Hi!
builtin_memcpy_read_str is a function meant to be called just as a callback
and verifies that we don't cross a '\0' boundary in the string. For
inline_string_cmp, we've checked that the length returned from c_getstr
is fine, so we can cross as many embedded NULs as there are within the
TREE_STRING_LENGTH.
The rest of the patch is just a temporary to avoid using as_a twice in
each loop iteration, and lots of formatting fixes, mostly to avoid trailing
whitespace.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2018-07-16 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/86526
* builtins.c (expand_builtin_memcmp): Formatting fixes.
(inline_expand_builtin_string_cmp): Likewise.
(inline_string_cmp): Likewise. Use c_readstr instead of
builtin_memcpy_read_str. Add unit_mode temporary.
* gcc.c-torture/compile/pr86526.c: New test.
--- gcc/builtins.c.jj 2018-07-16 09:42:25.743985945 +0200
+++ gcc/builtins.c 2018-07-16 11:47:46.535014889 +0200
@@ -4454,19 +4454,19 @@ expand_builtin_memcmp (tree exp, rtx tar
no_overflow = check_access (exp, /*dst=*/NULL_TREE, /*src=*/NULL_TREE,
len, /*maxread=*/NULL_TREE, size,
/*objsize=*/NULL_TREE);
- if (no_overflow)
+ if (no_overflow)
{
size = compute_objsize (arg2, 0);
no_overflow = check_access (exp, /*dst=*/NULL_TREE, /*src=*/NULL_TREE,
len, /*maxread=*/NULL_TREE, size,
/*objsize=*/NULL_TREE);
- }
+ }
- /* Due to the performance benefit, always inline the calls first
+ /* Due to the performance benefit, always inline the calls first
when result_eq is false. */
rtx result = NULL_RTX;
-
- if (!result_eq && fcode != BUILT_IN_BCMP && no_overflow)
+
+ if (!result_eq && fcode != BUILT_IN_BCMP && no_overflow)
{
result = inline_expand_builtin_string_cmp (exp, target, true);
if (result)
@@ -6748,7 +6748,7 @@ expand_builtin_goacc_parlevel_id_size (t
return target;
}
-/* Expand a string compare operation using a sequence of char comparison
+/* Expand a string compare operation using a sequence of char comparison
to get rid of the calling overhead, with result going to TARGET if
that's convenient.
@@ -6757,7 +6757,7 @@ expand_builtin_goacc_parlevel_id_size (t
LENGTH is the number of chars to compare;
CONST_STR_N indicates which source string is the constant string;
IS_MEMCMP indicates whether it's a memcmp or strcmp.
-
+
to: (assume const_str_n is 2, i.e., arg2 is a constant string)
target = var_str[0] - const_str[0];
@@ -6772,41 +6772,38 @@ expand_builtin_goacc_parlevel_id_size (t
*/
static rtx
-inline_string_cmp (rtx target, tree var_str, const char* const_str,
+inline_string_cmp (rtx target, tree var_str, const char *const_str,
unsigned HOST_WIDE_INT length,
int const_str_n, machine_mode mode,
- bool is_memcmp)
+ bool is_memcmp)
{
HOST_WIDE_INT offset = 0;
- rtx var_rtx_array
+ rtx var_rtx_array
= get_memory_rtx (var_str, build_int_cst (unsigned_type_node,length));
rtx var_rtx = NULL_RTX;
- rtx const_rtx = NULL_RTX;
- rtx result = target ? target : gen_reg_rtx (mode);
- rtx_code_label *ne_label = gen_label_rtx ();
+ rtx const_rtx = NULL_RTX;
+ rtx result = target ? target : gen_reg_rtx (mode);
+ rtx_code_label *ne_label = gen_label_rtx ();
tree unit_type_node = is_memcmp ? unsigned_char_type_node : char_type_node;
+ scalar_int_mode unit_mode
+ = as_a <scalar_int_mode> TYPE_MODE (unit_type_node);
start_sequence ();
for (unsigned HOST_WIDE_INT i = 0; i < length; i++)
{
- var_rtx
+ var_rtx
= adjust_address (var_rtx_array, TYPE_MODE (unit_type_node), offset);
- const_rtx
- = builtin_memcpy_read_str (CONST_CAST (char *, const_str),
- offset,
- as_a <scalar_int_mode>
- TYPE_MODE (unit_type_node));
+ const_rtx = c_readstr (const_str + offset, unit_mode);
rtx op0 = (const_str_n == 1) ? const_rtx : var_rtx;
rtx op1 = (const_str_n == 1) ? var_rtx : const_rtx;
-
- result = expand_simple_binop (mode, MINUS, op0, op1,
- result, is_memcmp ? 1 : 0, OPTAB_WIDEN);
- if (i < length - 1)
- emit_cmp_and_jump_insns (result, CONST0_RTX (mode), NE, NULL_RTX,
- mode, true, ne_label);
- offset
- += GET_MODE_SIZE (as_a <scalar_int_mode> TYPE_MODE (unit_type_node));
+
+ result = expand_simple_binop (mode, MINUS, op0, op1,
+ result, is_memcmp ? 1 : 0, OPTAB_WIDEN);
+ if (i < length - 1)
+ emit_cmp_and_jump_insns (result, CONST0_RTX (mode), NE, NULL_RTX,
+ mode, true, ne_label);
+ offset += GET_MODE_SIZE (unit_mode);
}
emit_label (ne_label);
@@ -6817,7 +6814,7 @@ inline_string_cmp (rtx target, tree var_
return result;
}
-/* Inline expansion a call to str(n)cmp, with result going to
+/* Inline expansion a call to str(n)cmp, with result going to
TARGET if that's convenient.
