On December 2, 2019 5:27:05 PM GMT+01:00, Richard Sandiford
<richard.sandif...@arm.com> wrote:
>In this PR, IPA-CP was misled into using NOP_EXPR rather than
>VIEW_CONVERT_EXPR to reinterpret a vector of 4 shorts as a vector
>of 2 ints. This tripped the tree-cfg.c assert I'd added in r278245.
>
>Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Hmm, but then it may create such conversion without verifying the target
supports it?
Richard.
>Richard
>
>
>2019-12-02 Richard Sandiford <richard.sandif...@arm.com>
>
>gcc/
> PR middle-end/92741
> * fold-const.c (fold_convertible_p): Check vector types more
> thoroughly.
>
>gcc/testsuite/
> PR middle-end/92741
> * gcc.dg/pr92741.c: New test.
>
>Index: gcc/fold-const.c
>===================================================================
>--- gcc/fold-const.c 2019-11-18 15:27:36.053367794 +0000
>+++ gcc/fold-const.c 2019-12-02 16:25:02.662405351 +0000
>@@ -2375,10 +2375,15 @@ fold_convertible_p (const_tree type, con
>
> case REAL_TYPE:
> case FIXED_POINT_TYPE:
>- case VECTOR_TYPE:
> case VOID_TYPE:
> return TREE_CODE (type) == TREE_CODE (orig);
>
>+ case VECTOR_TYPE:
>+ return (VECTOR_TYPE_P (orig)
>+ && known_eq (TYPE_VECTOR_SUBPARTS (type),
>+ TYPE_VECTOR_SUBPARTS (orig))
>+ && fold_convertible_p (TREE_TYPE (type), TREE_TYPE (orig)));
>+
> default:
> return false;
> }
>Index: gcc/testsuite/gcc.dg/pr92741.c
>===================================================================
>--- /dev/null 2019-09-17 11:41:18.176664108 +0100
>+++ gcc/testsuite/gcc.dg/pr92741.c 2019-12-02 16:25:02.662405351 +0000
>@@ -0,0 +1,19 @@
>+/* { dg-options "-O2 -fexceptions -fnon-call-exceptions -fno-inline" }
>*/
>+
>+typedef int vh __attribute__ ((__vector_size__ (2 * sizeof (int))));
>+typedef short int cq __attribute__ ((__vector_size__ (4 * sizeof
>(short int))));
>+
>+static void
>+id (int *r8, vh *tu)
>+{
>+ *(vh *) r8 = *tu;
>+}
>+
>+void
>+mr (void)
>+{
>+ int r8;
>+ cq he = { 0, };
>+
>+ id (&r8, (vh *) &he);
>+}
