[binutils-gdb] gas: move shift count check

[binutils-gdb] gas: move shift count check

[Jan Beulich]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=2b6132c33c27ea193288507e71d66498614af4f6

commit 2b6132c33c27ea193288507e71d66498614af4f6
Author: Jan Beulich <jbeulich@suse.com>
Date:   Fri Apr 28 08:19:53 2023 +0200

    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:
---
 gas/expr.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

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;