[PATCH 2/4] sparc: Skip all empty assembly statements

[Daniel Cederman]

This version detects multiple empty assembly statements in a row and also
detects non-memory barrier empty assembly statements (__asm__("")). It
can be used instead of next_active_insn().

gcc/ChangeLog:

        * config/sparc/sparc.c (next_active_non_empty_insn): New function
        that returns next active non empty assembly instruction.
        (sparc_do_work_around_errata): Use new function.
---
 gcc/config/sparc/sparc.c | 37 +++++++++++++++++++++++--------------
 1 file changed, 23 insertions(+), 14 deletions(-)

diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index fa78e0dc739..b087c5b3fc8 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -1082,6 +1082,26 @@ load_insn_p (rtx_insn *insn)
    && GET_CODE (PATTERN (INSN)) != USE                                 \
    && GET_CODE (PATTERN (INSN)) != CLOBBER)
 
+rtx_insn *
+next_active_non_empty_insn (rtx_insn *insn)
+{
+  insn = next_active_insn (insn);
+
+  while (insn
+        && ((GET_CODE (PATTERN (insn)) == UNSPEC_VOLATILE)
+            || (GET_CODE (PATTERN (insn)) == ASM_INPUT)
+            || (USEFUL_INSN_P (insn)
+                && (asm_noperands (PATTERN (insn))>=0)
+                && !strcmp (decode_asm_operands (PATTERN (insn),
+                                                 NULL, NULL, NULL,
+                                                 NULL, NULL), ""))))
+    {
+      insn = next_active_insn (insn);
+    }
+
+  return insn;
+}
+
 static unsigned int
 sparc_do_work_around_errata (void)
 {
@@ -1139,7 +1159,7 @@ sparc_do_work_around_errata (void)
                emit_insn_before (gen_nop (), target);
            }
 
-         next = next_active_insn (insn);
+         next = next_active_non_empty_insn (insn);
          if (!next)
            break;
 
@@ -1242,23 +1262,12 @@ sparc_do_work_around_errata (void)
          rtx_insn *after;
          int i;
 
-         next = next_active_insn (insn);
+         next = next_active_non_empty_insn (insn);
          if (!next)
            break;
 
          for (after = next, i = 0; i < 2; i++)
            {
-             /* Skip empty assembly statements.  */
-             if ((GET_CODE (PATTERN (after)) == UNSPEC_VOLATILE)
-                 || (USEFUL_INSN_P (after)
-                     && (asm_noperands (PATTERN (after))>=0)
-                     && !strcmp (decode_asm_operands (PATTERN (after),
-                                                      NULL, NULL, NULL,
-                                                      NULL, NULL), "")))
-               after = next_active_insn (after);
-             if (!after)
-               break;
-
              /* If the insn is a branch, then it cannot be problematic.  */
              if (!NONJUMP_INSN_P (after)
                  || GET_CODE (PATTERN (after)) == SEQUENCE)
@@ -1283,7 +1292,7 @@ sparc_do_work_around_errata (void)
                      && (MEM_P (SET_DEST (set)) || mem_ref (SET_SRC (set))))
                    break;
 
-                 after = next_active_insn (after);
+                 after = next_active_non_empty_insn (after);
                  if (!after)
                    break;
                }
-- 
2.25.1