On April 11, 2017 10:54:10 PM GMT+02:00, Jakub Jelinek <ja...@redhat.com> wrote:
>Hi!
>
>This is another case where we miss needed folding from argN or their
>arguments to the expected expression type (type has to be compatible
>with opN's type, but argN is after STRIP_NOPS).
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
>2017-04-11 Jakub Jelinek <ja...@redhat.com>
>
> PR sanitizer/80349
> * fold-const.c (fold_binary_loc) <case BIT_IOR_EXPR>: Convert arg0's
> first argument to type.
>
> * g++.dg/ubsan/pr80349.C: New test.
>
>--- gcc/fold-const.c.jj 2017-04-10 22:27:00.000000000 +0200
>+++ gcc/fold-const.c 2017-04-11 20:07:02.459839450 +0200
>@@ -9916,12 +9916,12 @@ fold_binary_loc (location_t loc,
> }
>
> if (c3 != c1)
>- return fold_build2_loc (loc, BIT_IOR_EXPR, type,
>- fold_build2_loc (loc, BIT_AND_EXPR, type,
>- TREE_OPERAND (arg0, 0),
>- wide_int_to_tree (type,
>- c3)),
>- arg1);
>+ {
>+ tem = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
>+ tem = fold_build2_loc (loc, BIT_AND_EXPR, type, tem,
>+ wide_int_to_tree (type, c3));
>+ return fold_build2_loc (loc, BIT_IOR_EXPR, type, tem, arg1);
>+ }
> }
>
> /* See if this can be simplified into a rotate first. If that
>--- gcc/testsuite/g++.dg/ubsan/pr80349.C.jj 2017-04-11
>20:29:10.154344673 +0200
>+++ gcc/testsuite/g++.dg/ubsan/pr80349.C 2017-04-11 20:28:38.000000000
>+0200
>@@ -0,0 +1,11 @@
>+// PR sanitizer/80349
>+// { dg-do compile }
>+// { dg-options "-fsanitize=undefined" }
>+
>+extern const long long int v;
>+
>+void
>+foo ()
>+{
>+ (int)((v & 50 | 051UL) << 0) << 0;
>+}
>
> Jakub
