The following backports a fix I applied to match.pd whilst merging
from match-and-simplify to the original tree-ssa-forwprop.c code
on the 4.9 branch.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2014-11-21 Richard Biener <rguent...@suse.de>
PR tree-optimization/61750
* tree-ssa-forwprop.c (simplify_vce): Verify type sizes
match for the resulting VIEW_CONVERT_EXPR.
Index: gcc/tree-ssa-forwprop.c
===================================================================
--- gcc/tree-ssa-forwprop.c (revision 217764)
+++ gcc/tree-ssa-forwprop.c (working copy)
@@ -3178,7 +3178,9 @@ simplify_vce (gimple_stmt_iterator *gsi)
&& (INTEGRAL_TYPE_P (TREE_TYPE (def_op))
|| POINTER_TYPE_P (TREE_TYPE (def_op)))
&& (TYPE_PRECISION (TREE_TYPE (op))
- == TYPE_PRECISION (TREE_TYPE (def_op))))
+ == TYPE_PRECISION (TREE_TYPE (def_op)))
+ && (TYPE_SIZE (TREE_TYPE (op))
+ == TYPE_SIZE (TREE_TYPE (def_op))))
{
TREE_OPERAND (gimple_assign_rhs1 (stmt), 0) = def_op;
update_stmt (stmt);
