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Diffstat (limited to 'contrib/compiler-rt/lib/builtins/divsi3.c')
-rw-r--r-- | contrib/compiler-rt/lib/builtins/divsi3.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/builtins/divsi3.c b/contrib/compiler-rt/lib/builtins/divsi3.c new file mode 100644 index 000000000000..bab4aefda30a --- /dev/null +++ b/contrib/compiler-rt/lib/builtins/divsi3.c @@ -0,0 +1,37 @@ +/* ===-- divsi3.c - Implement __divsi3 -------------------------------------=== + * + * The LLVM Compiler Infrastructure + * + * This file is dual licensed under the MIT and the University of Illinois Open + * Source Licenses. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + * + * This file implements __divsi3 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +/* Returns: a / b */ + +ARM_EABI_FNALIAS(idiv, divsi3) + +COMPILER_RT_ABI si_int +__divsi3(si_int a, si_int b) +{ + const int bits_in_word_m1 = (int)(sizeof(si_int) * CHAR_BIT) - 1; + si_int s_a = a >> bits_in_word_m1; /* s_a = a < 0 ? -1 : 0 */ + si_int s_b = b >> bits_in_word_m1; /* 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 */ + /* + * On CPUs without unsigned hardware division support, + * this calls __udivsi3 (notice the cast to su_int). + * On CPUs with unsigned hardware division support, + * this uses the unsigned division instruction. + */ + return ((su_int)a/(su_int)b ^ s_a) - s_a; /* negate if s_a == -1 */ +} |