Re: FPU Exception code

[Martin Husemann <martin%duskware.de@localhost>]

On Sun, Nov 16, 2008 at 03:59:14PM +0100, Martin Husemann wrote:
> I found this uncommited patch - I think I needed it to make
> mc68k pass all tests in src/regress/lib/libc/ieeefp/.
> 
> Could somebody test this on a machine w/o fpu?
> Any reason not to commit this?

That would be hard w/o the pach...

Martin

Index: trap.c
===================================================================
RCS file: /cvsroot/src/sys/arch/mac68k/mac68k/trap.c,v
retrieving revision 1.134
diff -c -u -p -r1.134 trap.c
--- trap.c      15 Oct 2008 06:51:18 -0000      1.134
+++ trap.c      16 Nov 2008 14:55:46 -0000
@@ -271,6 +271,22 @@ machine_userret(struct lwp *l, struct fr
        userret(l, f, t, 0, 0);
 }
 
+static u_int
+fpsr2siginfocode(u_int fpsr)
+{
+       if (fpsr & (1 << 10))
+               return FPE_FLTDIV;
+       if (fpsr & (1 << 11))
+               return FPE_FLTUND;
+       if (fpsr & (1 << 12))
+               return FPE_FLTOVF;
+       if (fpsr & (1 << 13))
+               return FPE_FLTINV;
+       if (fpsr & (1 << 9))
+               return FPE_FLTRES;
+       return 0;
+}
+
 /*
  * Trap is called from locore to handle most types of processor traps,
  * including events such as simulated software interrupts/AST's.
@@ -401,17 +417,11 @@ copyfault:
         */
        case T_FPERR|T_USER:
                /*
-                * We pass along the 68881 status register which locore
-                * stashed in code for us.  Note that there is a
-                * possibility that the bit pattern of this register
-                * will conflict with one of the FPE_* codes defined
-                * in signal.h.  Fortunately for us, the only such
-                * codes we use are all in the range 1-7 and the low
-                * 3 bits of the status register are defined as 0 so
-                * there is no clash.
+                * We decode the 68881 status register which locore
+                * stashed in code for us.
                 */
                ksi.ksi_signo = SIGFPE;
-               ksi.ksi_addr = (void *)code;
+               ksi.ksi_code = fpsr2siginfocode(code);
                break;
 
        /*