patch to fix PR55512

[Vladimir Makarov]

  The following patch fixes

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55512

  The patch was successfully tested and bootstrapped on x86/x86-64.

  Committed as rev. 193901.

2012-11-28  Vladimir Makarov  <vmaka...@redhat.com>

        PR rtl-optimization/55512
        * lra-assigns.c (assign_by_spills): Assigned arbitrary hard regs
        to failed reload pseudos instead of changing asm pattern.
        * lra-constraints.c (MAX_CONSTRAINT_ITERATION_NUMBER): Increase
        value.

2012-11-28  Vladimir Makarov  <vmaka...@redhat.com>

        PR rtl-optimization/55512
        * gcc.target/i386/pr55512-[1234].c: New tests.


Index: lra-assigns.c
===================================================================
--- lra-assigns.c       (revision 193871)
+++ lra-assigns.c       (working copy)
@@ -1220,8 +1220,17 @@ assign_by_spills (void)
 
          bitmap_initialize (&failed_reload_insns, &reg_obstack);
          for (i = 0; i < nfails; i++)
-           bitmap_ior_into (&failed_reload_insns,
-                            &lra_reg_info[sorted_pseudos[i]].insn_bitmap);
+           {
+             regno = sorted_pseudos[i];
+             bitmap_ior_into (&failed_reload_insns,
+                              &lra_reg_info[regno].insn_bitmap);
+             /* Assign an arbitrary hard register of regno class to
+                avoid further trouble with the asm insns.  */
+             bitmap_clear_bit (&all_spilled_pseudos, regno);
+             assign_hard_regno
+               (ira_class_hard_regs[regno_allocno_class_array[regno]][0],
+                regno);
+           }
          EXECUTE_IF_SET_IN_BITMAP (&failed_reload_insns, 0, u, bi)
            {
              insn = lra_insn_recog_data[u]->insn;
@@ -1230,9 +1239,6 @@ assign_by_spills (void)
                  asm_p = true;
                  error_for_asm (insn,
                                 "%<asm%> operand has impossible constraints");
-                 /* Avoid further trouble with this insn.      */
-                 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
-                 lra_invalidate_insn_data (insn);
                }
            }
          lra_assert (asm_p);
Index: lra-constraints.c
===================================================================
--- lra-constraints.c   (revision 193870)
+++ lra-constraints.c   (working copy)
@@ -3184,7 +3184,7 @@ loc_equivalence_change_p (rtx *loc)
 
 /* Maximum allowed number of constraint pass iterations after the last
    spill pass. It is for preventing LRA cycling in a bug case.  */
-#define MAX_CONSTRAINT_ITERATION_NUMBER 15
+#define MAX_CONSTRAINT_ITERATION_NUMBER 30
 
 /* Maximum number of generated reload insns per an insn.  It is for
    preventing this pass cycling in a bug case. */
Index: testsuite/gcc.target/i386/pr55512-1.c
===================================================================
--- testsuite/gcc.target/i386/pr55512-1.c       (revision 0)
+++ testsuite/gcc.target/i386/pr55512-1.c       (working copy)
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int
+foo (int x)
+{
+  asm goto ("" : : "r" (x), "r" (x + 1), "r" (x + 2), "r" (x + 3), /* { 
dg-error "operand has impossible constraints" } */
+           "r" (x + 4), "r" (x + 5), "r" (x + 6), "r" (x + 7),
+           "r" (x + 8), "r" (x + 9), "r" (x + 10), "r" (x + 11),
+           "r" (x + 12), "r" (x + 13), "r" (x + 14), "r" (x + 15) : : lab);
+  __builtin_unreachable ();
+ lab:
+  return 0;
+}
Index: testsuite/gcc.target/i386/pr55512-2.c
===================================================================
--- testsuite/gcc.target/i386/pr55512-2.c       (revision 0)
+++ testsuite/gcc.target/i386/pr55512-2.c       (working copy)
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#define __builtin_unreachable() do { } while (0)
+
+int
+foo (int x)
+{
+  asm goto ("" : : "r" (x), "r" (x + 1), "r" (x + 2), "r" (x + 3), /* { 
dg-error "operand has impossible constraints" } */
+           "r" (x + 4), "r" (x + 5), "r" (x + 6), "r" (x + 7),
+           "r" (x + 8), "r" (x + 9), "r" (x + 10), "r" (x + 11),
+           "r" (x + 12), "r" (x + 13), "r" (x + 14), "r" (x + 15) : : lab);
+  __builtin_unreachable ();
+ lab:
+  return 0;
+}
Index: testsuite/gcc.target/i386/pr55512-3.c
===================================================================
--- testsuite/gcc.target/i386/pr55512-3.c       (revision 0)
+++ testsuite/gcc.target/i386/pr55512-3.c       (working copy)
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int
+bar (int x)
+{
+  asm goto ("" : : "r" (x), "r" (x + 1), "r" (x + 2), "r" (x + 3), /* { 
dg-error "operand has impossible constraints" } */
+           "r" (x + 4), "r" (x + 5), "r" (x + 6), "r" (x + 7),
+           "r" (x + 8), "r" (x + 9), "r" (x + 10), "r" (x + 11),
+           "r" (x + 12), "r" (x + 13), "r" (x + 14), "r" (x + 15),
+           "r" (x + 16) : : lab);
+  __builtin_unreachable ();
+ lab:
+  return 0;
+}
Index: testsuite/gcc.target/i386/pr55512-4.c
===================================================================
--- testsuite/gcc.target/i386/pr55512-4.c       (revision 0)
+++ testsuite/gcc.target/i386/pr55512-4.c       (working copy)
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#define __builtin_unreachable() do { } while (0)
+
+int
+bar (int x)
+{
+  asm goto ("" : : "r" (x), "r" (x + 1), "r" (x + 2), "r" (x + 3), /* { 
dg-error "operand has impossible constraints" } */
+           "r" (x + 4), "r" (x + 5), "r" (x + 6), "r" (x + 7),
+           "r" (x + 8), "r" (x + 9), "r" (x + 10), "r" (x + 11),
+           "r" (x + 12), "r" (x + 13), "r" (x + 14), "r" (x + 15),
+           "r" (x + 16) : : lab);
+  __builtin_unreachable ();
+ lab:
+  return 0;
+}