LLVMBasicBlockRef) * natts);
  
     known_alignment = 0;
  
     LLVMPositionBuilderAtEnd(b, b_entry);
  
     /* perform allocas first, llvm only converts those to registers */
     v_offp = LLVMBuildAlloca(b, TypeSizeT, "v_offp");
  
     v_slot = LLVMGetParam(v_deform_fn, 0);
  
     v_tts_values =
         l_load_struct_gep(b, v_slot, FIELDNO_TUPLETABLESLOT_VALUES,
                           "tts_values");
     v_tts_nulls =
         l_load_struct_gep(b, v_slot, FIELDNO_TUPLETABLESLOT_ISNULL,
                           "tts_ISNULL");
     v_flagsp = LLVMBuildStructGEP(b, v_slot, FIELDNO_TUPLETABLESLOT_FLAGS, "");
     v_nvalidp = LLVMBuildStructGEP(b, v_slot, FIELDNO_TUPLETABLESLOT_NVALID, "");
  
     if (ops == &TTSOpsHeapTuple || ops == &TTSOpsBufferHeapTuple)
     {
         LLVMValueRef v_heapslot;
  
         v_heapslot =
             LLVMBuildBitCast(b,
                              v_slot,
                              l_ptr(StructHeapTupleTableSlot),
                              "heapslot");
         v_slotoffp = LLVMBuildStructGEP(b, v_heapslot, FIELDNO_HEAPTUPLETABLESLOT_OFF, "");
         v_tupleheaderp =
             l_load_struct_gep(b, v_heapslot, FIELDNO_HEAPTUPLETABLESLOT_TUPLE,
                               "tupleheader");
     }
     else if (ops == &TTSOpsMinimalTuple)
     {
         LLVMValueRef v_minimalslot;
  
         v_minimalslot =
             LLVMBuildBitCast(b,
                              v_slot,
                              l_ptr(StructMinimalTupleTableSlot),
                              "minimalslot");
         v_slotoffp = LLVMBuildStructGEP(b, v_minimalslot, FIELDNO_MINIMALTUPLETABLESLOT_OFF, "");
         v_tupleheaderp =
             l_load_struct_gep(b, v_minimalslot, FIELDNO_MINIMALTUPLETABLESLOT_TUPLE,
                               "tupleheader");
     }
     else
     {
         /* should've returned at the start of the function */
         pg_unreachable();
     }
  
     v_tuplep =
         l_load_struct_gep(b, v_tupleheaderp, FIELDNO_HEAPTUPLEDATA_DATA,
                           "tuple");
     v_bits =
         LLVMBuildBitCast(b,
                          LLVMBuildStructGEP(b, v_tuplep,
                                             FIELDNO_HEAPTUPLEHEADERDATA_BITS,
                                             ""),
                          l_ptr(LLVMInt8Type()),
                          "t_bits");
     v_infomask1 =
         l_load_struct_gep(b, v_tuplep,
                           FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK,
                           "infomask1");
     v_infomask2 =
         l_load_struct_gep(b,
                           v_tuplep, FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK2,
                           "infomask2");
  
     /* t_infomask & HEAP_HASNULL */
     v_hasnulls =
         LLVMBuildICmp(b, LLVMIntNE,
                       LLVMBuildAnd(b,
                                    l_int16_const(HEAP_HASNULL),
                                    v_infomask1, ""),
                       l_int16_const(0),
                       "hasnulls");
  
     /* t_infomask2 & HEAP_NATTS_MASK */
     v_maxatt = LLVMBuildAnd(b,
                             l_int16_const(HEAP_NATTS_MASK),
                             v_infomask2,
                             "maxatt");
  
