gas: xtensa: fix literal movement

Not all literals need to be moved in the presence of
--text-section-literals or --auto-litpools, but only those created by
.literal pseudo op or generated as a result of relaxation. Attempts to
move other literals may result in abnormal termination of the assembler
due to the following assertion failure:

  Internal error in xg_find_litpool at gas/config/tc-xtensa.c:11209.

The same assertion may also be triggered by attempting to assign literal
pools to literals in .init and .fini sections; don't try to do that.

gas/
2018-05-09  Max Filippov  <jcmvbkbc@gmail.com>

	* config/tc-xtensa.c (xtensa_is_init_fini): New function.
	(xtensa_move_literals): Only attempt to assign literal pool to
	literals with tc_frag_data.is_literal mark and not in .init or
	.fini sections.
	Join nested 'if' conditions to simplify function structure.
	(xtensa_switch_to_non_abs_literal_fragment): Use
	xtensa_is_init_fini to test for .init/.fini sections.
	* testsuite/gas/xtensa/all.exp (auto-litpools-3)
	(auto-litpools-4, text-section-literals-1): New tests.
	* testsuite/gas/xtensa/auto-litpools-3.d: New test results.
	* testsuite/gas/xtensa/auto-litpools-3.s: New test source.
	* testsuite/gas/xtensa/auto-litpools-4.d: New test results.
	* testsuite/gas/xtensa/auto-litpools-4.s: New test source.
	* testsuite/gas/xtensa/text-section-literals-1.d: New test results.
	* testsuite/gas/xtensa/text-section-literals-1.s: New test source.

diff --git a/gas/ChangeLog b/gas/ChangeLog
index b44c9e34ddeb4000fedf86e57450e65acc891ad2..424babacd68d21cd28f00cfeca18e976adbca608 100644 (file)
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,21 @@
+2018-05-09  Max Filippov  <jcmvbkbc@gmail.com>
+
+       * config/tc-xtensa.c (xtensa_is_init_fini): New function.
+       (xtensa_move_literals): Only attempt to assign literal pool to
+       literals with tc_frag_data.is_literal mark and not in .init or
+       .fini sections.
+       Join nested 'if' conditions to simplify function structure.
+       (xtensa_switch_to_non_abs_literal_fragment): Use
+       xtensa_is_init_fini to test for .init/.fini sections.
+       * testsuite/gas/xtensa/all.exp (auto-litpools-3)
+       (auto-litpools-4, text-section-literals-1): New tests.
+       * testsuite/gas/xtensa/auto-litpools-3.d: New test results.
+       * testsuite/gas/xtensa/auto-litpools-3.s: New test source.
+       * testsuite/gas/xtensa/auto-litpools-4.d: New test results.
+       * testsuite/gas/xtensa/auto-litpools-4.s: New test source.
+       * testsuite/gas/xtensa/text-section-literals-1.d: New test results.
+       * testsuite/gas/xtensa/text-section-literals-1.s: New test source.
+
 2018-05-09  Dimitar Dimitrov  <dimitar@dinux.eu>
 
        * config/tc-pru.c (md_apply_fix): Make LDI32 relocation conformant

diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
index 4db7ef57e8f13660d23b108af4b016ebb16be9a3..84211dd3e7360040f0dff72beb87bf46139215bb 100644 (file)
--- a/gas/config/tc-xtensa.c
+++ b/gas/config/tc-xtensa.c
@@ -11260,6 +11260,14 @@ static struct litpool_frag *xg_find_litpool (struct litpool_seg *lps,
   return lp;
 }
 
+static bfd_boolean xtensa_is_init_fini (segT seg)
+{
+  if (!seg)
+    return 0;
+  return strcmp (segment_name (seg), INIT_SECTION_NAME) == 0
+    || strcmp (segment_name (seg), FINI_SECTION_NAME) == 0;
+}
+
 static void
 xtensa_move_literals (void)
 {
@@ -11291,6 +11299,9 @@ xtensa_move_literals (void)
       struct litpool_frag *lpf = lps->frag_list.next;
       addressT addr = 0;
 
