On Thu, Nov 23, 2023 at 11:05 AM Jakub Jelinek <ja...@redhat.com> wrote:
>
> Hi!
>
> As the following testcase shows, we ICE when trying to emit ADDR_EXPR of
> a bitint variable which doesn't have mode width.
> The problem is in the EXTEND_BITINT stuff which makes sure we treat the
> padding bits on memory reads from user bitint vars as undefined.
> When expanding ADDR_EXPR on such vars inside outside of initializers,
> expand_expr_addr* uses EXPAND_CONST_ADDRESS modifier and EXTEND_BITINT
> does nothing, but in initializers it keeps using EXPAND_INITIALIZER
> modifier. So, we need to treat EXPAND_INITIALIZER the same as
> EXPAND_CONST_ADDRESS for this regard.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
> 2023-11-23 Jakub Jelinek <ja...@redhat.com>
>
> PR middle-end/112336
> * expr.cc (EXTEND_BITINT): Don't call reduce_to_bit_field_precision
> if modifier is EXPAND_INITIALIZER.
>
> * gcc.dg/bitint-41.c: New test.
>
> --- gcc/expr.cc.jj 2023-11-14 18:26:05.401613476 +0100
> +++ gcc/expr.cc 2023-11-22 19:03:59.121599029 +0100
> @@ -10698,6 +10698,7 @@ expand_expr_real_1 (tree exp, rtx target
> && mode != BLKmode \
> && modifier != EXPAND_MEMORY \
> && modifier != EXPAND_WRITE
> \
> + && modifier != EXPAND_INITIALIZER \
> && modifier != EXPAND_CONST_ADDRESS) \
> ? reduce_to_bit_field_precision ((expr), NULL_RTX, type) : (expr))
>
> --- gcc/testsuite/gcc.dg/bitint-41.c.jj 2023-11-22 19:09:48.986726861 +0100
> +++ gcc/testsuite/gcc.dg/bitint-41.c 2023-11-22 19:09:29.804993983 +0100
> @@ -0,0 +1,36 @@
> +/* PR middle-end/112336 */
> +/* { dg-do compile { target bitint } } */
> +/* { dg-options "-std=c2x" } */
> +
> +unsigned _BitInt(1) v1;
> +unsigned _BitInt(1) *p1 = &v1;
> +signed _BitInt(2) v2;
> +signed _BitInt(2) *p2 = &v2;
> +unsigned _BitInt(11) v11;
> +unsigned _BitInt(11) *p11 = &v11;
> +signed _BitInt(12) v12;
> +signed _BitInt(12) *p12 = &v12;
> +unsigned _BitInt(21) v21;
> +unsigned _BitInt(21) *p21 = &v21;
> +signed _BitInt(22) v22;
> +signed _BitInt(22) *p22 = &v22;
> +unsigned _BitInt(31) v31;
> +unsigned _BitInt(31) *p31 = &v31;
> +signed _BitInt(32) v32;
> +signed _BitInt(32) *p32 = &v32;
> +unsigned _BitInt(41) v41;
> +unsigned _BitInt(41) *p41 = &v41;
> +signed _BitInt(42) v42;
> +signed _BitInt(42) *p42 = &v42;
> +#if __BITINT_MAXWIDTH__ >= 128
> +unsigned _BitInt(127) v127;
> +unsigned _BitInt(127) *p127 = &v127;
> +signed _BitInt(128) v128;
> +signed _BitInt(128) *p128 = &v128;
> +#endif
> +#if __BITINT_MAXWIDTH__ >= 258
> +unsigned _BitInt(257) v257;
> +unsigned _BitInt(257) *p257 = &v257;
> +signed _BitInt(258) v258;
> +signed _BitInt(258) *p258 = &v258;
> +#endif
>
> Jakub
>
