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Linker and Libraries Guide

SPARC: Relocation Types

Field names in the following table tell whether the relocation type checks for overflow. A calculated relocation value can be larger than the intended field, and a relocation type can verify (V) the value fits or truncate (T) the result. As an example, V-simm13 means that the computed value can not have significant, nonzero bits outside the simm13 field.

Table 7–13 SPARC: ELF Relocation Types

Name 

Value 

Field 

Calculation 

R_SPARC_NONE

0

None

None

R_SPARC_8

1

V-byte8

S + A

R_SPARC_16

2

V-half16

S + A

R_SPARC_32

3

V-word32

S + A

R_SPARC_DISP8

4

V-byte8

S + A - P

R_SPARC_DISP16

5

V-half16

S + A - P

R_SPARC_DISP32

6

V-disp32

S + A - P

R_SPARC_WDISP30

7

V-disp30

(S + A - P) >> 2

R_SPARC_WDISP22

8

V-disp22

(S + A - P) >> 2

R_SPARC_HI22

9

T-imm22

(S + A) >> 10

R_SPARC_22

10

V-imm22

S + A

R_SPARC_13

11

V-simm13

S + A

R_SPARC_LO10

12

T-simm13

(S + A) & 0x3ff

R_SPARC_GOT10

13

T-simm13

G & 0x3ff

R_SPARC_GOT13

14

V-simm13

G

R_SPARC_GOT22

15

T-simm22

G >> 10

R_SPARC_PC10

16

T-simm13

(S + A - P) & 0x3ff

R_SPARC_PC22

17

V-disp22

(S + A - P) >> 10

R_SPARC_WPLT30

18

V-disp30

(L + A - P) >> 2

R_SPARC_COPY

19

None

Refer to the explanation following this table. 

R_SPARC_GLOB_DAT

20

V-word32

S + A

R_SPARC_JMP_SLOT

21

None

Refer to the explanation following this table. 

R_SPARC_RELATIVE

22

V-word32

B + A

R_SPARC_UA32

23

V-word32

S + A

R_SPARC_PLT32

24

V-word32

L + A

R_SPARC_HIPLT22

25

T-imm22

(L + A) >> 10

R_SPARC_LOPLT10

26

T-simm13

(L + A) & 0x3ff

R_SPARC_PCPLT32

27

V-word32

L + A - P

R_SPARC_PCPLT22

28

V-disp22

(L + A - P) >> 10

R_SPARC_PCPLT10

29

V-simm13

(L + A - P) & 0x3ff

R_SPARC_10

30

V-simm10

S + A

R_SPARC_11

31

V-simm11

S + A

R_SPARC_HH22

34

V-imm22

(S + A) >> 42

R_SPARC_HM10

35

T-simm13

((S + A) >> 32) & 0x3ff

R_SPARC_LM22

36

T-imm22

(S + A) >> 10

R_SPARC_PC_HH22

37

V-imm22

(S + A - P) >> 42

R_SPARC_PC_HM10

38

T-simm13

((S + A - P) >> 32) & 0x3ff

R_SPARC_PC_LM22

39

T-imm22

(S + A - P) >> 10

R_SPARC_WDISP16

40

V-d2/disp14

(S + A - P) >> 2

R_SPARC_WDISP19

41

V-disp19

(S + A - P) >> 2

R_SPARC_7

43

V-imm7

S + A

R_SPARC_5

44

V-imm5

S + A

R_SPARC_6

45

V-imm6

S + A

R_SPARC_HIX22

48

V-imm22

((S + A) ^ 0xffffffffffffffff) >> 10

R_SPARC_LOX10

49

T-simm13

((S + A) & 0x3ff) | 0x1c00

R_SPARC_H44

50

V-imm22

(S + A) >> 22

R_SPARC_M44

51

T-imm10

((S + A) >> 12) & 0x3ff

R_SPARC_L44

52

T-imm13

(S + A) & 0xfff

R_SPARC_REGISTER

53

V-word32

S + A

R_SPARC_UA16

55

V-half16

S + A

R_SPARC_GOTDATA_HIX22

80

V-imm22

((S + A - GOT) >> 10) ^ ((S + A - GOT) >> 31)

R_SPARC_GOTDATA_LOX10

81

T-imm13

((S + A - GOT) & 0x3ff) | (((S + A - GOT) >> 31) & 0x1c00)

R_SPARC_GOTDATA_OP_HIX22

82

T-imm22

(G >> 10) ^ (G >> 31)

R_SPARC_GOTDATA_OP_LOX10

83

T-imm13

(G & 0x3ff) | ((G >> 31) & 0x1c00)

R_SPARC_GOTDATA_OP

84

Word32

Refer to the explanation following this table. 

