From: Jan Beulich <jbeulich@suse.com>
Date: Tue, 4 Jul 2023 15:00:15 +0000 (+0200)
Subject: x86: re-work EVEX-z-without-masking check
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=07d618b91f50816f198abac7df116e83d47ca1be;p=binutils-gdb.git

x86: re-work EVEX-z-without-masking check

Rather than corrupting disassmbly altogether, flag EVEX.z set as bad
when masking isn't in effect in the first place at the time the
destination operand is actually processed.
---

diff --git a/gas/testsuite/gas/i386/avx512f-nondef.d b/gas/testsuite/gas/i386/avx512f-nondef.d
index a062fe335bc..8defd6972e5 100644
--- a/gas/testsuite/gas/i386/avx512f-nondef.d
+++ b/gas/testsuite/gas/i386/avx512f-nondef.d
@@ -15,8 +15,7 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	62 f2 55 1f 3b f4    	vpminud \{rn-bad\},%zmm4,%zmm5,%zmm6\{%k7\}
 [ 	]*[a-f0-9]+:	62 f2 7e 48 31 72 7f 	vpmovdb %zmm6,0x7f0\(%edx\)
 [ 	]*[a-f0-9]+:	62 f2 7e 58 31 72 7f 	vpmovdb %zmm6,0x7f0\(%edx\)\{bad\}
-[ 	]*[a-f0-9]+:	62 f1 7c 88 58       	\(bad\)
-[ 	]*[a-f0-9]+:	c3                   	ret
+[ 	]*[a-f0-9]+:	62 f1 7c 88 58 c3    	(\{evex\} )?vaddps %xmm3,%xmm0,%xmm0\{bad\}
 [ 	]*[a-f0-9]+:	62 f2 7d 4f 92 01    	vgatherdps \(bad\),%zmm0\{%k7\}
 [ 	]*[a-f0-9]+:	67 62 f2 7d 4f 92 01 	addr16 vgatherdps \(bad\),%zmm0\{%k7\}
 [ 	]*[a-f0-9]+:	62 f2 7d cf 92 04 08 	vgatherdps \(%eax,%zmm1(,1)?\),%zmm0\{%k7\}\{z\}/\(bad\)
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index 15a0e1b1080..690e336c6bc 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -9905,9 +9905,15 @@ print_insn (bfd_vma pc, disassemble_info *info, int intel_syntax)
 		      oappend (&ins, "{");
 		      oappend_register (&ins, reg_name);
 		      oappend (&ins, "}");
+
+		      if (ins.vex.zeroing)
+			oappend (&ins, "{z}");
+		    }
+		  else if (ins.vex.zeroing)
+		    {
+		      oappend (&ins, "{bad}");
+		      continue;
 		    }
-		  if (ins.vex.zeroing)
-		    oappend (&ins, "{z}");
 
 		  /* S/G insns require a mask and don't allow
 		     zeroing-masking.  */
@@ -9985,14 +9991,6 @@ print_insn (bfd_vma pc, disassemble_info *info, int intel_syntax)
       goto out;
     }
 
-  /* If EVEX.z is set, there must be an actual mask register in use.  */
-  if (ins.vex.zeroing && ins.vex.mask_register_specifier == 0)
-    {
-      i386_dis_printf (info, dis_style_text, "(bad)");
-      ret = ins.end_codep - priv.the_buffer;
-      goto out;
-    }
-
   switch (dp->prefix_requirement)
     {
     case PREFIX_DATA: