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To call an external function, the direct branch to the PLT entry can be
replaced by an indirect branch via the GOT slot, which is similar to the
first instruction in the PLT slot. Instead using the PLT slot as function
address, the function address is retrieved from the GOT slot. The
R_386_GOT32X relocation can be used to compute the address of the symbol’s
GOT entry without base register when PIC is disabled. In non-PIC
executable,
call/jmp *func@GOT
should be used for indirect branch via the GOT slot and
movl func@GOT, %eax
should be used to load function address. Unlike PIC case, no register
is needed to access GOT. If linker determines the function is defined
locally, it converts indirect branch via the GOT slot to direct branch
with a nop prefix and converts load via the GOT slot to load immediate
or lea.
* testsuite/ld-i386/libno-plt-1b.dd: New file.
* testsuite/ld-i386/libno-plt-1b.rd: Likewise.
* testsuite/ld-i386/no-plt-1a.dd: Likewise.
* testsuite/ld-i386/no-plt-1a.rd: Likewise.
* testsuite/ld-i386/no-plt-1b.dd: Likewise.
* testsuite/ld-i386/no-plt-1b.rd: Likewise.
* testsuite/ld-i386/no-plt-1c.dd: Likewise.
* testsuite/ld-i386/no-plt-1c.rd: Likewise.
* testsuite/ld-i386/no-plt-1d.dd: Likewise.
* testsuite/ld-i386/no-plt-1d.rd: Likewise.
* testsuite/ld-i386/no-plt-1e.dd: Likewise.
* testsuite/ld-i386/no-plt-1e.rd: Likewise.
* testsuite/ld-i386/no-plt-1f.dd: Likewise.
* testsuite/ld-i386/no-plt-1f.rd: Likewise.
* testsuite/ld-i386/no-plt-1g.dd: Likewise.
* testsuite/ld-i386/no-plt-1g.rd: Likewise.
* testsuite/ld-i386/no-plt-1h.dd: Likewise.
* testsuite/ld-i386/no-plt-1h.rd: Likewise.
* testsuite/ld-i386/no-plt-1i.dd: Likewise.
* testsuite/ld-i386/no-plt-1i.rd: Likewise.
* testsuite/ld-i386/no-plt-1j.dd: Likewise.
* testsuite/ld-i386/no-plt-1j.rd: Likewise.
* testsuite/ld-i386/no-plt-check1a.S: Likewise.
* testsuite/ld-i386/no-plt-check1b.S: Likewise.
* testsuite/ld-i386/no-plt-extern1a.S: Likewise.
* testsuite/ld-i386/no-plt-extern1b.S: Likewise.
* testsuite/ld-i386/no-plt-func1.c: Likewise.
* testsuite/ld-i386/no-plt-main1.c: Likewise.
* testsuite/ld-i386/no-plt.exp: Likewise.
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