A better fix for handling different FPU initial control words for different

ABIs:
- Store the FPU initial control word in the pcb for each thread.
- When first using the FPU, load the initial control word after restoring
  the clean state if it is not the standard control word.
- Provide a correct control word for Linux/i386 binaries under
  FreeBSD/amd64.
- Adjust the control word returned for fpugetregs()/npxgetregs() when a
  thread hasn't used the FPU yet to reflect the real initial control
  word for the current ABI.
- The Linux/i386 ABI for FreeBSD/i386 now properly sets the right control
  word instead of trashing whatever the current state of the FPU is.

Reviewed by:	bde

1 files changed, 5 insertions, 0 deletions

diff --git a/sys/compat/linux/linux_misc.h b/sys/compat/linux/linux_misc.h
index 37991f3..eddcd2c 100644
--- a/sys/compat/linux/linux_misc.h
+++ b/sys/compat/linux/linux_misc.h
@@ -60,4 +60,9 @@ extern const char *linux_platform;
 					 */
 #define	LINUX_AT_EXECFN		31	/* filename of program */
 
+/* Linux sets the i387 to extended precision. */
+#if defined(__i386__) || defined(__amd64__)
+#define	__LINUX_NPXCW__		0x37f
+#endif
+
 #endif	/* _LINUX_MISC_H_ */