Date: Fri, 10 Feb 2017 16:51:19 +0100 From: Alexandre Martins <alexandre.martins@stormshield.eu> To: freebsd-arm@freebsd.org Subject: bcopy/memmove optimization broken ? Message-ID: <5335118.oK1KXXDaG5@pc-alex>
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--nextPart5297990.tDBggcDrPZ Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" Hi all I see in the kernel code of bcopy/memmove an optimization if the copied= region=20 don't overlap: https://svnweb.freebsd.org/base/head/sys/arm/arm/support.S?view=3Dannot= ate#l403 I'm a newbie in ARM assembly, so, sorry if i'm wrong, but - R0 is the dst (1st parameter) - R1 is the src (2nd parameter) So : subcc r3, r0, r1 /* if (dst > src) r3 =3D dst - src */ subcs r3, r1, r0 /* if (src > dsr) r3 =3D src - dst */ cmp r3, r2 /* if (r3 < len) we have an overlap */ bcc PIC_SYM(_C_LABEL(memcpy), PLT) Seems to be inverted. Should it be that ? : subcs r3, r0, r1 /* if (dst > src) r3 =3D dst - src */ subcc r3, r1, r0 /* if (src > dsr) r3 =3D src - dst */ cmp r3, r2 /* if (r3 < len) we have an overlap */ bcs PIC_SYM(_C_LABEL(memcpy), PLT) Best regards =2D-=20 Alexandre Martins STORMSHIELD --nextPart5297990.tDBggcDrPZ Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCCOUw ggSGMIICbqADAgECAgUA28zw7TANBgkqhkiG9w0BAQsFADBIMQswCQYDVQQGEwJGUjEUMBIGA1UE CgwLU1RPUk1TSElFTEQxIzAhBgNVBAMMGlN0b3Jtc2hpZWxkIFJvb3QgQXV0aG9yaXR5MB4XDTE0 MDkwNDE1MDcxMFoXDTI0MDkwMTE1MDcxMFowSTELMAkGA1UEBhMCRlIxFDASBgNVBAoMC1NUT1JN U0hJRUxEMSQwIgYDVQQDDBtTdG9ybXNoaWVsZCBVc2VycyBBdXRob3JpdHkwggEiMA0GCSqGSIb3 DQEBAQUAA4IBDwAwggEKAoIBAQDChwWgC/6VWKL7jgWI3eA2sVvRdOwuHcXsRAAXVWdlMC0ygg7u 45E78GhAnpdl8QbIu7x/Q2zOq6KttspwDEIjkoMLTZngLLlGjYJZPfuSoC6hl9R7vRd5f8Fhu3v0 xQ/7vzKYz4C836IGCrk31gmrPO0H0fxkyxCMfhoTTzue3oXW1IsmQwCrOPOu2Y82QANDhbifWLjI WJetnj58YRKR82KBs3Flbqxtp0mi9+IswMvCCRSoT+ORB73Cl6URt7Qm7BcD+qnkJ9uwlUC94dIl T2hX4ybY/w/ssA17Ew418fgyRCWQXzgjZgZ/XUcw2WP9dIggA7Pg+c/xeROJH1zvAgMBAAGjdjB0 MB0GA1UdDgQWBBShbYRsooCFBXx8dXWANMETW5fXgTAfBgNVHSMEGDAWgBS4Qqn6Z0Twf9NhjOyl x1CutL3sozAPBgNVHRMBAf8EBTADAQH/MA4GA1UdDwEB/wQEAwIBBjARBglghkgBhvhCAQEEBAMC AQYwDQYJKoZIhvcNAQELBQADggIBAE6C9zkt2J6dPm2KLbzRS6rBIYZNFi0X59g3ekQ2Sc4UWsq+ B3L86j5xnQSRnIM/DKV1+Q2UHbU/qsh4cto2fwTV6V+aJ07Vu/bJE1rAN4AI4V26ytf7VoBcBjVZ Jq8pHOMp/G2eQH7F1xqzml68DpKku66aUalkcC9IM82m7AW3YAyvDoYEAchv4qyL8qhVLLp6LNru 8ZOhMELhZLWl4ulw/SFDMhcBS6I4wC6icj71MLGSrr61vMktMdwQ+CGFQ5z5JbaxM61VgzKay8+g lw+xTbpnitrDfhkzHs2fdwOOur3vtNnNsrdBWiYPseJ2k4VGD7ov5kITQZckmZyF/V+Ir//agJQG VuwhDZCXgXOvrje+FLYp7tQ9pgSvLbluh1A+ywfyHnFI4n6tZy9SD3MIDgWR4KwFLM1Qmt3NQb32 