[binutils-gdb] x86: simplify VexVVVV_SRC2 handling for the XOP case

[Jan Beulich]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6b15ec516579f8005e97d58ec06b1c98debf947b

commit 6b15ec516579f8005e97d58ec06b1c98debf947b
Author: Jan Beulich <jbeulich@suse.com>
Date:   Fri May 24 12:21:57 2024 +0200

    x86: simplify VexVVVV_SRC2 handling for the XOP case
    
    As already suggested during review, rather than having an extra
    conditional in build_modrm_byte() (a code path used for quite a few
    more insns, including even certain GPR ones), adjust the attribute in
    the installed template to properly describe things with operands
    swapped.

Diff:
---
 gas/config/tc-i386.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 69b2670bbbb..b1cc06851c5 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -9264,6 +9264,9 @@ match_template (char mnem_suffix)
 	 flipping VEX.W.  */
       i.tm.opcode_modifier.vexw ^= VEXW0 ^ VEXW1;
 
+      /* In 3-operand insns XOP.W changes which operand goes into XOP.vvvv.  */
+      i.tm.opcode_modifier.vexvvvv = VexVVVV_SRC1;
+
     swap_first_2:
       j = i.tm.operand_types[0].bitfield.imm8;
       i.tm.operand_types[j] = operand_types[j + 1];
@@ -10471,15 +10474,8 @@ build_modrm_byte (void)
     {
     /* VEX.vvvv encodes the last source register operand.  */
     case VexVVVV_SRC2:
-      if (source != op)
-	{
-	  v = source++;
-	  break;
-	}
-      /* For vprot*, vpshl*, and vpsha*, XOP.W controls the swapping of src1
-	 and src2, and it requires fall through when the operands are swapped.
-       */
-      /* Fall through.  */
+      v = source++;
+      break;
     /* VEX.vvvv encodes the first source register operand.  */
     case VexVVVV_SRC1:
       v =  dest - 1;