Skip to content

Fix fallback paths in fast_long_{add,sub}_function #17666

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 3 commits into from
Closed

Fix fallback paths in fast_long_{add,sub}_function #17666

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
54324c9
Fix fallback paths in fast_long_{add,sub}_function
nielsdos Feb 1, 2025
54a5d2f
Not needed to change this
nielsdos Feb 2, 2025
2b762af
Perform int math once
nielsdos Feb 3, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 14 additions & 4 deletions Zend/zend_operators.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -722,11 +722,13 @@ overflow: ZEND_ATTRIBUTE_COLD_LABEL
* have read the values of op1 and op2.
*/

zend_long sum = (zend_long) ((zend_ulong) Z_LVAL_P(op1) + (zend_ulong) Z_LVAL_P(op2));

if (UNEXPECTED((Z_LVAL_P(op1) & LONG_SIGN_MASK) == (Z_LVAL_P(op2) & LONG_SIGN_MASK)
&& (Z_LVAL_P(op1) & LONG_SIGN_MASK) != ((Z_LVAL_P(op1) + Z_LVAL_P(op2)) & LONG_SIGN_MASK))) {
&& (Z_LVAL_P(op1) & LONG_SIGN_MASK) != (sum & LONG_SIGN_MASK))) {
ZVAL_DOUBLE(result, (double) Z_LVAL_P(op1) + (double) Z_LVAL_P(op2));
} else {
ZVAL_LONG(result, Z_LVAL_P(op1) + Z_LVAL_P(op2));
ZVAL_LONG(result, sum);
}
#endif
}
Expand Down Expand Up @@ -804,11 +806,19 @@ overflow: ZEND_ATTRIBUTE_COLD_LABEL
ZVAL_LONG(result, llresult);
}
#else
ZVAL_LONG(result, Z_LVAL_P(op1) - Z_LVAL_P(op2));
/*
* 'result' may alias with op1 or op2, so we need to
* ensure that 'result' is not updated until after we
* have read the values of op1 and op2.
*/

zend_long sub = (zend_long) ((zend_ulong) Z_LVAL_P(op1) - (zend_ulong) Z_LVAL_P(op2));

if (UNEXPECTED((Z_LVAL_P(op1) & LONG_SIGN_MASK) != (Z_LVAL_P(op2) & LONG_SIGN_MASK)
&& (Z_LVAL_P(op1) & LONG_SIGN_MASK) != (Z_LVAL_P(result) & LONG_SIGN_MASK))) {
&& (Z_LVAL_P(op1) & LONG_SIGN_MASK) != (sub & LONG_SIGN_MASK))) {
ZVAL_DOUBLE(result, (double) Z_LVAL_P(op1) - (double) Z_LVAL_P(op2));
} else {
ZVAL_LONG(result, sub);
}
#endif
}
Expand Down
Loading