Turn MODES_TIEABLE_P into a target 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 (modes_tieable_p): New hook.
	* doc/tm.texi (MODES_TIEABLE_P): Replace with...
	(TARGET_MODES_TIEABLE_P): ...this.
	* doc/tm.texi.in: Regenerate.
	* hooks.h (hook_bool_mode_mode_true): Declare.
	* hooks.c (hook_bool_mode_mode_true): New function.
	* combine.c (subst): Use targetm.modes_tieable_p instead of
	MODES_TIEABLE_P.
	* dse.c (find_shift_sequence): Likewise.
	* expmed.c (extract_low_bits): Likewise.
	* lower-subreg.c: Include target.h.
	(find_decomposable_subregs): Use targetm.modes_tieable_p instead of
	MODES_TIEABLE_P.
	* rtlanal.c (rtx_cost): Likewise.
	* config/aarch64/aarch64.h (MODES_TIEABLE_P): Delete.
	* config/aarch64/aarch64-protos.h (aarch64_modes_tieable_p): Delete.
	* config/aarch64/aarch64.c (aarch64_modes_tieable_p): Make static.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/alpha/alpha.h (MODES_TIEABLE_P): Delete.
	* config/alpha/alpha.c (alpha_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/arc/arc.h (MODES_TIEABLE_P): Delete.
	* config/arc/arc.c (TARGET_MODES_TIEABLE_P): Redefine.
	(arc_modes_tieable_p): New function.
	* config/arm/arm.h (MODES_TIEABLE_P): Delete.
	* config/arm/arm-protos.h (arm_modes_tieable_p): Delete.
	* config/arm/arm.c (TARGET_MODES_TIEABLE_P): Redefine.
	(arm_modes_tieable_p): Make static.
	* config/avr/avr.h (MODES_TIEABLE_P): Delete.
	* config/bfin/bfin.h (MODES_TIEABLE_P): Delete.
	* config/bfin/bfin.c (bfin_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/c6x/c6x.h (MODES_TIEABLE_P): Delete.
	* config/c6x/c6x.c (c6x_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/cr16/cr16.h (MODES_TIEABLE_P): Delete.
	* config/cr16/cr16.c (TARGET_MODES_TIEABLE_P): Redefine.
	(cr16_modes_tieable_p): New function.
	* config/cris/cris.h (MODES_TIEABLE_P): Delete.
	* config/epiphany/epiphany.h (MODES_TIEABLE_P): Delete.
	* config/fr30/fr30.h (MODES_TIEABLE_P): Delete.
	(TRULY_NOOP_TRUNCATION): Update comment.
	* config/frv/frv.h (MODES_TIEABLE_P): Delete.
	(TRULY_NOOP_TRUNCATION): Update comment.
	* config/frv/frv.c (TARGET_MODES_TIEABLE_P): Redefine.
	(frv_modes_tieable_p): New function.
	* config/ft32/ft32.h (MODES_TIEABLE_P): Delete.
	* config/h8300/h8300.h (MODES_TIEABLE_P): Delete.
	* config/h8300/h8300.c (h8300_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/i386/i386.h (MODES_TIEABLE_P): Delete.
	* config/i386/i386-protos.h (ix86_modes_tieable_p): Delete.
	* config/i386/i386.c (ix86_modes_tieable_p): Make static.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/ia64/ia64.h (MODES_TIEABLE_P): Delete.
	* config/ia64/ia64.c (TARGET_MODES_TIEABLE_P): Redefine.
	(ia64_modes_tieable_p): New function.
	* config/iq2000/iq2000.h (MODES_TIEABLE_P): Delete.
	* config/iq2000/iq2000.c (TARGET_MODES_TIEABLE_P): Redefine.
	(iq2000_modes_tieable_p): New function.
	* config/lm32/lm32.h (MODES_TIEABLE_P): Delete.
	* config/lm32/lm32.c (TARGET_MODES_TIEABLE_P): Redefine.
	(lm32_modes_tieable_p): New function.
	* config/m32c/m32c.h (MODES_TIEABLE_P): Delete.
	* config/m32c/m32c-protos.h (m32c_modes_tieable_p): Delete.
	* config/m32c/m32c.c (m32c_modes_tieable_p): Make static.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/m32r/m32r.h (MODES_TIEABLE_P): Delete.
	* config/m32r/m32r.c (TARGET_MODES_TIEABLE_P): Redefine.
	(m32r_modes_tieable_p): New function.
	* config/m68k/m68k.h (MODES_TIEABLE_P): Delete.
	* config/m68k/m68k.c (TARGET_MODES_TIEABLE_P): Redefine.
	(m68k_modes_tieable_p): New function.
	* config/mcore/mcore.h (MODES_TIEABLE_P): Delete.
	* config/mcore/mcore.c (TARGET_MODES_TIEABLE_P): Redefine.
	(mcore_modes_tieable_p): New function.
	* config/microblaze/microblaze.h (MODES_TIEABLE_P): Delete.
	* config/microblaze/microblaze.c (microblaze_modes_tieable_p): New