+      if (xtensa_is_init_fini (lps->seg))
+       continue;
+
       for ( ; frchP; frchP = frchP->frch_next)
        {
          fragS *fragP;
@@ -11311,22 +11322,23 @@ xtensa_move_literals (void)
                  int slot;
                  for (slot = 0; slot < MAX_SLOTS; slot++)
                    {
-                     if (fragP->tc_frag_data.literal_frags[slot])
+                     fragS *litfrag = fragP->tc_frag_data.literal_frags[slot];
+
+                     if (litfrag
+                         && litfrag->tc_frag_data.is_literal
+                         && !litfrag->tc_frag_data.literal_frag)
                        {
-                         /* L32R; point its literal to the nearest litpool
-                            preferring non-"candidate" positions to avoid
-                            the jump-around.  */
-                         fragS *litfrag = fragP->tc_frag_data.literal_frags[slot];
-
-                         if (!litfrag->tc_frag_data.literal_frag)
-                           {
-                             struct litpool_frag *lp;
-
-                             lp = xg_find_litpool (lps, lpf, addr);
-                             /* Take earliest use of this literal to avoid
-                                forward refs.  */
-                             litfrag->tc_frag_data.literal_frag = lp->fragP;
-                           }
+                         /* L32R referring .literal or generated as a result
+                            of relaxation.  Point its literal to the nearest
+                            litpool preferring non-"candidate" positions to
+                            avoid the jump-around.  */
+
+                         struct litpool_frag *lp;
+
+                         lp = xg_find_litpool (lps, lpf, addr);
+                         /* Take earliest use of this literal to avoid
+                            forward refs.  */
+                         litfrag->tc_frag_data.literal_frag = lp->fragP;
                        }
                    }
                }
@@ -11594,14 +11606,11 @@ xtensa_switch_to_non_abs_literal_fragment (emit_state *result)
 {
   fragS *pool_location = get_literal_pool_location (now_seg);
   segT lit_seg;
-  bfd_boolean is_init =
-    (now_seg && !strcmp (segment_name (now_seg), INIT_SECTION_NAME));
-  bfd_boolean is_fini =
-    (now_seg && !strcmp (segment_name (now_seg), FINI_SECTION_NAME));
+  bfd_boolean is_init_fini = xtensa_is_init_fini (now_seg);
 
   if (pool_location == NULL
       && !use_literal_section
-      && !is_init && ! is_fini)
+      && !is_init_fini)
     {
       if (!auto_litpools)
        {
@@ -11615,7 +11624,7 @@ xtensa_switch_to_non_abs_literal_fragment (emit_state *result)
   xtensa_switch_section_emit_state (result, lit_seg, 0);
 
   if (!use_literal_section
-      && !is_init && !is_fini
+      && !is_init_fini
       && get_literal_pool_location (now_seg) != pool_location)
     {
       /* Close whatever frag is there.  */

diff --git a/gas/testsuite/gas/xtensa/all.exp b/gas/testsuite/gas/xtensa/all.exp
index 650a93223d46851eb906b5158acc49e270e16b94..beb6f35aad5bef42ddee37131d2fe44bc982935b 100644 (file)
--- a/gas/testsuite/gas/xtensa/all.exp
+++ b/gas/testsuite/gas/xtensa/all.exp
@@ -103,10 +103,13 @@ if [istarget xtensa*-*-*] then {
     run_dump_test "first_frag_align"
     run_dump_test "auto-litpools"
     run_dump_test "auto-litpools-2"
+    run_dump_test "auto-litpools-3"
+    run_dump_test "auto-litpools-4"
     run_dump_test "auto-litpools-first1"
     run_dump_test "auto-litpools-first2"
     run_dump_test "loc"
     run_dump_test "init-fini-literals"
+    run_dump_test "text-section-literals-1"
 }
 
