[PATCH, PR target/67761] Fix i686-*-* bootstrap comparison failure

[Ilya Enkovich]

Hi,

My recenttly introduced STV pass doesn't skip debug instructions and it causes 
transformation (mistly cost computation) depending on debug info.  It causes 
bootstrap comparison failure.  This patch fixes.  Bootstrapped for i686-linux.  
Testing for x86_64-unknown-linux-gnu{,m32} is in progress.  OK for trunk if 
pass?

Thanks,
Ilya
--
gcc/

2015-09-29  Ilya Enkovich  <enkovich....@gmail.com>

        * config/i386/i386.c (scalar_chain::analyze_register_chain): Ignore
        debug insns.
        (scalar_chain::convert_reg): Likewise.

gcc/testsuite/

2015-09-29  Ilya Enkovich  <enkovich....@gmail.com>

        * gcc.target/i386/pr67761.c: New test.


diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 6f2380f..7b3ffb0 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -2919,6 +2919,10 @@ scalar_chain::analyze_register_chain (bitmap candidates, 
df_ref ref)
   for (chain = DF_REF_CHAIN (ref); chain; chain = chain->next)
     {
       unsigned uid = DF_REF_INSN_UID (chain->ref);
+
+      if (!NONDEBUG_INSN_P (DF_REF_INSN (chain->ref)))
+       continue;
+
       if (!DF_REF_REG_MEM_P (chain->ref))
        {
          if (bitmap_bit_p (insns, uid))
@@ -3279,7 +3283,7 @@ scalar_chain::convert_reg (unsigned regno)
            bitmap_clear_bit (conv, DF_REF_INSN_UID (ref));
          }
       }
-    else
+    else if (NONDEBUG_INSN_P (DF_REF_INSN (ref)))
       {
        replace_rtx (DF_REF_INSN (ref), reg, scopy);
        df_insn_rescan (DF_REF_INSN (ref));
diff --git a/gcc/testsuite/gcc.target/i386/pr67761.c 
b/gcc/testsuite/gcc.target/i386/pr67761.c
new file mode 100644
index 0000000..9b13d58
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr67761.c
@@ -0,0 +1,13 @@
+/* PR target/pr67761 */
+/* { dg-do run { target { ia32 } } } */
+/* { dg-options "-O2 -march=slm -g" } */
+/* { dg-final { scan-assembler "paddq" } } */
+
+void
+test (long long *values, long long val, long long delta)
+{
+  unsigned i;
+
+  for (i = 0; i < 128; i++, val += delta)
+    values[i] = val;
+}