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[PATCH v4 4/5] x86: correct VFPCLASSP{S,D} operand size handling

Jan Beulich jbeulich@suse.com
Mon Feb 10 13:52:00 GMT 2020 
With AVX512VL disabled (e.g. when writing code for the Knights family
of processors) these insns aren't ambiguous when used with a memory
source, and hence should be accepted without suffix or operand size
specifier. When AVX512VL is enabled, to be consistent with this as
well as other ambiguous operand size handling it would seem better to
just warn about the ambiguity in AT&T mode, and still default to 512-bit
operands (on the assumption that the code may have been written without
AVX512VL in mind yet), but it was requested to leave AT&T syntax mode
alone here.

gas/
2020-01-XX  Jan Beulich  <jbeulich@suse.com>

	* config/tc-i386.c (avx512): New (at file scope), moved from
	(check_VecOperands): ... here.
	(process_suffix): Add [XYZ]MMword operand size handling.
	* testsuite/gas/i386/avx512dq-inval.s: Add VFPCLASS tests.
	* testsuite/gas/i386/noavx512-2.s: Add Intel syntax VFPCLASS
	tests.
	* testsuite/gas/i386/avx512dq-inval.l,
	testsuite/gas/i386/noavx512-2.l: Adjust expectations.

opcodes/
2020-01-XX  Jan Beulich  <jbeulich@suse.com>

	* i386-opc.tbl (vfpclasspd, vfpclassps): Add Intel sytax form
	with Unspecified, making the present one AT&T syntax only.
	* i386-tbl.h: Re-generate.
---
v4: Restrict to just Intel syntax mode. Re-base.
v3: Re-base.

--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -1835,6 +1835,8 @@ cpu_flags_and_not (i386_cpu_flags x, i38
   return x;
 }
 
+static const i386_cpu_flags avx512 = CPU_ANY_AVX512F_FLAGS;
+
 #define CPU_FLAGS_ARCH_MATCH		0x1
 #define CPU_FLAGS_64BIT_MATCH		0x2
 
@@ -5348,7 +5350,6 @@ check_VecOperands (const insn_template *
 {
   unsigned int op;
   i386_cpu_flags cpu;
-  static const i386_cpu_flags avx512 = CPU_ANY_AVX512F_FLAGS;
 
   /* Templates allowing for ZMMword as well as YMMword and/or XMMword for
      any one operand are implicity requiring AVX512VL support if the actual
@@ -6425,7 +6426,8 @@ process_suffix (void)
       /* Accept FLDENV et al without suffix.  */
       && (i.tm.opcode_modifier.no_ssuf || i.tm.opcode_modifier.floatmf))
     {
-      unsigned int suffixes;
+      unsigned int suffixes, evex = 0;
+      i386_cpu_flags cpu;
 
       suffixes = !i.tm.opcode_modifier.no_bsuf;
       if (!i.tm.opcode_modifier.no_wsuf)
@@ -6439,7 +6441,55 @@ process_suffix (void)
       if (flag_code == CODE_64BIT && !i.tm.opcode_modifier.no_qsuf)
 	suffixes |= 1 << 5;
 
