Re: [PATCH 4.9][AArch64][testsuite] Backport r211502: PR/59843 Fix ICE on singleton vector of float on AArch64

[Alan Lawrence <alan dot lawrence at arm dot com>]

Patch here.

Alan Lawrence wrote:
> No regressions on aarch64-none-elf; new tests passing on aarch64-none-elf, 
> arm-none-eabi, x86_64-unknown-linux-gnu:
>
> NA->PASS gcc.dg/vect/vect-singleton_1.c (test for warnings, line 20)
> NA->PASS gcc.dg/vect/vect-singleton_1.c (test for excess errors)
>
>
> gcc/ChangeLog:
>
>          * config/aarch64/aarch64-modes.def: Add V1DFmode.
>          * config/aarch64/aarch64.c (aarch64_vector_mode_supported_p):
>          Support V1DFmode.
>
> gcc/testsuite/ChangeLog:
>
>          * gcc.dg/vect/vect-singleton_1.c: New file.
diff --git a/gcc/config/aarch64/aarch64-modes.def b/gcc/config/aarch64/aarch64-modes.def
index 1d2cc76..f9c4369 100644
--- a/gcc/config/aarch64/aarch64-modes.def
+++ b/gcc/config/aarch64/aarch64-modes.def
@@ -31,6 +31,7 @@ VECTOR_MODES (INT, 8);        /*       V8QI V4HI V2SI.  */
 VECTOR_MODES (INT, 16);       /* V16QI V8HI V4SI V2DI.  */
 VECTOR_MODES (FLOAT, 8);      /*                 V2SF.  */
 VECTOR_MODES (FLOAT, 16);     /*            V4SF V2DF.  */
+VECTOR_MODE (FLOAT, DF, 1);   /*                 V1DF.  */
 
 /* Oct Int: 256-bit integer mode needed for 32-byte vector arguments.  */
 INT_MODE (OI, 32);
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 4838498..bf35031 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -6307,7 +6307,8 @@ aarch64_vector_mode_supported_p (enum machine_mode mode)
 	  || mode == V16QImode || mode == V2DImode
 	  || mode == V2SImode  || mode == V4HImode
 	  || mode == V8QImode || mode == V2SFmode
-	  || mode == V4SFmode || mode == V2DFmode))
+	  || mode == V4SFmode || mode == V2DFmode
+	  || mode == V1DFmode))
     return true;
 
   return false;
diff --git a/gcc/testsuite/gcc.dg/vect/vect-singleton_1.c b/gcc/testsuite/gcc.dg/vect/vect-singleton_1.c
new file mode 100644
index 0000000..6c2ff49
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/vect-singleton_1.c
@@ -0,0 +1,38 @@
+/* PR target/59843 ICE on function taking/returning vector of one float64_t.  */
+
+/* { dg-do compile } */
+/* { dg-options "-Warray-bounds -O2 -fno-inline -std=c99" } */
+
+#define TEST(BASETYPE, VECTYPE, SUFFIX)					     \
+  typedef BASETYPE VECTYPE						     \
+      __attribute__ ((__vector_size__ (sizeof (BASETYPE))));		     \
+  VECTYPE								     \
+  test_vadd_##SUFFIX (VECTYPE a, VECTYPE b)				     \
+  {									     \
+    return a + b;							     \
+  }									     \
+									     \
+  void									     \
+  test_##SUFFIX (BASETYPE val)						     \
+  {									     \
+    VECTYPE var = { val };						     \
+    BASETYPE v0 = var[0];						     \
+    BASETYPE v1 = var[1]; /* { dg-warning "index value is out of bound" } */ \
+  }
+
+TEST (double, float64x1_t, f64)
+
+/* Original bug was for above type;
+   in a nod to completeness, test other types too.  */
+
+TEST (long long, int64x1_t, s64)
+
+TEST (float, float32x1_t, f32)
+
+TEST (long, longx1_t, l)
+
+TEST (int, intx1_t, i)
+
+TEST (short, int16x1_t, s16)
+
+TEST (char, int8x1_t, s8)