From: "H.J. Lu" <hjl.tools@gmail.com>
To: Richard Biener <richard.guenther@gmail.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH v3] Simplify memchr with small constant strings
Date: Thu, 14 Jul 2022 14:09:15 -0700 [thread overview]
Message-ID: <CAMe9rOoegSi-h_L8HdOMtJW4d8f9pRnet4xCh3GcjpWkTNEmUw@mail.gmail.com> (raw)
In-Reply-To: <CAFiYyc3HFo03W4U0GLmNSYSLxi6rRTJ+EcuX-Beg+y-kN+1k_A@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 16298 bytes --]
On Wed, Jul 13, 2022 at 11:42 PM Richard Biener
<richard.guenther@gmail.com> wrote:
>
> On Wed, Jul 13, 2022 at 6:50 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > When memchr is applied on a constant string of no more than the bytes of
> > a word, simplify memchr by checking each byte in the constant string.
> >
> > int f (int a)
> > {
> > return __builtin_memchr ("AE", a, 2) != 0;
> > }
> >
> > is simplified to
> >
> > int f (int a)
> > {
> > return ((char) a == 'A' || (char) a == 'E') != 0;
> > }
> >
> > gcc/
> >
> > PR tree-optimization/103798
> > * tree-ssa-forwprop.cc: Include "tree-ssa-strlen.h".
> > (simplify_builtin_call): Inline memchr with constant strings of
> > no more than the bytes of a word.
> > * tree-ssa-strlen.cc (use_in_zero_equality): Make it global.
> > * tree-ssa-strlen.h (use_in_zero_equality): New.
> >
> > gcc/testsuite/
> >
> > PR tree-optimization/103798
> > * c-c++-common/pr103798-1.c: New test.
> > * c-c++-common/pr103798-2.c: Likewise.
> > * c-c++-common/pr103798-3.c: Likewise.
> > * c-c++-common/pr103798-4.c: Likewise.
> > * c-c++-common/pr103798-5.c: Likewise.
> > * c-c++-common/pr103798-6.c: Likewise.
> > * c-c++-common/pr103798-7.c: Likewise.
> > * c-c++-common/pr103798-8.c: Likewise.
> > * c-c++-common/pr103798-9.c: Likewise.
> > * c-c++-common/pr103798-10.c: Likewise.
> > ---
> > gcc/testsuite/c-c++-common/pr103798-1.c | 28 +++++++++
> > gcc/testsuite/c-c++-common/pr103798-10.c | 10 ++++
> > gcc/testsuite/c-c++-common/pr103798-2.c | 30 ++++++++++
> > gcc/testsuite/c-c++-common/pr103798-3.c | 28 +++++++++
> > gcc/testsuite/c-c++-common/pr103798-4.c | 28 +++++++++
> > gcc/testsuite/c-c++-common/pr103798-5.c | 26 +++++++++
> > gcc/testsuite/c-c++-common/pr103798-6.c | 27 +++++++++
> > gcc/testsuite/c-c++-common/pr103798-7.c | 27 +++++++++
> > gcc/testsuite/c-c++-common/pr103798-8.c | 27 +++++++++
> > gcc/testsuite/c-c++-common/pr103798-9.c | 10 ++++
> > gcc/tree-ssa-forwprop.cc | 73 ++++++++++++++++++++++++
> > gcc/tree-ssa-strlen.cc | 4 +-
> > gcc/tree-ssa-strlen.h | 2 +
> > 13 files changed, 318 insertions(+), 2 deletions(-)
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-1.c
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-10.c
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-2.c
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-3.c
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-4.c
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-5.c
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-6.c
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-7.c
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-8.c
> > create mode 100644 gcc/testsuite/c-c++-common/pr103798-9.c
> >
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-1.c b/gcc/testsuite/c-c++-common/pr103798-1.c
> > new file mode 100644
> > index 00000000000..cd3edf569fc
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-1.c
> > @@ -0,0 +1,28 @@
> > +/* { dg-do run } */
> > +/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
> > +
> > +__attribute__ ((weak))
> > +int
> > +f (char a)
> > +{
> > + return __builtin_memchr ("a", a, 1) == 0;
> > +}
> > +
> > +__attribute__ ((weak))
> > +int
> > +g (char a)
> > +{
> > + return a != 'a';
> > +}
> > +
> > +int
> > +main ()
> > +{
