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Diffstat (limited to 'gcc/invoke.texi')
| -rw-r--r-- | gcc/invoke.texi | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/gcc/invoke.texi b/gcc/invoke.texi index c2f45ad76c6..3be7f72f6e9 100644 --- a/gcc/invoke.texi +++ b/gcc/invoke.texi @@ -269,6 +269,7 @@ in the following sections. -mstructure-size-boundary= -mbsd -mxopen -mno-symrename -mabort-on-noreturn +-mlong-calls -mno-long-calls -mnop-fun-dllimport -mno-nop-fun-dllimport -msingle-pic-base -mno-single-pic-base -mpic-register= @@ -4608,6 +4609,32 @@ value as future versions of the toolchain may default to this value. Generate a call to the function abort at the end of a noreturn function. It will be executed if the function tries to return. +@item -mlong-calls +@itemx -mno-long-calls +Tells the compiler to perform function calls by first loading the +address of the function into a register and then performing a subroutine +call on this register. This switch is needed if the target function +will lie outside of the 64 megabyte addressing range of the offset based +version of subroutine call instruction. + +Even if this switch is enabled, not all function calls will be turned +into long calls. The heuristic is that static functions, functions +which have the @samp{short-call} attribute, functions that are inside +the scope of a @samp{#pragma no_long_calls} directive and functions whose +definitions have already been compiled within the current compilation +unit, will not be turned into long calls. The exception to this rule is +that weak function defintions, functions with the @samp{long-call} +attribute or the @samp{section} attribute, and functions that are within +the scope of a @samp{#pragma long_calls} directive, will always be +turned into long calls. + +This feature is not enabled by default. Specifying +@samp{--no-long-calls} will restore the default behaviour, as will +placing the function calls within the scope of a @samp{#pragma +long_calls_off} directive. Note these switches have no effect on how +the compiler generates code to handle function calls via function +pointers. + @item -mnop-fun-dllimport @kindex -mnop-fun-dllimport Disable the support for the @emph{dllimport} attribute. |