aarch64: SVE: ICE in expand_direct_optab_fn [PR98177]

Problem comes from using the wrong interface to get the index type for a
COND_REDUCTION. For fixed-length SVE we get a V2SI (a 64-bit Advanced
SIMD vector) instead of a VNx2SI (an SVE vector that stores SI elements
in DI containers).

Credits to Richard Sandiford for pointing out the issue's root cause.

Original PR snippet proposed to reproduce issue was only causing ICE for C++
compiler (see pr98177-1 test cases). I've slightly modified original
snippet in order to reproduce issue on both C and C++ compilers. These
are pr98177-2 test cases.

gcc/ChangeLog:

	PR target/98177
	* tree-vect-loop.c (vect_create_epilog_for_reduction): Use
	get_same_sized_vectype to obtain index type.
	(vectorizable_reduction): Likewise.

gcc/testsuite/ChangeLog:

	PR target/98177
	* g++.target/aarch64/sve/pr98177-1.C: New test.
	* g++.target/aarch64/sve/pr98177-2.C: New test.
	* gcc.target/aarch64/sve/pr98177-1.c: New test.
	* gcc.target/aarch64/sve/pr98177-2.c: New test.

diff --git a/gcc/testsuite/g++.target/aarch64/sve/pr98177-1.C b/gcc/testsuite/g++.target/aarch64/sve/pr98177-1.C
new file mode 100644 (file)
index 0000000..9789193
--- /dev/null
+++ b/gcc/testsuite/g++.target/aarch64/sve/pr98177-1.C
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Ofast -msve-vector-bits=128" } */
+
+int a, b;
+short c;
+void d(long e) {
+  for (int f = 0; f < b; f += 1)
+    for (short g = 0; g < c; g += 5)
+      a = (short)e;
+}

diff --git a/gcc/testsuite/g++.target/aarch64/sve/pr98177-2.C b/gcc/testsuite/g++.target/aarch64/sve/pr98177-2.C
new file mode 100644 (file)
index 0000000..c7244ef
--- /dev/null
+++ b/gcc/testsuite/g++.target/aarch64/sve/pr98177-2.C
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Ofast -msve-vector-bits=128" } */
+
+int a, b, c;
+
+void foo(long e) {
+  for (int f = 0; f < b; f ++)
+    for (int g = 0; g < c; g ++)
+      a = (short)e;
+}

diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pr98177-1.c b/gcc/testsuite/gcc.target/aarch64/sve/pr98177-1.c
new file mode 100644 (file)
index 0000000..9789193
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/pr98177-1.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Ofast -msve-vector-bits=128" } */
+
+int a, b;
+short c;
+void d(long e) {
+  for (int f = 0; f < b; f += 1)
+    for (short g = 0; g < c; g += 5)
+      a = (short)e;
+}

diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pr98177-2.c b/gcc/testsuite/gcc.target/aarch64/sve/pr98177-2.c
new file mode 100644 (file)
index 0000000..c7244ef
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/pr98177-2.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Ofast -msve-vector-bits=128" } */
+
+int a, b, c;
+
+void foo(long e) {
+  for (int f = 0; f < b; f ++)
+    for (int g = 0; g < c; g ++)
+      a = (short)e;
+}

diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 688538a4521c740d6982c23a4d3ea0e02c16f901..d6f1ffcd386c1e0b63cac21fabf8e5bad9be99ca 100644 (file)
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -5278,8 +5278,8 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo,
       int scalar_precision
        = GET_MODE_PRECISION (SCALAR_TYPE_MODE (scalar_type));
       tree scalar_type_unsigned = make_unsigned_type (scalar_precision);
-      tree vectype_unsigned = build_vector_type
-       (scalar_type_unsigned, TYPE_VECTOR_SUBPARTS (vectype));
+      tree vectype_unsigned = get_same_sized_vectype (scalar_type_unsigned,
+                                               vectype);
 
       /* First we need to create a vector (ZERO_VEC) of zeros and another
         vector (MAX_INDEX_VEC) filled with the last matching index, which we
@@ -6942,8 +6942,8 @@ vectorizable_reduction (loop_vec_info loop_vinfo,
       int scalar_precision
        = GET_MODE_PRECISION (SCALAR_TYPE_MODE (scalar_type));
       cr_index_scalar_type = make_unsigned_type (scalar_precision);
-      cr_index_vector_type = build_vector_type (cr_index_scalar_type,
-                                               nunits_out);
+      cr_index_vector_type = get_same_sized_vectype (cr_index_scalar_type,
+                                               vectype_out);
 
       if (direct_internal_fn_supported_p (IFN_REDUC_MAX, cr_index_vector_type,
                                          OPTIMIZE_FOR_SPEED))