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* [PATCH v2 0/9] aarch64: Implement TImode comparisons
@ 2020-03-21  2:42 Richard Henderson
  2020-03-21  2:42 ` [PATCH v2 1/9] aarch64: Accept 0 as first argument to compares Richard Henderson
                   ` (8 more replies)
  0 siblings, 9 replies; 21+ messages in thread
From: Richard Henderson @ 2020-03-21  2:42 UTC (permalink / raw)
  To: gcc-patches
  Cc: richard.earnshaw, richard.sandiford, marcus.shawcroft,
	kyrylo.tkachov, Wilco.Dijkstra

This is attacking case 3 of PR 94174.

Although I'm no longer using ccmp for most of the TImode comparisons.
Thanks to Wilco Dijkstra for pulling off my blinders and reminding me
that we can use subs+sbcs for (almost) all compares.

The first 5 patches clean up or add patterns to support the expansion
and not generate extraneous constant loads.

The aarch64_expand_addsubti patch tidies up the existing TImode
arithmetic expansions.

EXAMPLE __subvti3 (context diff is easier to read):

*** 12,27 ****
    10:	b7f800a3 	tbnz	x3, #63, 24 <__subvti3+0x24>
!   14:	eb02003f 	cmp	x1, x2
!   18:	5400010c 	b.gt	38 <__subvti3+0x38>
!   1c:	54000140 	b.eq	44 <__subvti3+0x44>  // b.none
    20:	d65f03c0 	ret
!   24:	eb01005f 	cmp	x2, x1
!   28:	5400008c 	b.gt	38 <__subvti3+0x38>
!   2c:	54ffffa1 	b.ne	20 <__subvti3+0x20>  // b.any
!   30:	eb00009f 	cmp	x4, x0
!   34:	54ffff69 	b.ls	20 <__subvti3+0x20>  // b.plast
!   38:	a9bf7bfd 	stp	x29, x30, [sp, #-16]!
!   3c:	910003fd 	mov	x29, sp
!   40:	94000000 	bl	0 <abort>
!   44:	eb04001f 	cmp	x0, x4
!   48:	54ffff88 	b.hi	38 <__subvti3+0x38>  // b.pmore
!   4c:	d65f03c0 	ret
--- 12,22 ----
    10:	b7f800a3 	tbnz	x3, #63, 24 <__subvti3+0x24>
!   14:	eb00009f 	cmp	x4, x0
!   18:	fa01005f 	sbcs	xzr, x2, x1
!   1c:	540000ab 	b.lt	30 <__subvti3+0x30>  // b.tstop
    20:	d65f03c0 	ret
!   24:	eb04001f 	cmp	x0, x4
!   28:	fa02003f 	sbcs	xzr, x1, x2
!   2c:	54ffffaa 	b.ge	20 <__subvti3+0x20>  // b.tcont
!   30:	a9bf7bfd 	stp	x29, x30, [sp, #-16]!
!   34:	910003fd 	mov	x29, sp
!   38:	94000000 	bl	0 <abort>

EXAMPLE from the pr:

void test3(__int128 a, uint64_t l)
{
        if ((__int128_t)a - l <= 1)
                doit();
}

*** 11,23 ****
        subs    x0, x0, x2
        sbc     x1, x1, xzr
!       cmp     x1, 0
!       ble     .L6
! .L1:
        ret
        .p2align 2,,3
- .L6:
-       bne     .L4
-       cmp     x0, 1
-       bhi     .L1
  .L4:
        b       doit
--- 11,19 ----
        subs    x0, x0, x2
        sbc     x1, x1, xzr
!       cmp     x0, 2
!       sbcs    xzr, x1, xzr
!       blt     .L4
        ret
        .p2align 2,,3
  .L4:
        b       doit


r~


Richard Henderson (9):
  aarch64: Accept 0 as first argument to compares
  aarch64: Accept zeros in add<GPI>3_carryin
  aarch64: Add <su>cmp_*_carryinC patterns
  aarch64: Add <su>cmp<GPI>_carryinC_m2
  aarch64: Provide expander for sub<GPI>3_compare1
  aarch64: Introduce aarch64_expand_addsubti
  aarch64: Adjust result of aarch64_gen_compare_reg
  aarch64: Implement TImode comparisons
  aarch64: Implement absti2

 gcc/config/aarch64/aarch64-protos.h       |  10 +-
 gcc/config/aarch64/aarch64.c              | 292 +++++++++-------
 gcc/config/aarch64/aarch64-simd.md        |  18 +-
 gcc/config/aarch64/aarch64-speculation.cc |   5 +-
 gcc/config/aarch64/aarch64.md             | 389 +++++++++++++---------
 5 files changed, 402 insertions(+), 312 deletions(-)

-- 
2.20.1


^ permalink raw reply	[flat|nested] 21+ messages in thread
end of thread, other threads:[~2020-04-01 17:14 UTC | newest]

Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-21  2:42 [PATCH v2 0/9] aarch64: Implement TImode comparisons Richard Henderson
2020-03-21  2:42 ` [PATCH v2 1/9] aarch64: Accept 0 as first argument to compares Richard Henderson
2020-03-31 16:55   ` Richard Sandiford
2020-03-31 17:15     ` Richard Henderson
2020-03-21  2:42 ` [PATCH v2 2/9] aarch64: Accept zeros in add<GPI>3_carryin Richard Henderson
2020-03-21  2:42 ` [PATCH v2 3/9] aarch64: Add <su>cmp_*_carryinC patterns Richard Henderson
2020-03-22 19:30   ` Segher Boessenkool
2020-03-22 20:40     ` Richard Henderson
2020-03-31 18:34   ` Richard Sandiford
2020-03-31 22:44     ` Richard Henderson
2020-04-01 12:37       ` Segher Boessenkool
2020-04-01 16:28       ` Richard Sandiford
2020-04-01 17:14         ` Richard Henderson
2020-03-21  2:42 ` [PATCH v2 4/9] aarch64: Add <su>cmp<GPI>_carryinC_m2 Richard Henderson
2020-03-21  2:42 ` [PATCH v2 5/9] aarch64: Provide expander for sub<GPI>3_compare1 Richard Henderson
2020-03-21  2:42 ` [PATCH v2 6/9] aarch64: Introduce aarch64_expand_addsubti Richard Henderson
2020-03-21  2:42 ` [PATCH v2 7/9] aarch64: Adjust result of aarch64_gen_compare_reg Richard Henderson
2020-03-22 21:55   ` Segher Boessenkool
2020-03-22 22:21     ` Richard Henderson
2020-03-21  2:42 ` [PATCH v2 8/9] aarch64: Implement TImode comparisons Richard Henderson
2020-03-21  2:42 ` [PATCH v2 9/9] aarch64: Implement absti2 Richard Henderson

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