static bool mips_matching_cpu_name_p (const char *, const char *);
static const struct mips_cpu_info *mips_parse_cpu (const char *, const char *);
static const struct mips_cpu_info *mips_cpu_info_from_isa (int);
-static int mips_adjust_cost (rtx, rtx, rtx, int);
static bool mips_return_in_memory (tree, tree);
static bool mips_strict_argument_naming (CUMULATIVE_ARGS *);
+static void mips_macc_chains_record (rtx);
+static void mips_macc_chains_reorder (rtx *, int);
+static void mips_promote_ready (rtx *, int, int);
+static int mips_sched_reorder (FILE *, int, rtx *, int *, int);
+static int mips_variable_issue (FILE *, int, rtx, int);
+static int mips_adjust_cost (rtx, rtx, rtx, int);
static int mips_issue_rate (void);
static int mips_use_dfa_pipeline_interface (void);
static int mips_multipass_dfa_lookahead (void);
#undef TARGET_ASM_SELECT_RTX_SECTION
#define TARGET_ASM_SELECT_RTX_SECTION mips_select_rtx_section
+#undef TARGET_SCHED_REORDER
+#define TARGET_SCHED_REORDER mips_sched_reorder
+#undef TARGET_SCHED_VARIABLE_ISSUE
+#define TARGET_SCHED_VARIABLE_ISSUE mips_variable_issue
#undef TARGET_SCHED_ADJUST_COST
#define TARGET_SCHED_ADJUST_COST mips_adjust_cost
#undef TARGET_SCHED_ISSUE_RATE
return 0;
}
\f
-/* Adjust the cost of INSN based on the relationship between INSN that
- is dependent on DEP_INSN through the dependence LINK. The default
- is to make no adjustment to COST.
-
- On the MIPS, ignore the cost of anti- and output-dependencies. */
-static int
-mips_adjust_cost (rtx insn ATTRIBUTE_UNUSED, rtx link,
- rtx dep ATTRIBUTE_UNUSED, int cost)
-{
- if (REG_NOTE_KIND (link) != 0)
- return 0; /* Anti or output dependence. */
- return cost;
-}
-
/* Implement HARD_REGNO_NREGS. The size of FP registers are controlled
by UNITS_PER_FPREG. All other registers are word sized. */
return !TARGET_OLDABI;
}
\f
+/* Return true if INSN is a multiply-add or multiply-subtract
+ instruction and PREV assigns to the accumulator operand. */
+
+bool
+mips_linked_madd_p (rtx prev, rtx insn)
+{
+ rtx x;
+
+ x = single_set (insn);
+ if (x == 0)
+ return false;
+
+ x = SET_SRC (x);
+
+ if (GET_CODE (x) == PLUS
+ && GET_CODE (XEXP (x, 0)) == MULT
+ && reg_set_p (XEXP (x, 1), prev))
+ return true;
+
+ if (GET_CODE (x) == MINUS
+ && GET_CODE (XEXP (x, 1)) == MULT
+ && reg_set_p (XEXP (x, 0), prev))
+ return true;
+
+ return false;
+}
+\f
+/* Used by TUNE_MACC_CHAINS to record the last scheduled instruction
+ that may clobber hi or lo. */
+
+static rtx mips_macc_chains_last_hilo;
+
+/* A TUNE_MACC_CHAINS helper function. Record that instruction INSN has
+ been scheduled, updating mips_macc_chains_last_hilo appropriately. */
+
+static void
+mips_macc_chains_record (rtx insn)
+{
+ if (get_attr_may_clobber_hilo (insn))
+ mips_macc_chains_last_hilo = insn;
+}
+
+/* A TUNE_MACC_CHAINS helper function. Search ready queue READY, which
+ has NREADY elements, looking for a multiply-add or multiply-subtract
+ instruction that is cumulative with mips_macc_chains_last_hilo.
