From 8f144eb566c0bbbe925e5fb81b67873ed6b9e8bd Mon Sep 17 00:00:00 2001 From: Jacek Caban Date: Mon, 8 Jun 2020 18:12:21 +0200 Subject: [PATCH] ntdll: Reimplement _alldiv using 32-bit arithmetic. Based on compiler-rt. Signed-off-by: Jacek Caban Signed-off-by: Alexandre Julliard --- dlls/ntdll/large_int.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/dlls/ntdll/large_int.c b/dlls/ntdll/large_int.c index e55d450e1ed..5f53a3f4042 100644 --- a/dlls/ntdll/large_int.c +++ b/dlls/ntdll/large_int.c @@ -736,7 +736,12 @@ static ULONGLONG udivmod(ULONGLONG a, ULONGLONG b, ULONGLONG *rem) */ LONGLONG WINAPI _alldiv( LONGLONG a, LONGLONG b ) { - return a / b; + LONGLONG s_a = a >> 63; /* s_a = a < 0 ? -1 : 0 */ + LONGLONG s_b = b >> 63; /* s_b = b < 0 ? -1 : 0 */ + a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ + b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ + s_a ^= s_b; /* sign of quotient */ + return (udivmod(a, b, NULL) ^ s_a) - s_a; /* negate if s_a == -1 */ }