	function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/mips/mips.h (MODES_TIEABLE_P): Delete.
	* config/mips/mips-protos.h (mips_modes_tieable_p): Delete.
	* config/mips/mips.c (mips_modes_tieable_p): Make static.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/mmix/mmix.h (MODES_TIEABLE_P): Delete.
	* config/mn10300/mn10300.h (MODES_TIEABLE_P): Delete.
	* config/mn10300/mn10300-protos.h (mn10300_modes_tieable): Delete.
	* config/mn10300/mn10300.c (mn10300_modes_tieable): Rename to...
	(mn10300_modes_tieable_p): ...this and make static.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/moxie/moxie.h (MODES_TIEABLE_P): Delete.
	* config/msp430/msp430.h (MODES_TIEABLE_P): Delete.
	* config/msp430/msp430-protos.h (msp430_modes_tieable_p): Delete.
	* config/msp430/msp430.c (TARGET_MODES_TIEABLE_P): Redefine.
	(msp430_modes_tieable_p): Make static.
	* config/nds32/nds32.h (MODES_TIEABLE_P): Delete.
	* config/nds32/nds32.c (nds32_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/nios2/nios2.h (MODES_TIEABLE_P): Delete.
	* config/nvptx/nvptx.h (MODES_TIEABLE_P): Delete.
	* config/nvptx/nvptx.c (nvptx_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/pa/pa.h (MODES_TIEABLE_P): Delete.
	* config/pa/pa-protos.h (pa_modes_tieable_p): Delete.
	* config/pa/pa.c (pa_modes_tieable_p): Make static.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/pdp11/pdp11.h (MODES_TIEABLE_P): Delete.
	* config/pdp11/pdp11.c (TARGET_MODES_TIEABLE_P): Redefine.
	(pdp11_modes_tieable_p): New function.
	* config/powerpcspe/powerpcspe.h (MODES_TIEABLE_P): Delete.
	* config/powerpcspe/powerpcspe.c (TARGET_MODES_TIEABLE_P): Redefine.
	(rs6000_modes_tieable_p): New function.
	(rs6000_debug_reg_global): Use it instead of MODES_TIEABLE_P.
	* config/powerpcspe/powerpcspe.md: Update comment.
	* config/riscv/riscv.h (MODES_TIEABLE_P): Delete.
	* config/riscv/riscv.c (riscv_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/rl78/rl78.h (MODES_TIEABLE_P): Delete.
	* config/rl78/rl78.c (TARGET_MODES_TIEABLE_P): Redefine.
	(rl78_modes_tieable_p): New function.
	* config/rs6000/rs6000.h (MODES_TIEABLE_P): Delete.
	* config/rs6000/rs6000.c (TARGET_MODES_TIEABLE_P): Redefine.
	(rs6000_modes_tieable_p): New function.
	(rs6000_debug_reg_global): Use it instead of MODES_TIEABLE_P.
	* config/rs6000/rs6000.md: Update comment.
	* config/rx/rx.h (MODES_TIEABLE_P): Delete.
	* config/rx/rx.c (rx_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/s390/s390.h (MODES_TIEABLE_P): Delete.
	* config/s390/s390.c (s390_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/sh/sh.h (MODES_TIEABLE_P): Delete.
	* config/sh/sh.c (TARGET_MODES_TIEABLE_P): Redefine.
	(sh_modes_tieable_p): New function.
	* config/sparc/sparc.h (MODES_TIEABLE_P): Delete.
	* config/sparc/sparc-protos.h (sparc_modes_tieable_p): Delete.
	* config/sparc/sparc.c (TARGET_MODES_TIEABLE_P): Redefine.
	(sparc_modes_tieable_p): Make static.
	* config/spu/spu.h (MODES_TIEABLE_P): Delete.
	* config/spu/spu.c (spu_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/stormy16/stormy16.h (MODES_TIEABLE_P): Delete.
	* config/stormy16/stormy16.c (xstormy16_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/tilegx/tilegx.h (MODES_TIEABLE_P): Delete.
	* config/tilepro/tilepro.h (MODES_TIEABLE_P): Delete.
	* config/v850/v850.h (MODES_TIEABLE_P): Delete.
	* config/v850/v850.c (v850_modes_tieable_p): New function.
	(TARGET_MODES_TIEABLE_P): Redefine.
	* config/vax/vax.h (MODES_TIEABLE_P): Delete.
	* config/visium/visium.h (MODES_TIEABLE_P): Delete.
	* config/visium/visium.c (TARGET_MODES_TIEABLE_P): Redefine.
	(visium_modes_tieable_p): New function.
	* config/xtensa/xtensa.h (MODES_TIEABLE_P): Delete.
	* config/xtensa/xtensa.c (TARGET_MODES_TIEABLE_P): Redefine.
	(xtensa_modes_tieable_p): New function.
	* system.h (MODES_TIEABLE_P): Poison.

