combine: Print insns we try to combine

This adds some extra debug info to the dump file for combine: print
the insns that are input to try_combine.  I was worried printing more
will make the dump file only harder to read, but especially the info
from the REG_DEAD notes is invaluable.

	* combine (try_combine): Print the insns input to try_combine to the
	dump file.

From-SVN: r254365

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d7a6f39287a01935d31f8e8a370efea41810e866..7502184f7db17fb9ffe569649b14318fa79f0945 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-11-02  Segher Boessenkool  <segher@kernel.crashing.org>
+
+       * combine (try_combine): Print the insns input to try_combine to the
+       dump file.
+
 2017-11-02  Steve Ellcey  <sellcey@cavium.com>
 
        PR target/79868

diff --git a/gcc/combine.c b/gcc/combine.c
index 968e6871e996b0f448e3f75b9cf7a0ed6d1e3120..eab10c599a61bffdbbecd1c37a38da0f30768cf8 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -2771,6 +2771,13 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
       else
        fprintf (dump_file, "\nTrying %d -> %d:\n",
                 INSN_UID (i2), INSN_UID (i3));
+
+      if (i0)
+       dump_insn_slim (dump_file, i0);
+      if (i1)
+       dump_insn_slim (dump_file, i1);
+      dump_insn_slim (dump_file, i2);
+      dump_insn_slim (dump_file, i3);
     }
 
   /* If multiple insns feed into one of I2 or I3, they can be in any