Re: [PATCH] Small hack for DECL_MODE lack of vector_type_mode-like behavior (PR target/78643, PR target/80583)

[Richard Biener <rguenther@suse.de>]

On December 2, 2017 1:14:15 AM GMT+01:00, Jakub Jelinek <jakub@redhat.com> wrote:
>Hi!
>
>In TYPE_MODE we have a hack for vector types where we dynamically
>adjust it based on whether it is used from a function where the vector
>mode
>is or isn't supported (depending on target attribute, function
>multiversioning, etc.), but we don't have anything like that in
>DECL_MODE.
>
>The following is just a small hack that should be backportable to
>adjust
>similarly DECL_MODE when looking at fields - for static VAR_DECLs we
>already
>have code to cope with that, furthermore we need to cope there with the
>case where DECL_RTL is created in one context and used in another one.
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK. 

Richard. 

>2017-12-01  Jakub Jelinek  <jakub@redhat.com>
>
>	PR target/78643
>	PR target/80583
>	* expr.c (get_inner_reference): If DECL_MODE of a non-bitfield
>	is BLKmode for vector field with vector raw mode, use TYPE_MODE
>	instead of DECL_MODE.
>
>	* gcc.target/i386/pr80583.c: New test.
>
>--- gcc/expr.c.jj	2017-11-27 09:27:41.000000000 +0100
>+++ gcc/expr.c	2017-12-01 11:36:19.011863308 +0100
>@@ -7032,7 +7032,16 @@ get_inner_reference (tree exp, HOST_WIDE
> 	     size.  */
> 	mode = TYPE_MODE (DECL_BIT_FIELD_TYPE (field));
>       else if (!DECL_BIT_FIELD (field))
>-	mode = DECL_MODE (field);
>+	{
>+	  mode = DECL_MODE (field);
>+	  /* For vector fields re-check the target flags, as DECL_MODE
>+	     could have been set with different target flags than
>+	     the current function has.  */
>+	  if (mode == BLKmode
>+	      && VECTOR_TYPE_P (TREE_TYPE (field))
>+	      && VECTOR_MODE_P (TYPE_MODE_RAW (TREE_TYPE (field))))
>+	    mode = TYPE_MODE (TREE_TYPE (field));
>+	}
>       else if (DECL_MODE (field) == BLKmode)
> 	blkmode_bitfield = true;
> 
>--- gcc/testsuite/gcc.target/i386/pr80583.c.jj	2017-12-01
>11:44:28.106603314 +0100
>+++ gcc/testsuite/gcc.target/i386/pr80583.c	2017-12-01
>11:44:12.000000000 +0100
>@@ -0,0 +1,13 @@
>+/* PR target/80583 */
>+/* { dg-do compile } */
>+/* { dg-options "-O0 -mno-avx" } */
>+
>+typedef int V __attribute__((__vector_size__(32)));
>+struct S { V a; };
>+
>+V __attribute__((target ("avx")))
>+foo (struct S *b)
>+{
>+  V x = b->a;
>+  return x;
>+}
>
>	Jakub