+2004-04-29 Chris Demetriou <cgd@broadcom.com>
+ Richard Sandiford <rsandifo@redhat.com>
+
+ * sim-main.h (MIPS_MACH_HAS_MT_HILO_HAZARD)
+ (MIPS_MACH_HAS_MULT_HILO_HAZARD, MIPS_MACH_HAS_DIV_HILO_HAZARD): New.
+ * mips.igen (check_mt_hilo, check_mult_hilo, check_div_hilo): Provide
+ separate implementations for mipsIV and mipsV. Use new macros to
+ determine whether the restrictions apply.
+
2004-01-19 Chris Demetriou <cgd@broadcom.com>
* mips.igen (check_mf_cycles, check_mt_hilo, check_mf_hilo)
// On the r3900, restriction (2) is not present, and restriction (3) is not
// present for multiplication.
//
-// For now this code is paranoid. Historically the simulator
-// enforced restrictions (2) and (3) for more ISAs and CPU types than
-// necessary. Unfortunately, at least some MIPS IV and later parts'
-// documentation describes them as having these hazards (e.g. vr5000),
-// so they can't be removed for at leats MIPS IV. MIPS V hasn't been
-// checked (since there are no known hardware implementations).
-//
+// Unfortunately, there seems to be some confusion about whether the last
+// two restrictions should apply to "MIPS IV" as well. One edition of
+// the MIPS IV ISA says they do, but references in later ISA documents
+// suggest they don't.
+//
+// In reality, some MIPS IV parts, such as the VR5000 and VR5400, do have
+// these restrictions, while others, like the VR5500, don't. To accomodate
+// such differences, the MIPS IV and MIPS V version of these helper functions
+// use auxillary routines to determine whether the restriction applies.
// check_mf_cycles:
//
*mipsI:
*mipsII:
*mipsIII:
-*mipsIV:
-*mipsV:
*vr4100:
*vr5000:
{
}
:function:::int:check_mt_hilo:hilo_history *history
+*mipsIV:
+*mipsV:
+{
+ signed64 time = sim_events_time (SD);
+ int ok = (! MIPS_MACH_HAS_MT_HILO_HAZARD (SD)
+ || check_mf_cycles (SD_, history, time, "MT"));
+ history->mt.timestamp = time;
+ history->mt.cia = CIA;
+ return ok;
+}
+
+:function:::int:check_mt_hilo:hilo_history *history
*mips32:
*mips64:
*r3900:
*mipsI:
*mipsII:
*mipsIII:
-*mipsIV:
-*mipsV:
*vr4100:
*vr5000:
{
}
:function:::int:check_mult_hilo:hilo_history *hi, hilo_history *lo
+*mipsIV:
+*mipsV:
+{
+ signed64 time = sim_events_time (SD);
+ int ok = (! MIPS_MACH_HAS_MULT_HILO_HAZARD (SD)
+ || (check_mf_cycles (SD_, hi, time, "OP")
+ && check_mf_cycles (SD_, lo, time, "OP")));
+ hi->op.timestamp = time;
+ lo->op.timestamp = time;
+ hi->op.cia = CIA;
+ lo->op.cia = CIA;
+ return ok;
+}
+
+:function:::int:check_mult_hilo:hilo_history *hi, hilo_history *lo
*mips32:
*mips64:
*r3900:
*mipsI:
*mipsII:
*mipsIII:
-*mipsIV:
-*mipsV:
*vr4100:
*vr5000:
*r3900:
}
:function:::int:check_div_hilo:hilo_history *hi, hilo_history *lo
+*mipsIV:
+*mipsV:
+{
+ signed64 time = sim_events_time (SD);
+ int ok = (! MIPS_MACH_HAS_DIV_HILO_HAZARD (SD)
+ || (check_mf_cycles (SD_, hi, time, "OP")
+ && check_mf_cycles (SD_, lo, time, "OP")));
+ hi->op.timestamp = time;
+ lo->op.timestamp = time;
+ hi->op.cia = CIA;
+ lo->op.cia = CIA;
+ return ok;
+}
+
+:function:::int:check_div_hilo:hilo_history *hi, hilo_history *lo
*mips32:
*mips64:
{
#define MIPS_MACH(SD) MIPS_MACH_DEFAULT
#endif
+/* Macros for determining whether a MIPS IV or MIPS V part is subject
+ to the hi/lo restrictions described in mips.igen. */
+
+#define MIPS_MACH_HAS_MT_HILO_HAZARD(SD) \
+ (MIPS_MACH (SD) != bfd_mach_mips5500)
+
+#define MIPS_MACH_HAS_MULT_HILO_HAZARD(SD) \
+ (MIPS_MACH (SD) != bfd_mach_mips5500)
+
+#define MIPS_MACH_HAS_DIV_HILO_HAZARD(SD) \
+ (MIPS_MACH (SD) != bfd_mach_mips5500)
+
#if H_REVEALS_MODULE_P (SIM_MAIN_INLINE)
#include "sim-main.c"
#endif