1 files changed, 112 insertions, 24 deletions

diff --git a/gcc/toplev.c b/gcc/toplev.c
index d108096..cf7bab6 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1197,29 +1197,120 @@ target_supports_section_anchors_p (void)
   return true;
 }
 
-/* Default the align_* variables to 1 if they're still unset, and
-   set up the align_*_log variables.  */
+/* Parse "N[:M][:...]" into struct align_flags A.
+   VALUES contains parsed values (in reverse order), all processed
+   values are popped.  */
+
 static void
-init_alignments (void)
+read_log_maxskip (auto_vec<unsigned> &values, align_flags_tuple *a)
 {
-  if (align_loops <= 0)
-    align_loops = 1;
-  if (align_loops_max_skip > align_loops)
-    align_loops_max_skip = align_loops - 1;
-  align_loops_log = floor_log2 (align_loops * 2 - 1);
-  if (align_jumps <= 0)
-    align_jumps = 1;
-  if (align_jumps_max_skip > align_jumps)
-    align_jumps_max_skip = align_jumps - 1;
-  align_jumps_log = floor_log2 (align_jumps * 2 - 1);
-  if (align_labels <= 0)
-    align_labels = 1;
-  align_labels_log = floor_log2 (align_labels * 2 - 1);
-  if (align_labels_max_skip > align_labels)
-    align_labels_max_skip = align_labels - 1;
-  if (align_functions <= 0)
-    align_functions = 1;
-  align_functions_log = floor_log2 (align_functions * 2 - 1);
+  unsigned n = values.pop ();
+  if (n != 0)
+    a->log = floor_log2 (n * 2 - 1);
+  if (values.is_empty ())
+    a->maxskip = n ? n - 1 : 0;
+  else
+    {
+      unsigned m = values.pop ();
+      if (m > n)
+	m = n;
+      /* -falign-foo=N:M means M-1 max bytes of padding, not M.  */
+      if (m > 0)
+	m--;
+      a->maxskip = m;
+    }
+}
+
+/* Parse "N[:M[:N2[:M2]]]" string FLAG into a pair of struct align_flags.  */
+
+static void
+parse_N_M (const char *flag, align_flags &a, unsigned int min_align_log)
+{
+  if (flag)
+    {
+      static hash_map <nofree_string_hash, align_flags> cache;
+      align_flags *entry = cache.get (flag);
+      if (entry)
+	{
+	  a = *entry;
+	  return;
+	}
+
+      auto_vec<unsigned> result_values;
+      bool r = parse_and_check_align_values (flag, NULL, result_values, false,
+					     UNKNOWN_LOCATION);
+      if (!r)
+	return;
+
+      /* Reverse values for easier manipulation.  */
+      result_values.reverse ();
+
+      read_log_maxskip (result_values, &a.levels[0]);
+      if (!result_values.is_empty ())
+	read_log_maxskip (result_values, &a.levels[1]);
+#ifdef SUBALIGN_LOG
+      else
+	{
+	  /* N2[:M2] is not specified.  This arch has a default for N2.
+	     Before -falign-foo=N:M:N2:M2 was introduced, x86 had a tweak.
+	     -falign-functions=N with N > 8 was adding secondary alignment.
+	     -falign-functions=10 was emitting this before every function:
+			.p2align 4,,9
+			.p2align 3
+	     Now this behavior (and more) can be explicitly requested:
+	     -falign-functions=16:10:8
+	     Retain old behavior if N2 is missing: */
+
+	  int align = 1 << a.levels[0].log;
+	  int subalign = 1 << SUBALIGN_LOG;
+
+	  if (a.levels[0].log > SUBALIGN_LOG
+	      && a.levels[0].maxskip >= subalign - 1)
+	    {
+	      /* Set N2 unless subalign can never have any effect.  */
+	      if (align > a.levels[0].maxskip + 1)
+		a.levels[1].log = SUBALIGN_LOG;
+	    }
+	}
+#endif
+
+      /* Cache seen value.  */
+      cache.put (flag, a);
+    }
+  else
+    {
+      /* Reset values to zero.  */
+      for (unsigned i = 0; i < 2; i++)
+	{
+	  a.levels[i].log = 0;
+	  a.levels[i].maxskip = 0;
+	}
+    }
+
+  if ((unsigned int)a.levels[0].log < min_align_log)
+    {
+      a.levels[0].log = min_align_log;
+      a.levels[0].maxskip = (1 << min_align_log) - 1;
+    }
+}
+
+/* Minimum alignment requirements, if arch has them.  */
+
+unsigned int min_align_loops_log = 0;
+unsigned int min_align_jumps_log = 0;
+unsigned int min_align_labels_log = 0;
+unsigned int min_align_functions_log = 0;
+
+/* Process -falign-foo=N[:M[:N2[:M2]]] options.  */
+
+void
+parse_alignment_opts (void)
+{
+  parse_N_M (str_align_loops, state_align_loops, min_align_loops_log);
+  parse_N_M (str_align_jumps, state_align_jumps, min_align_jumps_log);
+  parse_N_M (str_align_labels, state_align_labels, min_align_labels_log);
+  parse_N_M (str_align_functions, state_align_functions,
+	     min_align_functions_log);
 }
 
 /* Process the options that have been parsed.  */
@@ -1722,9 +1813,6 @@ process_options (void)
 static void
 backend_init_target (void)
 {
-  /* Initialize alignment variables.  */
-  init_alignments ();
-
   /* This depends on stack_pointer_rtx.  */
   init_fake_stack_mems ();