> > + for (int i = 0; i < 255; i++)
> > + if (f (i) != g (i))
> > + __builtin_abort ();
> > +
> > + return 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "memchr" } } */
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-10.c b/gcc/testsuite/c-c++-common/pr103798-10.c
> > new file mode 100644
> > index 00000000000..4677e9539fa
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-10.c
> > @@ -0,0 +1,10 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-Os -fdump-tree-optimized -save-temps" } */
> > +
> > +int
> > +f (char a)
> > +{
> > + return __builtin_memchr ("ac", a, 1) == 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler "memchr" } } */
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-2.c b/gcc/testsuite/c-c++-common/pr103798-2.c
> > new file mode 100644
> > index 00000000000..e7e99c3679e
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-2.c
> > @@ -0,0 +1,30 @@
> > +/* { dg-do run } */
> > +/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
> > +
> > +#include <string.h>
> > +
> > +__attribute__ ((weak))
> > +int
> > +f (int a)
> > +{
> > + return memchr ("aE", a, 2) != NULL;
> > +}
> > +
> > +__attribute__ ((weak))
> > +int
> > +g (char a)
> > +{
> > + return a == 'a' || a == 'E';
> > +}
> > +
> > +int
> > +main ()
> > +{
> > + for (int i = 0; i < 255; i++)
> > + if (f (i + 256) != g (i + 256))
> > + __builtin_abort ();
> > +
> > + return 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "memchr" } } */
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-3.c b/gcc/testsuite/c-c++-common/pr103798-3.c
> > new file mode 100644
> > index 00000000000..ddcedc7e238
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-3.c
> > @@ -0,0 +1,28 @@
> > +/* { dg-do run } */
> > +/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
> > +
> > +__attribute__ ((weak))
> > +int
> > +f (char a)
> > +{
> > + return __builtin_memchr ("aEgZ", a, 3) == 0;
> > +}
> > +
> > +__attribute__ ((weak))
> > +int
> > +g (char a)
> > +{
> > + return a != 'a' && a != 'E' && a != 'g';
> > +}
> > +
> > +int
> > +main ()
> > +{
> > + for (int i = 0; i < 255; i++)
> > + if (f (i) != g (i))
> > + __builtin_abort ();
> > +
> > + return 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "memchr" } } */
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-4.c b/gcc/testsuite/c-c++-common/pr103798-4.c
> > new file mode 100644
> > index 00000000000..00e8302a833
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-4.c
> > @@ -0,0 +1,28 @@
> > +/* { dg-do run } */
> > +/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
> > +
> > +__attribute__ ((weak))
> > +int
> > +f (char a)
> > +{
> > + return __builtin_memchr ("aEgi", a, 4) != 0;
> > +}
> > +
> > +__attribute__ ((weak))
> > +int
> > +g (char a)
> > +{
> > + return a == 'a' || a == 'E' || a == 'g' || a == 'i';
> > +}
> > +
> > +int
> > +main ()
> > +{
> > + for (int i = 0; i < 255; i++)
> > + if (f (i) != g (i))
> > + __builtin_abort ();
> > +
> > + return 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "memchr" } } */
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-5.c b/gcc/testsuite/c-c++-common/pr103798-5.c
> > new file mode 100644
> > index 00000000000..0d6487a13df
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-5.c
> > @@ -0,0 +1,26 @@
> > +/* { dg-do run { target int128 } } */
> > +/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
> > +
> > +__attribute__ ((weak))
> > +int f(char a)
> > +{
> > + return __builtin_memchr ("aEgiH", a, 5) == 0;
> > +}
> > +
> > +__attribute__ ((weak))
> > +int g(char a)
> > +{
> > + return a != 'a' && a != 'E' && a != 'g' && a != 'i' && a != 'H';
> > +}
> > +
> > +int
> > +main ()
> > +{
> > + for (int i = 0; i < 255; i++)
> > + if (f (i) != g (i))
> > + __builtin_abort ();