 if [info exists errorInfo] then {

diff --git a/gas/testsuite/gas/xtensa/auto-litpools-3.d b/gas/testsuite/gas/xtensa/auto-litpools-3.d
new file mode 100644 (file)
index 0000000..ee9e901
--- /dev/null
+++ b/gas/testsuite/gas/xtensa/auto-litpools-3.d
@@ -0,0 +1,11 @@
+#as: --auto-litpools
+#objdump: -dr
+#name: auto-litpools-3 (don't move arbitrary data referenced by l32r)
+
+.*: +file format .*xtensa.*
+#...
+Disassembly of section .text:
+#...
+ *0:.*l32r.*
+.*0:.*\.data
+#...

diff --git a/gas/testsuite/gas/xtensa/auto-litpools-3.s b/gas/testsuite/gas/xtensa/auto-litpools-3.s
new file mode 100644 (file)
index 0000000..cd0fb5d
--- /dev/null
+++ b/gas/testsuite/gas/xtensa/auto-litpools-3.s
@@ -0,0 +1,6 @@
+       .data
+a:
+       .word   0x12345678
+
+       .text
+       l32r    a2, a

diff --git a/gas/testsuite/gas/xtensa/auto-litpools-4.d b/gas/testsuite/gas/xtensa/auto-litpools-4.d
new file mode 100644 (file)
index 0000000..ba58c3e
--- /dev/null
+++ b/gas/testsuite/gas/xtensa/auto-litpools-4.d
@@ -0,0 +1,18 @@
+#as: --auto-litpools
+#objdump: -d
+#name: auto-litpools-4 (handle auto literal pools in .init and .fini)
+
+.*: +file format .*xtensa.*
+#...
+Disassembly of section .init.literal:
+#...
+Disassembly of section .fini.literal:
+#...
+Disassembly of section .init:
+#...
+ *0:.*l32r.*
+#...
+Disassembly of section .fini:
+#...
+ *0:.*l32r.*
+#...

diff --git a/gas/testsuite/gas/xtensa/auto-litpools-4.s b/gas/testsuite/gas/xtensa/auto-litpools-4.s
new file mode 100644 (file)
index 0000000..d46c04d
--- /dev/null
+++ b/gas/testsuite/gas/xtensa/auto-litpools-4.s
@@ -0,0 +1,6 @@
+       .section .init
+       .literal a, 0x12345678
+       movi    a2, 0x12345679
+       .section .fini
+       .literal b, 0x1234567a
+       movi    a2, 0x1234567b

diff --git a/gas/testsuite/gas/xtensa/text-section-literals-1.d b/gas/testsuite/gas/xtensa/text-section-literals-1.d
new file mode 100644 (file)
index 0000000..2c481f8
--- /dev/null
+++ b/gas/testsuite/gas/xtensa/text-section-literals-1.d
@@ -0,0 +1,18 @@
+#as: --text-section-literals
+#objdump: -d
+#name: text-section-literals (handle text section literal in .init and .fini without .literal_position)
+
+.*: +file format .*xtensa.*
+#...
+Disassembly of section .init.literal:
+#...
+Disassembly of section .fini.literal:
+#...
+Disassembly of section .init:
+#...
+ *0:.*l32r.*
+#...
+Disassembly of section .fini:
+#...
+ *0:.*l32r.*
+#...

diff --git a/gas/testsuite/gas/xtensa/text-section-literals-1.s b/gas/testsuite/gas/xtensa/text-section-literals-1.s
new file mode 100644 (file)
index 0000000..d46c04d
--- /dev/null
+++ b/gas/testsuite/gas/xtensa/text-section-literals-1.s
@@ -0,0 +1,6 @@
+       .section .init
+       .literal a, 0x12345678
+       movi    a2, 0x12345679
+       .section .fini
+       .literal b, 0x1234567a
+       movi    a2, 0x1234567b