diff --git a/gcc/compare-elim.c b/gcc/compare-elim.c
index 086fbc7..ed841a1 100644
--- a/gcc/compare-elim.c
+++ b/gcc/compare-elim.c
@@ -631,7 +631,16 @@ try_validate_parallel (rtx set_a, rtx set_b)
   rtx_insn *insn;
   insn = gen_rtx_INSN (VOIDmode, 0, 0, 0, par, 0, -1, 0);
 
-  return recog_memoized (insn) > 0 ? par : NULL_RTX;
+  if (recog_memoized (insn) > 0)
+    {
+      extract_insn (insn);
+
+      return constrain_operands (reload_completed,
+				 get_enabled_alternatives (insn))
+	? par : NULL_RTX;
+    }
+
+  return NULL_RTX;
 }
 
 /* For a comparison instruction described by CMP check if it compares a
diff --git a/gcc/testsuite/gcc.dg/pr82597.c b/gcc/testsuite/gcc.dg/pr82597.c
new file mode 100644
index 0000000..98ae264
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr82597.c
@@ -0,0 +1,40 @@
+/* PR rtl-optimization/82597 */
+/* { dg-do compile  }*/
+/* { dg-options "-O2 -funroll-loops" } */
+
+int pb;
+
+void
+ch (unsigned char np, char fc)
+{
+  unsigned char *y6 = &np;
+
+  if (fc != 0)
+    {
+      unsigned char *z1 = &np;
+
+      for (;;)
+        if (*y6 != 0)
+          for (fc = 0; fc < 12; ++fc)
+            {
+              int hh;
+              int tp;
+
+              if (fc != 0)
+                hh = (*z1 != 0) ? fc : 0;
+              else
+                hh = pb;
+
+              tp = fc > 0;
+              if (hh == tp)
+                *y6 = 1;
+            }
+    }
+
+  if (np != 0)
+    y6 = (unsigned char *)&fc;
+  if (pb != 0 && *y6 != 0)
+    for (;;)
+      {
+      }
+}
-- 
1.9.1