[PATCH] Fix a RTL sharing problem with CALL_INSN_FUNCTION_USAGE (PR middle-end/48722)

[Jakub Jelinek]

Hi!

As the testcase below shows (on i686-linux or x86_64-linux -m32),
we don't unshare expressions in CALL_INSN_FUNCTION_USAGE, which
with entry_value support now include MEMs.  The invalid sharing then
can lead to changes in unrelated insns affecting a call insn (or vice
versa), which results in DF being out of date and ICE afterwards.

Fixed thusly, bootstrapped/regtested (with rtl checking) on x86_64-linux and
i686-linux, ok for trunk?

2011-08-22  Jakub Jelinek  <ja...@redhat.com>

        PR middle-end/48722
        * emit-rtl.c (unshare_all_rtl_again): For CALL_INSNs,
        reset_used_flags also in CALL_INSN_FUNCTION_USAGE.
        (verify_rtl_sharing): Likewise and verify_rtx_sharing
        in there too.
        (unshare_all_rtl_in_chain): For CALL_INSNs
        copy_rtx_if_shared also CALL_INSN_FUNCTION_USAGE.

        * gcc.target/i386/pr48722.c: New test.

--- gcc/emit-rtl.c.jj   2011-08-18 08:36:00.000000000 +0200
+++ gcc/emit-rtl.c      2011-08-22 08:48:27.000000000 +0200
@@ -2444,6 +2444,8 @@ unshare_all_rtl_again (rtx insn)
       {
        reset_used_flags (PATTERN (p));
        reset_used_flags (REG_NOTES (p));
+       if (CALL_P (p))
+         reset_used_flags (CALL_INSN_FUNCTION_USAGE (p));
       }
 
   /* Make sure that virtual stack slots are not shared.  */
@@ -2610,6 +2612,8 @@ verify_rtl_sharing (void)
       {
        reset_used_flags (PATTERN (p));
        reset_used_flags (REG_NOTES (p));
+       if (CALL_P (p))
+         reset_used_flags (CALL_INSN_FUNCTION_USAGE (p));
        if (GET_CODE (PATTERN (p)) == SEQUENCE)
          {
            int i;
@@ -2621,6 +2625,8 @@ verify_rtl_sharing (void)
                gcc_assert (INSN_P (q));
                reset_used_flags (PATTERN (q));
                reset_used_flags (REG_NOTES (q));
+               if (CALL_P (q))
+                 reset_used_flags (CALL_INSN_FUNCTION_USAGE (q));
              }
          }
       }
@@ -2630,6 +2636,8 @@ verify_rtl_sharing (void)
       {
        verify_rtx_sharing (PATTERN (p), p);
        verify_rtx_sharing (REG_NOTES (p), p);
+       if (CALL_P (p))
+         verify_rtx_sharing (CALL_INSN_FUNCTION_USAGE (p), p);
       }
 
   timevar_pop (TV_VERIFY_RTL_SHARING);
@@ -2646,6 +2654,9 @@ unshare_all_rtl_in_chain (rtx insn)
       {
        PATTERN (insn) = copy_rtx_if_shared (PATTERN (insn));
        REG_NOTES (insn) = copy_rtx_if_shared (REG_NOTES (insn));
+       if (CALL_P (insn))
+         CALL_INSN_FUNCTION_USAGE (insn)
+           = copy_rtx_if_shared (CALL_INSN_FUNCTION_USAGE (insn));
       }
 }
 
--- gcc/testsuite/gcc.target/i386/pr48722.c.jj  2011-08-22 08:53:10.000000000 
+0200
+++ gcc/testsuite/gcc.target/i386/pr48722.c     2011-08-22 08:52:37.000000000 
+0200
@@ -0,0 +1,13 @@
+/* PR middle-end/48722 */
+/* { dg-do compile } */
+/* { dg-options "-Os -mno-push-args" } */
+
+extern long long a;
+extern int b;
+void bar (int, long long);
+
+void
+foo (void)
+{
+  bar (a > 0x85, b);
+}

        Jakub