+ If there is one, promote it ahead of anything else that might
+ clobber hi or lo. */
+
+static void
+mips_macc_chains_reorder (rtx *ready, int nready)
+{
+ int i, j;
+
+ if (mips_macc_chains_last_hilo != 0)
+ for (i = nready - 1; i >= 0; i--)
+ if (mips_linked_madd_p (mips_macc_chains_last_hilo, ready[i]))
+ {
+ for (j = nready - 1; j > i; j--)
+ if (recog_memoized (ready[j]) >= 0
+ && get_attr_may_clobber_hilo (ready[j]))
+ {
+ mips_promote_ready (ready, i, j);
+ break;
+ }
+ break;
+ }
+}
+\f
+/* Remove the instruction at index LOWER from ready queue READY and
+ reinsert it in front of the instruction at index HIGHER. LOWER must
+ be <= HIGHER. */
+
+static void
+mips_promote_ready (rtx *ready, int lower, int higher)
+{
+ rtx new_head;
+ int i;
+
+ new_head = ready[lower];
+ for (i = lower; i < higher; i++)
+ ready[i] = ready[i + 1];
+ ready[i] = new_head;
+}
+
+/* Implement TARGET_SCHED_REORDER. */
+
+static int
+mips_sched_reorder (FILE *file ATTRIBUTE_UNUSED, int verbose ATTRIBUTE_UNUSED,
+ rtx *ready, int *nreadyp, int cycle)
+{
+ if (!reload_completed && TUNE_MACC_CHAINS)
+ {
+ if (cycle == 0)
+ mips_macc_chains_last_hilo = 0;
+ if (*nreadyp > 0)
+ mips_macc_chains_reorder (ready, *nreadyp);
+ }
+ return mips_issue_rate ();
+}
+
+/* Implement TARGET_SCHED_VARIABLE_ISSUE. */
+
+static int
+mips_variable_issue (FILE *file ATTRIBUTE_UNUSED, int verbose ATTRIBUTE_UNUSED,
+ rtx insn, int more)
+{
+ switch (GET_CODE (PATTERN (insn)))
+ {
+ case USE:
+ case CLOBBER:
+ /* Don't count USEs and CLOBBERs against the issue rate. */
+ break;
+
+ default:
+ more--;
+ if (!reload_completed && TUNE_MACC_CHAINS)
+ mips_macc_chains_record (insn);
+ break;
+ }
+ return more;
+}
+\f
+/* Implement TARGET_SCHED_ADJUST_COST. We assume that anti and output
+ dependencies have no cost. */
+
+static int
+mips_adjust_cost (rtx insn ATTRIBUTE_UNUSED, rtx link,
+ rtx dep ATTRIBUTE_UNUSED, int cost)
+{
+ if (REG_NOTE_KIND (link) != 0)
+ return 0;
+ return cost;
+}
+
/* Return the number of instructions that can be issued per cycle. */
static int
#define TUNE_MIPS9000 (mips_tune == PROCESSOR_R9000)
#define TUNE_SB1 (mips_tune == PROCESSOR_SB1)
+/* True if the pre-reload scheduler should try to create chains of
+ multiply-add or multiply-subtract instructions. For example,
+ suppose we have:
+
+ t1 = a * b
+ t2 = t1 + c * d
+ t3 = c * d
+ t4 = t3 - c * d
+
+ t1 will have a higher priority and t2 and t3 will have a higher
+ priority than t4. However, before reload, there is no dependence
+ between t1 and t3, and they can often have similar priorities.
+ The scheduler will then tend to prefer:
+
+ t1 = a * b
+ t3 = e * f
+ t2 = t1 + c * d
+ t4 = t3 - g * h
+
+ which stops us from making full use of macc/madd-style instructions.
+ This sort of situation occurs frequently in Fourier transforms and
+ in unrolled loops.
+
+ To counter this, the TUNE_MACC_CHAINS code will reorder the ready
+ queue so that chained multiply-add and multiply-subtract instructions
+ appear ahead of any other instruction that is likely to clobber lo.
+ In the example above, if t2 and t3 become ready at the same time,
+ the code ensures that t2 is scheduled first.
+
+ Multiply-accumulate instructions are a bigger win for some targets
+ than others, so this macro is defined on an opt-in basis. */
+#define TUNE_MACC_CHAINS TUNE_MIPS5500
+
#define TARGET_OLDABI (mips_abi == ABI_32 || mips_abi == ABI_O64)
#define TARGET_NEWABI (mips_abi == ABI_N32 || mips_abi == ABI_64)
projects / gcc.git / commitdiff