From: Richard Henderson <richard.henderson@linaro.org>
To: Peter Maydell <peter.maydell@linaro.org>,
qemu-arm@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [PATCH 47/55] target/arm: Implement MVE VQDMLADH and VQRDMLADH
Date: Wed, 9 Jun 2021 13:05:40 -0700 [thread overview]
Message-ID: <91f3abe8-f3b9-5401-10fd-e9f01dd0d319@linaro.org> (raw)
In-Reply-To: <20210607165821.9892-48-peter.maydell@linaro.org>
On 6/7/21 9:58 AM, Peter Maydell wrote:
> +static int32_t do_vqdmladh_w(int32_t a, int32_t b, int32_t c, int32_t d,
> + int round, bool *sat)
> +{
> + int64_t m1 = (int64_t)a * b;
> + int64_t m2 = (int64_t)c * d;
> + int64_t r;
> + /*
> + * Architecturally we should do the entire add, double, round
> + * and then check for saturation. We do three saturating adds,
> + * but we need to be careful about the order. If the first
> + * m1 + m2 saturates then it's impossible for the *2+rc to
> + * bring it back into the non-saturated range. However, if
> + * m1 + m2 is negative then it's possible that doing the doubling
> + * would take the intermediate result below INT64_MAX and the
> + * addition of the rounding constant then brings it back in range.
> + * So we add half the rounding constant before doubling rather
> + * than adding the rounding constant after the doubling.
> + */
> + if (sadd64_overflow(m1, m2, &r) ||
> + sadd64_overflow(r, (round << 30), &r) ||
> + sadd64_overflow(r, r, &r)) {
Ooh, ahh, an operation that doesn't even exist in SVE2.
Nice use of the new interface, btw.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
next prev parent reply other threads:[~2021-06-09 20:06 UTC|newest]
Thread overview: 130+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-07 16:57 [PATCH 00/55] target/arm: First slice of MVE implementation Peter Maydell
2021-06-07 16:57 ` [PATCH 01/55] tcg: Introduce tcg_remove_ops_after Peter Maydell
2021-06-07 16:57 ` [PATCH 02/55] target/arm: Enable FPSCR.QC bit for MVE Peter Maydell
2021-06-07 19:02 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 03/55] target/arm: Handle VPR semantics in existing code Peter Maydell
2021-06-07 21:19 ` Richard Henderson
2021-06-10 9:28 ` Peter Maydell
2021-06-07 16:57 ` [PATCH 04/55] target/arm: Add handling for PSR.ECI/ICI Peter Maydell
2021-06-07 23:33 ` Richard Henderson
2021-06-10 10:17 ` Peter Maydell
2021-06-10 13:39 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 05/55] target/arm: Let vfp_access_check() handle late NOCP checks Peter Maydell
2021-06-07 23:50 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 06/55] target/arm: Implement MVE LCTP Peter Maydell
2021-06-08 0:05 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 07/55] target/arm: Implement MVE WLSTP insn Peter Maydell
2021-06-08 1:42 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 08/55] target/arm: Implement MVE DLSTP Peter Maydell
2021-06-08 2:56 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 09/55] target/arm: Implement MVE LETP insn Peter Maydell
2021-06-08 3:40 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 10/55] target/arm: Add framework for MVE decode Peter Maydell
2021-06-08 3:59 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 11/55] target/arm: Implement MVE VLDR/VSTR (non-widening forms) Peter Maydell
2021-06-08 21:33 ` Richard Henderson
2021-06-08 21:43 ` Richard Henderson
2021-06-09 10:01 ` Peter Maydell
2021-06-09 17:09 ` Richard Henderson
2021-06-10 14:01 ` Peter Maydell
2021-06-07 16:57 ` [PATCH 12/55] target/arm: Implement widening/narrowing MVE VLDR/VSTR insns Peter Maydell
2021-06-08 21:46 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 13/55] target/arm: Implement MVE VCLZ Peter Maydell
2021-06-08 22:10 ` Richard Henderson
2021-06-10 12:40 ` Peter Maydell
2021-06-10 14:03 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 14/55] target/arm: Implement MVE VCLS Peter Maydell
2021-06-08 22:12 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 15/55] bitops.h: Provide hswap32(), hswap64(), wswap64() swapping operations Peter Maydell
2021-06-08 6:53 ` Philippe Mathieu-Daudé
2021-06-08 22:14 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 16/55] target/arm: Implement MVE VREV16, VREV32, VREV64 Peter Maydell
2021-06-08 22:23 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 17/55] target/arm: Implement MVE VMVN (register) Peter Maydell
2021-06-08 22:27 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 18/55] target/arm: Implement MVE VABS Peter Maydell
2021-06-08 22:34 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 19/55] target/arm: Implement MVE VNEG Peter Maydell
2021-06-08 22:40 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 20/55] target/arm: Implement MVE VDUP Peter Maydell
2021-06-08 23:17 ` Richard Henderson
2021-06-09 10:06 ` Peter Maydell
2021-06-09 17:16 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 21/55] target/arm: Implement MVE VAND, VBIC, VORR, VORN, VEOR Peter Maydell
