Turn HARD_REGNO_CALL_PART_CLOBBERED into a target hook

The SVE patches change the size of a machine_mode from a compile-time
constant to a runtime invariant.  However, target-specific code can
continue to treat the modes as constant-sized if the target only has
constant-sized modes.

The main snag with this approach is that target-independent code still
uses macros from the target .h file.  This patch is one of several that
converts a target macro to a hook.

2017-09-04  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* target.def (hard_regno_call_part_clobbered): New hook.
	* doc/tm.texi.in (HARD_REGNO_CALL_PART_CLOBBERED): Replace with...
	(TARGET_HARD_REGNO_CALL_PART_CLOBBERED): ...this hook.
	* doc/tm.texi: Regenerate.
	* hooks.h (hook_bool_uint_mode_false): Declare.
	* hooks.c (hook_bool_uint_mode_false): New function.
	* regs.h (HARD_REGNO_CALL_PART_CLOBBERED): Delete.
	* cselib.c (cselib_process_insn): Use
	targetm.hard_regno_call_part_clobbered instead of
	HARD_REGNO_CALL_PART_CLOBBERED.
	* ira-conflicts.c (ira_build_conflicts): Likewise.
	* ira-costs.c (ira_tune_allocno_costs): Likewise.
	* lra-constraints.c (need_for_call_save_p): Likewise.
	* lra-lives.c: Include target.h.
	(check_pseudos_live_through_calls): Use
	targetm.hard_regno_call_part_clobbered instead of
	HARD_REGNO_CALL_PART_CLOBBERED.
	* regcprop.c: Include target.h.
	(copyprop_hardreg_forward_1): Use
	targetm.hard_regno_call_part_clobbered instead of
	HARD_REGNO_CALL_PART_CLOBBERED.
	* reginfo.c (choose_hard_reg_mode): Likewise.
	* regrename.c (check_new_reg_p): Likewise.
	* reload.c (find_equiv_reg): Likewise.
	* reload1.c (emit_reload_insns): Likewise.
	* sched-deps.c (deps_analyze_insn): Likewise.
	* sel-sched.c (init_regs_for_mode): Likewise.
	(mark_unavailable_hard_regs): Likewise.
	* targhooks.c (default_dwarf_frame_reg_mode): Likewise.
	* config/aarch64/aarch64.h (HARD_REGNO_CALL_PART_CLOBBERED): Delete.
	* config/aarch64/aarch64.c (aarch64_hard_regno_call_part_clobbered):
	New function.
	(TARGET_HARD_REGNO_CALL_PART_CLOBBERED): Redefine.
	* config/avr/avr.h (HARD_REGNO_CALL_PART_CLOBBERED): Delete.
	* config/avr/avr-protos.h (avr_hard_regno_call_part_clobbered):
	Delete.
	* config/avr/avr.c (avr_hard_regno_call_part_clobbered): Make static
	and return a bool.
	(TARGET_HARD_REGNO_CALL_PART_CLOBBERED): Redefine.
	* config/i386/i386.h (HARD_REGNO_CALL_PART_CLOBBERED): Delete.
	* config/i386/i386.c (ix86_hard_regno_call_part_clobbered): New
	function.
	(TARGET_HARD_REGNO_CALL_PART_CLOBBERED): Redefine.
	* config/mips/mips.h (HARD_REGNO_CALL_PART_CLOBBERED): Delete.
	* config/mips/mips.c (mips_hard_regno_call_part_clobbered): New
	function.
	(TARGET_HARD_REGNO_CALL_PART_CLOBBERED): Redefine.
	* config/powerpcspe/powerpcspe.h (HARD_REGNO_CALL_PART_CLOBBERED):
	Delete.
	* config/powerpcspe/powerpcspe.c
	(rs6000_hard_regno_call_part_clobbered): New function.
	(TARGET_HARD_REGNO_CALL_PART_CLOBBERED): Redefine.
	* config/rs6000/rs6000.h (HARD_REGNO_CALL_PART_CLOBBERED): Delete.
	* config/rs6000/rs6000.c (rs6000_hard_regno_call_part_clobbered):
	New function.
	(TARGET_HARD_REGNO_CALL_PART_CLOBBERED): Redefine.
	* config/s390/s390.h (HARD_REGNO_CALL_PART_CLOBBERED): Delete.
	* config/s390/s390.c (s390_hard_regno_call_part_clobbered): New
	function.
	(TARGET_HARD_REGNO_CALL_PART_CLOBBERED): Redefine.
	* config/sh/sh.h (HARD_REGNO_CALL_PART_CLOBBERED): Delete.
	* system.h (HARD_REGNO_CALL_PART_CLOBBERED): Poison.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r251645

2 files changed, 11 insertions, 14 deletions

diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index ae51e75..0c77b53 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -1869,16 +1869,19 @@ This macro is optional.  If not specified, it defaults to the value
 of @code{CALL_USED_REGISTERS}.
 @end defmac
 
-@defmac HARD_REGNO_CALL_PART_CLOBBERED (@var{regno}, @var{mode})
 @cindex call-used register
 @cindex call-clobbered register
 @cindex call-saved register
-A C expression that is nonzero if it is not permissible to store a
-value of mode @var{mode} in hard register number @var{regno} across a
-call without some part of it being clobbered.  For most machines this
-macro need not be defined.  It is only required for machines that do not
-preserve the entire contents of a register across a call.
-@end defmac
+@deftypefn {Target Hook} bool TARGET_HARD_REGNO_CALL_PART_CLOBBERED (unsigned int @var{regno}, machine_mode @var{mode})
+This hook should return true if @var{regno} is partly call-saved and
+partly call-clobbered, and if a value of mode @var{mode} would be partly
+clobbered by a call.  For example, if the low 32 bits of @var{regno} are
+preserved across a call but higher bits are clobbered, this hook should
+return true for a 64-bit mode but false for a 32-bit mode.
+
+The default implementation returns false, which is correct
+for targets that don't have partly call-clobbered registers.
+@end deftypefn
 
 @findex fixed_regs
 @findex call_used_regs
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 6df08a2..3fec545 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -1698,16 +1698,10 @@ This macro is optional.  If not specified, it defaults to the value
 of @code{CALL_USED_REGISTERS}.
 @end defmac
 
-@defmac HARD_REGNO_CALL_PART_CLOBBERED (@var{regno}, @var{mode})
 @cindex call-used register
 @cindex call-clobbered register
 @cindex call-saved register
-A C expression that is nonzero if it is not permissible to store a
-value of mode @var{mode} in hard register number @var{regno} across a
-call without some part of it being clobbered.  For most machines this
-macro need not be defined.  It is only required for machines that do not
-preserve the entire contents of a register across a call.
-@end defmac
+@hook TARGET_HARD_REGNO_CALL_PART_CLOBBERED
 
 @findex fixed_regs
 @findex call_used_regs