From 0de704b9cdd3ca093317820d15134b7f72f5a7e1 Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@suse.com>
Date: Fri, 10 Mar 2023 11:06:17 +0100
Subject: [PATCH] x86: move more disp processing out of md_assemble()

Put it in optimize_disp() such that it can then be re-used by .insn
handling. The movement makes it necessary (or at least very desirable,
to avoid introducing a fragile cast) to convert to local variable to
"unsigned", which in turn requires an adjustment to the pre-existing
loop header.

Having the caller pass in the specific template under consideration has
another benefit then: We can replace the two uses of current_templates
in the function as well, thus no longer looking at some merely "related"
template. (This may allow further tightening, but if so that's to be the
subject of another change.)
---
 gas/config/tc-i386.c | 89 +++++++++++++++++++++++---------------------
 1 file changed, 46 insertions(+), 43 deletions(-)

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 13e33d18ac3..571fc3aacaf 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -165,7 +165,7 @@ static void swap_operands (void);
 static void swap_2_operands (unsigned int, unsigned int);
 static enum flag_code i386_addressing_mode (void);
 static void optimize_imm (void);
-static void optimize_disp (void);
+static bool optimize_disp (const insn_template *t);
 static const insn_template *match_template (char);
 static int check_string (void);
 static int process_suffix (void);
@@ -4966,42 +4966,8 @@ md_assemble (char *line)
   if (i.imm_operands)
     optimize_imm ();
 
-  if (i.disp_operands && !want_disp32 (t)
-      && (!t->opcode_modifier.jump
-	  || i.jumpabsolute || i.types[0].bitfield.baseindex))
-    {
-      for (j = 0; j < i.operands; ++j)
-	{
-	  const expressionS *exp = i.op[j].disps;
-
-	  if (!operand_type_check (i.types[j], disp))
-	    continue;
-
-	  if (exp->X_op != O_constant)
-	    continue;
-
-	  /* Since displacement is signed extended to 64bit, don't allow
-	     disp32 if it is out of range.  */
-	  if (fits_in_signed_long (exp->X_add_number))
-	    continue;
-
-	  i.types[j].bitfield.disp32 = 0;
-	  if (i.types[j].bitfield.baseindex)
-	    {
-	      as_bad (_("0x%" PRIx64 " out of range of signed 32bit displacement"),
-		      (uint64_t) exp->X_add_number);
-	      return;
-	    }
-	}
-    }
-
-  /* Don't optimize displacement for movabs since it only takes 64bit
-     displacement.  */
-  if (i.disp_operands
-      && i.disp_encoding <= disp_encoding_8bit
-      && (flag_code != CODE_64BIT
-	  || strcmp (mnemonic, "movabs") != 0))
-    optimize_disp ();
+  if (i.disp_operands && !optimize_disp (t))
+    return;
 
   /* Next, we find a template that matches the given insn,
      making sure the overlap of the given operands types is consistent
@@ -6130,12 +6096,47 @@ optimize_imm (void)
 }
 
 /* Try to use the smallest displacement type too.  */
-static void
-optimize_disp (void)
+static bool
+optimize_disp (const insn_template *t)
 {
-  int op;
+  unsigned int op;
 
-  for (op = i.operands; --op >= 0;)
+  if (!want_disp32 (t)
+      && (!t->opcode_modifier.jump
+	  || i.jumpabsolute || i.types[0].bitfield.baseindex))
+    {
+      for (op = 0; op < i.operands; ++op)
+	{
+	  const expressionS *exp = i.op[op].disps;
+
+	  if (!operand_type_check (i.types[op], disp))
+	    continue;
+
+	  if (exp->X_op != O_constant)
+	    continue;
+
+	  /* Since displacement is signed extended to 64bit, don't allow
+	     disp32 if it is out of range.  */
+	  if (fits_in_signed_long (exp->X_add_number))
+	    continue;
+
+	  i.types[op].bitfield.disp32 = 0;
+	  if (i.types[op].bitfield.baseindex)
+	    {
+	      as_bad (_("0x%" PRIx64 " out of range of signed 32bit displacement"),
+		      (uint64_t) exp->X_add_number);
+	      return false;
+	    }
+	}
+    }
+
+  /* Don't optimize displacement for movabs since it only takes 64bit
+     displacement.  */
+  if (i.disp_encoding > disp_encoding_8bit
+      || (flag_code == CODE_64BIT && t->mnem_off == MN_movabs))
+    return true;
+
+  for (op = i.operands; op-- > 0;)
     if (operand_type_check (i.types[op], disp))
       {
 	if (i.op[op].disps->X_op == O_constant)
@@ -6164,8 +6165,8 @@ optimize_disp (void)
 	    /* Optimize 64-bit displacement to 32-bit for 64-bit BFD.  */
 	    if ((flag_code != CODE_64BIT
 		 ? i.types[op].bitfield.disp32
-		 : want_disp32 (current_templates->start)
-		   && (!current_templates->start->opcode_modifier.jump
+		 : want_disp32 (t)
+		   && (!t->opcode_modifier.jump
 		       || i.jumpabsolute || i.types[op].bitfield.baseindex))
 		&& fits_in_unsigned_long (op_disp))
 	      {
@@ -6201,6 +6202,8 @@ optimize_disp (void)
 	  /* We only support 64bit displacement on constants.  */
 	  i.types[op].bitfield.disp64 = 0;
       }
+
+  return true;
 }
 
 /* Return 1 if there is a match in broadcast bytes between operand
-- 
2.30.2