     /*
      * Need to zext, as getelementptr otherwise treats hoff as a signed 8bit
      * integer, which'd yield a negative offset for t_hoff > 127.
      */
     v_hoff =
         LLVMBuildZExt(b,
                       l_load_struct_gep(b, v_tuplep,
                                         FIELDNO_HEAPTUPLEHEADERDATA_HOFF,
                                         ""),
                       LLVMInt32Type(), "t_hoff");
  
     v_tupdata_base =
         LLVMBuildGEP(b,
                      LLVMBuildBitCast(b,
                                       v_tuplep,
                                       l_ptr(LLVMInt8Type()),
                                       ""),
                      &v_hoff, 1,
                      "v_tupdata_base");
  
     /*
      * Load tuple start offset from slot. Will be reset below in case there's
      * no existing deformed columns in slot.
      */
     {
         LLVMValueRef v_off_start;
  
         v_off_start = LLVMBuildLoad(b, v_slotoffp, "v_slot_off");
         v_off_start = LLVMBuildZExt(b, v_off_start, TypeSizeT, "");
         LLVMBuildStore(b, v_off_start, v_offp);
     }
  
     /* build the basic block for each attribute, need them as jump target */
     for (attnum = 0; attnum < natts; attnum++)
     {
         attcheckattnoblocks[attnum] =
             l_bb_append_v(v_deform_fn, "block.attr.%d.attcheckattno", attnum);
         attstartblocks[attnum] =
             l_bb_append_v(v_deform_fn, "block.attr.%d.start", attnum);
         attisnullblocks[attnum] =
             l_bb_append_v(v_deform_fn, "block.attr.%d.attisnull", attnum);
         attcheckalignblocks[attnum] =
             l_bb_append_v(v_deform_fn, "block.attr.%d.attcheckalign", attnum);
         attalignblocks[attnum] =
             l_bb_append_v(v_deform_fn, "block.attr.%d.align", attnum);
         attstoreblocks[attnum] =
             l_bb_append_v(v_deform_fn, "block.attr.%d.store", attnum);
     }
  
     /*
      * Check if it is guaranteed that all the desired attributes are available
      * in the tuple (but still possibly NULL), by dint of either the last
      * to-be-deformed column being NOT NULL, or subsequent ones not accessed
      * here being NOT NULL.  If that's not guaranteed the tuple headers natt's
      * has to be checked, and missing attributes potentially have to be
      * fetched (using slot_getmissingattrs().
      */
     if ((natts - 1) <= guaranteed_column_number)
     {
         /* just skip through unnecessary blocks */
         LLVMBuildBr(b, b_adjust_unavail_cols);
         LLVMPositionBuilderAtEnd(b, b_adjust_unavail_cols);
         LLVMBuildBr(b, b_find_start);
     }
     else
     {
         LLVMValueRef v_params[3];
  
         /* branch if not all columns available */
         LLVMBuildCondBr(b,
                         LLVMBuildICmp(b, LLVMIntULT,
                                       v_maxatt,
                                       l_int16_const(natts),
                                       ""),
                         b_adjust_unavail_cols,
                         b_find_start);
  
         /* if not, memset tts_isnull of relevant cols to true */
         LLVMPositionBuilderAtEnd(b, b_adjust_unavail_cols);
  
         v_params[0] = v_slot;
         v_params[1] = LLVMBuildZExt(b, v_maxatt, LLVMInt32Type(), "");
         v_params[2] = l_int32_const(natts);
         LLVMBuildCall(b, llvm_pg_func(mod, "slot_getmissingattrs"),
                       v_params, lengthof(v_params), "");
         LLVMBuildBr(b, b_find_start);
     }
  
     LLVMPositionBuilderAtEnd(b, b_find_start);
  
     v_nvalid = LLVMBuildLoad(b, v_nvalidp, "");
  
     /*
      * Build switch to go from nvalid to the right startblock.  Callers
      * currently don't have the knowledge, but it'd be good for performance to
      * avoid this check when it's known that the slot is empty (e.g. in scan
      * nodes).
      */
     if (true)
     {
         LLVMValueRef v_switch = LLVMBuildSwitch(b, v_nvalid,
                                                 b_dead, natts);
  
         for (attnum = 0; attnum < natts; attnum++)
         {
             LLVMValueRef v_attno = l_int16_const(attnum);
  
