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author | Richard Sandiford <richard.sandiford@linaro.org> | 2017-09-15 12:56:34 +0000 |
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committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2017-09-15 12:56:34 +0000 |
commit | 0d803030650a6c671b295d3e7d5161e64b59b2f6 (patch) | |
tree | 854fba2d2be98f794a0e01b4efb9f6621aab2d03 /gcc/doc | |
parent | fa0cdfb651f59951d10331b782c422baad93d3e4 (diff) | |
download | gcc-0d803030650a6c671b295d3e7d5161e64b59b2f6.zip gcc-0d803030650a6c671b295d3e7d5161e64b59b2f6.tar.gz gcc-0d803030650a6c671b295d3e7d5161e64b59b2f6.tar.bz2 |
Turn CANNOT_CHANGE_MODE_CLASS into a hook
This also seemed like a good opportunity to reverse the sense of the
hook to "can", to avoid the awkward double negative in !CANNOT.
2017-09-15 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayard <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>
gcc/
* target.def (can_change_mode_class): New hook.
(mode_rep_extended): Refer to it instead of CANNOT_CHANGE_MODE_CLASS.
(hard_regno_nregs): Likewise.
* hooks.h (hook_bool_mode_mode_reg_class_t_true): Declare.
* hooks.c (hook_bool_mode_mode_reg_class_t_true): New function.
* doc/tm.texi.in (CANNOT_CHANGE_MODE_CLASS): Replace with...
(TARGET_CAN_CHANGE_MODE_CLASS): ...this.
(LOAD_EXTEND_OP): Update accordingly.
* doc/tm.texi: Regenerate.
* doc/rtl.texi: Refer to TARGET_CAN_CHANGE_MODE_CLASS instead of
CANNOT_CHANGE_MODE_CLASS.
* hard-reg-set.h (REG_CANNOT_CHANGE_MODE_P): Replace with...
(REG_CAN_CHANGE_MODE_P): ...this new macro.
* combine.c (simplify_set): Update accordingly.
* emit-rtl.c (validate_subreg): Likewise.
* recog.c (general_operand): Likewise.
* regcprop.c (mode_change_ok): Likewise.
* reload1.c (choose_reload_regs): Likewise.
(inherit_piecemeal_p): Likewise.
* rtlanal.c (simplify_subreg_regno): Likewise.
* postreload.c (reload_cse_simplify_set): Use REG_CAN_CHANGE_MODE_P
instead of CANNOT_CHANGE_MODE_CLASS.
(reload_cse_simplify_operands): Likewise.
* reload.c (push_reload): Use targetm.can_change_mode_class
instead of CANNOT_CHANGE_MODE_CLASS.
(push_reload): Likewise. Also use REG_CAN_CHANGE_MODE_P instead of
REG_CANNOT_CHANGE_MODE_P.
* config/alpha/alpha.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/alpha/alpha.c (alpha_can_change_mode_class): New function.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
* config/arm/arm.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/arm/arm.c (TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(arm_can_change_mode_class): New function.
* config/arm/neon.md: Refer to TARGET_CAN_CHANGE_MODE_CLASS rather
than CANNOT_CHANGE_MODE_CLASS in comments.
* config/i386/i386.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/i386/i386-protos.h (ix86_cannot_change_mode_class): Delete.
* config/i386/i386.c (ix86_cannot_change_mode_class): Replace with...
(ix86_can_change_mode_class): ...this new function, inverting the
sense of the return value.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
* config/ia64/ia64.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/ia64/ia64.c (TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(ia64_can_change_mode_class): New function.
* config/m32c/m32c.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/m32c/m32c-protos.h (m32c_cannot_change_mode_class): Delete.
* config/m32c/m32c.c (m32c_cannot_change_mode_class): Replace with...
(m32c_can_change_mode_class): ...this new function, inverting the
sense of the return value.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
* config/mips/mips.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/mips/mips-protos.h (mips_cannot_change_mode_class): Delete.
* config/mips/mips.c (mips_cannot_change_mode_class): Replace with...
(mips_can_change_mode_class): ...this new function, inverting the
sense of the return value.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
* config/msp430/msp430.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/msp430/msp430.c (TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(msp430_can_change_mode_class): New function.
