[PATCH 2/3] x86: drop FloatR

[Jan Beulich]

There are just 4 templates using it, which can be easily identified by
other means, as D is set only on a very limited number of FPU templates.
Also move the respective conditional out of the code path taken by all
"reverse match" insns (it probably should have been this way already
before, to avoid the one conditional in the common case).

With this the templates which had FloatR dropped no longer differ from
their AT&T syntax + mnemonic counterparts - the only difference is now
which of the two would be recognized. For this, however, we don't need
two templates - we can simply arrange the condition for setting
Opcode_FloatR accordingly.

--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -6800,12 +6800,18 @@ match_template (char mnem_suffix)
 		  specific_error = progress (i.error);
 		  continue;
 		}
-	      /* found_reverse_match holds which of D or FloatR
+	      /* found_reverse_match holds which variant of D
 		 we've found.  */
 	      if (!t->opcode_modifier.d)
 		found_reverse_match = 0;
 	      else if (operand_types[0].bitfield.tbyte)
-		found_reverse_match = Opcode_FloatD;
+		{
+		  found_reverse_match = Opcode_FloatD;
+		  /* FSUB{,R} and FDIV{,R} may need a 2nd bit flipped.  */
+		  if ((t->base_opcode & 0x20)
+		      && (intel_syntax || intel_mnemonic))
+		    found_reverse_match |= Opcode_FloatR;
+		}
 	      else if (t->opcode_modifier.vexsources)
 		{
 		  found_reverse_match = Opcode_VexW;
@@ -6820,8 +6826,6 @@ match_template (char mnem_suffix)
 				      ? Opcode_ExtD : Opcode_SIMD_IntD;
 	      else
 		found_reverse_match = Opcode_D;
-	      if (t->opcode_modifier.floatr)
-		found_reverse_match |= Opcode_FloatR;
 	    }
 	  else
 	    {
--- a/opcodes/i386-gen.c
+++ b/opcodes/i386-gen.c
@@ -731,7 +731,6 @@ static bitfield opcode_modifiers[] =
   BITFIELD (Modrm),
   BITFIELD (Jump),
   BITFIELD (FloatMF),
-  BITFIELD (FloatR),
   BITFIELD (Size),
   BITFIELD (CheckRegSize),
   BITFIELD (OperandConstraint),
--- a/opcodes/i386-opc.h
+++ b/opcodes/i386-opc.h
@@ -487,8 +487,6 @@ enum
   Jump,
   /* FP insn memory format bit, sized by 0x4 */
   FloatMF,
-  /* src/dest swap for floats. */
-  FloatR,
   /* needs size prefix if in 32-bit mode */
 #define SIZE16 1
   /* needs size prefix if in 16-bit mode */
@@ -743,7 +741,6 @@ typedef struct i386_opcode_modifier
   unsigned int modrm:1;
   unsigned int jump:3;
   unsigned int floatmf:1;
-  unsigned int floatr:1;
   unsigned int size:2;
   unsigned int checkregsize:1;
   unsigned int operandconstraint:4;
--- a/opcodes/i386-opc.tbl
+++ b/opcodes/i386-opc.tbl
@@ -694,11 +694,10 @@ faddp, 0xdec0, None, CpuFP, NoSuf|Ugh, {
 
 // subtract
 fsub, 0xd8e0, None, CpuFP, NoSuf, { FloatReg }
-fsub, 0xd8e0, None, CpuFP, D|NoSuf|ATTMnemonic|ATTSyntax, { FloatReg, FloatAcc }
+fsub, 0xd8e0, None, CpuFP, D|NoSuf, { FloatReg, FloatAcc }
 // alias for fsubp
 fsub, 0xdee1, None, CpuFP, NoSuf|Ugh|ATTMnemonic|ATTSyntax, {}
 fsub, 0xdee9, None, CpuFP, NoSuf|Ugh|ATTMnemonic, {}
-fsub, 0xd8e0, None, CpuFP, NoSuf|D|FloatR, { FloatReg, FloatAcc }
 fsub, 0xd8, 4, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Dword|Qword|Unspecified|BaseIndex }
 fisub, 0xde, 4, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Word|Dword|Unspecified|BaseIndex }
 
@@ -711,11 +710,10 @@ fsubp, 0xdee9, None, CpuFP, NoSuf, {}
 
 // subtract reverse
 fsubr, 0xd8e8, None, CpuFP, NoSuf, { FloatReg }
-fsubr, 0xd8e8, None, CpuFP, D|NoSuf|ATTMnemonic|ATTSyntax, { FloatReg, FloatAcc }
+fsubr, 0xd8e8, None, CpuFP, D|NoSuf, { FloatReg, FloatAcc }
 // alias for fsubrp
 fsubr, 0xdee9, None, CpuFP, NoSuf|Ugh|ATTMnemonic|ATTSyntax, {}
 fsubr, 0xdee1, None, CpuFP, NoSuf|Ugh|ATTMnemonic, {}
-fsubr, 0xd8e8, None, CpuFP, NoSuf|D|FloatR, { FloatReg, FloatAcc }
 fsubr, 0xd8, 5, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Dword|Qword|Unspecified|BaseIndex }
 fisubr, 0xde, 5, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Word|Dword|Unspecified|BaseIndex }
 
@@ -741,11 +739,10 @@ fmulp, 0xdec8, None, CpuFP, NoSuf|Ugh, {
 
 // divide
 fdiv, 0xd8f0, None, CpuFP, NoSuf, { FloatReg }
-fdiv, 0xd8f0, None, CpuFP, D|NoSuf|ATTMnemonic|ATTSyntax, { FloatReg, FloatAcc }
+fdiv, 0xd8f0, None, CpuFP, D|NoSuf, { FloatReg, FloatAcc }
 // alias for fdivp
 fdiv, 0xdef1, None, CpuFP, NoSuf|Ugh|ATTMnemonic|ATTSyntax, {}
 fdiv, 0xdef9, None, CpuFP, NoSuf|Ugh|ATTMnemonic, {}
-fdiv, 0xd8f0, None, CpuFP, NoSuf|D|FloatR, { FloatReg, FloatAcc }
 fdiv, 0xd8, 6, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Dword|Qword|Unspecified|BaseIndex }
 fidiv, 0xde, 6, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Word|Dword|Unspecified|BaseIndex }
 
@@ -758,11 +755,10 @@ fdivp, 0xdef9, None, CpuFP, NoSuf, {}
 
 // divide reverse
 fdivr, 0xd8f8, None, CpuFP, NoSuf, { FloatReg }
-fdivr, 0xd8f8, None, CpuFP, D|NoSuf|ATTMnemonic|ATTSyntax, { FloatReg, FloatAcc }
+fdivr, 0xd8f8, None, CpuFP, D|NoSuf, { FloatReg, FloatAcc }
 // alias for fdivrp
 fdivr, 0xdef9, None, CpuFP, NoSuf|Ugh|ATTMnemonic|ATTSyntax, {}
 fdivr, 0xdef1, None, CpuFP, NoSuf|Ugh|ATTMnemonic, {}
-fdivr, 0xd8f8, None, CpuFP, NoSuf|D|FloatR, { FloatReg, FloatAcc }
 fdivr, 0xd8, 7, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Dword|Qword|Unspecified|BaseIndex }
 fidivr, 0xde, 7, CpuFP, Modrm|FloatMF|No_bSuf|No_wSuf|No_qSuf|No_ldSuf, { Word|Dword|Unspecified|BaseIndex }