> > +
> > + return 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "memchr" } } */
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-6.c b/gcc/testsuite/c-c++-common/pr103798-6.c
> > new file mode 100644
> > index 00000000000..5ccb5ee66e0
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-6.c
> > @@ -0,0 +1,27 @@
> > +/* { dg-do run { target int128 } } */
> > +/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
> > +
> > +__attribute__ ((weak))
> > +int f(char a)
> > +{
> > + return __builtin_memchr ("aEgiHx", a, 6) != 0;
> > +}
> > +
> > +__attribute__ ((weak))
> > +int g(char a)
> > +{
> > + return (a == 'a' || a == 'E' || a == 'g' || a == 'i' || a == 'H'
> > + || a == 'x');
> > +}
> > +
> > +int
> > +main ()
> > +{
> > + for (int i = 0; i < 255; i++)
> > + if (f (i) != g (i))
> > + __builtin_abort ();
> > +
> > + return 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "memchr" } } */
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-7.c b/gcc/testsuite/c-c++-common/pr103798-7.c
> > new file mode 100644
> > index 00000000000..40fd38257d1
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-7.c
> > @@ -0,0 +1,27 @@
> > +/* { dg-do run { target int128 } } */
> > +/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
> > +
> > +__attribute__ ((weak))
> > +int f(char a)
> > +{
> > + return __builtin_memchr ("aEgiHjZ", a, 7) == 0;
> > +}
> > +
> > +__attribute__ ((weak))
> > +int g(char a)
> > +{
> > + return (a != 'a' && a != 'E' && a != 'g' && a != 'i' && a != 'H'
> > + && a != 'j' && a != 'Z');
> > +}
> > +
> > +int
> > +main ()
> > +{
> > + for (int i = 0; i < 255; i++)
> > + if (f (i) != g (i))
> > + __builtin_abort ();
> > +
> > + return 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "memchr" } } */
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-8.c b/gcc/testsuite/c-c++-common/pr103798-8.c
> > new file mode 100644
> > index 00000000000..0841b18cea4
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-8.c
> > @@ -0,0 +1,27 @@
> > +/* { dg-do run { target int128 } } */
> > +/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
> > +
> > +__attribute__ ((weak))
> > +int f(int a)
> > +{
> > + return __builtin_memchr ("aEgiHx19ABC", a, 8) != 0;
> > +}
> > +
> > +__attribute__ ((weak))
> > +int g(char a)
> > +{
> > + return (a == 'a' || a == 'E' || a == 'g' || a == 'i' || a == 'H'
> > + || a == 'x' || a == '1' || a == '9');
> > +}
> > +
> > +int
> > +main ()
> > +{
> > + for (int i = 0; i < 255; i++)
> > + if (f (i + 256) != g (i + 256))
> > + __builtin_abort ();
> > +
> > + return 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "memchr" } } */
> > diff --git a/gcc/testsuite/c-c++-common/pr103798-9.c b/gcc/testsuite/c-c++-common/pr103798-9.c
> > new file mode 100644
> > index 00000000000..c5f0f94a4b5
> > --- /dev/null
> > +++ b/gcc/testsuite/c-c++-common/pr103798-9.c
> > @@ -0,0 +1,10 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-Os -fdump-tree-optimized -save-temps" } */
> > +
> > +int
> > +f (char a)
> > +{
> > + return __builtin_memchr ("a", a, 1) == 0;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "memchr" } } */
> > diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
> > index 69567ab3275..28549c85f76 100644
> > --- a/gcc/tree-ssa-forwprop.cc
> > +++ b/gcc/tree-ssa-forwprop.cc
> > @@ -42,6 +42,7 @@ along with GCC; see the file COPYING3. If not see
> > #include "tree-dfa.h"
> > #include "tree-ssa-propagate.h"
> > #include "tree-ssa-dom.h"
> > +#include "tree-ssa-strlen.h"
> > #include "builtins.h"
> > #include "tree-cfgcleanup.h"
> > #include "cfganal.h"
> > @@ -1177,6 +1178,15 @@ constant_pointer_difference (tree p1, tree p2)
> > memcpy (p, "abcd ", 7);
> > call if the latter can be stored by pieces during expansion.