             LLVMAddCase(v_switch, v_attno, attcheckattnoblocks[attnum]);
         }
     }
     else
     {
         /* jump from entry block to first block */
         LLVMBuildBr(b, attcheckattnoblocks[0]);
     }
  
     LLVMPositionBuilderAtEnd(b, b_dead);
     LLVMBuildUnreachable(b);
  
     /*
      * Iterate over each attribute that needs to be deformed, build code to
      * deform it.
      */
     for (attnum = 0; attnum < natts; attnum++)
     {
         Form_pg_attribute att = TupleDescAttr(desc, attnum);
         LLVMValueRef v_incby;
         int         alignto;
         LLVMValueRef l_attno = l_int16_const(attnum);
         LLVMValueRef v_attdatap;
         LLVMValueRef v_resultp;
  
         /* build block checking whether we did all the necessary attributes */
         LLVMPositionBuilderAtEnd(b, attcheckattnoblocks[attnum]);
  
         /*
          * If this is the first attribute, slot->tts_nvalid was 0. Therefore
          * also reset offset to 0, it may be from a previous execution.
          */
         if (attnum == 0)
         {
             LLVMBuildStore(b, l_sizet_const(0), v_offp);
         }
  
         /*
          * Build check whether column is available (i.e. whether the tuple has
          * that many columns stored). We can avoid the branch if we know
          * there's a subsequent NOT NULL column.
          */
         if (attnum <= guaranteed_column_number)
         {
             LLVMBuildBr(b, attstartblocks[attnum]);
         }
         else
         {
             LLVMValueRef v_islast;
  
             v_islast = LLVMBuildICmp(b, LLVMIntUGE,
                                      l_attno,
                                      v_maxatt,
                                      "heap_natts");
             LLVMBuildCondBr(b, v_islast, b_out, attstartblocks[attnum]);
         }
         LLVMPositionBuilderAtEnd(b, attstartblocks[attnum]);
  
         /*
          * Check for nulls if necessary. No need to take missing attributes
          * into account, because if they're present the heaptuple's natts
          * would have indicated that a slot_getmissingattrs() is needed.
          */
         if (!att->attnotnull)
         {
             LLVMBasicBlockRef b_ifnotnull;
             LLVMBasicBlockRef b_ifnull;
             LLVMBasicBlockRef b_next;
             LLVMValueRef v_attisnull;
             LLVMValueRef v_nullbyteno;
             LLVMValueRef v_nullbytemask;
             LLVMValueRef v_nullbyte;
             LLVMValueRef v_nullbit;
  
             b_ifnotnull = attcheckalignblocks[attnum];
             b_ifnull = attisnullblocks[attnum];
  
             if (attnum + 1 == natts)
                 b_next = b_out;
             else
                 b_next = attcheckattnoblocks[attnum + 1];
  
             v_nullbyteno = l_int32_const(attnum >> 3);
             v_nullbytemask = l_int8_const(1 << ((attnum) & 0x07));
             v_nullbyte = l_load_gep1(b, v_bits, v_nullbyteno, "attnullbyte");
  
             v_nullbit = LLVMBuildICmp(b,
                                       LLVMIntEQ,
                                       LLVMBuildAnd(b, v_nullbyte, v_nullbytemask, ""),
                                       l_int8_const(0),
                                       "attisnull");
  
             v_attisnull = LLVMBuildAnd(b, v_hasnulls, v_nullbit, "");
  
             LLVMBuildCondBr(b, v_attisnull, b_ifnull, b_ifnotnull);
  
             LLVMPositionBuilderAtEnd(b, b_ifnull);
  
             /* store null-byte */
             LLVMBuildStore(b,
                            l_int8_const(1),
                            LLVMBuildGEP(b, v_tts_nulls, &l_attno, 1, ""));
             /* store zero datum */
             LLVMBuildStore(b,
                            l_sizet_const(0),
                            LLVMBuildGEP(b, v_tts_values, &l_attno, 1, ""));
  
