From: Alan Modra <amodra@gmail.com>
To: binutils@sourceware.org
Subject: resolve gas shift expressions with large exponents to zero
Date: Fri, 27 Jan 2023 08:22:23 +1030 [thread overview]
Message-ID: <Y9L2F1zkVoK5AqSW@squeak.grove.modra.org> (raw)
* expr.c (resolve_expression <O_left_shift, O_right_shift>): Resolve
shifts exceeding bits in a valueT to zero.
diff --git a/gas/expr.c b/gas/expr.c
index ba3d2109b9d..794be6f09d8 100644
--- a/gas/expr.c
+++ b/gas/expr.c
@@ -2320,8 +2320,18 @@ resolve_expression (expressionS *expressionP)
return 0;
left = (offsetT) left % (offsetT) right;
break;
- case O_left_shift: left <<= right; break;
- case O_right_shift: left >>= right; break;
+ case O_left_shift:
+ if (right >= sizeof (left) * CHAR_BIT)
+ left = 0;
+ else
+ left <<= right;
+ break;
+ case O_right_shift:
+ if (right >= sizeof (left) * CHAR_BIT)
+ left = 0;
+ else
+ left >>= right;
+ break;
case O_bit_inclusive_or: left |= right; break;
case O_bit_or_not: left |= ~right; break;
case O_bit_exclusive_or: left ^= right; break;
--
Alan Modra
Australia Development Lab, IBM
reply other threads:[~2023-01-26 21:52 UTC|newest]
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