Re: [ARM Patch 1/n] PR53447: optimizations of 64bit ALU operation with constant

[Ramana Radhakrishnan <ramana dot radhakrishnan at linaro dot org>]

On 29 June 2012 12:23, Carrot Wei <carrot@google.com> wrote:
> Hi
>
> So the following is updated patch. Tested on qemu with arm/thumb modes

Assuming this testing was with and without neon ? Because the patterns
changed are different whether you use Neon or not.

> without regression.

Can you add some tests for all 4 cases ? See comments inline below for
some changes ?

Ok with those changes if no regressions for above mentioned testing.

>
> thanks
> Carrot
>
>
> 2012-06-29 ?Wei Guozhi ?<carrot@google.com>
>
> ? ? ? ?PR target/53447
> ? ? ? ?* gcc.target/arm/pr53447-1.c: New testcase.
> ? ? ? ?* gcc.target/arm/pr53447-2.c: New testcase.
>
>
> 2012-06-29 ?Wei Guozhi ?<carrot@google.com>
>
> ? ? ? ?PR target/53447
> ? ? ? ?* config/arm/arm-protos.h (const_ok_for_dimode_op): New prototype.
> ? ? ? ?* config/arm/arm.c (const_ok_for_dimode_op): New function.
> ? ? ? ?* config/arm/constraints.md (Dd): New constraint.
> ? ? ? ?* config/arm/predicates.md (arm_adddi_operand): New predicate.
> ? ? ? ?* config/arm/arm.md (adddi3): Extend it to handle constants.
> ? ? ? ?(arm_adddi3): Likewise.
> ? ? ? ?(addsi3_carryin_<optab>): Extend it to handle sbc case.
> ? ? ? ?* config/arm/neon.md (adddi3_neon): Extend it to handle constants.
>
>
> Index: testsuite/gcc.target/arm/pr53447-1.c
> ===================================================================
> --- testsuite/gcc.target/arm/pr53447-1.c ? ? ? ?(revision 0)
> +++ testsuite/gcc.target/arm/pr53447-1.c ? ? ? ?(revision 0)
> @@ -0,0 +1,8 @@
> +/* { dg-options "-O2" } ?*/
> +/* { dg-require-effective-target arm32 } */
> +/* { dg-final { scan-assembler-not "mov" } } */
> +
> +void t0p(long long * p)
> +{
> + ?*p += 0x100000001;
> +}
> Index: testsuite/gcc.target/arm/pr53447-2.c
> ===================================================================
> --- testsuite/gcc.target/arm/pr53447-2.c ? ? ? ?(revision 0)
> +++ testsuite/gcc.target/arm/pr53447-2.c ? ? ? ?(revision 0)
> @@ -0,0 +1,8 @@
> +/* { dg-options "-O2" } ?*/
> +/* { dg-require-effective-target arm32 } */
> +/* { dg-final { scan-assembler-not "mov" } } */
> +
> +void t0p(long long * p)
> +{
> + ?*p -= 0x100000008;
> +}
> Index: config/arm/arm.c
> ===================================================================
> --- config/arm/arm.c ? ?(revision 187751)
> +++ config/arm/arm.c ? ?(working copy)
> @@ -2497,6 +2497,28 @@
> ? ? }
> ?}
>
> +/* Return true if I is a valid di mode constant for the operation CODE. ?*/
> +int
> +const_ok_for_dimode_op (HOST_WIDE_INT i, enum rtx_code code)
> +{
> + ?HOST_WIDE_INT hi_val = (i >> 32) & 0xFFFFFFFF;
> + ?HOST_WIDE_INT lo_val = i & 0xFFFFFFFF;
> + ?rtx hi = GEN_INT (hi_val);
> + ?rtx lo = GEN_INT (lo_val);
> +
> + ?if (TARGET_THUMB1)
> + ? ?return 0;
> +
> + ?switch (code)
> + ? ?{
> + ? ?case PLUS:
> + ? ? ?return arm_not_operand (hi, SImode) && arm_add_operand (lo, SImode);
> +
> + ? ?default:
> + ? ? ?return 0;
