Jakub Jelinek <ja...@redhat.com> writes:
> Hi!
>
> The following testcase ICEs, because aarch64_gen_compare_reg_maybe_ze emits
> invalid RTL.
> For y_mode [QH]Imode it expects y to be of that mode (or CONST_INT that fits
> into that mode) and x being SImode; for non-CONST_INT y it zero extends y
> into SImode and compares that against x, for CONST_INT y it zero extends y
> into SImode. The problem is that when the zero extended constant isn't
> usable directly, it forces it into a REG, but with y_mode mode, and then
> compares against y. That is wrong, because it should force it into a SImode
> REG and compare that way.
>
> The following patch fixes that, bootstrapped/regtested on aarch64-linux, ok
> for trunk?
>
> 2020-04-01 Jakub Jelinek <ja...@redhat.com>
>
> PR target/94435
> * config/aarch64/aarch64.c (aarch64_gen_compare_reg_maybe_ze): For
> y_mode E_[QH]Imode and y being a CONST_INT, change y_mode to SImode.
>
> * gcc.target/aarch64/pr94435.c: New test.
OK, thanks.
Richard
>
> --- gcc/config/aarch64/aarch64.c.jj 2020-03-30 17:02:28.000000000 +0200
> +++ gcc/config/aarch64/aarch64.c 2020-04-01 11:32:48.877900235 +0200
> @@ -2371,7 +2371,10 @@ aarch64_gen_compare_reg_maybe_ze (RTX_CO
> if (y_mode == E_QImode || y_mode == E_HImode)
> {
> if (CONST_INT_P (y))
> - y = GEN_INT (INTVAL (y) & GET_MODE_MASK (y_mode));
> + {
> + y = GEN_INT (INTVAL (y) & GET_MODE_MASK (y_mode));
> + y_mode = SImode;
> + }
> else
> {
> rtx t, cc_reg;
> --- gcc/testsuite/gcc.target/aarch64/pr94435.c.jj 2020-04-01
> 11:36:21.172797217 +0200
> +++ gcc/testsuite/gcc.target/aarch64/pr94435.c 2020-04-01
> 11:36:36.493573280 +0200
> @@ -0,0 +1,25 @@
> +/* PR target/94435 */
> +/* { dg-do compile } */
> +/* { dg-options "-march=armv8-a+nolse -moutline-atomics" } */
> +
> +int b, c, d, e, f, h;
> +short g;
> +int foo (int) __attribute__ ((__const__));
> +
> +void
> +bar (void)
> +{
> + while (1)
> + {
> + while (1)
> + {
> + __atomic_load_n (&e, 0);
> + if (foo (2))
> + __sync_val_compare_and_swap (&c, 0, f);
> + b = 1;
> + if (h == e)
> + break;
> + }
> + __sync_val_compare_and_swap (&g, -1, f);
> + }
> +}
>
> Jakub
