middle-end/96814 - fix VECTOR_BOOLEAN_TYPE_P CTOR RTL expansion

The RTL expansion code for CTORs doesn't handle VECTOR_BOOLEAN_TYPE_P
with bit-precision elements correctly as the testcase shows before
the PR97085 fix.  The following makes it do the correct thing
(not 100% sure for CTOR of sub-vectors due to the lack of a testcase).

The alternative would be to assert such CTORs do not happen (and also
add IL verification for this).

The GIMPLE FE needs a way to declare the VECTOR_BOOLEAN_TYPE_P vectors
(thus the C FE needs that).

2020-09-25  Richard Biener  <rguenther@suse.de>

	PR middle-end/96814
	* expr.c (store_constructor): Handle VECTOR_BOOLEAN_TYPE_P
	CTORs correctly.

	* gcc.target/i386/pr96814.c: New testcase.

diff --git a/gcc/expr.c b/gcc/expr.c
index 1a15f24b3979abae628c0fd9857f62d70c149d33..1c79518ee4dcb2de0628cc39e4367e90888fb2d2 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -6922,7 +6922,7 @@ store_constructor (tree exp, rtx target, int cleared, poly_int64 size,
        insn_code icode = CODE_FOR_nothing;
        tree elt;
        tree elttype = TREE_TYPE (type);
-       int elt_size = tree_to_uhwi (TYPE_SIZE (elttype));
+       int elt_size = vector_element_bits (type);
        machine_mode eltmode = TYPE_MODE (elttype);
        HOST_WIDE_INT bitsize;
        HOST_WIDE_INT bitpos;
@@ -6987,6 +6987,15 @@ store_constructor (tree exp, rtx target, int cleared, poly_int64 size,
              }
          }
 
+       /* Compute the size of the elements in the CTOR.  It differs
+          from the size of the vector type elements only when the
+          CTOR elements are vectors themselves.  */
+       tree val_type = TREE_TYPE (CONSTRUCTOR_ELT (exp, 0)->value);
+       if (VECTOR_TYPE_P (val_type))
+         bitsize = tree_to_uhwi (TYPE_SIZE (val_type));
+       else
+         bitsize = elt_size;
+
        /* If the constructor has fewer elements than the vector,
           clear the whole array first.  Similarly if this is static
           constructor of a non-BLKmode object.  */
@@ -7001,11 +7010,7 @@ store_constructor (tree exp, rtx target, int cleared, poly_int64 size,
 
            FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
              {
-               tree sz = TYPE_SIZE (TREE_TYPE (value));
-               int n_elts_here
-                 = tree_to_uhwi (int_const_binop (TRUNC_DIV_EXPR, sz,
-                                                  TYPE_SIZE (elttype)));
-
+               int n_elts_here = bitsize / elt_size;
                count += n_elts_here;
                if (mostly_zeros_p (value))
                  zero_count += n_elts_here;
@@ -7045,7 +7050,6 @@ store_constructor (tree exp, rtx target, int cleared, poly_int64 size,
            HOST_WIDE_INT eltpos;
            tree value = ce->value;
 
-           bitsize = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (value)));
            if (cleared && initializer_zerop (value))
              continue;
 

diff --git a/gcc/testsuite/gcc.target/i386/pr96814.c b/gcc/testsuite/gcc.target/i386/pr96814.c
new file mode 100644 (file)
index 0000000..b280c73
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96814.c
@@ -0,0 +1,19 @@
+/* { dg-do run } */
+/* { dg-options "-mavx512vl -mavx512bw" } */
+/* { dg-require-effective-target avx512bw } */
+/* { dg-require-effective-target avx512vl } */
+
+typedef unsigned char __attribute__ ((__vector_size__ (32))) V;
+
+void
+test (void)
+{
+  V x = ((V){8} > 0) == 0;
+  for (unsigned i = 0; i < sizeof (x); i++)
+    if (x[i] != (i ? 0xff : 0)) __builtin_abort();
+}
+
+#define DO_TEST test
+#define AVX512VL
+#define AVX512BW
+#include "avx512-check.h"