* config/nvptx/nvptx.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/nvptx/nvptx.c (nvptx_can_change_mode_class): New function.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
* config/pa/pa32-regs.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/pa/pa64-regs.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/pa/pa-protos.h (pa_cannot_change_mode_class): Delete.
* config/pa/pa.c (TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(pa_cannot_change_mode_class): Replace with...
(pa_can_change_mode_class): ...this new function, inverting the
sense of the return value.
(pa_modes_tieable_p): Refer to TARGET_CAN_CHANGE_MODE_CLASS rather
than CANNOT_CHANGE_MODE_CLASS in comments.
* config/pdp11/pdp11.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/pdp11/pdp11-protos.h (pdp11_cannot_change_mode_class): Delete.
* config/pdp11/pdp11.c (TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(pdp11_cannot_change_mode_class): Replace with...
(pdp11_can_change_mode_class): ...this new function, inverting the
sense of the return value.
* config/powerpcspe/powerpcspe.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/powerpcspe/powerpcspe-protos.h
(rs6000_cannot_change_mode_class_ptr): Delete.
* config/powerpcspe/powerpcspe.c
(rs6000_cannot_change_mode_class_ptr): Delete.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(rs6000_option_override_internal): Assign to
targetm.can_change_mode_class instead of
rs6000_cannot_change_mode_class_ptr.
(rs6000_cannot_change_mode_class): Replace with...
(rs6000_can_change_mode_class): ...this new function, inverting the
sense of the return value.
(rs6000_debug_cannot_change_mode_class): Replace with...
(rs6000_debug_can_change_mode_class): ...this new function.
* config/riscv/riscv.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/riscv/riscv.c (riscv_can_change_mode_class): New function.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
* config/rs6000/rs6000.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/rs6000/rs6000-protos.h (rs6000_cannot_change_mode_class_ptr):
Delete.
* config/rs6000/rs6000.c (rs6000_cannot_change_mode_class_ptr): Delete.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(rs6000_option_override_internal): Assign to
targetm.can_change_mode_class instead of
rs6000_cannot_change_mode_class_ptr.
(rs6000_cannot_change_mode_class): Replace with...
(rs6000_can_change_mode_class): ...this new function, inverting the
sense of the return value.
(rs6000_debug_cannot_change_mode_class): Replace with...
(rs6000_debug_can_change_mode_class): ...this new function.
* config/s390/s390.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/s390/s390-protos.h (s390_cannot_change_mode_class): Delete.
* config/s390/s390.c (s390_cannot_change_mode_class): Replace with...
(s390_can_change_mode_class): ...this new function, inverting the
sense of the return value.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
* config/sh/sh.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/sh/sh-protos.h (sh_cannot_change_mode_class): Delete.
* config/sh/sh.c (TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(sh_cannot_change_mode_class): Replace with...
(sh_can_change_mode_class): ...this new function, inverting the
sense of the return value.
* config/sparc/sparc.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/sparc/sparc.c (TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(sparc_can_change_mode_class): New function.
* config/spu/spu.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/spu/spu.c (spu_can_change_mode_class): New function.
(TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
* config/visium/visium.h (CANNOT_CHANGE_MODE_CLASS): Delete.
* config/visium/visium.c (TARGET_CAN_CHANGE_MODE_CLASS): Redefine.
(visium_can_change_mode_class): New function.
* system.h (CANNOT_CHANGE_MODE_CLASS): Poison.
Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r252816
Diffstat (limited to 'gcc/doc')
-rw-r--r-- | gcc/doc/rtl.texi | 6 | ||||
-rw-r--r-- | gcc/doc/tm.texi | 41 | ||||
-rw-r--r-- | gcc/doc/tm.texi.in | 33 |
3 files changed, 27 insertions, 53 deletions
diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi index 12355c2..3b2b247 100644 --- a/gcc/doc/rtl.texi +++ b/gcc/doc/rtl.texi @@ -2024,17 +2024,17 @@ has an unknown number of undefined bits, so the assignment: does not guarantee that @samp{(subreg:HI (reg:PSI 0) 0)} has the value @samp{(reg:HI 4)}. -@cindex @code{CANNOT_CHANGE_MODE_CLASS} and subreg semantics +@cindex @code{TARGET_CAN_CHANGE_MODE_CLASS} and subreg semantics The rules above apply to both pseudo @var{reg}s and hard @var{reg}s. If the semantics are not correct for particular combinations of @var{m1}, @var{m2} and hard @var{reg}, the target-specific code must ensure that those combinations are never used. For example: @smallexample -CANNOT_CHANGE_MODE_CLASS (@var{m2}, @var{m1}, @var{class}) +TARGET_CAN_CHANGE_MODE_CLASS (@var{m2}, @var{m1}, @var{class}) @end smallexample -must be true for every class @var{class} that includes @var{reg}. +must be false for every class @var{class} that includes @var{reg}. @findex SUBREG_REG @findex SUBREG_BYTE diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index 0403801..5b9e2b3 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -2018,8 +2018,8 @@ This hook returns the number of consecutive hard registers, starting at register number @var{regno}, required to hold a value of mode @var{mode}. This hook must never return zero, even if a register cannot hold the requested mode - indicate that with -@code{TARGET_HARD_REGNO_MODE_OK} and/or @code{CANNOT_CHANGE_MODE_CLASS} -instead. +@code{TARGET_HARD_REGNO_MODE_OK} and/or +@code{TARGET_CAN_CHANGE_MODE_CLASS} instead. The default definition returns the number of words in @var{mode}. @end deftypefn @@ -2814,25 +2814,27 @@ This macro helps control the handling of multiple-word values in the reload pass. @end defmac -@defmac CANNOT_CHANGE_MODE_CLASS (@var{from}, @var{to}, @var{class}) -If defined, a C expression that returns nonzero for a @var{class} for which -a change from mode @var{from} to mode @var{to} is invalid. +@deftypefn {Target Hook} bool TARGET_CAN_CHANGE_MODE_CLASS (machine_mode @var{from}, machine_mode @var{to}, reg_class_t @var{rclass}) +This hook returns true if it is possible to bitcast values held in +registers of class @var{rclass} from mode @var{from} to mode @var{to} +and if doing so preserves the low-order bits that are common to both modes. +The result is only meaningful if @var{rclass} has registers that can hold +both @code{from} and @code{to}. The default implementation returns true. -For example, loading 32-bit integer or floating-point objects into -floating-point registers on Alpha extends them to 64 bits. -Therefore loading a 64-bit object and then storing it as a 32-bit object -does not store the low-order 32 bits, as would be the case for a normal -register. Therefore, @file{alpha.h} defines @code{CANNOT_CHANGE_MODE_CLASS} -as below: +As an example of when such bitcasting is invalid, loading 32-bit integer or +floating-point objects into floating-point registers on Alpha extends them +to 64 bits. Therefore loading a 64-bit object and then storing it as a +32-bit object does not store the low-order 32 bits, as would be the case +for a normal register. Therefore, @file{alpha.h} defines +@code{TARGET_CAN_CHANGE_MODE_CLASS} to return: @smallexample -#define CANNOT_CHANGE_MODE_CLASS(FROM, TO, CLASS) \ - (GET_MODE_SIZE (FROM) != GET_MODE_SIZE (TO) \ - ? reg_classes_intersect_p (FLOAT_REGS, (CLASS)) : 0) +(GET_MODE_SIZE (from) == GET_MODE_SIZE (to) + || !reg_classes_intersect_p (FLOAT_REGS, rclass)) @end smallexample Even if storing from a register in mode @var{to} would be valid, -if both @var{from} and @code{raw_reg_mode} for @var{class} are wider +if both @var{from} and @code{raw_reg_mode} for @var{rclass} are wider than @code{word_mode}, then we must prevent @var{to} narrowing the mode. This happens when the middle-end assumes that it can load or store pieces of an @var{N}-word pseudo, and that the pseudo will @@ -2840,8 +2842,7 @@ eventually be allocated to @var{N} @code{word_mode} hard registers. Failure to prevent this kind of mode change