[gcc r12-8710] vect: Don't allow vect_emulated_vector_p type in vectorizable_call [PR106322]

[Kewen Lin]

https://gcc.gnu.org/g:9f532fec01d6651cc3cc136073f044a7953d8560

commit r12-8710-g9f532fec01d6651cc3cc136073f044a7953d8560
Author: Kewen Lin <linkw@linux.ibm.com>
Date:   Tue Aug 16 00:18:51 2022 -0500

    vect: Don't allow vect_emulated_vector_p type in vectorizable_call [PR106322]
    
    As PR106322 shows, in some cases for some vector type whose
    TYPE_MODE is a scalar integral mode instead of a vector mode,
    it's possible to obtain wrong target support information when
    querying with the scalar integral mode.  For example, for the
    test case in PR106322, on ppc64 32bit vectorizer gets vector
    type "vector(2) short unsigned int" for scalar type "short
    unsigned int", its mode is SImode instead of V2HImode.  The
    target support querying checks umul_highpart optab with SImode
    and considers it's supported, then vectorizer further generates
    .MULH IFN call for that vector type.  Unfortunately it's wrong
    to use SImode support for that vector type multiply highpart
    here.
    
    This patch is to teach vectorizable_call analysis not to allow
    vect_emulated_vector_p type for both vectype_in and vectype_out
    as Richi suggested.
    
            PR tree-optimization/106322
    
    gcc/ChangeLog:
    
            * tree-vect-stmts.cc (vectorizable_call): Don't allow
            vect_emulated_vector_p type for both vectype_in and vectype_out.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/i386/pr106322.c: New test.
            * gcc.target/powerpc/pr106322.c: New test.
    
    (cherry picked from commit 5239e2bd48fb1e6a1d1b06a1bac49bee0a742e98)

Diff:
---
 gcc/testsuite/gcc.target/i386/pr106322.c    | 51 +++++++++++++++++++++++++++++
 gcc/testsuite/gcc.target/powerpc/pr106322.c | 50 ++++++++++++++++++++++++++++
 gcc/tree-vect-stmts.cc                      |  8 +++++
 3 files changed, 109 insertions(+)

diff --git a/gcc/testsuite/gcc.target/i386/pr106322.c b/gcc/testsuite/gcc.target/i386/pr106322.c
new file mode 100644
index 00000000000..31333c5fdcc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr106322.c
@@ -0,0 +1,51 @@
+/* { dg-do run } */
+/* { dg-require-effective-target ia32 } */
+/* { dg-options "-O2 -mtune=generic -march=i686" } */
+
+/* As PR106322, verify this can execute well (not abort).  */
+
+#define N 64
+typedef unsigned short int uh;
+typedef unsigned short int uw;
+uh a[N];
+uh b[N];
+uh c[N];
+uh e[N];
+
+__attribute__ ((noipa)) void
+foo ()
+{
+  for (int i = 0; i < N; i++)
+    c[i] = ((uw) b[i] * (uw) a[i]) >> 16;
+}
+
+__attribute__ ((optimize ("-O0"))) void
+init ()
+{
+  for (int i = 0; i < N; i++)
+    {
+      a[i] = (uh) (0x7ABC - 0x5 * i);
+      b[i] = (uh) (0xEAB + 0xF * i);
+      e[i] = ((uw) b[i] * (uw) a[i]) >> 16;
+    }
+}
+
+__attribute__ ((optimize ("-O0"))) void
+check ()
+{
+  for (int i = 0; i < N; i++)
+    {
+      if (c[i] != e[i])
+	__builtin_abort ();
+    }
+}
+
+int
+main ()
+{
+  init ();
+  foo ();
+  check ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/powerpc/pr106322.c b/gcc/testsuite/gcc.target/powerpc/pr106322.c
new file mode 100644
index 00000000000..c05072d3416
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr106322.c
@@ -0,0 +1,50 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -mdejagnu-cpu=power4" } */
+
+/* As PR106322, verify this can execute well (not abort).  */
+
+#define N 64
+typedef unsigned short int uh;
+typedef unsigned short int uw;
+uh a[N];
+uh b[N];
+uh c[N];
+uh e[N];
+
+__attribute__ ((noipa)) void
+foo ()
+{
+  for (int i = 0; i < N; i++)
+    c[i] = ((uw) b[i] * (uw) a[i]) >> 16;
+}
+
+__attribute__ ((optimize ("-O0"))) void
+init ()
+{
+  for (int i = 0; i < N; i++)
+    {
+      a[i] = (uh) (0x7ABC - 0x5 * i);
+      b[i] = (uh) (0xEAB + 0xF * i);
+      e[i] = ((uw) b[i] * (uw) a[i]) >> 16;
+    }
+}
+
+__attribute__ ((optimize ("-O0"))) void
+check ()
+{
+  for (int i = 0; i < N; i++)
+    {
+      if (c[i] != e[i])
+	__builtin_abort ();
+    }
+}
+
+int
+main ()
+{
+  init ();
+  foo ();
+  check ();
+
+  return 0;
+}
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index d8da13e312a..4c5d20a0e2c 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -3419,6 +3419,14 @@ vectorizable_call (vec_info *vinfo,
       return false;
     }
 
+  if (vect_emulated_vector_p (vectype_in) || vect_emulated_vector_p (vectype_out))
+  {
+      if (dump_enabled_p ())
+	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			 "use emulated vector type for call\n");
+      return false;
+  }
+
   /* FORNOW */
   nunits_in = TYPE_VECTOR_SUBPARTS (vectype_in);
   nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);