> >
> > + Optimize
> > + memchr ("abcd", a, 4) == 0;
> > + or
> > + memchr ("abcd", a, 4) != 0;
> > + to
> > + (a == 'a' || a == 'b' || a == 'c' || a == 'd') == 0
> > + or
> > + (a == 'a' || a == 'b' || a == 'c' || a == 'd') != 0
> > +
> > Also canonicalize __atomic_fetch_op (p, x, y) op x
> > to __atomic_op_fetch (p, x, y) or
> > __atomic_op_fetch (p, x, y) iop x
> > @@ -1193,8 +1203,71 @@ simplify_builtin_call (gimple_stmt_iterator *gsi_p, tree callee2)
> > return false;
> > stmt1 = SSA_NAME_DEF_STMT (vuse);
> >
> > + tree res;
> > +
> > switch (DECL_FUNCTION_CODE (callee2))
> > {
> > + case BUILT_IN_MEMCHR:
> > + if (gimple_call_num_args (stmt2) == 3
> > + && (res = gimple_call_lhs (stmt2)) != nullptr
> > + && use_in_zero_equality (res) != nullptr
> > + && CHAR_BIT == 8
> > + && BITS_PER_UNIT == 8)
> > + {
> > + tree ptr = gimple_call_arg (stmt2, 0);
> > + if (TREE_CODE (ptr) != ADDR_EXPR
> > + || TREE_CODE (TREE_OPERAND (ptr, 0)) != STRING_CST)
> > + break;
> > + unsigned HOST_WIDE_INT slen
> > + = TREE_STRING_LENGTH (TREE_OPERAND (ptr, 0));
> > + /* It must be a non-empty string constant. */
> > + if (slen < 2)
> > + break;
> > + /* For -Os, only simplify strings with a single character. */
> > + if (!optimize_bb_for_speed_p (gimple_bb (stmt2))
> > + && slen > 2)
> > + break;
> > + tree size = gimple_call_arg (stmt2, 2);
> > + /* Size must be a constant which is <= UNITS_PER_WORD and
> > + <= the string length. */
> > + if (TREE_CODE (size) != INTEGER_CST || integer_zerop (size))
> > + break;
> > +
> > + if (!tree_fits_uhwi_p (size))
> > + break;
> > +
> > + unsigned HOST_WIDE_INT sz = tree_to_uhwi (size);
> > + if (sz > UNITS_PER_WORD || sz >= slen)
> > + break;
> > +
> > + tree ch = gimple_call_arg (stmt2, 1);
> > + location_t loc = gimple_location (stmt2);
> > + if (!useless_type_conversion_p (char_type_node,
> > + TREE_TYPE (ch)))
> > + ch = fold_convert_loc (loc, char_type_node, ch);
> > + const char *p = TREE_STRING_POINTER (TREE_OPERAND (ptr, 0));
> > + unsigned int isize = sz;
> > + tree *op = new tree[isize];
>
> minor nit - sorry for not spotting earlier. Please use
>
> tree *op = XALLOCAVEC (tree, isize);
>
> Ok with that change.
> Richard.
Fixed.
This is the patch I am checking in.
Thanks.
> > + for (unsigned int i = 0; i < isize; i++)
> > + {
> > + op[i] = build_int_cst (char_type_node, p[i]);
> > + op[i] = fold_build2_loc (loc, EQ_EXPR, boolean_type_node,
> > + op[i], ch);
> > + }
> > + for (unsigned int i = isize - 1; i >= 1; i--)
> > + op[i - 1] = fold_convert_loc (loc, boolean_type_node,
> > + fold_build2_loc (loc,
> > + BIT_IOR_EXPR,
> > + boolean_type_node,
> > + op[i - 1],
> > + op[i]));
> > + res = fold_convert_loc (loc, TREE_TYPE (res), op[0]);
> > + gimplify_and_update_call_from_tree (gsi_p, res);
> > + delete[] op;
> > + return true;
> > + }
> > + break;
> > +
> > case BUILT_IN_MEMSET:
> > if (gimple_call_num_args (stmt2) != 3
> > || gimple_call_lhs (stmt2)
> > diff --git a/gcc/tree-ssa-strlen.cc b/gcc/tree-ssa-strlen.cc
> > index 7b3e3899ea2..5afbae1b72e 100644
> > --- a/gcc/tree-ssa-strlen.cc
> > +++ b/gcc/tree-ssa-strlen.cc
> > @@ -3913,8 +3913,8 @@ strlen_pass::handle_builtin_memset (bool *zero_write)
> > nonnull if and only RES is used in such expressions exclusively and
> > in none other. */
> >
> > -static gimple *
> > -use_in_zero_equality (tree res, bool exclusive = true)
> > +gimple *
> > +use_in_zero_equality (tree res, bool exclusive)
> > {
> > gimple *first_use = NULL;
> >
> > diff --git a/gcc/tree-ssa-strlen.h b/gcc/tree-ssa-strlen.h
> > index 8d155450db8..fdb4d9d7783 100644
> > --- a/gcc/tree-ssa-strlen.h
> > +++ b/gcc/tree-ssa-strlen.h
> > @@ -35,6 +35,8 @@ struct c_strlen_data;
> > extern void get_range_strlen_dynamic (tree, gimple *, c_strlen_data *,
> > pointer_query &);
> >
> > +extern gimple *use_in_zero_equality (tree, bool = true);
> > +
> > /* APIs internal to strlen pass. Defined in gimple-ssa-sprintf.cc. */
> > extern bool handle_printf_call (gimple_stmt_iterator *, pointer_query &);
> >
> > --
> > 2.36.1
> >
--
H.J.
