[PATCH] i386: Skip decimal float vector modes in type_natural_mode [PR79754]

[Uros Bizjak via Gcc-patches]

2022-02-12  Uroš Bizjak  <ubiz...@gmail.com>

gcc/ChangeLog:

    PR target/79754
    * config/i386/i386.cc (type_natural_mode):
    Skip decimal float vector modes.

gcc/testsuite/ChangeLog:

    PR target/79754
    * gcc.target/i386/pr79754.c: New test.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

Pushed to master.

Uros.

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 6b97a2b0e50..cf246e74e57 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -1876,10 +1876,14 @@ type_natural_mode (const_tree type, const 
CUMULATIVE_ARGS *cum,
        {
          machine_mode innermode = TYPE_MODE (TREE_TYPE (type));
 
-         /* There are no XFmode vector modes.  */
+         /* There are no XFmode vector modes ...  */
          if (innermode == XFmode)
            return mode;
 
+         /* ... and no decimal float vector modes.  */
+         if (DECIMAL_FLOAT_MODE_P (innermode))
+           return mode;
+
          if (TREE_CODE (TREE_TYPE (type)) == REAL_TYPE)
            mode = MIN_MODE_VECTOR_FLOAT;
          else
diff --git a/gcc/testsuite/gcc.target/i386/pr79754.c 
b/gcc/testsuite/gcc.target/i386/pr79754.c
new file mode 100644
index 00000000000..27845c9d5b9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr79754.c
@@ -0,0 +1,7 @@
+/* PR target/79754 */
+/* { dg-do compile } */
+/* { dg-options "-Wno-psabi" } */
+
+typedef _Decimal32 V __attribute__ ((vector_size(16)));
+
+V fn1 (V a) { return a; }