[AArch64] Fix strict aliasing issue in gcc.target/aarch64/simd/vminmaxnm_1.c

While doing some unrelated work the gcc.target/aarch64/simd/vminmaxnm_1.c testcase started failing for me.
Upon investigation it turns out that it breaks the C strict aliasing rules in the CHECK macro by casting
a pointer to an incompatible type and dereferencing it. GCC even warns about it if compiled with -Wstrict-aliasing.

This patch fixes the testcase by making it use memcmp to compare the vector elements.
This avoids the undefined behaviour.

The testcase still passes on trunk.

    * gcc.target/aarch64/simd/vminmaxnm_1.c: Fix strict aliasing issues.

From-SVN: r249972

gcc/testsuite/ChangeLog

+2017-07-04  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* gcc.target/aarch64/simd/vminmaxnm_1.c: Fix strict aliasing issues.
+
 2017-07-04  Marek Polacek  <polacek@redhat.com>
 
 	PR c/81231

gcc/testsuite/gcc.target/aarch64/simd/vminmaxnm_1.c

@@ -7,12 +7,10 @@
 
 extern void abort ();
 
-#define CHECK(T, N, R, E) \
+#define CHECK(R, E) \
   {\
-    int i = 0;\
-    for (; i < N; i++)\
-      if (* (T *) &R[i] != * (T *) &E[i])\
-	abort ();\
+    if (__builtin_memcmp (&R, &E, sizeof (R)) != 0)\
+      abort ();\
   }
 
 int
@@ -26,8 +24,8 @@ main (int argc, char **argv)
   float32x2_t f32x2_ret_minnm  = vminnm_f32 (f32x2_input1, f32x2_input2);
   float32x2_t f32x2_ret_maxnm  = vmaxnm_f32 (f32x2_input1, f32x2_input2);
 
-  CHECK (uint32_t, 2, f32x2_ret_minnm, f32x2_exp_minnm);
-  CHECK (uint32_t, 2, f32x2_ret_maxnm, f32x2_exp_maxnm);
+  CHECK (f32x2_ret_minnm, f32x2_exp_minnm);
+  CHECK (f32x2_ret_maxnm, f32x2_exp_maxnm);
 
   /* v{min|max}nm_f32 NaN.  */
   f32x2_input1 = vdup_n_f32 (__builtin_nanf (""));
@@ -37,8 +35,8 @@ main (int argc, char **argv)
   f32x2_ret_minnm  = vminnm_f32 (f32x2_input1, f32x2_input2);
   f32x2_ret_maxnm  = vmaxnm_f32 (f32x2_input1, f32x2_input2);
 
-  CHECK (uint32_t, 2, f32x2_ret_minnm, f32x2_exp_minnm);
-  CHECK (uint32_t, 2, f32x2_ret_maxnm, f32x2_exp_maxnm);
+  CHECK (f32x2_ret_minnm, f32x2_exp_minnm);
+  CHECK (f32x2_ret_maxnm, f32x2_exp_maxnm);
 
   /* v{min|max}nmq_f32 normal.  */
   float32x4_t f32x4_input1 = vdupq_n_f32 (-1024.0);
@@ -48,8 +46,8 @@ main (int argc, char **argv)
   float32x4_t f32x4_ret_minnm  = vminnmq_f32 (f32x4_input1, f32x4_input2);
   float32x4_t f32x4_ret_maxnm  = vmaxnmq_f32 (f32x4_input1, f32x4_input2);
 
-  CHECK (uint32_t, 4, f32x4_ret_minnm, f32x4_exp_minnm);
-  CHECK (uint32_t, 4, f32x4_ret_maxnm, f32x4_exp_maxnm);
+  CHECK (f32x4_ret_minnm, f32x4_exp_minnm);
+  CHECK (f32x4_ret_maxnm, f32x4_exp_maxnm);
 
   /* v{min|max}nmq_f32 NaN.  */
   f32x4_input1 = vdupq_n_f32 (-__builtin_nanf (""));
@@ -59,8 +57,8 @@ main (int argc, char **argv)
   f32x4_ret_minnm  = vminnmq_f32 (f32x4_input1, f32x4_input2);
   f32x4_ret_maxnm  = vmaxnmq_f32 (f32x4_input1, f32x4_input2);
 
-  CHECK (uint32_t, 4, f32x4_ret_minnm, f32x4_exp_minnm);
-  CHECK (uint32_t, 4, f32x4_ret_maxnm, f32x4_exp_maxnm);
+  CHECK (f32x4_ret_minnm, f32x4_exp_minnm);
+  CHECK (f32x4_ret_maxnm, f32x4_exp_maxnm);
 
