On Fri, Aug 9, 2024 at 9:29 AM Jakub Jelinek <[email protected]> wrote:
>
> Hi!
>
> The GENERIC folding of these builtins have cases where it folds to a
> constant regardless of the value of the first operand. If so, we need
> to use omit_one_operand to avoid throwing away side-effects in the first
> operand if any. The cases which verify the first argument is INTEGER_CST
> don't need that, INTEGER_CST doesn't have side-effects.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2024-08-09 Jakub Jelinek <[email protected]>
>
> PR target/116287
> * config/i386/i386.cc (ix86_fold_builtin) <case IX86_BUILTIN_BEXTR32>:
> When folding into zero without checking whether first argument is
> constant, use omit_one_operand.
> (ix86_fold_builtin) <case IX86_BUILTIN_BZHI32>: Likewise.
>
> * gcc.target/i386/bmi-pr116287.c: New test.
> * gcc.target/i386/bmi2-pr116287.c: New test.
> * gcc.target/i386/tbm-pr116287.c: New test.
Rubberstamp OK.
Thanks,
Uros.
>
> --- gcc/config/i386/i386.cc.jj 2024-08-01 14:33:28.172801480 +0200
> +++ gcc/config/i386/i386.cc 2024-08-08 12:55:12.780696418 +0200
> @@ -18549,9 +18549,11 @@ ix86_fold_builtin (tree fndecl, int n_ar
> unsigned int prec = TYPE_PRECISION (TREE_TYPE (args[0]));
> unsigned int start = tree_to_uhwi (args[1]);
> unsigned int len = (start & 0xff00) >> 8;
> + tree lhs_type = TREE_TYPE (TREE_TYPE (fndecl));
> start &= 0xff;
> if (start >= prec || len == 0)
> - res = 0;
> + return omit_one_operand (lhs_type, build_zero_cst (lhs_type),
> + args[0]);
> else if (!tree_fits_uhwi_p (args[0]))
> break;
> else
> @@ -18560,7 +18562,7 @@ ix86_fold_builtin (tree fndecl, int n_ar
> len = prec;
> if (len < HOST_BITS_PER_WIDE_INT)
> res &= (HOST_WIDE_INT_1U << len) - 1;
> - return build_int_cstu (TREE_TYPE (TREE_TYPE (fndecl)), res);
> + return build_int_cstu (lhs_type, res);
> }
> break;
>
> @@ -18570,15 +18572,17 @@ ix86_fold_builtin (tree fndecl, int n_ar
> if (tree_fits_uhwi_p (args[1]))
> {
> unsigned int idx = tree_to_uhwi (args[1]) & 0xff;
> + tree lhs_type = TREE_TYPE (TREE_TYPE (fndecl));
> if (idx >= TYPE_PRECISION (TREE_TYPE (args[0])))
> return args[0];
> if (idx == 0)
> - return build_int_cst (TREE_TYPE (TREE_TYPE (fndecl)), 0);
> + return omit_one_operand (lhs_type, build_zero_cst (lhs_type),
> + args[0]);
> if (!tree_fits_uhwi_p (args[0]))
> break;
> unsigned HOST_WIDE_INT res = tree_to_uhwi (args[0]);
> res &= ~(HOST_WIDE_INT_M1U << idx);
> - return build_int_cstu (TREE_TYPE (TREE_TYPE (fndecl)), res);
> + return build_int_cstu (lhs_type, res);
> }
> break;
>
> --- gcc/testsuite/gcc.target/i386/bmi-pr116287.c.jj 2024-08-08
> 13:14:25.566827913 +0200
> +++ gcc/testsuite/gcc.target/i386/bmi-pr116287.c 2024-08-08
> 13:21:32.718312216 +0200
> @@ -0,0 +1,28 @@
> +/* PR target/116287 */
> +/* { dg-do run { target bmi } } */
> +/* { dg-options "-O2 -mbmi" } */
> +
> +#include <x86intrin.h>
> +
> +#include "bmi-check.h"
> +
> +static void
> +bmi_test ()
> +{
> + unsigned int a = 0;
> + if (__builtin_ia32_bextr_u32 (a++, 0) != 0)
> + abort ();
> + if (__builtin_ia32_bextr_u32 (a++, 0x120) != 0)
> + abort ();
> + if (a != 2)
> + abort ();
> +#ifdef __x86_64__
> + unsigned long long b = 0;
> + if (__builtin_ia32_bextr_u64 (b++, 0) != 0)
> + abort ();
> + if (__builtin_ia32_bextr_u64 (b++, 0x140) != 0)
> + abort ();
> + if (b != 2)
> + abort ();
> +#endif
> +}
> --- gcc/testsuite/gcc.target/i386/bmi2-pr116287.c.jj 2024-08-08
> 13:22:55.263246127 +0200
> +++ gcc/testsuite/gcc.target/i386/bmi2-pr116287.c 2024-08-08
> 13:30:44.851181267 +0200
> @@ -0,0 +1,24 @@
> +/* PR target/116287 */
> +/* { dg-do run { target bmi2 } } */
> +/* { dg-options "-O2 -mbmi2" } */
> +
> +#include <x86intrin.h>
> +
> +#include "bmi2-check.h"
> +
> +static void
> +bmi2_test ()
> +{
> + unsigned int a = 0;
> + if (__builtin_ia32_bzhi_si (a++, 0) != 0)
> + abort ();
> + if (a != 1)
> + abort ();
> +#ifdef __x86_64__
> + unsigned long long b = 0;
> + if (__builtin_ia32_bzhi_di (b++, 0) != 0)
> + abort ();
> + if (b != 1)
> + abort ();
> +#endif
> +}
> --- gcc/testsuite/gcc.target/i386/tbm-pr116287.c.jj 2024-08-08
> 13:14:48.453532722 +0200
> +++ gcc/testsuite/gcc.target/i386/tbm-pr116287.c 2024-08-08
> 13:22:36.940482770 +0200
> @@ -0,0 +1,29 @@
> +/* PR target/116287 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mtbm -fdump-tree-optimized" } */
> +/* { dg-final { scan-tree-dump-not "link_error \\\(\\\);" "optimized" } } */
> +
> +#include <x86intrin.h>
> +
> +extern void link_error (void);
> +
> +void
> +tbm_test ()
> +{
> + unsigned int a = 0;
> + if (__builtin_ia32_bextri_u32 (a++, 0) != 0)
> + link_error ();
> + if (__builtin_ia32_bextri_u32 (a++, 0x120) != 0)
> + link_error ();
> + if (a != 2)
> + link_error ();
> +#ifdef __x86_64__
> + unsigned long long b = 0;
> + if (__builtin_ia32_bextr_u64 (b++, 0) != 0)
> + link_error ();
> + if (__builtin_ia32_bextr_u64 (b++, 0x140) != 0)
> + link_error ();
> + if (b != 2)
> + link_error ();
> +#endif
> +}
>
> Jakub
>