2021-06-08 23:23 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 22/55] target/arm: Implement MVE VADD, VSUB, VMUL Peter Maydell
2021-06-08 23:25 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 23/55] target/arm: Implement MVE VMULH Peter Maydell
2021-06-08 23:29 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 24/55] target/arm: Implement MVE VRMULH Peter Maydell
2021-06-08 23:33 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 25/55] target/arm: Implement MVE VMAX, VMIN Peter Maydell
2021-06-08 23:35 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 26/55] target/arm: Implement MVE VABD Peter Maydell
2021-06-08 23:39 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 27/55] target/arm: Implement MVE VHADD, VHSUB Peter Maydell
2021-06-08 23:43 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 28/55] target/arm: Implement MVE VMULL Peter Maydell
2021-06-08 23:52 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 29/55] target/arm: Implement MVE VMLALDAV Peter Maydell
2021-06-09 0:46 ` Richard Henderson
2021-06-09 0:46 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 30/55] target/arm: Implement MVE VMLSLDAV Peter Maydell
2021-06-09 0:47 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 31/55] include/qemu/int128.h: Add function to create Int128 from int64_t Peter Maydell
2021-06-08 6:45 ` Philippe Mathieu-Daudé
2021-06-09 0:51 ` Richard Henderson
2021-06-07 16:57 ` [PATCH 32/55] target/arm: Implement MVE VRMLALDAVH, VRMLSLDAVH Peter Maydell
2021-06-09 1:05 ` Richard Henderson
2021-06-14 10:19 ` Peter Maydell
2021-06-07 16:57 ` [PATCH 33/55] target/arm: Implement MVE VADD (scalar) Peter Maydell
2021-06-09 17:58 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 34/55] target/arm: Implement MVE VSUB, VMUL (scalar) Peter Maydell
2021-06-09 18:00 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 35/55] target/arm: Implement MVE VHADD, VHSUB (scalar) Peter Maydell
2021-06-09 18:02 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 36/55] target/arm: Implement MVE VBRSR Peter Maydell
2021-06-09 18:08 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 37/55] target/arm: Implement MVE VPST Peter Maydell
2021-06-09 18:23 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 38/55] target/arm: Implement MVE VQADD and VQSUB Peter Maydell
2021-06-09 18:46 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 39/55] target/arm: Implement MVE VQDMULH and VQRDMULH (scalar) Peter Maydell
2021-06-09 18:58 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 40/55] target/arm: Implement MVE VQDMULL scalar Peter Maydell
2021-06-09 19:11 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 41/55] target/arm: Implement MVE VQDMULH, VQRDMULH (vector) Peter Maydell
2021-06-09 19:13 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 42/55] target/arm: Implement MVE VQADD, VQSUB (vector) Peter Maydell
2021-06-09 19:15 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 43/55] target/arm: Implement MVE VQSHL (vector) Peter Maydell
2021-06-09 19:26 ` Richard Henderson
2021-06-14 11:04 ` Peter Maydell
2021-06-07 16:58 ` [PATCH 44/55] target/arm: Implement MVE VQRSHL Peter Maydell
2021-06-09 19:29 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 45/55] target/arm: Implement MVE VSHL insn Peter Maydell
2021-06-09 19:40 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 46/55] target/arm: Implement MVE VRSHL Peter Maydell
2021-06-09 19:43 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 47/55] target/arm: Implement MVE VQDMLADH and VQRDMLADH Peter Maydell
2021-06-09 20:05 ` Richard Henderson [this message]
2021-06-07 16:58 ` [PATCH 48/55] target/arm: Implement MVE VQDMLSDH and VQRDMLSDH Peter Maydell
2021-06-09 20:08 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 49/55] target/arm: Implement MVE VQDMULL (vector) Peter Maydell
2021-06-09 20:20 ` Richard Henderson
2021-06-10 19:08 ` Peter Maydell
2021-06-10 19:34 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 50/55] target/arm: Implement MVE VRHADD Peter Maydell
2021-06-09 20:24 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 51/55] target/arm: Implement MVE VADC, VSBC Peter Maydell
2021-06-09 21:06 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 52/55] target/arm: Implement MVE VCADD Peter Maydell
2021-06-09 21:16 ` Richard Henderson
2021-06-10 19:16 ` Peter Maydell
2021-06-07 16:58 ` [PATCH 53/55] target/arm: Implement MVE VHCADD Peter Maydell
2021-06-10 3:50 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 54/55] target/arm: Implement MVE VADDV Peter Maydell
2021-06-10 14:06 ` Richard Henderson
2021-06-07 16:58 ` [PATCH 55/55] target/arm: Make VMOV scalar <-> gpreg beatwise for MVE Peter Maydell
2021-06-10 14:14 ` Richard Henderson
2021-06-09 14:33 ` [PATCH 00/55] target/arm: First slice of MVE implementation no-reply
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