diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c58d419556b..ac283a63a9e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2018-02-13  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR rtl-optimization/84169
+	* combine.c (try_combine): New variable split_i2i3.  Set it to true if
+	we generated a parallel as new i3 and we split that to new i2 and i3
+	instructions.  Handle split_i2i3 similar to swap_i2i3: scan the
+	LOG_LINKs of i3 to see which of those need to link to i2 now.  Link
+	those to i2, not i1.  Partially rewrite this scan code.
+
 2018-02-13  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/82210
diff --git a/gcc/combine.c b/gcc/combine.c
index a9929f2a3e2..c4d55eb85a4 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -2665,6 +2665,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
   /* Notes that I1, I2 or I3 is a MULT operation.  */
   int have_mult = 0;
   int swap_i2i3 = 0;
+  int split_i2i3 = 0;
   int changed_i3_dest = 0;
 
   int maxreg;
@@ -4091,6 +4092,9 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
 	    }
 
 	  insn_code_number = recog_for_combine (&newpat, i3, &new_i3_notes);
+
+	  if (insn_code_number >= 0)
+	    split_i2i3 = 1;
 	}
     }
 
@@ -4258,44 +4262,45 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
 
   if (swap_i2i3)
     {
-      rtx_insn *insn;
-      struct insn_link *link;
-      rtx ni2dest;
-
       /* I3 now uses what used to be its destination and which is now
 	 I2's destination.  This requires us to do a few adjustments.  */
       PATTERN (i3) = newpat;
       adjust_for_new_dest (i3);
+    }
 
-      /* We need a LOG_LINK from I3 to I2.  But we used to have one,
-	 so we still will.
+  if (swap_i2i3 || split_i2i3)
+    {
+      /* We might need a LOG_LINK from I3 to I2.  But then we used to
+	 have one, so we still will.
 
 	 However, some later insn might be using I2's dest and have
-	 a LOG_LINK pointing at I3.  We must remove this link.
-	 The simplest way to remove the link is to point it at I1,
-	 which we know will be a NOTE.  */
+	 a LOG_LINK pointing at I3.  We should change it to point at
+	 I2 instead.  */
 
       /* newi2pat is usually a SET here; however, recog_for_combine might
 	 have added some clobbers.  */
-      if (GET_CODE (newi2pat) == PARALLEL)
-	ni2dest = SET_DEST (XVECEXP (newi2pat, 0, 0));
-      else
-	ni2dest = SET_DEST (newi2pat);
+      rtx x = newi2pat;
+      if (GET_CODE (x) == PARALLEL)
+	x = XVECEXP (newi2pat, 0, 0);
 
-      for (insn = NEXT_INSN (i3);
-	   insn && (this_basic_block->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)
-		    || insn != BB_HEAD (this_basic_block->next_bb));
+      unsigned int regno = REGNO (SET_DEST (x));
+
+      bool done = false;
+      for (rtx_insn *insn = NEXT_INSN (i3);
+	   !done
+	   && insn
+	   && NONDEBUG_INSN_P (insn)
+	   && BLOCK_FOR_INSN (insn) == this_basic_block;
 	   insn = NEXT_INSN (insn))
 	{
-	  if (NONDEBUG_INSN_P (insn)
-	      && reg_referenced_p (ni2dest, PATTERN (insn)))
-	    {
-	      FOR_EACH_LOG_LINK (link, insn)
-		if (link->insn == i3)
-		  link->insn = i1;
-
-	      break;
-	    }
+	  struct insn_link *link;
+	  FOR_EACH_LOG_LINK (link, insn)
+	    if (link->insn == i3 && link->regno == regno)
+	      {
+		link->insn = i2;
+		done = true;
+		break;
+	      }
 	}
     }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e14dd7d7a17..034931bad9b 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-02-13  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR rtl-optimization/84169
+	* gcc.c-torture/execute/pr84169.c: New.
+
 2018-02-13  Peter Bergner  <bergner@vnet.ibm.com>
 
 	PR target/84370
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr84169.c b/gcc/testsuite/gcc.c-torture/execute/pr84169.c
new file mode 100644
index 00000000000..ba8f8fc4c05
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr84169.c
@@ -0,0 +1,25 @@
+/* PR rtl-optimization/84169 */
+
+#ifdef __SIZEOF_INT128__
+typedef unsigned __int128 T;
+#else
+typedef unsigned long long T;
+#endif
+
+T b;
+
+static __attribute__ ((noipa)) T
+foo (T c, T d, T e, T f, T g, T h)
+{
+  __builtin_mul_overflow ((unsigned char) h, -16, &h);
+  return b + h;
+}
+
+int
+main ()
+{
+  T x = foo (0, 0, 0, 0, 0, 4);
+  if (x != -64)
+    __builtin_abort ();
+  return 0;
+}