-      /* Are multiple suffixes allowed?  */
+      /* For [XYZ]MMWORD operands inspect operand sizes.  */
+      cpu = cpu_flags_and (i.tm.cpu_flags, avx512);
+      if (!cpu_flags_all_zero (&cpu) && !i.broadcast)
+	{
+	  unsigned int op;
+
+	  for (op = 0; op < i.tm.operands; ++op)
+	    {
+	      if (!cpu_arch_flags.bitfield.cpuavx512vl)
+		{
+		  if (i.tm.operand_types[op].bitfield.ymmword)
+		    i.tm.operand_types[op].bitfield.xmmword = 0;
+		  if (i.tm.operand_types[op].bitfield.zmmword)
+		    i.tm.operand_types[op].bitfield.ymmword = 0;
+		  if (!i.tm.opcode_modifier.evex
+		      || i.tm.opcode_modifier.evex == EVEXDYN)
+		    i.tm.opcode_modifier.evex = EVEX512;
+		}
+
+	      if (i.tm.operand_types[op].bitfield.xmmword
+		  + i.tm.operand_types[op].bitfield.ymmword
+		  + i.tm.operand_types[op].bitfield.zmmword < 2)
+		continue;
+
+	      /* Any properly sized operand disambiguates the insn.  */
+	      if (i.types[op].bitfield.xmmword
+		  || i.types[op].bitfield.ymmword
+		  || i.types[op].bitfield.zmmword)
+		{
+		  suffixes &= ~(7 << 6);
+		  evex = 0;
+		  break;
+		}
+
+	      if ((i.flags[op] & Operand_Mem)
+		  && i.tm.operand_types[op].bitfield.unspecified)
+		{
+		  if (i.tm.operand_types[op].bitfield.xmmword)
+		    suffixes |= 1 << 6;
+		  if (i.tm.operand_types[op].bitfield.ymmword)
+		    suffixes |= 1 << 7;
+		  if (i.tm.operand_types[op].bitfield.zmmword)
+		    suffixes |= 1 << 8;
+		  evex = EVEX512;
+		}
+	    }
+	}
+
+      /* Are multiple suffixes / operand sizes allowed?  */
       if (suffixes & (suffixes - 1))
 	{
 	  if (intel_syntax
@@ -6469,6 +6519,8 @@ process_suffix (void)
 		   || (i.tm.base_opcode == 0x63
 		       && i.tm.cpu_flags.bitfield.cpu64))
 	    /* handled below */;
+	  else if (evex)
+	    i.tm.opcode_modifier.evex = evex;
 	  else if (flag_code == CODE_16BIT)
 	    i.suffix = WORD_MNEM_SUFFIX;
 	  else if (!i.tm.opcode_modifier.no_lsuf)
--- a/gas/testsuite/gas/i386/avx512dq-inval.l
+++ b/gas/testsuite/gas/i386/avx512dq-inval.l
@@ -11,3 +11,7 @@
 .*:[0-9]*: Error:.* `vpinsrq' .*
 .*:[0-9]*: Error:.* `vpinsrq' .*
 .*:[0-9]*: Error:.* `vpinsrq' .*
+.*:[0-9]*: Error:.* `vfpclasspd'
+.*:[0-9]*: Error:.* `vfpclassps'
+.*:[0-9]*: Error:.* `vfpclasspd'
+.*:[0-9]*: Error:.* `vfpclassps'
--- a/gas/testsuite/gas/i386/avx512dq-inval.s
+++ b/gas/testsuite/gas/i386/avx512dq-inval.s
@@ -1,4 +1,4 @@
-# Check AVX512DQ instructions not to be accepted outside of 64-bit mode
+# Check AVX512DQ instructions not to be accepted (in part only outside of 64-bit mode)
 
 	.text
 _start:
@@ -20,3 +20,10 @@ _start:
 	       vpinsrq	xmm0, xmm0, qword ptr [eax], 0
 	{evex} vpinsrq	xmm0, xmm0, qword ptr [eax], 0
 
+	vfpclasspd	k0, [eax], 0
+	vfpclassps	k0, [eax], 0
+
+	.att_syntax prefix
+
+	vfpclasspd	$0, (%eax), %k0
+	vfpclassps	$0, (%eax), %k0
--- a/gas/testsuite/gas/i386/noavx512-2.l
+++ b/gas/testsuite/gas/i386/noavx512-2.l
@@ -101,5 +101,10 @@ GAS LISTING .*
 [ 	]*50[ 	]+F5
 [ 	]*51[ 	]+\?\?\?\? 660F58F4 		addpd %xmm4, %xmm6
 [ 	]*52[ 	]+
-[ 	]*53[ 	]+\?\?\?\? 0F1F00   		\.p2align 4
+[ 	]*[1-9][0-9]*[ 	]+\.intel_syntax noprefix
+[ 	]*[1-9][0-9]*[ 	]+\?\?\?\? 62F3FD48 		vfpclasspd k0, \[eax], 0
+[ 	]*[1-9][0-9]*[ 	]+660000
+[ 	]*[1-9][0-9]*[ 	]+\?\?\?\? 62F37D48 		vfpclassps k0, \[eax], 0
+[ 	]*[1-9][0-9]*[ 	]+660000
+[ 	]*[1-9][0-9]*[ 	]+
 #pass
--- a/gas/testsuite/gas/i386/noavx512-2.s
+++ b/gas/testsuite/gas/i386/noavx512-2.s
@@ -50,4 +50,8 @@
 	pabsb %xmm5, %xmm6
 	addpd %xmm4, %xmm6
 
