ubsan errors when 32-bit bfd
Alan Modra
amodra@gmail.com
Sat Jun 19 01:25:51 GMT 2021
A shift count exceeding the size of the value is undefined behaviour,
and so is negating a signed LONG_MIN.
* config/tc-z80.c (signed_overflow, unsigned_overflow): Avoid UB.
diff --git a/gas/config/tc-z80.c b/gas/config/tc-z80.c
index 47d1405c2b6..303296b7dab 100644
--- a/gas/config/tc-z80.c
+++ b/gas/config/tc-z80.c
@@ -3703,14 +3703,14 @@ md_assemble (char *str)
static int
signed_overflow (signed long value, unsigned bitsize)
{
- signed long max = (signed long)(1UL << (bitsize-1));
- return value < -max || value >= max;
+ signed long max = (signed long) ((1UL << (bitsize - 1)) - 1);
+ return value < -max - 1 || value > max;
}
static int
unsigned_overflow (unsigned long value, unsigned bitsize)
{
- return (value >> bitsize) != 0;
+ return value >> (bitsize - 1) >> 1 != 0;
}
static int
--
Alan Modra
Australia Development Lab, IBM
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