> + ? ?}
> +}
> +
> ?/* Emit a sequence of insns to handle a large constant.
> ? ?CODE is the code of the operation required, it can be any of SET, PLUS,
> ? ?IOR, AND, XOR, MINUS;
> Index: config/arm/arm-protos.h
> ===================================================================
> --- config/arm/arm-protos.h ? ? (revision 187751)
> +++ config/arm/arm-protos.h ? ? (working copy)
> @@ -49,6 +49,7 @@
> ?extern bool arm_modes_tieable_p (enum machine_mode, enum machine_mode);
> ?extern int const_ok_for_arm (HOST_WIDE_INT);
> ?extern int const_ok_for_op (HOST_WIDE_INT, enum rtx_code);
> +extern int const_ok_for_dimode_op (HOST_WIDE_INT, enum rtx_code);
> ?extern int arm_split_constant (RTX_CODE, enum machine_mode, rtx,
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? HOST_WIDE_INT, rtx, rtx, int);
> ?extern RTX_CODE arm_canonicalize_comparison (RTX_CODE, rtx *, rtx *);
> Index: config/arm/neon.md
> ===================================================================
> --- config/arm/neon.md ?(revision 187751)
> +++ config/arm/neon.md ?(working copy)
> @@ -588,9 +588,9 @@
> ?)
>
> ?(define_insn "adddi3_neon"
> - ?[(set (match_operand:DI 0 "s_register_operand" "=w,?&r,?&r,?w")
> - ? ? ? ?(plus:DI (match_operand:DI 1 "s_register_operand" "%w,0,0,w")
> - ? ? ? ? ? ? ? ? (match_operand:DI 2 "s_register_operand" "w,r,0,w")))
> + ?[(set (match_operand:DI 0 "s_register_operand" "=w,?&r,?&r,?w,?&r,?&r,?&r")
> + ? ? ? ?(plus:DI (match_operand:DI 1 "s_register_operand" "%w,0,0,w,r,0,r")
> + ? ? ? ? ? ? ? ? (match_operand:DI 2 "arm_adddi_operand"
> "w,r,0,w,r,Dd,Dd")))
> ? ?(clobber (reg:CC CC_REGNUM))]
> ? "TARGET_NEON"
> ?{
> @@ -600,13 +600,16 @@
> ? ? case 3: return "vadd.i64\t%P0, %P1, %P2";
> ? ? case 1: return "#";
> ? ? case 2: return "#";
> + ? ?case 4: return "#";
> + ? ?case 5: return "#";
> + ? ?case 6: return "#";
> ? ? default: gcc_unreachable ();
> ? ? }
> ?}
> - ?[(set_attr "neon_type" "neon_int_1,*,*,neon_int_1")
> - ? (set_attr "conds" "*,clob,clob,*")
> - ? (set_attr "length" "*,8,8,*")
> - ? (set_attr "arch" "nota8,*,*,onlya8")]
> + ?[(set_attr "neon_type" "neon_int_1,*,*,neon_int_1,*,*,*")
> + ? (set_attr "conds" "*,clob,clob,*,clob,clob,clob")
> + ? (set_attr "length" "*,8,8,*,8,8,8")
> + ? (set_attr "arch" "nota8,*,*,onlya8,*,*,*")]
> ?)
>
> ?(define_insn "*sub<mode>3_neon"
> Index: config/arm/constraints.md
> ===================================================================
> --- config/arm/constraints.md ? (revision 187751)
> +++ config/arm/constraints.md ? (working copy)
> @@ -29,7 +29,7 @@
> ?;; in Thumb-1 state: I, J, K, L, M, N, O
>
> ?;; The following multi-letter normal constraints have been used:
> -;; in ARM/Thumb-2 state: Da, Db, Dc, Dn, Dl, DL, Dv, Dy, Di, Dt, Dz
> +;; in ARM/Thumb-2 state: Da, Db, Dc, Dd, Dn, Dl, DL, Dv, Dy, Di, Dt, Dz
> ?;; in Thumb-1 state: Pa, Pb, Pc, Pd, Pe
> ?;; in Thumb-2 state: Pj, PJ, Ps, Pt, Pu, Pv, Pw, Px, Py
>
> @@ -251,6 +251,12 @@
> ? ? ? (match_test "TARGET_32BIT && arm_const_double_inline_cost (op) == 4
