From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id 31CFD3858D1E; Mon,  6 May 2024 10:00:01 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 31CFD3858D1E
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1714989601;
	bh=iLRWtFYYcU4hszOLi5ztdZZlFGSa7EREy812c76fNs8=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=Bh5E9uFfP+09sqGww3PYMXRcbhUfMpkITBiBi7g5oS2GUwfbzDSzcSacPqVQjJxAy
	 EU5tz5ffmGLEFUK5dBK6jQlulpmd4QifekVNtNqpmylTX5g/5ktzYmVcU9K9/5zpem
	 6iiBBw3U8QhBIyzzfJNMTOWWW7A9YJNM32Yku/es=
From: "mkretz at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/114908] fails to optimize avx2 in-register
 permute written with std::experimental::simd
Date: Mon, 06 May 2024 10:00:01 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: mkretz at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-114908-4-aLAM5IXdYT@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-114908-4@http.gcc.gnu.org/bugzilla/>
References: <bug-114908-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D114908

--- Comment #5 from Matthias Kretz (Vir) <mkretz at gcc dot gnu.org> ---
https://godbolt.org/z/P6cfbjT9f

#include <stdint.h>

typedef uint64_t T;

typedef T V [[gnu::vector_size(32)]];

typedef struct simd4 {
    V data;
} simd4;

typedef struct simd1 {
    T data;
} simd1;

typedef struct tup3_1 {
    simd4 a;
    simd1 b;
} tup3_1;

simd1 load1(const T* ptr) {
    simd1 ret =3D {ptr[0]};
    return ret;
}

simd4 load3(const T* ptr) {
    simd4 ret =3D {};
    __builtin_memcpy(&ret, ptr, 3 * sizeof(T));
    return ret;
}

tup3_1 split3_1(simd4 x) {
    const T* ptr =3D (T*)&x;
    tup3_1 ret =3D {load3(ptr), load1(ptr + 3)};
    return ret;
}

simd4 concat1_3(simd1 a, simd4 b) {
    simd4 ret =3D {};
    char* ptr =3D (char*)&ret;
    __builtin_memcpy(ptr, &a, sizeof(T));
    __builtin_memcpy(ptr + sizeof(T), &b, 3 * sizeof(T));
    return ret;
}

simd4 perm(simd4 data) {
    tup3_1 carry =3D split3_1(data);
    simd1 zero =3D {};
    return concat1_3(zero, carry.a);
}=