[-- Attachment #2: 0001-Simplify-memchr-with-small-constant-strings.patch --]
[-- Type: text/x-patch, Size: 13425 bytes --]
From 01cc3401ba3b6b5ba1a4c26b8b5bf9a38feb92fa Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 17 Jun 2022 07:33:06 -0700
Subject: [PATCH] Simplify memchr with small constant strings
When memchr is applied on a constant string of no more than the bytes of
a word, simplify memchr by checking each byte in the constant string.
int f (int a)
{
return __builtin_memchr ("AE", a, 2) != 0;
}
is simplified to
int f (int a)
{
return ((char) a == 'A' || (char) a == 'E') != 0;
}
gcc/
PR tree-optimization/103798
* tree-ssa-forwprop.cc: Include "tree-ssa-strlen.h".
(simplify_builtin_call): Inline memchr with constant strings of
no more than the bytes of a word.
* tree-ssa-strlen.cc (use_in_zero_equality): Make it global.
* tree-ssa-strlen.h (use_in_zero_equality): New.
gcc/testsuite/
PR tree-optimization/103798
* c-c++-common/pr103798-1.c: New test.
* c-c++-common/pr103798-2.c: Likewise.
* c-c++-common/pr103798-3.c: Likewise.
* c-c++-common/pr103798-4.c: Likewise.
* c-c++-common/pr103798-5.c: Likewise.
* c-c++-common/pr103798-6.c: Likewise.
* c-c++-common/pr103798-7.c: Likewise.
* c-c++-common/pr103798-8.c: Likewise.
* c-c++-common/pr103798-9.c: Likewise.
* c-c++-common/pr103798-10.c: Likewise.
---
gcc/testsuite/c-c++-common/pr103798-1.c | 28 +++++++++
gcc/testsuite/c-c++-common/pr103798-10.c | 10 ++++
gcc/testsuite/c-c++-common/pr103798-2.c | 30 ++++++++++
gcc/testsuite/c-c++-common/pr103798-3.c | 28 +++++++++
gcc/testsuite/c-c++-common/pr103798-4.c | 28 +++++++++
gcc/testsuite/c-c++-common/pr103798-5.c | 26 +++++++++
gcc/testsuite/c-c++-common/pr103798-6.c | 27 +++++++++
gcc/testsuite/c-c++-common/pr103798-7.c | 27 +++++++++
gcc/testsuite/c-c++-common/pr103798-8.c | 27 +++++++++
gcc/testsuite/c-c++-common/pr103798-9.c | 10 ++++
gcc/tree-ssa-forwprop.cc | 72 ++++++++++++++++++++++++
gcc/tree-ssa-strlen.cc | 4 +-
gcc/tree-ssa-strlen.h | 2 +
13 files changed, 317 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/pr103798-1.c
create mode 100644 gcc/testsuite/c-c++-common/pr103798-10.c
create mode 100644 gcc/testsuite/c-c++-common/pr103798-2.c
create mode 100644 gcc/testsuite/c-c++-common/pr103798-3.c
create mode 100644 gcc/testsuite/c-c++-common/pr103798-4.c
create mode 100644 gcc/testsuite/c-c++-common/pr103798-5.c
create mode 100644 gcc/testsuite/c-c++-common/pr103798-6.c
create mode 100644 gcc/testsuite/c-c++-common/pr103798-7.c
create mode 100644 gcc/testsuite/c-c++-common/pr103798-8.c
create mode 100644 gcc/testsuite/c-c++-common/pr103798-9.c
diff --git a/gcc/testsuite/c-c++-common/pr103798-1.c b/gcc/testsuite/c-c++-common/pr103798-1.c
new file mode 100644
index 00000000000..cd3edf569fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-1.c
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
+
+__attribute__ ((weak))
+int
+f (char a)
+{
+ return __builtin_memchr ("a", a, 1) == 0;
+}
+
+__attribute__ ((weak))
+int
+g (char a)
+{
+ return a != 'a';
+}
+
+int
+main ()
+{
