diff options
Diffstat (limited to 'gcc/tm.texi')
| -rw-r--r-- | gcc/tm.texi | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/gcc/tm.texi b/gcc/tm.texi index 1a1396f91a8..7d9610c6245 100644 --- a/gcc/tm.texi +++ b/gcc/tm.texi @@ -2316,9 +2316,11 @@ during virtual register instantiation. The default value for this macro is @code{FIRST_PARM_OFFSET (fundecl)}, which is correct for most machines; in general, the arguments are found -immediately before the stack frame. See @file{function.c} for details. +immediately before the stack frame. Note that this is not the case on +some targets that save registers into the caller's frame, such as SPARC +and rs6000, and so such targets need to define this macro. -You only need to define this macro if this default is incorrect, and you +You only need to define this macro if the default is incorrect, and you want to support call frame debugging information like that provided by DWARF 2. @@ -2628,15 +2630,24 @@ errors in certain cases of mismatch, it also makes for better code on certain machines. If the macro is not defined in target header files, it defaults to 0. +@findex PUSH_ARGS +@item PUSH_ARGS +A C expression. If nonzero, push insns will be used to pass +outgoing arguments. +If the target machine does not have a push instruction, set it to zero. +That directs GCC to use an alternate strategy: to +allocate the entire argument block and then store the arguments into +it. When PUSH_ARGS is nonzero, PUSH_ROUNDING must be defined too. +On some machines, the definition + +@findex PUSH_ROUNDING +@item PUSH_ROUNDING (@var{npushed}) +A C expression that is the number of bytes actually pushed onto the +stack when an instruction attempts to push @var{npushed} bytes. @findex PUSH_ROUNDING @item PUSH_ROUNDING (@var{npushed}) A C expression that is the number of bytes actually pushed onto the stack when an instruction attempts to push @var{npushed} bytes. - -If the target machine does not have a push instruction, do not define -this macro. That directs GCC to use an alternate strategy: to -allocate the entire argument block and then store the arguments into -it. On some machines, the definition @@ -2656,13 +2667,13 @@ alignment. Then the definition should be @findex ACCUMULATE_OUTGOING_ARGS @findex current_function_outgoing_args_size @item ACCUMULATE_OUTGOING_ARGS -If defined, the maximum amount of space required for outgoing arguments +A C expression. If nonzero, the maximum amount of space required for outgoing arguments will be computed and placed into the variable @code{current_function_outgoing_args_size}. No space will be pushed onto the stack for each call; instead, the function prologue should increase the stack frame size by this amount. -Defining both @code{PUSH_ROUNDING} and @code{ACCUMULATE_OUTGOING_ARGS} +Setting both @code{PUSH_ARGS} and @code{ACCUMULATE_OUTGOING_ARGS} is not proper. @findex REG_PARM_STACK_SPACE @@ -7931,4 +7942,12 @@ Note that this functionality is part of POSIX. Defining @code{TARGET_HAS_F_SETLKW} will enable the test coverage code to use file locking when exiting a program, which avoids race conditions if the program has forked. + +@findex MAX_CONDITIONAL_EXECUTE +@item MAX_CONDITIONAL_EXECUTE + +A C expression for the maximum number of instructions to execute via +conditional execution instructions instead of a branch. A value of +@code{BRANCH_COST}+1 is the default if the machine does not use cc0, and +1 if it does use cc0. @end table |