tkq9Vm0jUcQXFfbnWKLA9krw3m8NmCqhL5PzpfOegYOc0QJWfMQamxeWxXMLk6uKisS//+VqfpCa 5Jx53t+9DmoN1+ob4jOprPaX6tfBBr5djah2yzPGjHEB52VgWXxIF9lCM2z7Qw+zFb2PIdNeSjIk NEFg/1orKAAa5gQXAQynN2J7E+aLf2XLhHcS0v+9yoisPEw9+Tb5F1uQh+gzYD5JUUYcYWncnX8g P8k6X+F5mQ/81IoNL/IejxJgy/LoMIIEVzCCAz+gAwIBAgIFAIUoy7swDQYJKoZIhvcNAQELBQAw STELMAkGA1UEBhMCRlIxFDASBgNVBAoMC1NUT1JNU0hJRUxEMSQwIgYDVQQDDBtTdG9ybXNoaWVs ZCBVc2VycyBBdXRob3JpdHkwHhcNMTYwOTAxMTUxMTA4WhcNMTcwOTAxMTUxMTA4WjBwMQswCQYD VQQGEwJGUjEUMBIGA1UECgwLU1RPUk1TSElFTEQxGjAYBgNVBAMMEUFsZXhhbmRyZSBNQVJUSU5T MS8wLQYJKoZIhvcNAQkBFiBhbGV4YW5kcmUubWFydGluc0BzdG9ybXNoaWVsZC5ldTCCASIwDQYJ KoZIhvcNAQEBBQADggEPADCCAQoCggEBAMN+CnvE13jKEwJ+OyMzwBpC02dY+LpD5luJwnJTVnV2 9aUjEMI+xGFMMHd9kSIVInbk4WDe1ELOKerg0dzgnkRiOHECSGum1UhcZABxQgY2cmSffNQ6JVro 52UaBlt3aTOk3imYJCHUIGgOWMvOtRc8BxyBHdi15FZPj/F9I+AKufRFsBXUakplFIAPEwy3m2eR a/eCMLqGJUyK7YmsAlEnYn2mA38zIoqtKvL6KPHtrV8fw1SRLQ13+j9nu1LlCaqhmLtILFxhV0/9 uDTvx5cKtZ8Xj1nPM6NUUrso9qlXwm4On6Y34pVTtnYGMQRuljil3Hiz84RJjPDJYRGwbgkCAwEA AaOCAR0wggEZMB0GA1UdDgQWBBTmRLIwSfhNwbdfV13xt0G0JHYjPDAfBgNVHSMEGDAWgBShbYRs ooCFBXx8dXWANMETW5fXgTAJBgNVHRMEAjAAMA4GA1UdDwEB/wQEAwID6DARBglghkgBhvhCAQEE BAMCBLAwHQYDVR0lBBYwFAYIKwYBBQUHAwQGCCsGAQUFBwMCMEoGA1UdHwRDMEEwP6A9oDuGOWh0 dHBzOi8vcGtpLm5ldGFzcS5jb20vYXV0aC9jZXJ0aWZpY2F0ZXJldm9jYXRpb25saXN0LmNybDAR BgNVHSAECjAIMAYGBFUdIAAwKwYDVR0RBCQwIoEgYWxleGFuZHJlLm1hcnRpbnNAc3Rvcm1zaGll bGQuZXUwDQYJKoZIhvcNAQELBQADggEBALT9NWiAaE6nDev34vShhsyb9lWBOQfCnAMyKwtFy/cU uIoHsxyOanIIQHz0ZtB76GCHDo7RStMyp6RYIefIsxABLhSr4hHapJka9g/X/nxexyr0xyT3IpYQ dmyMSHRT18Z/ZaBlQdyfnS2PYkPHJAHl4iqB4SnQlh3rwFdKTJMgCz413cDxQHytgRPGTiXOhyV7 aS3ANJFha6ZHA8HU9sTslY8ZXSUu94iD3t2kcF3gBb432UKALwryKqnrwzFX68pFpqO5QAjEHaF6 6p1agMb2b3HlQGZrME5wSO6rsZJPYvJEyvrwHxCxjSTkOdPw6GriWGTMrVMU0fVrfptMS1gxggIT MIICDwIBATBSMEkxCzAJBgNVBAYTAkZSMRQwEgYDVQQKDAtTVE9STVNISUVMRDEkMCIGA1UEAwwb U3Rvcm1zaGllbGQgVXNlcnMgQXV0aG9yaXR5AgUAhSjLuzANBglghkgBZQMEAgEFAKCBkzAYBgkq hkiG9w0BCQMxCwYJKoZIhvcNAQcBMBwGCSqGSIb3DQEJBTEPFw0xNzAyMTAxNTUxMTlaMCgGCSqG SIb3DQEJDzEbMBkwCwYJYIZIAWUDBAECMAoGCCqGSIb3DQMHMC8GCSqGSIb3DQEJBDEiBCCxGLwW 2Vm7yBv+GC53rePsv3IPBgxmcXTlOHCkId0VojANBgkqhkiG9w0BAQEFAASCAQBRWpUF06Wa6/C4 pOH4tEjpGzaXgdSh9M1yuYIFnq7ZtqdfuYxDvq4zy8roBzX+gUbBQt/fswAPA7B3687s/jcaewYq cJ4/oiPihSfDfhqfopuOnqMP2w4TF8SKYBiXvXM9L2j+qTvTIJJYAADhUGPmtXUCSBpdiBmSI7XT 1+oE53S/Z+FtxoW/SJ4IDlBUe0tjRaqc4/LiRA5Tzhc+cegTjPNo1KzDbvnPmH8uAx+0Zx2rzgrU 3XgOCj83BewKkoNLzU2OpjK9jm+RuUyAbTiOiAvhntiDzBhqMYQB+xKsMwz7zvafPI4sgg8UFe1I 0csvamR4tKRnNFXUYoqX66fcAAAAAAAA --nextPart5297990.tDBggcDrPZ--
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