diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d9a0bf89569..1f108e7339a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2015-12-04  Segher Boessenkool  <segher&kernel.crashing.org>
+
+	* (cstore<mode>4_signed): New expander.
+	(cstore<mode>4): Call it.
+
 2015-12-04  Jakub Jelinek  <jakub@redhat.com>
 
 	* tree-tailcall.c (find_tail_calls): Ignore GIMPLE_NOPs.
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 26b0962ae7d..f346cba8e08 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -10525,6 +10525,47 @@
   DONE;
 }")
 
+(define_expand "cstore<mode>4_signed"
+  [(use (match_operator 1 "signed_comparison_operator"
+         [(match_operand:P 2 "gpc_reg_operand")
+          (match_operand:P 3 "gpc_reg_operand")]))
+   (clobber (match_operand:P 0 "gpc_reg_operand"))]
+  ""
+{
+  enum rtx_code cond_code = GET_CODE (operands[1]);
+
+  rtx op0 = operands[0];
+  rtx op1 = operands[2];
+  rtx op2 = operands[3];
+
+  if (cond_code == GE || cond_code == LT)
+    {
+      cond_code = swap_condition (cond_code);
+      std::swap (op1, op2);
+    }
+
+  rtx tmp1 = gen_reg_rtx (<MODE>mode);
+  rtx tmp2 = gen_reg_rtx (<MODE>mode);
+  rtx tmp3 = gen_reg_rtx (<MODE>mode);
+
+  int sh = GET_MODE_BITSIZE (<MODE>mode) - 1;
+  emit_insn (gen_lshr<mode>3 (tmp1, op1, GEN_INT (sh)));
+  emit_insn (gen_ashr<mode>3 (tmp2, op2, GEN_INT (sh)));
+
+  emit_insn (gen_subf<mode>3_carry (tmp3, op1, op2));
+
+  if (cond_code == LE)
+    emit_insn (gen_add<mode>3_carry_in (op0, tmp1, tmp2));
+  else
+    {
+      rtx tmp4 = gen_reg_rtx (<MODE>mode);
+      emit_insn (gen_add<mode>3_carry_in (tmp4, tmp1, tmp2));
+      emit_insn (gen_xor<mode>3 (op0, tmp4, const1_rtx));
+    }
+
+  DONE;
+})
+
 (define_expand "cstore<mode>4_unsigned"
   [(use (match_operator 1 "unsigned_comparison_operator"
          [(match_operand:P 2 "gpc_reg_operand" "")
@@ -10751,6 +10792,12 @@
     emit_insn (gen_cstore<mode>4_unsigned_imm (operands[0], operands[1],
 					       operands[2], operands[3]));
 
+  /* We also do not want to use mfcr for signed comparisons.  */
+  else if (<MODE>mode == Pmode
+	   && signed_comparison_operator (operands[1], VOIDmode))
+    emit_insn (gen_cstore<mode>4_signed (operands[0], operands[1],
+					 operands[2], operands[3]));
+
   /* Everything else, use the mfcr brute force.  */
   else
     rs6000_emit_sCOND (<MODE>mode, operands);