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-rw-r--r--lib/builtins/mulosi4.c93
1 files changed, 42 insertions, 51 deletions
diff --git a/lib/builtins/mulosi4.c b/lib/builtins/mulosi4.c
index 422528085..fea431129 100644
--- a/lib/builtins/mulosi4.c
+++ b/lib/builtins/mulosi4.c
@@ -1,58 +1,49 @@
-/*===-- mulosi4.c - Implement __mulosi4 -----------------------------------===
- *
- * 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 __mulosi4 for the compiler_rt library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- mulosi4.c - Implement __mulosi4 -----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __mulosi4 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
#include "int_lib.h"
-/* Returns: a * b */
+// Returns: a * b
-/* Effects: sets *overflow to 1 if a * b overflows */
+// Effects: sets *overflow to 1 if a * b overflows
-COMPILER_RT_ABI si_int
-__mulosi4(si_int a, si_int b, int* overflow)
-{
- const int N = (int)(sizeof(si_int) * CHAR_BIT);
- const si_int MIN = (si_int)1 << (N-1);
- const si_int MAX = ~MIN;
- *overflow = 0;
- si_int result = a * b;
- if (a == MIN)
- {
- if (b != 0 && b != 1)
- *overflow = 1;
- return result;
- }
- if (b == MIN)
- {
- if (a != 0 && a != 1)
- *overflow = 1;
- return result;
- }
- si_int sa = a >> (N - 1);
- si_int abs_a = (a ^ sa) - sa;
- si_int sb = b >> (N - 1);
- si_int abs_b = (b ^ sb) - sb;
- if (abs_a < 2 || abs_b < 2)
- return result;
- if (sa == sb)
- {
- if (abs_a > MAX / abs_b)
- *overflow = 1;
- }
- else
- {
- if (abs_a > MIN / -abs_b)
- *overflow = 1;
- }
+COMPILER_RT_ABI si_int __mulosi4(si_int a, si_int b, int *overflow) {
+ const int N = (int)(sizeof(si_int) * CHAR_BIT);
+ const si_int MIN = (si_int)1 << (N - 1);
+ const si_int MAX = ~MIN;
+ *overflow = 0;
+ si_int result = a * b;
+ if (a == MIN) {
+ if (b != 0 && b != 1)
+ *overflow = 1;
return result;
+ }
+ if (b == MIN) {
+ if (a != 0 && a != 1)
+ *overflow = 1;
+ return result;
+ }
+ si_int sa = a >> (N - 1);
+ si_int abs_a = (a ^ sa) - sa;
+ si_int sb = b >> (N - 1);
+ si_int abs_b = (b ^ sb) - sb;
+ if (abs_a < 2 || abs_b < 2)
+ return result;
+ if (sa == sb) {
+ if (abs_a > MAX / abs_b)
+ *overflow = 1;
+ } else {
+ if (abs_a > MIN / -abs_b)
+ *overflow = 1;
+ }
+ return result;
}