Changeset 17c14273 in mainline

Timestamp:

2018-01-17T18:11:05Z (6 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

e347396

Parents:

2467b41

Message:

Work around SPARC's multiplication insanity.

File:

• uspace/lib/c/generic/strtol.c (modified) (2 diffs)

uspace/lib/c/generic/strtol.c

@@ -55 +55 @@
         }
         return INT_MAX;
+}
+
+/* FIXME: workaround for GCC "optimizing" the overflow check
+ * into soft-emulated 128b multiplication using `__multi3`,
+ * which we don't currently implement.
+ */
+__attribute__((noinline)) static uintmax_t _max_value(int base)
+{
+        return UINTMAX_MAX / base;
 }
 
@@ -111 +120 @@
 
         uintmax_t result = 0;
+        uintmax_t max = _max_value(base);
         int digit;
 
         while (digit = _digit_value(*nptr), digit < base) {
 
-                if (__builtin_mul_overflow(result, base, &result) ||
-                    __builtin_add_overflow(result, digit, &result)) {
+                if (result > max ||
+                    __builtin_add_overflow(result * base, digit, &result)) {
 
                         errno = ERANGE;