> ? ? ? ? ? ? ? ? ? && !(optimize_size || arm_ld_sched)")))
>
> +(define_constraint "Dd"
> + "@internal
> + ?In ARM/Thumb-2 state a const_int that can be used by insn adddi."
> + (and (match_code "const_int")
> + ? ? ?(match_test "TARGET_32BIT && const_ok_for_dimode_op (ival, PLUS)")))
> +
> ?(define_constraint "Di"
> ?"@internal
> ? In ARM/Thumb-2 state a const_int or const_double where both the high
> Index: config/arm/predicates.md
> ===================================================================
> --- config/arm/predicates.md ? ?(revision 187751)
> +++ config/arm/predicates.md ? ?(working copy)
> @@ -154,6 +154,11 @@
> ? (ior (match_operand 0 "arm_rhs_operand")
> ? ? ? ?(match_operand 0 "arm_neg_immediate_operand")))
>
> +(define_predicate "arm_adddi_operand"
> + ?(ior (match_operand 0 "s_register_operand")
> + ? ? ? (and (match_code "const_int")
> + ? ? ? ? ? (match_test "const_ok_for_dimode_op (INTVAL (op), PLUS)"))))
> +
> ?(define_predicate "arm_addimm_operand"
> ? (ior (match_operand 0 "arm_immediate_operand")
> ? ? ? ?(match_operand 0 "arm_neg_immediate_operand")))
> Index: config/arm/arm.md
> ===================================================================
> --- config/arm/arm.md ? (revision 187751)
> +++ config/arm/arm.md ? (working copy)
> @@ -574,7 +574,7 @@
> ?[(parallel
> ? ?[(set (match_operand:DI ? ? ? ? ? 0 "s_register_operand" "")
> ? ? ? ? ?(plus:DI (match_operand:DI 1 "s_register_operand" "")
> - ? ? ? ? ? ? ? ? ?(match_operand:DI 2 "s_register_operand" "")))
> + ? ? ? ? ? ? ? ? ?(match_operand:DI 2 "arm_adddi_operand" ?"")))
> ? ? (clobber (reg:CC CC_REGNUM))])]
> ? "TARGET_EITHER"
> ? "
> @@ -609,10 +609,10 @@
> ? [(set_attr "length" "4")]
> ?)
>
> -(define_insn_and_split "*arm_adddi3"
> - ?[(set (match_operand:DI ? ? ? ? ?0 "s_register_operand" "=&r,&r")
> - ? ? ? (plus:DI (match_operand:DI 1 "s_register_operand" "%0, 0")
> - ? ? ? ? ? ? ? ?(match_operand:DI 2 "s_register_operand" "r, ?0")))
> +(define_insn_and_split "arm_adddi3"
> + ?[(set (match_operand:DI ? ? ? ? ?0 "s_register_operand" "=&r,&r,&r,&r,&r")
> + ? ? ? (plus:DI (match_operand:DI 1 "s_register_operand" "%0, 0, r, 0, r")
> + ? ? ? ? ? ? ? ?(match_operand:DI 2 "arm_adddi_operand" ?"r, ?0, r, Dd, Dd")))
> ? ?(clobber (reg:CC CC_REGNUM))]
> ? "TARGET_32BIT && !(TARGET_HARD_FLOAT && TARGET_MAVERICK) && !TARGET_NEON"
> ? "#"
> @@ -630,8 +630,17 @@
> ? ? operands[0] = gen_lowpart (SImode, operands[0]);
> ? ? operands[4] = gen_highpart (SImode, operands[1]);
> ? ? operands[1] = gen_lowpart (SImode, operands[1]);
> - ? ?operands[5] = gen_highpart (SImode, operands[2]);
> - ? ?operands[2] = gen_lowpart (SImode, operands[2]);
> + ? ?if (GET_CODE (operands[2]) == CONST_INT)
> + ? ? ?{
> + ? ? ? HOST_WIDE_INT v = INTVAL (operands[2]);
> + ? ? ? operands[5] = GEN_INT (ARM_SIGN_EXTEND ((v >> 32) & 0xFFFFFFFF));
> + ? ? ? operands[2] = GEN_INT (ARM_SIGN_EXTEND (v & 0xFFFFFFFF));
> + ? ? ?}
> + ? ?else
> + ? ? ?{
> + ? ? ? operands[5] = gen_highpart (SImode, operands[2]);
> + ? ? ? operands[2] = gen_lowpart (SImode, operands[2]);
> + ? ? ?}

