On Sun, Mar 2, 2008 at 2:00 PM, Joseph S. Myers <[EMAIL PROTECTED]> wrote:
> On Sat, 1 Mar 2008, Richard Guenther wrote:
>
> > I missed once point noticed by Joseph also, that the libgcc implementation
> > uses signed types in the implementation of the trapping arithmetics.
> > Where we of course optimize away the overflow check, so the libgcc
> > routines will never trap. (if it does work in some cases then this
> > would be a missed optimization, so sooner or later it is going to
> > break more)
>
> This is of course trivial to fix. OK to commit the following patch?
> Bootstrapped with no regressions on i686-pc-linux-gnu.
Ok.
Thanks,
Richard.
> 2008-03-02 Joseph Myers <[EMAIL PROTECTED]>
>
> * libgcc2.c (__addvSI3, __addvsi3, __addvDI3, __subvSI3,
> __subvsi3, __subvDI3, __negvSI2, __negvsi2, __negvDI2, __absvSI2,
> __absvsi2, __absvDI2): Use unsigned arithmetic.
>
> Index: libgcc2.c
> ===================================================================
> --- libgcc2.c (revision 132803)
> +++ libgcc2.c (working copy)
> @@ -84,7 +84,7 @@
> Wtype
> __addvSI3 (Wtype a, Wtype b)
> {
> - const Wtype w = a + b;
> + const Wtype w = (UWtype) a + (UWtype) b;
>
> if (b >= 0 ? w < a : w > a)
> abort ();
> @@ -95,7 +95,7 @@
> SItype
> __addvsi3 (SItype a, SItype b)
> {
> - const SItype w = a + b;
> + const SItype w = (USItype) a + (USItype) b;
>
> if (b >= 0 ? w < a : w > a)
> abort ();
> @@ -109,7 +109,7 @@
> DWtype
> __addvDI3 (DWtype a, DWtype b)
> {
> - const DWtype w = a + b;
> + const DWtype w = (UDWtype) a + (UDWtype) b;
>
> if (b >= 0 ? w < a : w > a)
> abort ();
> @@ -122,7 +122,7 @@
> Wtype
> __subvSI3 (Wtype a, Wtype b)
> {
> - const Wtype w = a - b;
> + const Wtype w = (UWtype) a - (UWtype) b;
>
> if (b >= 0 ? w > a : w < a)
> abort ();
> @@ -133,7 +133,7 @@
> SItype
> __subvsi3 (SItype a, SItype b)
> {
> - const SItype w = a - b;
> + const SItype w = (USItype) a - (USItype) b;
>
> if (b >= 0 ? w > a : w < a)
> abort ();
> @@ -147,7 +147,7 @@
> DWtype
> __subvDI3 (DWtype a, DWtype b)
> {
> - const DWtype w = a - b;
> + const DWtype w = (UDWtype) a - (UDWtype) b;
>
> if (b >= 0 ? w > a : w < a)
> abort ();
> @@ -187,7 +187,7 @@
> Wtype
> __negvSI2 (Wtype a)
> {
> - const Wtype w = -a;
> + const Wtype w = -(UWtype) a;
>
> if (a >= 0 ? w > 0 : w < 0)
> abort ();
> @@ -198,7 +198,7 @@
> SItype
> __negvsi2 (SItype a)
> {
> - const SItype w = -a;
> + const SItype w = -(USItype) a;
>
> if (a >= 0 ? w > 0 : w < 0)
> abort ();
> @@ -212,7 +212,7 @@
> DWtype
> __negvDI2 (DWtype a)
> {
> - const DWtype w = -a;
> + const DWtype w = -(UDWtype) a;
>
> if (a >= 0 ? w > 0 : w < 0)
> abort ();
> @@ -231,7 +231,7 @@
> #ifdef L_negvsi2
> w = __negvSI2 (a);
> #else
> - w = -a;
> + w = -(UWtype) a;
>
> if (w < 0)
> abort ();
> @@ -249,7 +249,7 @@
> #ifdef L_negvsi2
> w = __negvsi2 (a);
> #else
> - w = -a;
> + w = -(USItype) a;
>
> if (w < 0)
> abort ();
> @@ -270,7 +270,7 @@
> #ifdef L_negvdi2
> w = __negvDI2 (a);
> #else
> - w = -a;
> + w = -(UDWtype) a;
>
> if (w < 0)
> abort ();
>
>
>
> --
> Joseph S. Myers
> [EMAIL PROTECTED]
>