+ for (int i = 0; i < 255; i++)
+ if (f (i) != g (i))
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "memchr" } } */
diff --git a/gcc/testsuite/c-c++-common/pr103798-10.c b/gcc/testsuite/c-c++-common/pr103798-10.c
new file mode 100644
index 00000000000..4677e9539fa
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-10.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Os -fdump-tree-optimized -save-temps" } */
+
+int
+f (char a)
+{
+ return __builtin_memchr ("ac", a, 1) == 0;
+}
+
+/* { dg-final { scan-assembler "memchr" } } */
diff --git a/gcc/testsuite/c-c++-common/pr103798-2.c b/gcc/testsuite/c-c++-common/pr103798-2.c
new file mode 100644
index 00000000000..e7e99c3679e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-2.c
@@ -0,0 +1,30 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
+
+#include <string.h>
+
+__attribute__ ((weak))
+int
+f (int a)
+{
+ return memchr ("aE", a, 2) != NULL;
+}
+
+__attribute__ ((weak))
+int
+g (char a)
+{
+ return a == 'a' || a == 'E';
+}
+
+int
+main ()
+{
+ for (int i = 0; i < 255; i++)
+ if (f (i + 256) != g (i + 256))
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "memchr" } } */
diff --git a/gcc/testsuite/c-c++-common/pr103798-3.c b/gcc/testsuite/c-c++-common/pr103798-3.c
new file mode 100644
index 00000000000..ddcedc7e238
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-3.c
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
+
+__attribute__ ((weak))
+int
+f (char a)
+{
+ return __builtin_memchr ("aEgZ", a, 3) == 0;
+}
+
+__attribute__ ((weak))
+int
+g (char a)
+{
+ return a != 'a' && a != 'E' && a != 'g';
+}
+
+int
+main ()
+{
+ for (int i = 0; i < 255; i++)
+ if (f (i) != g (i))
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "memchr" } } */
diff --git a/gcc/testsuite/c-c++-common/pr103798-4.c b/gcc/testsuite/c-c++-common/pr103798-4.c
new file mode 100644
index 00000000000..00e8302a833
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-4.c
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
+
+__attribute__ ((weak))
+int
+f (char a)
+{
+ return __builtin_memchr ("aEgi", a, 4) != 0;
+}
+
+__attribute__ ((weak))
+int
+g (char a)
+{
+ return a == 'a' || a == 'E' || a == 'g' || a == 'i';
+}
+
+int
+main ()
+{
+ for (int i = 0; i < 255; i++)
+ if (f (i) != g (i))
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "memchr" } } */
diff --git a/gcc/testsuite/c-c++-common/pr103798-5.c b/gcc/testsuite/c-c++-common/pr103798-5.c
new file mode 100644
index 00000000000..0d6487a13df
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-5.c
@@ -0,0 +1,26 @@
+/* { dg-do run { target int128 } } */
+/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
+
+__attribute__ ((weak))
+int f(char a)
+{
+ return __builtin_memchr ("aEgiH", a, 5) == 0;
+}
+
+__attribute__ ((weak))
+int g(char a)
+{
+ return a != 'a' && a != 'E' && a != 'g' && a != 'i' && a != 'H';
+}
+
+int
+main ()
+{
+ for (int i = 0; i < 255; i++)
+ if (f (i) != g (i))
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "memchr" } } */