             LLVMBuildBr(b, b_next);
             attguaranteedalign = false;
         }
         else
         {
             /* nothing to do */
             LLVMBuildBr(b, attcheckalignblocks[attnum]);
             LLVMPositionBuilderAtEnd(b, attisnullblocks[attnum]);
             LLVMBuildBr(b, attcheckalignblocks[attnum]);
         }
         LLVMPositionBuilderAtEnd(b, attcheckalignblocks[attnum]);
  
         /* determine required alignment */
         if (att->attalign == TYPALIGN_INT)
             alignto = ALIGNOF_INT;
         else if (att->attalign == TYPALIGN_CHAR)
             alignto = 1;
         else if (att->attalign == TYPALIGN_DOUBLE)
             alignto = ALIGNOF_DOUBLE;
         else if (att->attalign == TYPALIGN_SHORT)
             alignto = ALIGNOF_SHORT;
         else
         {
             elog(ERROR, "unknown alignment");
             alignto = 0;
         }
  
         /* ------
          * Even if alignment is required, we can skip doing it if provably
          * unnecessary:
          * - first column is guaranteed to be aligned
          * - columns following a NOT NULL fixed width datum have known
          *   alignment, can skip alignment computation if that known alignment
          *   is compatible with current column.
          * ------
          */
         if (alignto > 1 &&
             (known_alignment < 0 || known_alignment != TYPEALIGN(alignto, known_alignment)))
         {
             /*
              * When accessing a varlena field, we have to "peek" to see if we
              * are looking at a pad byte or the first byte of a 1-byte-header
              * datum.  A zero byte must be either a pad byte, or the first
              * byte of a correctly aligned 4-byte length word; in either case,
              * we can align safely.  A non-zero byte must be either a 1-byte
              * length word, or the first byte of a correctly aligned 4-byte
              * length word; in either case, we need not align.
              */
             if (att->attlen == -1)
             {
                 LLVMValueRef v_possible_padbyte;
                 LLVMValueRef v_ispad;
                 LLVMValueRef v_off;
  
                 /* don't know if short varlena or not */
                 attguaranteedalign = false;
  
                 v_off = LLVMBuildLoad(b, v_offp, "");
  
                 v_possible_padbyte =
                     l_load_gep1(b, v_tupdata_base, v_off, "padbyte");
                 v_ispad =
                     LLVMBuildICmp(b, LLVMIntEQ,
                                   v_possible_padbyte, l_int8_const(0),
                                   "ispadbyte");
                 LLVMBuildCondBr(b, v_ispad,
                                 attalignblocks[attnum],
                                 attstoreblocks[attnum]);
             }
             else
             {
                 LLVMBuildBr(b, attalignblocks[attnum]);
             }
  
             LLVMPositionBuilderAtEnd(b, attalignblocks[attnum]);
  
             /* translation of alignment code (cf TYPEALIGN()) */
             {
                 LLVMValueRef v_off_aligned;
                 LLVMValueRef v_off = LLVMBuildLoad(b, v_offp, "");
  
                 /* ((ALIGNVAL) - 1) */
                 LLVMValueRef v_alignval = l_sizet_const(alignto - 1);
  
                 /* ((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) */
                 LLVMValueRef v_lh = LLVMBuildAdd(b, v_off, v_alignval, "");
  
                 /* ~((uintptr_t) ((ALIGNVAL) - 1)) */
                 LLVMValueRef v_rh = l_sizet_const(~(alignto - 1));
  
                 v_off_aligned = LLVMBuildAnd(b, v_lh, v_rh, "aligned_offset");
  
                 LLVMBuildStore(b, v_off_aligned, v_offp);
             }
  
             /*
              * As alignment either was unnecessary or has been performed, we
              * now know the current alignment. This is only safe because this
              * value isn't used for varlena and nullable columns.
              */
             if (known_alignment >= 0)
             {
                 Assert(known_alignment != 0);
                 known_alignment = TYPEALIGN(alignto, known_alignment);
             }
  
