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Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index d68eb0e..fb4cf78 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -471,7 +471,7 @@ in the following sections. -mgas -mgp32 -mgp64 -mhard-float -mint64 -mips1 @gol -mips2 -mips3 -mips4 -mips32 -mips32r2 -mips64 @gol -mlong64 -mlong32 -mlong-calls -mmemcpy @gol --mmips-as -mmips-tfile -mno-abicalls @gol +-mmips-as -mmips-tfile -mno-abicalls -mxgot @gol -mno-embedded-data -mno-uninit-const-in-rodata @gol -mno-embedded-pic -mno-long-calls @gol -mno-memcpy -mno-mips-tfile -mno-rnames @gol @@ -8067,6 +8067,35 @@ Emit (or do not emit) the pseudo operations @samp{.abicalls}, @samp{.cpload}, and @samp{.cprestore} that some System V.4 ports use for position independent code. +@item -mxgot +@itemx -mno-xgot +@opindex mxgot +@opindex mno-xgot +Lift (or do not lift) the usual restrictions on the size of the global +offset table. + +GCC normally uses a single instruction to load values from the GOT. +While this is relatively efficient, it will only work if the GOT +is smaller than about 64k. Anything larger will cause the linker +to report an error such as: + +@cindex relocation truncated to fit (MIPS) +@smallexample +relocation truncated to fit: R_MIPS_GOT16 foobar +@end smallexample + +If this happens, you should recompile your code with @option{-mxgot}. +It should then work with very large GOTs, although it will also be +less efficient, since it will take three instructions to fetch the +value of a global symbol. + +Note that some linkers can create multiple GOTs. If you have such a +linker, you should only need to use @option{-mxgot} when a single object +file accesses more than 64k's worth of GOT entries. Very few do. + +These options have no effect unless GCC is generating position +independent code. + @item -mlong-calls @itemx -mno-long-calls @opindex mlong-calls |