[binutils-gdb] ubsan: ns32k: left shift cannot be represented in type 'int'

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=fb4cb4e26d16f928f00973fcdc99934c9174c957

commit fb4cb4e26d16f928f00973fcdc99934c9174c957
Author: Alan Modra <amodra@gmail.com>
Date:   Wed Dec 11 08:34:57 2019 +1030

    ubsan: ns32k: left shift cannot be represented in type 'int'
    
    	* ns32k-dis.c (bit_extract): Use unsigned arithmetic.
    	(bit_extract_simple, sign_extend): Likewise.

Diff:
---
 opcodes/ChangeLog   |  5 +++++
 opcodes/ns32k-dis.c | 16 +++++++---------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index b36a9e2..ddf8cd0 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,5 +1,10 @@
 2019-12-11  Alan Modra  <amodra@gmail.com>
 
+	* ns32k-dis.c (bit_extract): Use unsigned arithmetic.
+	(bit_extract_simple, sign_extend): Likewise.
+
+2019-12-11  Alan Modra  <amodra@gmail.com>
+
 	* nios2-dis.c (nios2_print_insn_arg): Use 1u << 31.
 
 2019-12-11  Alan Modra  <amodra@gmail.com>
diff --git a/opcodes/ns32k-dis.c b/opcodes/ns32k-dis.c
index 22a9389..5e6f096 100644
--- a/opcodes/ns32k-dis.c
+++ b/opcodes/ns32k-dis.c
@@ -262,8 +262,8 @@ list_search (int reg_value, const struct ns32k_option *optionP, char *result)
 static int
 bit_extract (bfd_byte *buffer, int offset, int count)
 {
-  int result;
-  int bit;
+  unsigned int result;
+  unsigned int bit;
 
   if (offset < 0 || count < 0)
     return 0;
@@ -291,8 +291,8 @@ bit_extract (bfd_byte *buffer, int offset, int count)
 static int
 bit_extract_simple (bfd_byte *buffer, int offset, int count)
 {
-  int result;
-  int bit;
+  unsigned int result;
+  unsigned int bit;
 
   if (offset < 0 || count < 0)
     return 0;
@@ -325,12 +325,10 @@ bit_copy (bfd_byte *buffer, int offset, int count, char *to)
 }
 
 static int
-sign_extend (int value, int bits)
+sign_extend (unsigned int value, unsigned int bits)
 {
-  value = value & ((1 << bits) - 1);
-  return (value & (1 << (bits - 1))
-	  ? value | (~((1 << bits) - 1))
-	  : value);
+  unsigned int sign = 1u << bits;
+  return ((value & (sign - 1)) ^ sign) - sign;
 }
 
 static void