On Fri, Aug 16, 2019 at 1:10 PM Richard Biener wrote:
>
>
> The following fixes PR91469 where STV replaced uses inside address
> expressions. The issue arises here because convert_regs is called
> before convert_insns which eventually splits out memory operands.
>
> Bootstrapped / tested on x86_64-unknown-linux-gnu, OK?
>
> Thanks,
> Richard.
>
> 2019-08-16 Richard Biener
>
> PR target/91469
> * config/i386/i386-features.c
> (general_scalar_chain::replace_with_subreg): Stop at memory operands.
>
> * gcc.target/i386/pr91469-1.c: New testcase.
> * gcc.target/i386/pr91469-2.c: Likewise.
OK.
Thanks,
Uros.
> Index: gcc/config/i386/i386-features.c
> ===
> --- gcc/config/i386/i386-features.c (revision 274536)
> +++ gcc/config/i386/i386-features.c (working copy)
> @@ -613,6 +613,10 @@ general_scalar_chain::replace_with_subre
>if (x == reg)
> return gen_rtx_SUBREG (vmode, new_reg, 0);
>
> + /* But not in memory addresses. */
> + if (MEM_P (x))
> +return x;
> +
>const char *fmt = GET_RTX_FORMAT (GET_CODE (x));
>int i, j;
>for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
> Index: gcc/testsuite/gcc.target/i386/pr91469-1.c
> ===
> --- gcc/testsuite/gcc.target/i386/pr91469-1.c (nonexistent)
> +++ gcc/testsuite/gcc.target/i386/pr91469-1.c (working copy)
> @@ -0,0 +1,17 @@
> +/* { dg-do compile } */
> +/* { dg-options "-funroll-loops -O2 -fno-gcse -mavx512vbmi -fno-ivopts
> -mstv" } */
> +
> +int a, b, e;
> +long long c;
> +int d[6];
> +
> +void fn1() {
> +int i;
> +unsigned f;
> +c = a;
> +f = i;
> +for (; i < b; i++)
> + if (d[i] > f)
> + f = d[i];
> +e = f;
> +}
> Index: gcc/testsuite/gcc.target/i386/pr91469-2.c
> ===
> --- gcc/testsuite/gcc.target/i386/pr91469-2.c (nonexistent)
> +++ gcc/testsuite/gcc.target/i386/pr91469-2.c (working copy)
> @@ -0,0 +1,11 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Os --param scev-max-expr-size=0 -mavx512vnni
> -funroll-all-loops" } */
> +
> +int a, b, c, d;
> +int *e;
> +void fn1()
> +{
> + b = c > 0 ? c : 0;
> + d += e[b];
> + a = d > 0 ? d : 0;
> +}
