[PATCH 1/3] x86: fix 3-operand insn reverse-matching

[Jan Beulich]

The middle operand would have gone entirely unchecked, allowing e.g.

	vmovss		%xmm0, %esp, %xmm2

to assemble successfully, or e.g.

	vmovss		%xmm0, $4, %xmm2

causing an internal error. Alongside dealing with this also drop a
related comment, which hasn't been applicable anymore since the
introduction of 3-operand patterns with D set (and which perhaps never
had been logical to be there, as reverse-matched insns don't make it
there in the first place).

--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -6724,8 +6724,12 @@ match_template (char mnem_suffix)
 	      /* Try reversing direction of operands.  */
 	      overlap0 = operand_type_and (i.types[0], operand_types[i.operands - 1]);
 	      overlap1 = operand_type_and (i.types[i.operands - 1], operand_types[0]);
+	      overlap2 = operand_type_and (i.types[1], operand_types[1]);
+	      gas_assert (t->operands != 3 || !check_register);
 	      if (!operand_type_match (overlap0, i.types[0])
 		  || !operand_type_match (overlap1, i.types[i.operands - 1])
+		  || (t->operands == 3
+		      && !operand_type_match (overlap2, i.types[1]))
 		  || (check_register
 		      && !operand_type_register_match (i.types[0],
 						       operand_types[i.operands - 1],
@@ -6797,8 +6801,6 @@ match_template (char mnem_suffix)
 		    continue;
 		  /* Fall through.  */
 		case 3:
-		  /* Here we make use of the fact that there are no
-		     reverse match 3 operand instructions.  */
 		  if (!operand_type_match (overlap2, i.types[2])
 		      || ((check_register & 5) == 5
 			  && !operand_type_register_match (i.types[0],
--- a/gas/testsuite/gas/i386/inval-avx.l
+++ b/gas/testsuite/gas/i386/inval-avx.l
@@ -2,20 +2,13 @@
 .*:4: Error: .*
 .*:5: Error: .*
 .*:6: Error: .*
-.*:9: Error:.* ambiguous .* `vcvtpd2dq'
-.*:10: Error:.* ambiguous .* `vcvtpd2ps'
-.*:11: Error:.* ambiguous .* `vcvttpd2dq'
+.*:8: Error: .*
+.*:9: Error: .*
+.*:10: Error: .*
+.*:11: Error: .*
+.*:12: Error: .*
+.*:15: Error:.* ambiguous .* `vcvtpd2dq'
+.*:16: Error:.* ambiguous .* `vcvtpd2ps'
+.*:17: Error:.* ambiguous .* `vcvttpd2dq'
 GAS LISTING .*
-
-
-[ 	]*1[ 	]+\# Check illegal AVX instructions
-[ 	]*2[ 	]+\.text
-[ 	]*3[ 	]+_start:
-[ 	]*4[ 	]+vcvtpd2dq \(%ecx\),%xmm2
-[ 	]*5[ 	]+vcvtpd2ps \(%ecx\),%xmm2
-[ 	]*6[ 	]+vcvttpd2dq \(%ecx\),%xmm2
-[ 	]*7[ 	]+
-[ 	]*8[ 	]+\.intel_syntax noprefix
-[ 	]*9[ 	]+vcvtpd2dq xmm2,\[ecx\]
-[ 	]*10[ 	]+vcvtpd2ps xmm2,\[ecx\]
-[ 	]*11[ 	]+vcvttpd2dq xmm2,\[ecx\]
+#pass
--- a/gas/testsuite/gas/i386/inval-avx.s
+++ b/gas/testsuite/gas/i386/inval-avx.s
@@ -5,6 +5,12 @@ _start:
 	vcvtpd2ps (%ecx),%xmm2
 	vcvttpd2dq (%ecx),%xmm2
 
+	vmovss %xmm0, (%esp), %xmm2
+	vmovss %xmm0, $4, %xmm2
+	vmovss %xmm0, %cr0, %xmm2
+	vmovss %xmm0, %ymm4, %xmm2
+	vmovss %xmm0, %mm4, %xmm2
+
 	.intel_syntax noprefix
 	vcvtpd2dq xmm2,[ecx]
 	vcvtpd2ps xmm2,[ecx]