| invoke.texi (169690) | invoke.texi (181540) |
|---|---|
| 1@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2@c 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. 3@c This is part of the GCC manual. 4@c For copying conditions, see the file gcc.texi. 5 6@ignore 7@c man begin INCLUDE 8@include gcc-vers.texi --- 5663 unchanged lines hidden (view full) --- 5672 5673This option should never be turned on by any @option{-O} option since 5674it can result in incorrect output for programs which depend on 5675an exact implementation of IEEE or ISO rules/specifications for 5676math functions. 5677 5678The default is @option{-fmath-errno}. 5679 | 1@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2@c 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. 3@c This is part of the GCC manual. 4@c For copying conditions, see the file gcc.texi. 5 6@ignore 7@c man begin INCLUDE 8@include gcc-vers.texi --- 5663 unchanged lines hidden (view full) --- 5672 5673This option should never be turned on by any @option{-O} option since 5674it can result in incorrect output for programs which depend on 5675an exact implementation of IEEE or ISO rules/specifications for 5676math functions. 5677 5678The default is @option{-fmath-errno}. 5679 |
| 5680On Darwin systems, the math library never sets @code{errno}. There is therefore | 5680On Darwin and FreeBSD systems, the math library never sets @code{errno}. 5681There is therefore |
| 5681no reason for the compiler to consider the possibility that it might, 5682and @option{-fno-math-errno} is the default. 5683 5684@item -funsafe-math-optimizations 5685@opindex funsafe-math-optimizations 5686Allow optimizations for floating-point arithmetic that (a) assume 5687that arguments and results are valid and (b) may violate IEEE or 5688ANSI standards. When used at link-time, it may include libraries --- 3813 unchanged lines hidden (view full) --- 9502 9503The option @option{-mno-fp-ret-in-387} causes such values to be returned 9504in ordinary CPU registers instead. 9505 9506@item -mno-fancy-math-387 9507@opindex mno-fancy-math-387 9508Some 387 emulators do not support the @code{sin}, @code{cos} and 9509@code{sqrt} instructions for the 387. Specify this option to avoid | 5682no reason for the compiler to consider the possibility that it might, 5683and @option{-fno-math-errno} is the default. 5684 5685@item -funsafe-math-optimizations 5686@opindex funsafe-math-optimizations 5687Allow optimizations for floating-point arithmetic that (a) assume 5688that arguments and results are valid and (b) may violate IEEE or 5689ANSI standards. When used at link-time, it may include libraries --- 3813 unchanged lines hidden (view full) --- 9503 9504The option @option{-mno-fp-ret-in-387} causes such values to be returned 9505in ordinary CPU registers instead. 9506 9507@item -mno-fancy-math-387 9508@opindex mno-fancy-math-387 9509Some 387 emulators do not support the @code{sin}, @code{cos} and 9510@code{sqrt} instructions for the 387. Specify this option to avoid |
| 9510generating those instructions. This option is the default on FreeBSD, | 9511generating those instructions. This option is the default on |
| 9511OpenBSD and NetBSD@. This option is overridden when @option{-march} 9512indicates that the target cpu will always have an FPU and so the 9513instruction will not need emulation. As of revision 2.6.1, these 9514instructions are not generated unless you also use the 9515@option{-funsafe-math-optimizations} switch. 9516 9517@item -malign-double 9518@itemx -mno-align-double --- 4638 unchanged lines hidden --- | 9512OpenBSD and NetBSD@. This option is overridden when @option{-march} 9513indicates that the target cpu will always have an FPU and so the 9514instruction will not need emulation. As of revision 2.6.1, these 9515instructions are not generated unless you also use the 9516@option{-funsafe-math-optimizations} switch. 9517 9518@item -malign-double 9519@itemx -mno-align-double --- 4638 unchanged lines hidden --- |