On Thu, Mar 21, 2024 at 9:35 AM liuhongt wrote:
>
> wi::from_mpz doesn't take a sign argument, we want it to be wrapped
> instead of saturation, so pass utype and true to it, and it fixes the
> bug.
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}.
> Ok for trunk and backport to gcc13?
OK for both.
Thanks,
Richard.
> gcc/ChangeLog:
>
> PR tree-optimization/114396
> * tree-vect-loop.cc (vect_peel_nonlinear_iv_init): Pass utype
> and true to wi::from_mpz.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/pr114396.c: New test.
> ---
> gcc/testsuite/gcc.target/i386/pr114396.c | 105 +++
> gcc/tree-vect-loop.cc| 2 +-
> 2 files changed, 106 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr114396.c
>
> diff --git a/gcc/testsuite/gcc.target/i386/pr114396.c
> b/gcc/testsuite/gcc.target/i386/pr114396.c
> new file mode 100644
> index 000..4c4015f871f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr114396.c
> @@ -0,0 +1,105 @@
> +/* { dg-do run } */
> +/* { dg-options "-O1 -fwrapv -fno-vect-cost-model" } */
> +
> +short a = 0xF;
> +short b[16];
> +unsigned short ua = 0xF;
> +unsigned short ub[16];
> +
> +short
> +__attribute__((noipa))
> +foo (short a)
> +{
> + for (int e = 0; e < 9; e += 1)
> +b[e] = a *= 5;
> + return a;
> +}
> +
> +short
> +__attribute__((noipa))
> +foo1 (short a)
> +{
> + for (int e = 0; e < 9; e += 1)
> +b[e] = a *= -5;
> + return a;
> +}
> +
> +unsigned short
> +__attribute__((noipa))
> +foou (unsigned short a)
> +{
> + for (int e = 0; e < 9; e += 1)
> +ub[e] = a *= -5;
> + return a;
> +}
> +
> +unsigned short
> +__attribute__((noipa))
> +foou1 (unsigned short a)
> +{
> + for (int e = 0; e < 9; e += 1)
> +ub[e] = a *= 5;
> + return a;
> +}
> +
> +short
> +__attribute__((noipa,optimize("O3")))
> +foo_o3 (short a)
> +{
> + for (int e = 0; e < 9; e += 1)
> +b[e] = a *= 5;
> + return a;
> +}
> +
> +short
> +__attribute__((noipa,optimize("O3")))
> +foo1_o3 (short a)
> +{
> + for (int e = 0; e < 9; e += 1)
> +b[e] = a *= -5;
> + return a;
> +}
> +
> +unsigned short
> +__attribute__((noipa,optimize("O3")))
> +foou_o3 (unsigned short a)
> +{
> + for (int e = 0; e < 9; e += 1)
> +ub[e] = a *= -5;
> + return a;
> +}
> +
> +unsigned short
> +__attribute__((noipa,optimize("O3")))
> +foou1_o3 (unsigned short a)
> +{
> + for (int e = 0; e < 9; e += 1)
> +ub[e] = a *= 5;
> + return a;
> +}
> +
> +int main() {
> + unsigned short uexp, ures;
> + short exp, res;
> + exp = foo (a);
> + res = foo_o3 (a);
> + if (exp != res)
> +__builtin_abort ();
> +
> + exp = foo1 (a);
> + res = foo1_o3 (a);
> + if (uexp != ures)
> +__builtin_abort ();
> +
> + uexp = foou (a);
> + ures = foou_o3 (a);
> + if (uexp != ures)
> +__builtin_abort ();
> +
> + uexp = foou1 (a);
> + ures = foou1_o3 (a);
> + if (uexp != ures)
> +__builtin_abort ();
> +
> + return 0;
> +}
> diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
> index 4375ebdcb49..2921a9e6aa1 100644
> --- a/gcc/tree-vect-loop.cc
> +++ b/gcc/tree-vect-loop.cc
> @@ -9454,7 +9454,7 @@ vect_peel_nonlinear_iv_init (gimple_seq* stmts, tree
> init_expr,
> wi::to_mpz (skipn, exp, UNSIGNED);
> mpz_ui_pow_ui (mod, 2, TYPE_PRECISION (type));
> mpz_powm (res, base, exp, mod);
> - begin = wi::from_mpz (type, res, TYPE_SIGN (type));
> + begin = wi::from_mpz (utype, res, true);
> tree mult_expr = wide_int_to_tree (utype, begin);
> init_expr = gimple_build (stmts, MULT_EXPR, utype,
> init_expr, mult_expr);
> --
> 2.31.1
>
