Hi,

rdrand<mode>_1 must be marked with unspec_volatile since it returns
a different value every time.  OK for trunk, 4.7 and 4.6?

Thanks.

H.J.
----
        PR target/53416
        * config/i386/i386.md (UNSPEC_RDRAND): Renamed to ...
        (UNSPECV_RDRAND): This.
        (rdrand<mode>_1): Updated.

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index cce78b5..9327acf 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -176,9 +176,6 @@
   ;; For CRC32 support
   UNSPEC_CRC32
 
-  ;; For RDRAND support
-  UNSPEC_RDRAND
-
   ;; For BMI support
   UNSPEC_BEXTR
 
@@ -208,6 +205,9 @@
   UNSPECV_WRFSBASE
   UNSPECV_WRGSBASE
 
+  ;; For RDRAND support
+  UNSPECV_RDRAND
+
   ;; For RTM support
   UNSPECV_XBEGIN
   UNSPECV_XEND
@@ -18399,9 +18399,9 @@
 
 (define_insn "rdrand<mode>_1"
   [(set (match_operand:SWI248 0 "register_operand" "=r")
-       (unspec:SWI248 [(const_int 0)] UNSPEC_RDRAND))
+       (unspec_volatile:SWI248 [(const_int 0)] UNSPECV_RDRAND))
    (set (reg:CCC FLAGS_REG)
-       (unspec:CCC [(const_int 0)] UNSPEC_RDRAND))]
+       (unspec_volatile:CCC [(const_int 0)] UNSPECV_RDRAND))]
   "TARGET_RDRND"
   "rdrand\t%0"
   [(set_attr "type" "other")

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