Date: Thu, 29 Mar 2012 02:04:16 +0000 (UTC) From: Juli Mallett <jmallett@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r233638 - head/sys/mips/mips Message-ID: <201203290204.q2T24Glj070210@svn.freebsd.org>
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Author: jmallett Date: Thu Mar 29 02:04:15 2012 New Revision: 233638 URL: http://svn.freebsd.org/changeset/base/233638 Log: Disable FP instruction emulation by default on !o32 because of ABI concerns. Note that in practice this isn't needed because we get a coprocessor unusable exception first, but that's actually something like a bug. Modified: head/sys/mips/mips/trap.c Modified: head/sys/mips/mips/trap.c ============================================================================== --- head/sys/mips/mips/trap.c Thu Mar 29 02:03:06 2012 (r233637) +++ head/sys/mips/mips/trap.c Thu Mar 29 02:04:15 2012 (r233638) @@ -290,6 +290,20 @@ static int allow_unaligned_acc = 1; SYSCTL_INT(_vm, OID_AUTO, allow_unaligned_acc, CTLFLAG_RW, &allow_unaligned_acc, 0, "Allow unaligned accesses"); +/* + * FP emulation is assumed to work on O32, but the code is outdated and crufty + * enough that it's a more sensible default to have it disabled when using + * other ABIs. At the very least, it needs a lot of help in using + * type-semantic ABI-oblivious macros for everything it does. + */ +#if defined(__mips_o32) +static int emulate_fp = 1; +#else +static int emulate_fp = 0; +#endif +SYSCTL_INT(_machdep, OID_AUTO, emulate_fp, CTLFLAG_RW, + &allow_unaligned_acc, 0, "Emulate unimplemented FPU instructions"); + static int emulate_unaligned_access(struct trapframe *frame, int mode); extern void fswintrberr(void); /* XXX */ @@ -988,6 +1002,11 @@ dofault: #endif case T_FPE + T_USER: + if (!emulate_fp) { + i = SIGILL; + addr = trapframe->pc; + break; + } MipsFPTrap(trapframe->sr, trapframe->cause, trapframe->pc); goto out;
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