[arm][aarch64] Handle no_insn in TARGET_SCHED_VARIABLE_ISSUE

Since no_insn patterns expand to no instructions, they shouldn't
count against the issue rate, just like USEs and CLOBBERs don't.

2019-09-17  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64.c (aarch64_sched_variable_issue): New
	function.
	(TARGET_SCHED_VARIABLE_ISSUE): New macro.
	* config/arm/arm.c (arm_sched_variable_issue): New function.
	(TARGET_SCHED_VARIABLE_ISSUE): New macro.

From-SVN: r275808

gcc/ChangeLog

 2019-09-17  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* config/aarch64/aarch64.c (aarch64_sched_variable_issue): New
+	function.
+	(TARGET_SCHED_VARIABLE_ISSUE): New macro.
+	* config/arm/arm.c (arm_sched_variable_issue): New function.
+	(TARGET_SCHED_VARIABLE_ISSUE): New macro.
+
+2019-09-17  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* config/arm/types.md (no_reservation): New reservation.
 	* config/aarch64/falkor.md (falkor_other_0_nothing): Don't handle
 	no_insn here.

gcc/config/aarch64/aarch64.c

@@ -11804,6 +11804,23 @@ aarch64_sched_issue_rate (void)
   return aarch64_tune_params.issue_rate;
 }
 
+/* Implement TARGET_SCHED_VARIABLE_ISSUE.  */
+static int
+aarch64_sched_variable_issue (FILE *, int, rtx_insn *insn, int more)
+{
+  if (DEBUG_INSN_P (insn))
+    return more;
+
+  rtx_code code = GET_CODE (PATTERN (insn));
+  if (code == USE || code == CLOBBER)
+    return more;
+
+  if (get_attr_type (insn) == TYPE_NO_INSN)
+    return more;
+
+  return more - 1;
+}
+
 static int
 aarch64_sched_first_cycle_multipass_dfa_lookahead (void)
 {
@@ -20584,6 +20601,9 @@ aarch64_libgcc_floating_mode_supported_p
 #undef TARGET_SCHED_ISSUE_RATE
 #define TARGET_SCHED_ISSUE_RATE aarch64_sched_issue_rate
 
+#undef TARGET_SCHED_VARIABLE_ISSUE
+#define TARGET_SCHED_VARIABLE_ISSUE aarch64_sched_variable_issue
+
 #undef TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD
 #define TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD \
   aarch64_sched_first_cycle_multipass_dfa_lookahead

gcc/config/arm/arm.c

@@ -257,6 +257,7 @@ static bool arm_sched_can_speculate_insn (rtx_insn *);
 static bool arm_macro_fusion_p (void);
 static bool arm_cannot_copy_insn_p (rtx_insn *);
 static int arm_issue_rate (void);
+static int arm_sched_variable_issue (FILE *, int, rtx_insn *, int);
 static int arm_first_cycle_multipass_dfa_lookahead (void);
 static int arm_first_cycle_multipass_dfa_lookahead_guard (rtx_insn *, int);
 static void arm_output_dwarf_dtprel (FILE *, int, rtx) ATTRIBUTE_UNUSED;
@@ -665,6 +666,9 @@ static const struct attribute_spec arm_attribute_table[] =
 #undef TARGET_SCHED_ISSUE_RATE
 #define TARGET_SCHED_ISSUE_RATE arm_issue_rate
 
+#undef TARGET_SCHED_VARIABLE_ISSUE
+#define TARGET_SCHED_VARIABLE_ISSUE arm_sched_variable_issue
+
 #undef TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD
 #define TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD \
   arm_first_cycle_multipass_dfa_lookahead
@@ -28495,6 +28499,23 @@ arm_issue_rate (void)
   return current_tune->issue_rate;
 }
 
+/* Implement TARGET_SCHED_VARIABLE_ISSUE.  */
+static int
+arm_sched_variable_issue (FILE *, int, rtx_insn *insn, int more)
+{
+  if (DEBUG_INSN_P (insn))
+    return more;
+
+  rtx_code code = GET_CODE (PATTERN (insn));
+  if (code == USE || code == CLOBBER)
+    return more;
+
+  if (get_attr_type (insn) == TYPE_NO_INSN)
+    return more;
+
+  return more - 1;
+}
+
 /* Return how many instructions should scheduler lookahead to choose the
    best one.  */
 static int