will result in the entire @code{raw_reg_mode} being modified instead of the partial value that the middle-end intended. - -@end defmac +@end deftypefn @deftypefn {Target Hook} reg_class_t TARGET_IRA_CHANGE_PSEUDO_ALLOCNO_CLASS (int, @var{reg_class_t}, @var{reg_class_t}) A target hook which can change allocno class for given pseudo from @@ -10695,12 +10696,12 @@ define it as the constant @code{SIGN_EXTEND} or @code{ZERO_EXTEND}. You may return a non-@code{UNKNOWN} value even if for some hard registers the sign extension is not performed, if for the @code{REGNO_REG_CLASS} -of these hard registers @code{CANNOT_CHANGE_MODE_CLASS} returns nonzero +of these hard registers @code{TARGET_CAN_CHANGE_MODE_CLASS} returns false when the @var{from} mode is @var{mem_mode} and the @var{to} mode is any integral mode larger than this but not larger than @code{word_mode}. You must return @code{UNKNOWN} if for some hard registers that allow this -mode, @code{CANNOT_CHANGE_MODE_CLASS} says that they cannot change to +mode, @code{TARGET_CAN_CHANGE_MODE_CLASS} says that they cannot change to @code{word_mode}, but that they can change to another integral mode that is larger then @var{mem_mode} but still smaller than @code{word_mode}. @end defmac @@ -10813,7 +10814,7 @@ widest integral mode and currently we take advantage of this fact.) Similarly to @code{LOAD_EXTEND_OP} you may return a non-@code{UNKNOWN} value even if the extension is not performed on certain hard registers as long as for the @code{REGNO_REG_CLASS} of these hard registers -@code{CANNOT_CHANGE_MODE_CLASS} returns nonzero. +@code{TARGET_CAN_CHANGE_MODE_CLASS} returns false. Note that @code{TARGET_MODE_REP_EXTENDED} and @code{LOAD_EXTEND_OP} describe two related properties. If you define diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in index f6a0d09..57b017f 100644 --- a/gcc/doc/tm.texi.in +++ b/gcc/doc/tm.texi.in @@ -2334,34 +2334,7 @@ This macro helps control the handling of multiple-word values in the reload pass. @end defmac -@defmac CANNOT_CHANGE_MODE_CLASS (@var{from}, @var{to}, @var{class}) -If defined, a C expression that returns nonzero for a @var{class} for which -a change from mode @var{from} to mode @var{to} is invalid. - -For example, loading 32-bit integer or floating-point objects into -floating-point registers on Alpha extends them to 64 bits. -Therefore loading a 64-bit object and then storing it as a 32-bit object -does not store the low-order 32 bits, as would be the case for a normal -register. Therefore, @file{alpha.h} defines @code{CANNOT_CHANGE_MODE_CLASS} -as below: - -@smallexample -#define CANNOT_CHANGE_MODE_CLASS(FROM, TO, CLASS) \ - (GET_MODE_SIZE (FROM) != GET_MODE_SIZE (TO) \ - ? reg_classes_intersect_p (FLOAT_REGS, (CLASS)) : 0) -@end smallexample - -Even if storing from a register in mode @var{to} would be valid, -if both @var{from} and @code{raw_reg_mode} for @var{class} are wider -than @code{word_mode}, then we must prevent @var{to} narrowing the -mode. This happens when the middle-end assumes that it can load -or store pieces of an @var{N}-word pseudo, and that the pseudo will -eventually be allocated to @var{N} @code{word_mode} hard registers. -Failure to prevent this kind of mode change will result in the -entire @code{raw_reg_mode} being modified instead of the partial -value that the middle-end intended. - -@end defmac +@hook TARGET_CAN_CHANGE_MODE_CLASS @hook TARGET_IRA_CHANGE_PSEUDO_ALLOCNO_CLASS @@ -7451,12 +7424,12 @@ define it as the constant @code{SIGN_EXTEND} or @code{ZERO_EXTEND}. You may return a non-@code{UNKNOWN} value even if for some hard registers the sign extension is not performed, if for the @code{REGNO_REG_CLASS} -of these hard registers @code{CANNOT_CHANGE_MODE_CLASS} returns nonzero +of these hard registers @code{TARGET_CAN_CHANGE_MODE_CLASS} returns false when the @var{from} mode is @var{mem_mode} and the @var{to} mode is any integral mode larger than this but not larger than @code{word_mode}. You must return @code{UNKNOWN} if for some hard registers that allow this -mode, @code{CANNOT_CHANGE_MODE_CLASS} says that they cannot change to +mode, @code{TARGET_CAN_CHANGE_MODE_CLASS} says that they cannot change to @code{word_mode}, but that they can change to another integral mode that is larger then @var{mem_mode} but still smaller than @code{word_mode}. @end defmac |