From e9f82fd3babf682fb126a8359715dca8c3c4660b Mon Sep 17 00:00:00 2001 From: hjl Date: Thu, 2 Jun 2016 13:46:20 +0000 Subject: [PATCH] Update TARGET_FUNCTION_INCOMING_ARG documentation On x86, interrupt handlers are only called by processors which push interrupt data onto stack at the address where the normal return address is. Since interrupt handlers must access interrupt data via pointers so that they can update interrupt data, the pointer argument is passed as "argument pointer - word". TARGET_FUNCTION_INCOMING_ARG defines how callee sees its argument. Normally it returns REG, NULL, or CONST_INT. This patch adds arbitrary address computation based on hard register, which can be forced into a register, to the list. When copying an incoming argument onto stack, assign_parm_setup_stack has: if (argument in memory) copy argument in memory to stack else move argument to stack Since an arbitrary address computation may be passed as an argument, we change it to: if (argument in memory) copy argument in memory to stack else { if (argument isn't in register) force argument into a register move argument to stack } * function.c (assign_parm_setup_stack): Force source into a register if needed. * target.def (function_incoming_arg): Update documentation to allow arbitrary address computation based on hard register. * doc/tm.texi: Regenerated. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@237037 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 9 +++++++++ gcc/doc/tm.texi | 14 +++++++++----- gcc/function.c | 6 +++++- gcc/target.def | 16 +++++++++------- 4 files changed, 32 insertions(+), 13 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d4af6afc87e..770df0732f8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2016-06-02 H.J. Lu + Julia Koval + + * function.c (assign_parm_setup_stack): Force source into a + register if needed. + * target.def (function_incoming_arg): Update documentation to + allow arbitrary address computation based on hard register. + * doc/tm.texi: Regenerated. + 2016-06-02 Martin Liska * predict.c (combine_predictions_for_bb): Fix first match in diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index 8c7f2a124fe..a343e913eda 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -3938,17 +3938,21 @@ documentation. @end deftypefn @deftypefn {Target Hook} rtx TARGET_FUNCTION_INCOMING_ARG (cumulative_args_t @var{ca}, machine_mode @var{mode}, const_tree @var{type}, bool @var{named}) -Define this hook if the target machine has ``register windows'', so -that the register in which a function sees an arguments is not -necessarily the same as the one in which the caller passed the -argument. +Define this hook if the caller and callee on the target have different +views of where arguments are passed. Also define this hook if there are +functions that are never directly called, but are invoked by the hardware +and which have nonstandard calling conventions. -For such machines, @code{TARGET_FUNCTION_ARG} computes the register in +In this case @code{TARGET_FUNCTION_ARG} computes the register in which the caller passes the value, and @code{TARGET_FUNCTION_INCOMING_ARG} should be defined in a similar fashion to tell the function being called where the arguments will arrive. +@code{TARGET_FUNCTION_INCOMING_ARG} can also return arbitrary address +computation using hard register, which can be forced into a register, +so that it can be used to pass special arguments. + If @code{TARGET_FUNCTION_INCOMING_ARG} is not defined, @code{TARGET_FUNCTION_ARG} serves both purposes. @end deftypefn diff --git a/gcc/function.c b/gcc/function.c index 726c20ca017..c15d47d2103 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -3466,7 +3466,11 @@ assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm, BLOCK_OP_NORMAL); } else - emit_move_insn (dest, src); + { + if (!REG_P (src)) + src = force_reg (GET_MODE (src), src); + emit_move_insn (dest, src); + } } if (to_conversion) diff --git a/gcc/target.def b/gcc/target.def index 6392e73b197..5285e57345c 100644 --- a/gcc/target.def +++ b/gcc/target.def @@ -4468,21 +4468,23 @@ a register.", bool named), default_function_arg) -/* Likewise, but for machines with register windows. Return the - location where the argument will appear to the callee. */ DEFHOOK (function_incoming_arg, - "Define this hook if the target machine has ``register windows'', so\n\ -that the register in which a function sees an arguments is not\n\ -necessarily the same as the one in which the caller passed the\n\ -argument.\n\ + "Define this hook if the caller and callee on the target have different\n\ +views of where arguments are passed. Also define this hook if there are\n\ +functions that are never directly called, but are invoked by the hardware\n\ +and which have nonstandard calling conventions.\n\ \n\ -For such machines, @code{TARGET_FUNCTION_ARG} computes the register in\n\ +In this case @code{TARGET_FUNCTION_ARG} computes the register in\n\ which the caller passes the value, and\n\ @code{TARGET_FUNCTION_INCOMING_ARG} should be defined in a similar\n\ fashion to tell the function being called where the arguments will\n\ arrive.\n\ \n\ +@code{TARGET_FUNCTION_INCOMING_ARG} can also return arbitrary address\n\ +computation using hard register, which can be forced into a register,\n\ +so that it can be used to pass special arguments.\n\ +\n\ If @code{TARGET_FUNCTION_INCOMING_ARG} is not defined,\n\ @code{TARGET_FUNCTION_ARG} serves both purposes.", rtx, (cumulative_args_t ca, machine_mode mode, const_tree type, -- 2.11.4.GIT