R_SPARC_SIZE32

86

V-word32

Z + A

Note –

Additional relocations are available for thread-local storage references. These relocations are covered in Chapter 8, Thread-Local Storage.

Some relocation types have semantics beyond simple calculation.

R_SPARC_GOT10

Resembles R_SPARC_LO10, except that the relocation refers to the address of the symbol's GOT entry. Additionally, R_SPARC_GOT10 instructs the link-editor to create a global offset table.

R_SPARC_GOT13

Resembles R_SPARC_13, except that the relocation refers to the address of the symbol's GOT entry. Additionally, R_SPARC_GOT13 instructs the link-editor to create a global offset table.

R_SPARC_GOT22

Resembles R_SPARC_22, except that the relocation refers to the address of the symbol's GOT entry. Additionally, R_SPARC_GOT22 instructs the link-editor to create a global offset table.

R_SPARC_WPLT30

Resembles R_SPARC_WDISP30, except that the relocation refers to the address of the symbol's procedure linkage table entry. Additionally, R_SPARC_WPLT30 instructs the link-editor to create a procedure linkage table.

R_SPARC_COPY

Created by the link-editor for dynamic executables to preserve a read-only text segment. The relocation offset member refers to a location in a writable segment. The symbol table index specifies a symbol that should exist both in the current object file and in a shared object. During execution, the runtime linker copies data associated with the shared object's symbol to the location specified by the offset. See Copy Relocations.

R_SPARC_GLOB_DAT

Resembles R_SPARC_32, except that the relocation sets a GOT entry to the address of the specified symbol. The special relocation type enables you to determine the correspondence between symbols and GOT entries.

R_SPARC_JMP_SLOT

Created by the link-editor for dynamic objects to provide lazy binding. The relocation offset member gives the location of a procedure linkage table entry. The runtime linker modifies the procedure linkage table entry to transfer control to the designated symbol address.

R_SPARC_RELATIVE

Created by the link-editor for dynamic objects. The relocation offset member gives the location within a shared object that contains a value representing a relative address. The runtime linker computes the corresponding virtual address by adding the virtual address at which the shared object is loaded to the relative address. Relocation entries for this type must specify a value of zero for the symbol table index.

R_SPARC_UA32

Resembles R_SPARC_32, except that the relocation refers to an unaligned word. The word to be relocated must be treated as four separate bytes with arbitrary alignment, not as a word aligned according to the architecture requirements.

R_SPARC_LM22

Resembles R_SPARC_HI22, except that the relocation truncates rather than validates.

R_SPARC_PC_LM22

Resembles R_SPARC_PC22, except that the relocation truncates rather than validates.

R_SPARC_HIX22

Used with R_SPARC_LOX10 for executables that are confined to the uppermost 4 gigabytes of the 64–bit address space. Similar to R_SPARC_HI22, but supplies ones complement of linked value.

R_SPARC_LOX10

Used with R_SPARC_HIX22. Similar to R_SPARC_LO10, but always sets bits 10 through 12 of the linked value.

R_SPARC_L44

Used with the R_SPARC_H44 and R_SPARC_M44 relocation types to generate a 44-bit absolute addressing model.

R_SPARC_REGISTER

Used to initialize a register symbol. The relocation offset member contains the register number to be initialized. A corresponding register symbol must exist for this register. The symbol must be of type SHN_ABS.

R_SPARC_GOTDATA_OP_HIX22, R_SPARC_GOTDATA_OP_LOX10, and R_SPARC_GOTDATA_OP

These relocations provide for code transformations.