If the call is not been inlined, return NULL_RTX. */
static rtx
@@ -6829,7 +6826,7 @@ inline_expand_builtin_string_cmp (tree e
bool is_ncmp = (fcode == BUILT_IN_STRNCMP || fcode == BUILT_IN_MEMCMP);
gcc_checking_assert (fcode == BUILT_IN_STRCMP
- || fcode == BUILT_IN_STRNCMP
+ || fcode == BUILT_IN_STRNCMP
|| fcode == BUILT_IN_MEMCMP);
tree arg1 = CALL_EXPR_ARG (exp, 0);
@@ -6842,7 +6839,7 @@ inline_expand_builtin_string_cmp (tree e
const char *src_str1 = c_getstr (arg1, &len1);
const char *src_str2 = c_getstr (arg2, &len2);
-
+
/* If neither strings is constant string, the call is not qualify. */
if (!src_str1 && !src_str2)
return NULL_RTX;
@@ -6867,16 +6864,16 @@ inline_expand_builtin_string_cmp (tree e
if (is_ncmp && (len3 = tree_to_uhwi (len3_tree)) < length)
length = len3;
- /* If the length of the comparision is larger than the threshold,
+ /* If the length of the comparision is larger than the threshold,
do nothing. */
- if (length > (unsigned HOST_WIDE_INT)
+ if (length > (unsigned HOST_WIDE_INT)
PARAM_VALUE (BUILTIN_STRING_CMP_INLINE_LENGTH))
return NULL_RTX;
machine_mode mode = TYPE_MODE (TREE_TYPE (exp));
/* Now, start inline expansion the call. */
- return inline_string_cmp (target, (const_str_n == 1) ? arg2 : arg1,
+ return inline_string_cmp (target, (const_str_n == 1) ? arg2 : arg1,
(const_str_n == 1) ? src_str1 : src_str2, length,
const_str_n, mode, is_memcmp);
}
@@ -7282,7 +7279,7 @@ expand_builtin (tree exp, rtx target, rt
return target;
break;
- /* Expand it as BUILT_IN_MEMCMP_EQ first. If not successful, change it
+ /* Expand it as BUILT_IN_MEMCMP_EQ first. If not successful, change it
back to a BUILT_IN_STRCMP. Remember to delete the 3rd paramater
when changing it to a strcmp call. */
case BUILT_IN_STRCMP_EQ:
@@ -7291,7 +7288,7 @@ expand_builtin (tree exp, rtx target, rt
return target;
/* Change this call back to a BUILT_IN_STRCMP. */
- TREE_OPERAND (exp, 1)
+ TREE_OPERAND (exp, 1)
= build_fold_addr_expr (builtin_decl_explicit (BUILT_IN_STRCMP));
/* Delete the last parameter. */
@@ -7317,7 +7314,7 @@ expand_builtin (tree exp, rtx target, rt
return target;
/* Change it back to a BUILT_IN_STRNCMP. */
- TREE_OPERAND (exp, 1)
+ TREE_OPERAND (exp, 1)
= build_fold_addr_expr (builtin_decl_explicit (BUILT_IN_STRNCMP));
/* FALLTHROUGH */
--- gcc/testsuite/gcc.c-torture/compile/pr86526.c.jj 2018-07-16
11:50:30.756223270 +0200
+++ gcc/testsuite/gcc.c-torture/compile/pr86526.c 2018-07-16
11:50:16.205203998 +0200
@@ -0,0 +1,8 @@
+/* PR tree-optimization/86526 */
+
+void
+foo (char *x)
+{
+ if (__builtin_memcmp (x, "\0a", 3))
+ __builtin_abort ();
+}
Jakub