+	.intel_syntax noprefix
+	vfpclasspd k0, [eax], 0
+	vfpclassps k0, [eax], 0
+
 	.p2align 4
--- a/opcodes/i386-opc.tbl
+++ b/opcodes/i386-opc.tbl
@@ -4500,12 +4500,14 @@ vextracti64x2, 3, 0x6639, None, 1, CpuAV
 vinsertf64x2, 4, 0x6618, None, 1, CpuAVX512DQ, Modrm|Masking=3|VexOpcode=2|VexVVVV=1|VexW=2|Disp8MemShift=4|CheckRegSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegXMM|Unspecified|BaseIndex, RegYMM|RegZMM, RegYMM|RegZMM }
 vinserti64x2, 4, 0x6638, None, 1, CpuAVX512DQ, Modrm|Masking=3|VexOpcode=2|VexVVVV=1|VexW=2|Disp8MemShift=4|CheckRegSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegXMM|Unspecified|BaseIndex, RegYMM|RegZMM, RegYMM|RegZMM }
 
-vfpclasspd, 3, 0x6666, None, 1, CpuAVX512DQ, Modrm|Masking=2|VexOpcode=2|VexW=2|Broadcast|Disp8ShiftVL|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegXMM|RegYMM|RegZMM|Qword|BaseIndex, RegMask }
+vfpclasspd, 3, 0x6666, None, 1, CpuAVX512DQ, Modrm|Masking=2|VexOpcode=2|VexW=2|Broadcast|Disp8ShiftVL|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Imm8, RegXMM|RegYMM|RegZMM|Qword|BaseIndex, RegMask }
+vfpclasspd, 3, 0x6666, None, 1, CpuAVX512DQ, Modrm|Masking=2|VexOpcode=2|VexW=2|Broadcast|Disp8ShiftVL|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IntelSyntax, { Imm8, RegXMM|RegYMM|RegZMM|Qword|Unspecified|BaseIndex, RegMask }
 vfpclasspdz, 3, 0x6666, None, 1, CpuAVX512DQ, Modrm|EVex=1|Masking=2|VexOpcode=2|VexW=2|Broadcast|Disp8MemShift=6|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegZMM|Qword|Unspecified|BaseIndex, RegMask }
 vfpclasspdx, 3, 0x6666, None, 1, CpuAVX512DQ|CpuAVX512VL, Modrm|EVex=2|Masking=2|VexOpcode=2|VexW=2|Broadcast|Disp8MemShift=4|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegXMM|Qword|Unspecified|BaseIndex, RegMask }
 vfpclasspdy, 3, 0x6666, None, 1, CpuAVX512DQ|CpuAVX512VL, Modrm|EVex=3|Masking=2|VexOpcode=2|VexW=2|Broadcast|Disp8MemShift=5|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegYMM|Qword|Unspecified|BaseIndex, RegMask }
 
-vfpclassps, 3, 0x6666, None, 1, CpuAVX512DQ, Modrm|Masking=2|VexOpcode=2|VexW=1|Broadcast|Disp8ShiftVL|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegXMM|RegYMM|RegZMM|Dword|BaseIndex, RegMask }
+vfpclassps, 3, 0x6666, None, 1, CpuAVX512DQ, Modrm|Masking=2|VexOpcode=2|VexW=1|Broadcast|Disp8ShiftVL|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Imm8, RegXMM|RegYMM|RegZMM|Dword|BaseIndex, RegMask }
+vfpclassps, 3, 0x6666, None, 1, CpuAVX512DQ, Modrm|Masking=2|VexOpcode=2|VexW=1|Broadcast|Disp8ShiftVL|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IntelSyntax, { Imm8, RegXMM|RegYMM|RegZMM|Dword|Unspecified|BaseIndex, RegMask }
 vfpclasspsz, 3, 0x6666, None, 1, CpuAVX512DQ, Modrm|EVex=1|Masking=2|VexOpcode=2|VexW=1|Broadcast|Disp8MemShift=6|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegZMM|Dword|Unspecified|BaseIndex, RegMask }
 vfpclasspsx, 3, 0x6666, None, 1, CpuAVX512DQ|CpuAVX512VL, Modrm|EVex=2|Masking=2|VexOpcode=2|VexW=1|Broadcast|Disp8MemShift=4|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegXMM|Dword|Unspecified|BaseIndex, RegMask }
 vfpclasspsy, 3, 0x6666, None, 1, CpuAVX512DQ|CpuAVX512VL, Modrm|EVex=3|Masking=2|VexOpcode=2|VexW=1|Broadcast|Disp8MemShift=5|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegYMM|Dword|Unspecified|BaseIndex, RegMask }
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