From: Jan Beulich <jbeulich@suse.com>
Date: Fri, 28 Apr 2023 06:19:53 +0000 (+0200)
Subject: gas: move shift count check
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=2b6132c33c27ea193288507e71d66498614af4f6;p=binutils-gdb.git

gas: move shift count check

... out of mainline code, grouping together the two case labels. This
then also make more obvious that the comment there applies to both forms
of shifts.
---

diff --git a/gas/expr.c b/gas/expr.c
index 680ec13b192..05b210ba98b 100644
--- a/gas/expr.c
+++ b/gas/expr.c
@@ -1954,14 +1954,6 @@ expr (int rankarg,		/* Larger # is higher rank.  */
 	      as_warn (_("division by zero"));
 	      v = 1;
 	    }
-	  if ((valueT) v >= sizeof(valueT) * CHAR_BIT
-	      && (op_left == O_left_shift || op_left == O_right_shift))
-	    {
-	      as_warn_value_out_of_range (_("shift count"), v, 0,
-					  sizeof(valueT) * CHAR_BIT - 1,
-					  NULL, 0);
-	      resultP->X_add_number = v = 0;
-	    }
 	  switch (op_left)
 	    {
 	    default:			goto general;
@@ -1974,6 +1966,7 @@ expr (int rankarg,		/* Larger # is higher rank.  */
 	    case O_divide:		resultP->X_add_number /= v; break;
 	    case O_modulus:		resultP->X_add_number %= v; break;
 	    case O_left_shift:
+	    case O_right_shift:
 	      /* We always use unsigned shifts.  According to the ISO
 		 C standard, left shift of a signed type having a
 		 negative value is undefined behaviour, and right
@@ -1982,12 +1975,19 @@ expr (int rankarg,		/* Larger # is higher rank.  */
 		 when the result overflows is also undefined
 		 behaviour.  So don't trigger ubsan warnings or rely
 		 on characteristics of the compiler.  */
-	      resultP->X_add_number
-		= (valueT) resultP->X_add_number << (valueT) v;
-	      break;
-	    case O_right_shift:
-	      resultP->X_add_number
-		= (valueT) resultP->X_add_number >> (valueT) v;
+	      if ((valueT) v >= sizeof (valueT) * CHAR_BIT)
+		{
+		  as_warn_value_out_of_range (_("shift count"), v, 0,
+					      sizeof (valueT) * CHAR_BIT - 1,
+					      NULL, 0);
+		  resultP->X_add_number = 0;
+		}
+	      else if (op_left == O_left_shift)
+		resultP->X_add_number
+		  = (valueT) resultP->X_add_number << (valueT) v;
+	      else
+		resultP->X_add_number
+		  = (valueT) resultP->X_add_number >> (valueT) v;
 	      break;
 	    case O_bit_inclusive_or:	resultP->X_add_number |= v; break;
 	    case O_bit_or_not:		resultP->X_add_number |= ~v; break;