[binutils-gdb] x86: flag EVEX.z set when destination is memory

[binutils-gdb] x86: flag EVEX.z set when destination is memory

[Jan Beulich]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=1f83c96159d55af9caa96aa8f335ca1fd501a953

commit 1f83c96159d55af9caa96aa8f335ca1fd501a953
Author: Jan Beulich <jbeulich@suse.com>
Date:   Tue Jul 4 17:01:10 2023 +0200

    x86: flag EVEX.z set when destination is memory
    
    Zeroing-masking is not permitted in this case. See the code comment for
    how this is being dealt with.

Diff:
---
 gas/testsuite/gas/i386/avx512f-nondef.d | 1 +
 gas/testsuite/gas/i386/avx512f-nondef.s | 3 +++
 opcodes/i386-dis.c                      | 7 +++++++
 3 files changed, 11 insertions(+)

diff --git a/gas/testsuite/gas/i386/avx512f-nondef.d b/gas/testsuite/gas/i386/avx512f-nondef.d
index efa3f58a621..9c1d3272669 100644
--- a/gas/testsuite/gas/i386/avx512f-nondef.d
+++ b/gas/testsuite/gas/i386/avx512f-nondef.d
@@ -21,4 +21,5 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	62 f2 7d cf 92 04 08 	vgatherdps \(%eax,%zmm1(,1)?\),%zmm0\{%k7\}\{z\}/\(bad\)
 [ 	]*[a-f0-9]+:	62 f2 7d 48 92 04 08 	vgatherdps \(%eax,%zmm1(,1)?\),%zmm0/\(bad\)
 [ 	]*[a-f0-9]+:	62 f1 7c cf c2 c0 00 	vcmpeqps %zmm0,%zmm0,%k0\{%k7\}\{z\}/\(bad\)
+[ 	]*[a-f0-9]+:	62 f1 7c cf 29 00    	vmovaps %zmm0,\(%eax\)\{%k7\}\{z\}/\(bad\)
 #pass
diff --git a/gas/testsuite/gas/i386/avx512f-nondef.s b/gas/testsuite/gas/i386/avx512f-nondef.s
index 0216003f347..77426b1b7f5 100644
--- a/gas/testsuite/gas/i386/avx512f-nondef.s
+++ b/gas/testsuite/gas/i386/avx512f-nondef.s
@@ -29,3 +29,6 @@
 
 	# vcmpeqps %zmm0, %zmm0, %k0{%k7} with EVEX.z set
 	.insn EVEX.0f 0xc2, $0, %zmm0, %zmm0, %k0{%k7}{z}
+
+	# vmovaps %zmm0, (%eax){%k7} with EVEX.z set
+	.insn EVEX.0f 0x29, %zmm0, (%eax){%k7}{z}
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index e440b694f1a..7c4130245e1 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -11855,6 +11855,13 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
 
   if (ins->vex.evex)
     {
+
+      /* Zeroing-masking is invalid for memory destinations. Set the flag
+	 uniformly, as the consumer will inspect it only for the destination
+	 operand.  */
+      if (ins->vex.zeroing)
+	ins->illegal_masking = true;
+
       switch (bytemode)
 	{
 	case dw_mode: