Date: Mon, 13 Feb 2017 10:51:06 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-arm@FreeBSD.org Subject: [Bug 217065] Memmove / bcopy optimization bug Message-ID: <bug-217065-7@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=217065 Bug ID: 217065 Summary: Memmove / bcopy optimization bug Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: arm Assignee: freebsd-arm@FreeBSD.org Reporter: alexandre.martins@stormshield.eu Hello, During the optimization phase of our project on an Armada 380, I have see that an optimization on bcopy/memmove is broken. https://svnweb.freebsd.org/base/head/sys/arm/arm/support.S?view=annotate#l403 The condition on the following line are reserved: > subcc r3, r0, r1 /* if (dst > src) r3 = dst - src */ > subcs r3, r1, r0 /* if (src > dsr) r3 = src - dst */ > cmp r3, r2 /* if (r3 < len) we have an overlap */ > bcc PIC_SYM(_C_LABEL(memcpy), PLT) Should be: > subcs r3, r0, r1 /* if (dst > src) r3 = dst - src */ > subcc r3, r1, r0 /* if (src > dsr) r3 = src - dst */ > cmp r3, r2 /* if (r3 < len) we have an overlap */ > bcs PIC_SYM(_C_LABEL(memcpy), PLT) This code may produce bugs if an unlikely copy of more that 2Gb is done (I don't see how). I have already reported that on the mailling list: https://docs.freebsd.org/cgi/getmsg.cgi?fetch=462567+0+archive/2017/freebsd-arm/20170212.freebsd-arm Best regards, Alexandre Martins -- You are receiving this mail because: You are the assignee for the bug.home | help
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