   /* v{min|max}nm_f64 normal.  */
   float64x1_t f64x1_input1 = vdup_n_f64 (1.23);
@@ -69,16 +67,16 @@ main (int argc, char **argv)
   float64x1_t f64x1_exp_maxnm  = vdup_n_f64 (4.56);
   float64x1_t f64x1_ret_minnm  = vminnm_f64 (f64x1_input1, f64x1_input2);
   float64x1_t f64x1_ret_maxnm  = vmaxnm_f64 (f64x1_input1, f64x1_input2);
-  CHECK (uint64_t, 1, f64x1_ret_minnm, f64x1_exp_minnm);
-  CHECK (uint64_t, 1, f64x1_ret_maxnm, f64x1_exp_maxnm);
+  CHECK (f64x1_ret_minnm, f64x1_exp_minnm);
+  CHECK (f64x1_ret_maxnm, f64x1_exp_maxnm);
 
   /* v{min|max}_f64 normal.  */
   float64x1_t f64x1_exp_min  = vdup_n_f64 (1.23);
   float64x1_t f64x1_exp_max  = vdup_n_f64 (4.56);
   float64x1_t f64x1_ret_min  = vmin_f64 (f64x1_input1, f64x1_input2);
   float64x1_t f64x1_ret_max  = vmax_f64 (f64x1_input1, f64x1_input2);
-  CHECK (uint64_t, 1, f64x1_ret_min, f64x1_exp_min);
-  CHECK (uint64_t, 1, f64x1_ret_max, f64x1_exp_max);
+  CHECK (f64x1_ret_min, f64x1_exp_min);
+  CHECK (f64x1_ret_max, f64x1_exp_max);
 
   /* v{min|max}nmq_f64 normal.  */
   float64x2_t f64x2_input1 = vdupq_n_f64 (1.23);
@@ -87,8 +85,8 @@ main (int argc, char **argv)
   float64x2_t f64x2_exp_maxnm  = vdupq_n_f64 (4.56);
   float64x2_t f64x2_ret_minnm  = vminnmq_f64 (f64x2_input1, f64x2_input2);
   float64x2_t f64x2_ret_maxnm  = vmaxnmq_f64 (f64x2_input1, f64x2_input2);
-  CHECK (uint64_t, 2, f64x2_ret_minnm, f64x2_exp_minnm);
-  CHECK (uint64_t, 2, f64x2_ret_maxnm, f64x2_exp_maxnm);
+  CHECK (f64x2_ret_minnm, f64x2_exp_minnm);
+  CHECK (f64x2_ret_maxnm, f64x2_exp_maxnm);
 
   /* v{min|max}nm_f64 NaN.  */
   f64x1_input1 = vdup_n_f64 (-__builtin_nanf (""));
@@ -98,8 +96,8 @@ main (int argc, char **argv)
   f64x1_ret_minnm  = vminnm_f64 (f64x1_input1, f64x1_input2);
   f64x1_ret_maxnm  = vmaxnm_f64 (f64x1_input1, f64x1_input2);
 
-  CHECK (uint64_t, 1, f64x1_ret_minnm, f64x1_exp_minnm);
-  CHECK (uint64_t, 1, f64x1_ret_maxnm, f64x1_exp_maxnm);
+  CHECK (f64x1_ret_minnm, f64x1_exp_minnm);
+  CHECK (f64x1_ret_maxnm, f64x1_exp_maxnm);
 
   /* v{min|max}_f64 NaN.  */
   f64x1_input1 = vdup_n_f64 (-__builtin_nanf (""));
@@ -109,8 +107,8 @@ main (int argc, char **argv)
   f64x1_ret_minnm  = vmin_f64 (f64x1_input1, f64x1_input2);
   f64x1_ret_maxnm  = vmax_f64 (f64x1_input1, f64x1_input2);
 
-  CHECK (uint64_t, 1, f64x1_ret_minnm, f64x1_exp_minnm);
-  CHECK (uint64_t, 1, f64x1_ret_maxnm, f64x1_exp_maxnm);
+  CHECK (f64x1_ret_minnm, f64x1_exp_minnm);
+  CHECK (f64x1_ret_maxnm, f64x1_exp_maxnm);
 
   /* v{min|max}nmq_f64 NaN.  */
   f64x2_input1 = vdupq_n_f64 (-__builtin_nan (""));
@@ -120,8 +118,8 @@ main (int argc, char **argv)
   f64x2_ret_minnm  = vminnmq_f64 (f64x2_input1, f64x2_input2);
   f64x2_ret_maxnm  = vmaxnmq_f64 (f64x2_input1, f64x2_input2);
 
-  CHECK (uint64_t, 2, f64x2_ret_minnm, f64x2_exp_minnm);
-  CHECK (uint64_t, 2, f64x2_ret_maxnm, f64x2_exp_maxnm);
+  CHECK (f64x2_ret_minnm, f64x2_exp_minnm);
+  CHECK (f64x2_ret_maxnm, f64x2_exp_maxnm);
 
   return 0;
 }