la, lla, and lga — load a symbol address

These macros materialize an address and attach the relocations needed for the linker. Their canonical two-instruction forms may later be relaxed.

lla — local address

lla rd, symbol

lla requests a PC-relative address directly, conventionally:

.Lanchor:
    auipc rd, %pcrel_hi(symbol)
    addi  rd, rd, %pcrel_lo(.Lanchor)

It is normally two instructions, uses no register besides rd, and is not selected by the PIC setting. The paired relocations are essential: the low relocation refers to the auipc anchor, not independently to symbol.

lga — global address

lga rd, symbol

lga obtains a potentially preemptible global symbol through the global offset table (GOT):

.Lanchor:
    auipc rd, %got_pcrel_hi(symbol)
    ld    rd, %pcrel_lo(.Lanchor)(rd)    # RV64

RV32 uses lw instead of ld. The destination doubles as the GOT-address temporary, so no extra register is consumed. The expansion depends on the ABI, XLEN, relocations, symbol binding, and linker relaxation.

la — load address

la rd, symbol

la chooses between the two policies:

• With .option nopic (the usual default), it behaves like lla.
• With .option pic, it behaves like lga.

That makes la convenient but deliberately not a fixed instruction sequence. Use lla or lga when the distinction is important to the reader.

Relocation and relaxation

All three forms are relocation-dependent and normally begin as two instructions. The linker can sometimes relax the sequence when symbol binding and distance permit. Disassemble the linked output, not only the .o file, to measure the final sequence.