             LLVMBuildBr(b, attstoreblocks[attnum]);
             LLVMPositionBuilderAtEnd(b, attstoreblocks[attnum]);
         }
         else
         {
             LLVMPositionBuilderAtEnd(b, attcheckalignblocks[attnum]);
             LLVMBuildBr(b, attalignblocks[attnum]);
             LLVMPositionBuilderAtEnd(b, attalignblocks[attnum]);
             LLVMBuildBr(b, attstoreblocks[attnum]);
         }
         LLVMPositionBuilderAtEnd(b, attstoreblocks[attnum]);
  
         /*
          * Store the current offset if known to be constant. That allows LLVM
          * to generate better code. Without that LLVM can't figure out that
          * the offset might be constant due to the jumps for previously
          * decoded columns.
          */
         if (attguaranteedalign)
         {
             Assert(known_alignment >= 0);
             LLVMBuildStore(b, l_sizet_const(known_alignment), v_offp);
         }
  
         /* compute what following columns are aligned to */
         if (att->attlen < 0)
         {
             /* can't guarantee any alignment after variable length field */
             known_alignment = -1;
             attguaranteedalign = false;
         }
         else if (att->attnotnull && attguaranteedalign && known_alignment >= 0)
         {
             /*
              * If the offset to the column was previously known, a NOT NULL &
              * fixed-width column guarantees that alignment is just the
              * previous alignment plus column width.
              */
             Assert(att->attlen > 0);
             known_alignment += att->attlen;
         }
         else if (att->attnotnull && (att->attlen % alignto) == 0)
         {
             /*
              * After a NOT NULL fixed-width column with a length that is a
              * multiple of its alignment requirement, we know the following
              * column is aligned to at least the current column's alignment.
              */
             Assert(att->attlen > 0);
             known_alignment = alignto;
             Assert(known_alignment > 0);
             attguaranteedalign = false;
         }
         else
         {
             known_alignment = -1;
             attguaranteedalign = false;
         }
  
  
         /* compute address to load data from */
         {
             LLVMValueRef v_off = LLVMBuildLoad(b, v_offp, "");
  
             v_attdatap =
                 LLVMBuildGEP(b, v_tupdata_base, &v_off, 1, "");
         }
  
         /* compute address to store value at */
         v_resultp = LLVMBuildGEP(b, v_tts_values, &l_attno, 1, "");
  
         /* store null-byte (false) */
         LLVMBuildStore(b, l_int8_const(0),
                        LLVMBuildGEP(b, v_tts_nulls, &l_attno, 1, ""));
  
         /*
          * Store datum. For byval: datums copy the value, extend to Datum's
          * width, and store. For byref types: store pointer to data.
          */
         if (att->attbyval)
         {
             LLVMValueRef v_tmp_loaddata;
             LLVMTypeRef vartypep =
                 LLVMPointerType(LLVMIntType(att->attlen * 8), 0);
  
             v_tmp_loaddata =
                 LLVMBuildPointerCast(b, v_attdatap, vartypep, "");
             v_tmp_loaddata = LLVMBuildLoad(b, v_tmp_loaddata, "attr_byval");
             v_tmp_loaddata = LLVMBuildZExt(b, v_tmp_loaddata, TypeSizeT, "");
  
             LLVMBuildStore(b, v_tmp_loaddata, v_resultp);
         }
         else
         {
             LLVMValueRef v_tmp_loaddata;
  
             /* store pointer */
             v_tmp_loaddata =
                 LLVMBuildPtrToInt(b,
                                   v_attdatap,
                                   TypeSizeT,
                                   "attr_ptr");
             LLVMBuildStore(b, v_tmp_loaddata, v_resultp);
         }
  