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

From-SVN: r251647

1 files changed, 21 insertions, 2 deletions

diff --git a/gcc/target.def b/gcc/target.def
index ca9dc87b542..b6bcb86a995 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -5406,8 +5406,8 @@ all narrower integer modes, it is not necessary on any machine for\n\
 this hook to distinguish between these modes, provided you define\n\
 patterns @samp{movhi}, etc., to take advantage of this.  This is\n\
 useful because of the interaction between @code{TARGET_HARD_REGNO_MODE_OK}\n\
-and @code{MODES_TIEABLE_P}; it is very desirable for all integer modes\n\
-to be tieable.\n\
+and @code{TARGET_MODES_TIEABLE_P}; it is very desirable for all integer\n\
+modes to be tieable.\n\
 \n\
 Many machines have special registers for floating point arithmetic.\n\
 Often people assume that floating point machine modes are allowed only\n\
@@ -5440,6 +5440,25 @@ be used unless some pattern's constraint asks for one.",
  bool, (unsigned int regno, machine_mode mode),
  hook_bool_uint_mode_true)
 
+DEFHOOK
+(modes_tieable_p,
+ "This hook returns true if a value of mode @var{mode1} is accessible\n\
+in mode @var{mode2} without copying.\n\
+\n\
+If @code{TARGET_HARD_REGNO_MODE_OK (@var{r}, @var{mode1})} and\n\
+@code{TARGET_HARD_REGNO_MODE_OK (@var{r}, @var{mode2})} are always\n\
+the same for any @var{r}, then\n\
+@code{TARGET_MODES_TIEABLE_P (@var{mode1}, @var{mode2})}\n\
+should be true.  If they differ for any @var{r}, you should define\n\
+this hook to return false unless some other mechanism ensures the\n\
+accessibility of the value in a narrower mode.\n\
+\n\
+You should define this hook to return true in as many cases as\n\
+possible since doing so will allow GCC to perform better register\n\
+allocation.  The default definition returns true unconditionally.",
+ bool, (machine_mode mode1, machine_mode mode2),
+ hook_bool_mode_mode_true)
+
 /* Return true if is OK to use a hard register REGNO as scratch register
    in peephole2.  */
 DEFHOOK