Andreas Jaeger wrote:
>
> > saves/restores the FP registers in setjmp/longjmp, the
>
> Any ideas how this can be done?
>
> > model of "simply sending SIGILL/SIGFPE" will result
> > in *all* processes being terminated with extreme prejudice,
> > starting with init!
>
There is a patch for glibc2.0.7, which I think was done by Jay Carlson. It
basically works for glibc2.0.6 as well. See the one for glibc2.0.6 attached
below.
I think the patch is not "clean", in the sense that you only want to apply it
if you want to configure with "--without-fp". Otherwise the patch will break
other configurations.
Jun
--- glibc-2.0.6/sysdeps/mips/__longjmp.c.orig-rpm Sat Sep 11 00:01:44 1999
+++ glibc-2.0.6/sysdeps/mips/__longjmp.c Sat Sep 11 00:02:36 1999
@@ -35,6 +35,7 @@
along the way. */
register int val asm ("a1");
+#ifdef __HAVE_FPU__
/* Pull back the floating point callee-saved registers. */
asm volatile ("l.d $f20, %0" : : "m" (env[0].__fpregs[0]));
asm volatile ("l.d $f22, %0" : : "m" (env[0].__fpregs[1]));
@@ -42,13 +43,16 @@
asm volatile ("l.d $f26, %0" : : "m" (env[0].__fpregs[3]));
asm volatile ("l.d $f28, %0" : : "m" (env[0].__fpregs[4]));
asm volatile ("l.d $f30, %0" : : "m" (env[0].__fpregs[5]));
+#endif
/* Restore the stack pointer. */
asm volatile ("lw $29, %0" : : "m" (env[0].__sp));
+#ifdef __HAVE_FPU__
/* Get and reconstruct the floating point csr. */
asm volatile ("lw $2, %0" : : "m" (env[0].__fpc_csr));
asm volatile ("ctc1 $2, $31");
+#endif
/* Get the FP. */
asm volatile ("lw $30, %0" : : "m" (env[0].__fp));
--- glibc-2.0.6/sysdeps/mips/setjmp_aux.c.orig-rpm Sat Sep 11 00:04:00 1999
+++ glibc-2.0.6/sysdeps/mips/setjmp_aux.c Sat Sep 11 00:04:24 1999
@@ -26,6 +26,7 @@
int
__sigsetjmp_aux (jmp_buf env, int savemask, int sp, int fp)
{
+#ifdef __HAVE_FPU__
/* Store the floating point callee-saved registers... */
asm volatile ("s.d $f20, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[0]));
asm volatile ("s.d $f22, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[1]));
@@ -33,6 +34,7 @@
asm volatile ("s.d $f26, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[3]));
asm volatile ("s.d $f28, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[4]));
asm volatile ("s.d $f30, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[5]));
+#endif
/* .. and the PC; */
asm volatile ("sw $31, %0" : : "m" (env[0].__jmpbuf[0].__pc));
@@ -56,8 +58,10 @@
asm volatile ("sw $22, %0" : : "m" (env[0].__jmpbuf[0].__regs[6]));
asm volatile ("sw $23, %0" : : "m" (env[0].__jmpbuf[0].__regs[7]));
+#ifdef __HAVE_FPU__
/* .. and finally get and reconstruct the floating point csr. */
asm ("cfc1 %0, $31" : "=r" (env[0].__jmpbuf[0].__fpc_csr));
+#endif
/* Save the signal mask if requested. */
return __sigjmp_save (env, savemask);
--- glibc-2.0.6/sysdeps/mips/fpu_control.h.orig-rpm Sat Sep 11 00:18:51 1999
+++ glibc-2.0.6/sysdeps/mips/fpu_control.h Sat Sep 11 00:10:44 1999
@@ -83,8 +83,13 @@
typedef unsigned int fpu_control_t __attribute__ ((__mode__ (__HI__)));
/* Macros for accessing the hardware control word. */
+#ifdef __HAVE_FPU__
#define _FPU_GETCW(cw) __asm__ ("cfc1 %0,$31" : "=r" (cw) : )
#define _FPU_SETCW(cw) __asm__ ("ctc1 %0,$31" : : "r" (cw))
+#else
+#define _FPU_GETCW(cw) (_FPU_DEFAULT)
+#define _FPU_SETCW(cw)
+#endif
/* Default control word set at startup. */
extern fpu_control_t __fpu_control;
