Index: gcc/testsuite/gcc.dg/tree-ssa/pr55008.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/pr55008.c	(revision 0)
+++ gcc/testsuite/gcc.dg/tree-ssa/pr55008.c	(revision 0)
@@ -0,0 +1,17 @@
+/* This used to fail to compile; see PR55008.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -w" } */
+
+typedef unsigned long long T;
+
+void f(void)
+{
+    int a, *p;
+
+    T b = 6309343725;
+
+    if(*p ? (b = 1) : 0)
+        if(b - (a = b /= 0) ? : (a + b))
+            while(1);
+}
+
Index: gcc/gimple-ssa-strength-reduction.c
===================================================================
--- gcc/gimple-ssa-strength-reduction.c	(revision 192691)
+++ gcc/gimple-ssa-strength-reduction.c	(working copy)
@@ -366,6 +366,7 @@ find_basis_for_candidate (slsr_cand_t c)
       slsr_cand_t one_basis = chain->cand;
 
       if (one_basis->kind != c->kind
+	  || one_basis->cand_stmt == c->cand_stmt
 	  || !operand_equal_p (one_basis->stride, c->stride, 0)
 	  || !types_compatible_p (one_basis->cand_type, c->cand_type)
 	  || !dominated_by_p (CDI_DOMINATORS,