Instead


  operands[5] = gen_highpart_mode (SImode, DImode, operands[2]);
  operands[2] = gen_lowpart (SImode, operands[2]);

So you don't need a check there.



> ? }"
> ? [(set_attr "conds" "clob")
> ? ?(set_attr "length" "8")]
> @@ -980,12 +989,14 @@
> ?)
>
> ?(define_insn "*addsi3_carryin_<optab>"
> - ?[(set (match_operand:SI 0 "s_register_operand" "=r")
> - ? ? ? (plus:SI (plus:SI (match_operand:SI 1 "s_register_operand" "%r")
> - ? ? ? ? ? ? ? ? ? ? ? ? (match_operand:SI 2 "arm_rhs_operand" "rI"))
> + ?[(set (match_operand:SI 0 "s_register_operand" "=r,r")
> + ? ? ? (plus:SI (plus:SI (match_operand:SI 1 "s_register_operand" "%r,r")
> + ? ? ? ? ? ? ? ? ? ? ? ? (match_operand:SI 2 "arm_not_operand" "rI,K"))
> ? ? ? ? ? ? ? ? (LTUGEU:SI (reg:<cnb> CC_REGNUM) (const_int 0))))]
> ? "TARGET_32BIT"
> - ?"adc%?\\t%0, %1, %2"
> + ?"@
> + ? adc%?\\t%0, %1, %2
> + ? sbc%?\\t%0, %1, #%B2"
> ? [(set_attr "conds" "use")]
> ?)

Any reason why you didn't consider making these changes to the
*addsi3_carryin_alt2<optab> pattern ?


regards,
Ramana


>
>
>
>
> On Thu, Jun 28, 2012 at 7:48 PM, Ramana Radhakrishnan
> <ramana.radhakrishnan@linaro.org> wrote:
>>
>> > ?subs -lo ; sbc ~hi - lower negative, upper negative
>> > ?subs -lo ; adc hi ?- lower negative, upper positive
>>
>> Yes.
>>
>> <snip>
>>
>> >>
>> >>>
>> >>>> ? ? ? ? ? ? ? ? (LTUGEU:SI (reg:<cnb> CC_REGNUM) (const_int 0))))]
>> >>>> ? "TARGET_32BIT"
>> >>>> - ?"adc%?\\t%0, %1, %2"
>> >>>> + ?"@
>> >>>> + ?adc%?\\t%0, %1, %2
>> >>>> + ?sbc%?\\t%0, %1, %#n2"
>> >
>> > Since constraint "K" is logical not, not negative, should the last
>> > line be following?
>> >
>> > + ?sbc%?\\t%0, %1, #%B2"
>>
>> Indeed that was a typo on my part. Sorry about that.
>>
>> Ramana