         /* increment data pointer */
         if (att->attlen > 0)
         {
             v_incby = l_sizet_const(att->attlen);
         }
         else if (att->attlen == -1)
         {
             v_incby = LLVMBuildCall(b,
                                     llvm_pg_func(mod, "varsize_any"),
                                     &v_attdatap, 1,
                                     "varsize_any");
             l_callsite_ro(v_incby);
             l_callsite_alwaysinline(v_incby);
         }
         else if (att->attlen == -2)
         {
             v_incby = LLVMBuildCall(b,
                                     llvm_pg_func(mod, "strlen"),
                                     &v_attdatap, 1, "strlen");
  
             l_callsite_ro(v_incby);
  
             /* add 1 for NUL byte */
             v_incby = LLVMBuildAdd(b, v_incby, l_sizet_const(1), "");
         }
         else
         {
             Assert(false);
             v_incby = NULL;     /* silence compiler */
         }
  
         if (attguaranteedalign)
         {
             Assert(known_alignment >= 0);
             LLVMBuildStore(b, l_sizet_const(known_alignment), v_offp);
         }
         else
         {
             LLVMValueRef v_off = LLVMBuildLoad(b, v_offp, "");
  
             v_off = LLVMBuildAdd(b, v_off, v_incby, "increment_offset");
             LLVMBuildStore(b, v_off, v_offp);
         }
  
         /*
          * jump to next block, unless last possible column, or all desired
          * (available) attributes have been fetched.
          */
         if (attnum + 1 == natts)
         {
             /* jump out */
             LLVMBuildBr(b, b_out);
         }
         else
         {
             LLVMBuildBr(b, attcheckattnoblocks[attnum + 1]);
         }
     }
  
  
     /* build block that returns */
     LLVMPositionBuilderAtEnd(b, b_out);
  
     {
         LLVMValueRef v_off = LLVMBuildLoad(b, v_offp, "");
         LLVMValueRef v_flags;
  
         LLVMBuildStore(b, l_int16_const(natts), v_nvalidp);
         v_off = LLVMBuildTrunc(b, v_off, LLVMInt32Type(), "");
         LLVMBuildStore(b, v_off, v_slotoffp);
         v_flags = LLVMBuildLoad(b, v_flagsp, "tts_flags");
         v_flags = LLVMBuildOr(b, v_flags, l_int16_const(TTS_FLAG_SLOW), "");
         LLVMBuildStore(b, v_flags, v_flagsp);
         LLVMBuildRetVoid(b);
     }
  
     LLVMDisposeBuilder(b);
  
     return v_deform_fn;
 }
References Assert(), attnum, AttributeTemplate, b, elog(), ERROR, FIELDNO_HEAPTUPLEDATA_DATA, FIELDNO_HEAPTUPLEHEADERDATA_BITS, FIELDNO_HEAPTUPLEHEADERDATA_HOFF, FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK, FIELDNO_HEAPTUPLEHEADERDATA_INFOMASK2, FIELDNO_HEAPTUPLETABLESLOT_OFF, FIELDNO_HEAPTUPLETABLESLOT_TUPLE, FIELDNO_MINIMALTUPLETABLESLOT_OFF, FIELDNO_MINIMALTUPLETABLESLOT_TUPLE, FIELDNO_TUPLETABLESLOT_FLAGS, FIELDNO_TUPLETABLESLOT_ISNULL, FIELDNO_TUPLETABLESLOT_NVALID, FIELDNO_TUPLETABLESLOT_VALUES, funcname, HEAP_HASNULL, HEAP_NATTS_MASK, lengthof, llvm_copy_attributes(), llvm_expand_funcname(), llvm_mutable_module(), llvm_pg_func(), TupleDescData::natts, palloc(), pg_unreachable, StructHeapTupleTableSlot, StructMinimalTupleTableSlot, StructTupleTableSlot, TTS_FLAG_SLOW, TTSOpsBufferHeapTuple, TTSOpsHeapTuple, TTSOpsMinimalTuple, TTSOpsVirtual, TupleDescAttr, TYPEALIGN, and TypeSizeT.
Functions

Function Documentation

◆ slot_compile_deform()
