diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6222a3f74ef5..aa260995e8dd 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2018-12-14  Alan Modra  <amodra@gmail.com>
+
+	PR rtl-optimization/88311
+	* config/rs6000/rs6000.c (rs6000_call_sysv): Do not mask cookie.
+	(rs6000_sibcall_sysv): Likewise.
+
 2018-12-14  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	PR rtl-optimization/88001
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 88f4f620ae46..c4682fce6cd7 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -37978,8 +37978,7 @@ rs6000_call_sysv (rtx value, rtx func_desc, rtx tlsarg, rtx cookie)
   if (value != NULL_RTX)
     call[0] = gen_rtx_SET (value, call[0]);
 
-  unsigned int mask = CALL_V4_SET_FP_ARGS | CALL_V4_CLEAR_FP_ARGS;
-  call[1] = gen_rtx_USE (VOIDmode, GEN_INT (INTVAL (cookie) & mask));
+  call[1] = gen_rtx_USE (VOIDmode, cookie);
   call[2] = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (Pmode, LR_REGNO));
 
   insn = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (3, call));
@@ -38043,8 +38042,7 @@ rs6000_sibcall_sysv (rtx value, rtx func_desc, rtx tlsarg, rtx cookie)
   if (value != NULL_RTX)
     call[0] = gen_rtx_SET (value, call[0]);
 
-  unsigned int mask = CALL_V4_SET_FP_ARGS | CALL_V4_CLEAR_FP_ARGS;
-  call[1] = gen_rtx_USE (VOIDmode, GEN_INT (INTVAL (cookie) & mask));
+  call[1] = gen_rtx_USE (VOIDmode, cookie);
   call[2] = simple_return_rtx;
 
   insn = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (3, call));