diff --git a/gcc/testsuite/c-c++-common/pr103798-6.c b/gcc/testsuite/c-c++-common/pr103798-6.c
new file mode 100644
index 00000000000..5ccb5ee66e0
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-6.c
@@ -0,0 +1,27 @@
+/* { dg-do run { target int128 } } */
+/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
+
+__attribute__ ((weak))
+int f(char a)
+{
+ return __builtin_memchr ("aEgiHx", a, 6) != 0;
+}
+
+__attribute__ ((weak))
+int g(char a)
+{
+ return (a == 'a' || a == 'E' || a == 'g' || a == 'i' || a == 'H'
+ || a == 'x');
+}
+
+int
+main ()
+{
+ for (int i = 0; i < 255; i++)
+ if (f (i) != g (i))
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "memchr" } } */
diff --git a/gcc/testsuite/c-c++-common/pr103798-7.c b/gcc/testsuite/c-c++-common/pr103798-7.c
new file mode 100644
index 00000000000..40fd38257d1
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-7.c
@@ -0,0 +1,27 @@
+/* { dg-do run { target int128 } } */
+/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
+
+__attribute__ ((weak))
+int f(char a)
+{
+ return __builtin_memchr ("aEgiHjZ", a, 7) == 0;
+}
+
+__attribute__ ((weak))
+int g(char a)
+{
+ return (a != 'a' && a != 'E' && a != 'g' && a != 'i' && a != 'H'
+ && a != 'j' && a != 'Z');
+}
+
+int
+main ()
+{
+ for (int i = 0; i < 255; i++)
+ if (f (i) != g (i))
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "memchr" } } */
diff --git a/gcc/testsuite/c-c++-common/pr103798-8.c b/gcc/testsuite/c-c++-common/pr103798-8.c
new file mode 100644
index 00000000000..0841b18cea4
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-8.c
@@ -0,0 +1,27 @@
+/* { dg-do run { target int128 } } */
+/* { dg-options "-O2 -fdump-tree-optimized -save-temps" } */
+
+__attribute__ ((weak))
+int f(int a)
+{
+ return __builtin_memchr ("aEgiHx19ABC", a, 8) != 0;
+}
+
+__attribute__ ((weak))
+int g(char a)
+{
+ return (a == 'a' || a == 'E' || a == 'g' || a == 'i' || a == 'H'
+ || a == 'x' || a == '1' || a == '9');
+}
+
+int
+main ()
+{
+ for (int i = 0; i < 255; i++)
+ if (f (i + 256) != g (i + 256))
+ __builtin_abort ();
+
+ return 0;
+}
+
+/* { dg-final { scan-assembler-not "memchr" } } */
diff --git a/gcc/testsuite/c-c++-common/pr103798-9.c b/gcc/testsuite/c-c++-common/pr103798-9.c
new file mode 100644
index 00000000000..c5f0f94a4b5
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr103798-9.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Os -fdump-tree-optimized -save-temps" } */
+
+int
+f (char a)
+{
+ return __builtin_memchr ("a", a, 1) == 0;
+}
+
+/* { dg-final { scan-assembler-not "memchr" } } */
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 69567ab3275..fdc4bc8909d 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -42,6 +42,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-dfa.h"
#include "tree-ssa-propagate.h"
#include "tree-ssa-dom.h"
+#include "tree-ssa-strlen.h"
#include "builtins.h"
#include "tree-cfgcleanup.h"
#include "cfganal.h"
@@ -1177,6 +1178,15 @@ constant_pointer_difference (tree p1, tree p2)
memcpy (p, "abcd ", 7);
call if the latter can be stored by pieces during expansion.
