Re: [patch][nvptx] libgomp: Split testcase in order to XFAIL __sync_val_compare_and_swap_16 (was: [PATCH] nvptx: Add support for subword compare-and-swap)

[Tom de Vries]

On 9/1/20 2:58 PM, Tom de Vries wrote:
> On 9/1/20 1:41 PM, Tobias Burnus wrote:
>> Hi Tom, hello all,
>>
>> it turned out that the testcase fails on PowerPC (but not x86_64)
>> as the nvptx lto complains: unresolved symbol
>> __sync_val_compare_and_swap_16
>>
>> The testcase uses int128 – and that's the culprit, but I have no idea
>> why it only fails with PowerPC and not with x86-64.
>>
> 

Reproduced on x86_64 using trigger patch:
...
$ git diff
diff --git a/gcc/config/i386/sync.md b/gcc/config/i386/sync.md
index ed17bb00205..eccedac192f 100644
--- a/gcc/config/i386/sync.md
+++ b/gcc/config/i386/sync.md
@@ -153,9 +153,15 @@
     (DI "TARGET_64BIT || (TARGET_CMPXCHG8B && (TARGET_80387 ||
TARGET_SSE))")
    ])

+ (define_mode_iterator ATOMIC2
+    [QI HI SI
+     (DI "TARGET_64BIT || (TARGET_CMPXCHG8B && (TARGET_80387 ||
TARGET_SSE))")
+    TI
+    ])
+
 (define_expand "atomic_load<mode>"
-  [(set (match_operand:ATOMIC 0 "nonimmediate_operand")
-       (unspec:ATOMIC [(match_operand:ATOMIC 1 "memory_operand")
+  [(set (match_operand:ATOMIC2 0 "nonimmediate_operand")
+       (unspec:ATOMIC2 [(match_operand:ATOMIC2 1 "memory_operand")
                        (match_operand:SI 2 "const_int_operand")]
                       UNSPEC_LDA))]
   ""
diff --git a/libgomp/testsuite/libgomp.c-c++-common/reduction-16.c
b/libgomp/testsuite/libgomp.c-c++-common/reduction-16.c
index d0e82b04790..62b0e032c33 100644
--- a/libgomp/testsuite/libgomp.c-c++-common/reduction-16.c
+++ b/libgomp/testsuite/libgomp.c-c++-common/reduction-16.c
@@ -1,4 +1,5 @@
 /* { dg-do run } */
+/* { dg-additional-options "-mcx16" } */

 #include <stdlib.h>

...

Thanks,
- Tom