IA-32 compatibility patch: FP denormal handling

The following patch makes ia64 compatible with i386 with respect to siginfo.si_code on FP denormal operands. This is necessary for the correct emulation of many IA-32 apps.

Please apply to both 2.4 and 2.5.

-Arun

@@ -325,6 +325,10 @@
 			siginfo.si_addr = (void *) (regs->cr_iip + ia64_psr(regs)->ri);
 			if (isr & 0x11) {
 				siginfo.si_code = FPE_FLTINV;
+			} else if (isr & 0x22) {
+				/* denormal operand gets the same si_code as underflow 
+				* see arch/i386/kernel/traps.c:math_error()  */
+				siginfo.si_code = FPE_FLTUND;
 			} else if (isr & 0x44) {
 				siginfo.si_code = FPE_FLTDIV;
 			}

Arun> The following patch makes ia64 compatible with i386 with Arun> respect to siginfo.si_code on FP denormal operands. This is Arun> necessary for the correct emulation of many IA-32 apps.

Arun> Please apply to both 2.4 and 2.5.

Looks good to me. I applied it (apologies for the garbled bk changelog entry...).

	--david

Applied for 2.4, thanks!