+ Optimize
+ memchr ("abcd", a, 4) == 0;
+ or
+ memchr ("abcd", a, 4) != 0;
+ to
+ (a == 'a' || a == 'b' || a == 'c' || a == 'd') == 0
+ or
+ (a == 'a' || a == 'b' || a == 'c' || a == 'd') != 0
+
Also canonicalize __atomic_fetch_op (p, x, y) op x
to __atomic_op_fetch (p, x, y) or
__atomic_op_fetch (p, x, y) iop x
@@ -1193,8 +1203,70 @@ simplify_builtin_call (gimple_stmt_iterator *gsi_p, tree callee2)
return false;
stmt1 = SSA_NAME_DEF_STMT (vuse);
+ tree res;
+
switch (DECL_FUNCTION_CODE (callee2))
{
+ case BUILT_IN_MEMCHR:
+ if (gimple_call_num_args (stmt2) == 3
+ && (res = gimple_call_lhs (stmt2)) != nullptr
+ && use_in_zero_equality (res) != nullptr
+ && CHAR_BIT == 8
+ && BITS_PER_UNIT == 8)
+ {
+ tree ptr = gimple_call_arg (stmt2, 0);
+ if (TREE_CODE (ptr) != ADDR_EXPR
+ || TREE_CODE (TREE_OPERAND (ptr, 0)) != STRING_CST)
+ break;
+ unsigned HOST_WIDE_INT slen
+ = TREE_STRING_LENGTH (TREE_OPERAND (ptr, 0));
+ /* It must be a non-empty string constant. */
+ if (slen < 2)
+ break;
+ /* For -Os, only simplify strings with a single character. */
+ if (!optimize_bb_for_speed_p (gimple_bb (stmt2))
+ && slen > 2)
+ break;
+ tree size = gimple_call_arg (stmt2, 2);
+ /* Size must be a constant which is <= UNITS_PER_WORD and
+ <= the string length. */
+ if (TREE_CODE (size) != INTEGER_CST || integer_zerop (size))
+ break;
+
+ if (!tree_fits_uhwi_p (size))
+ break;
+
+ unsigned HOST_WIDE_INT sz = tree_to_uhwi (size);
+ if (sz > UNITS_PER_WORD || sz >= slen)
+ break;
+
+ tree ch = gimple_call_arg (stmt2, 1);
+ location_t loc = gimple_location (stmt2);
+ if (!useless_type_conversion_p (char_type_node,
+ TREE_TYPE (ch)))
+ ch = fold_convert_loc (loc, char_type_node, ch);
+ const char *p = TREE_STRING_POINTER (TREE_OPERAND (ptr, 0));
+ unsigned int isize = sz;
+ tree *op = XALLOCAVEC (tree, isize);
+ for (unsigned int i = 0; i < isize; i++)
+ {
+ op[i] = build_int_cst (char_type_node, p[i]);
+ op[i] = fold_build2_loc (loc, EQ_EXPR, boolean_type_node,
+ op[i], ch);
+ }
+ for (unsigned int i = isize - 1; i >= 1; i--)
+ op[i - 1] = fold_convert_loc (loc, boolean_type_node,
+ fold_build2_loc (loc,
+ BIT_IOR_EXPR,
+ boolean_type_node,
+ op[i - 1],
+ op[i]));
+ res = fold_convert_loc (loc, TREE_TYPE (res), op[0]);
+ gimplify_and_update_call_from_tree (gsi_p, res);
+ return true;
+ }
+ break;
+
case BUILT_IN_MEMSET:
if (gimple_call_num_args (stmt2) != 3
|| gimple_call_lhs (stmt2)
diff --git a/gcc/tree-ssa-strlen.cc b/gcc/tree-ssa-strlen.cc
index 7b3e3899ea2..5afbae1b72e 100644
--- a/gcc/tree-ssa-strlen.cc
+++ b/gcc/tree-ssa-strlen.cc
@@ -3913,8 +3913,8 @@ strlen_pass::handle_builtin_memset (bool *zero_write)
nonnull if and only RES is used in such expressions exclusively and
in none other. */
-static gimple *
-use_in_zero_equality (tree res, bool exclusive = true)
+gimple *
+use_in_zero_equality (tree res, bool exclusive)
{
gimple *first_use = NULL;
diff --git a/gcc/tree-ssa-strlen.h b/gcc/tree-ssa-strlen.h
index 8d155450db8..fdb4d9d7783 100644
--- a/gcc/tree-ssa-strlen.h
+++ b/gcc/tree-ssa-strlen.h
@@ -35,6 +35,8 @@ struct c_strlen_data;
extern void get_range_strlen_dynamic (tree, gimple *, c_strlen_data *,
pointer_query &);
+extern gimple *use_in_zero_equality (tree, bool = true);
+
/* APIs internal to strlen pass. Defined in gimple-ssa-sprintf.cc. */
extern bool handle_printf_call (gimple_stmt_iterator *, pointer_query &);
--
2.36.1
next prev parent reply other threads:[~2022-07-14 21:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-13 16:50 H.J. Lu
2022-07-14 6:42 ` Richard Biener
2022-07-14 21:09 ` H.J. Lu [this message]
2022-09-07 10:57 ` Jan-Benedict Glaw
2022-09-07 12:00 ` Richard Biener
2022-09-10 5:38 ` Jan-Benedict Glaw
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