Index: gcc/varasm.c
===================================================================
--- gcc/varasm.c	(revision 254556)
+++ gcc/varasm.c	(working copy)
@@ -3118,10 +3118,16 @@ compare_constant (const tree t1, const t
       return tree_int_cst_equal (t1, t2);
 
     case REAL_CST:
-      /* Real constants are the same only if the same width of type.  */
+      /* Real constants are the same only if the same width of type.  In
+	 addition to the same width, we need to check whether the modes are the
+	 same.  There might be two floating point modes that are the same size
+	 but have different representations, such as the PowerPC that has 2
+	 different 128-bit floating point types (IBM extended double and IEEE
+	 128-bit floating point).  */
       if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
 	return 0;
-
+      if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
+	return 0;
       return real_identical (&TREE_REAL_CST (t1), &TREE_REAL_CST (t2));
 
     case FIXED_CST:
Index: gcc/testsuite/gcc.target/powerpc/pr82333.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/pr82333.c	(revision 0)
+++ gcc/testsuite/gcc.target/powerpc/pr82333.c	(revision 0)
@@ -0,0 +1,34 @@
+/* { dg-do compile { target { powerpc*-*-linux* } } } */
+/* { dg-require-effective-target ppc_float128_sw } */
+/* { dg-require-effective-target vsx_hw } */
+/* { dg-options "-mvsx -O2 -mabi=ibmlongdouble -Wno-psabi" } */
+
+/* PR 82333 was an internal compiler abort where the compiler thought that a
+   long double _Complex constant was the same as __float128 _Complex.  */
+
+_Complex long double vld;
+_Complex _Float128 vf128;
+
+_Complex long double
+fld (_Complex long double arg0)
+{
+  return 0;
+}
+
+_Complex _Float128
+ff128 (_Complex _Float128 arg0)
+{
+  return 0;
+}
+
+void
+tld (void)
+{
+  vld = fld (vld);
+}
+
+void
+tf128 (void)
+{
+  vf128 = ff128 (vf128);
+}