[binutils-gdb] PR26610, ARM's "VFPv3 vldr to vmov" gas testcase fail

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7e30b1ebbf2fcf5e6bcfc3a7791d9a52614dcc43

commit 7e30b1ebbf2fcf5e6bcfc3a7791d9a52614dcc43
Author: Alan Modra <amodra@gmail.com>
Date:   Tue Sep 15 20:55:02 2020 +0930

    PR26610, ARM's "VFPv3 vldr to vmov" gas testcase fail
    
    I removed a few too many parentheses in git commit 7af677524e2.  This
    patch fixes that problem, rewriting the expression so it won't happen
    again.  The patch also avoids more UB with shifts of signed values.
    
            PR 26610
            * config/tc-arm.c (move_or_literal_pool): Correct extraction of
            bignum.  Use unsigned "v"
            (is_double_a_single): Make "v" and "mantissa" unsigned.  Formatting.
            (double_to_single): Likewise.

Diff:
---
 gas/ChangeLog       |  8 ++++++++
 gas/config/tc-arm.c | 39 ++++++++++++++++++++-------------------
 2 files changed, 28 insertions(+), 19 deletions(-)

diff --git a/gas/ChangeLog b/gas/ChangeLog
index add14d82749..4082e8a0a09 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,11 @@
+2020-09-15  Alan Modra  <amodra@gmail.com>
+
+	PR 26610
+	* config/tc-arm.c (move_or_literal_pool): Correct extraction of
+	bignum.  Use unsigned "v"
+	(is_double_a_single): Make "v" and "mantissa" unsigned.  Formatting.
+	(double_to_single): Likewise.
+
 2020-09-15  Nick Clifton  <nickc@redhat.com>
 
 	* read.c (s_nop): Preserve the input_line_pointer around the call
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index a645ffec901..32feaa1ca09 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -8757,25 +8757,25 @@ neon_cmode_for_move_imm (unsigned immlo, unsigned immhi, int float_p,
    to single precision without loss of accuracy.  */
 
 static bfd_boolean
-is_double_a_single (bfd_int64_t v)
+is_double_a_single (bfd_uint64_t v)
 {
-  int exp = (int)((v >> 52) & 0x7FF);
-  bfd_int64_t mantissa = (v & (bfd_int64_t)0xFFFFFFFFFFFFFULL);
+  int exp = (v >> 52) & 0x7FF;
+  bfd_uint64_t mantissa = v & 0xFFFFFFFFFFFFFULL;
 
-  return (exp == 0 || exp == 0x7FF
-	  || (exp >= 1023 - 126 && exp <= 1023 + 127))
-    && (mantissa & 0x1FFFFFFFl) == 0;
+  return ((exp == 0 || exp == 0x7FF
+	   || (exp >= 1023 - 126 && exp <= 1023 + 127))
+	  && (mantissa & 0x1FFFFFFFL) == 0);
 }
 
 /* Returns a double precision value casted to single precision
    (ignoring the least significant bits in exponent and mantissa).  */
 
 static int
-double_to_single (bfd_int64_t v)
+double_to_single (bfd_uint64_t v)
 {
   unsigned int sign = (v >> 63) & 1;
   int exp = (v >> 52) & 0x7FF;
-  bfd_int64_t mantissa = (v & (bfd_int64_t) 0xFFFFFFFFFFFFFULL);
+  bfd_uint64_t mantissa = v & 0xFFFFFFFFFFFFFULL;
 
   if (exp == 0x7FF)
     exp = 0xFF;
@@ -8848,9 +8848,9 @@ move_or_literal_pool (int i, enum lit_type t, bfd_boolean mode_3)
       || inst.relocs[0].exp.X_op == O_big)
     {
 #if defined BFD_HOST_64_BIT
-      bfd_int64_t v;
+      bfd_uint64_t v;
 #else
-      offsetT v;
+      valueT v;
 #endif
       if (inst.relocs[0].exp.X_op == O_big)
 	{
@@ -8867,16 +8867,17 @@ move_or_literal_pool (int i, enum lit_type t, bfd_boolean mode_3)
 	    l = generic_bignum;
 
 #if defined BFD_HOST_64_BIT
-	  v = ((((bfd_uint64_t) l[3] & LITTLENUM_MASK)
-		<< LITTLENUM_NUMBER_OF_BITS)
-	       | (((bfd_int64_t) l[2] & LITTLENUM_MASK)
-		  << LITTLENUM_NUMBER_OF_BITS)
-	       | (((bfd_uint64_t) l[1] & LITTLENUM_MASK)
-		  << LITTLENUM_NUMBER_OF_BITS)
-	       | (l[0] & LITTLENUM_MASK));
+	  v = l[3] & LITTLENUM_MASK;
+	  v <<= LITTLENUM_NUMBER_OF_BITS;
+	  v |= l[2] & LITTLENUM_MASK;
+	  v <<= LITTLENUM_NUMBER_OF_BITS;
+	  v |= l[1] & LITTLENUM_MASK;
+	  v <<= LITTLENUM_NUMBER_OF_BITS;
+	  v |= l[0] & LITTLENUM_MASK;
 #else
-	  v = ((((valueT) l[1] & LITTLENUM_MASK) << LITTLENUM_NUMBER_OF_BITS)
-	       | (l[0] & LITTLENUM_MASK));
+	  v = l[1] & LITTLENUM_MASK;
+	  v <<= LITTLENUM_NUMBER_OF_BITS;
+	  v |= l[0] & LITTLENUM_MASK;
 #endif
 	}
       else