Re: PATCH: PR target/53416: Wrong code when optimising loop involving _rdrand32_step

[H.J. Lu]

On Sun, May 20, 2012 at 12:03 PM, Uros Bizjak <ubiz...@gmail.com> wrote:
> On Sun, May 20, 2012 at 8:43 PM, Andrew Pinski <pins...@gmail.com> wrote:
>
>> #include <stdio.h>
>>
>>  int
>>  main(int argc, char **argv)
>>  {
>>  unsigned int number = 0;
>>  int result0, result1, result2, result3;
>>
>>  result0 = __builtin_ia32_rdrand32_step (&number);
>>  result1 = __builtin_ia32_rdrand32_step (&number);
>>  result2 = __builtin_ia32_rdrand32_step (&number);
>>  result3 = __builtin_ia32_rdrand32_step (&number);
>>  printf("%d: %d\n", result0, number);
>>  printf("%d: %d\n", result1, number);
>>  printf("%d: %d\n", result2, number);
>>  printf("%d: %d\n", result3, number);
>>  return 0;
>>  }
>>
>
> int test (void)
> {
>  unsigned int number = 0;
>  int result0, result1, result2, result3;
>
>  result0 = __builtin_ia32_rdrand32_step (&number);
>  result1 = __builtin_ia32_rdrand32_step (&number);
>  result2 = __builtin_ia32_rdrand32_step (&number);
>  result3 = __builtin_ia32_rdrand32_step (&number);
>
>  return result0 + result1 +result2 + result3;;
> }
>
> This is the simplest, and also good test.
>

Is this patck OK for trunk, 4.7 and 4.6?

Thanks.


-- 
H.J.
---
gcc/

2012-05-20  H.J. Lu  <hongjiu...@intel.com>

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

gcc/testsuite/

2012-05-20  Uros Bizjak  <ubiz...@gmail.com>
            H.J. Lu  <hongjiu...@intel.com>

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")
diff --git a/gcc/testsuite/gcc.target/i386/pr53416.c
b/gcc/testsuite/gcc.target/i386/pr53416.c
new file mode 100644
index 0000000..d0a159b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr53416.c
@@ -0,0 +1,17 @@
+/* PR target/53416 */
+/* { dg-options "-O2 -mrdrnd" } */
+
+int test (void)
+{
+  unsigned int number = 0;
+  int result0, result1, result2, result3;
+
+  result0 = __builtin_ia32_rdrand32_step (&number);
+  result1 = __builtin_ia32_rdrand32_step (&number);
+  result2 = __builtin_ia32_rdrand32_step (&number);
+  result3 = __builtin_ia32_rdrand32_step (&number);
+
+  return result0 + result1 +result2 + result3;;
+}
+
+/* { dg-final { scan-assembler-times "rdrand" 4 } } */