[PATCH 05/12] x86-64: adjust MOVQ to/from SReg attributes
Jan Beulich
jbeulich@suse.com
Fri Aug 5 12:22:15 GMT 2022
It is unclear to me why the corresponding MOV (no Q suffix) can be
issued without REX.W, but MOVQ has to have that prefix (bit). Add
NoRex64 and in exchange drop Size64.
--- a/gas/testsuite/gas/i386/x86-64-segment.l
+++ b/gas/testsuite/gas/i386/x86-64-segment.l
@@ -5,8 +5,15 @@
5 0002 8C18 mov %ds,\(%rax\)
6 0004 8E18 movw \(%rax\),%ds
7 0006 8E18 mov \(%rax\),%ds
- 8 # test segment reg insns with REX
- 9 0008 488CD8 movq %ds,%rax
- 10 000b 488ED8 movq %rax,%ds
- 11 # Force a good alignment.
- 12 000e 0000 .p2align 4,0
+ 8 # test segment reg insns with avoided REX
+ 9 0008 8CD8 mov %ds,%rax
+ 10 000a 8CD8 movq %ds,%rax
+ 11 000c 8ED8 mov %rax,%ds
+ 12 000e 8ED8 movq %rax,%ds
+ 13 # test segment reg insns with REX
+ 14 0010 418CD8 mov %ds,%r8
+ 15 0013 418CD8 movq %ds,%r8
+ 16 0016 418ED8 mov %r8,%ds
+ 17 0019 418ED8 movq %r8,%ds
+ 18 # Force a good alignment.
+ 19 001c 0+ + *\.p2align 4,0
--- a/gas/testsuite/gas/i386/x86-64-segment.s
+++ b/gas/testsuite/gas/i386/x86-64-segment.s
@@ -5,8 +5,15 @@
mov %ds,(%rax)
movw (%rax),%ds
mov (%rax),%ds
-# test segment reg insns with REX
+# test segment reg insns with avoided REX
+ mov %ds,%rax
movq %ds,%rax
+ mov %rax,%ds
movq %rax,%ds
+# test segment reg insns with REX
+ mov %ds,%r8
+ movq %ds,%r8
+ mov %r8,%ds
+ movq %r8,%ds
# Force a good alignment.
.p2align 4,0
--- a/opcodes/i386-opc.tbl
+++ b/opcodes/i386-opc.tbl
@@ -148,7 +148,7 @@ movq, 0xb8, None, Cpu64, Size64|No_bSuf|
// implementation defined value is zero).
mov, 0x8c, None, 0, RegMem|No_bSuf|No_sSuf|No_qSuf|No_ldSuf|NoRex64, { SReg, Reg16|Reg32|Reg64 }
mov, 0x8c, None, 0, D|Modrm|IgnoreSize|No_bSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { SReg, Word|Unspecified|BaseIndex }
-movq, 0x8c, None, Cpu64, D|RegMem|Size64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { SReg, Reg64 }
+movq, 0x8c, None, Cpu64, D|RegMem|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|NoRex64, { SReg, Reg64 }
mov, 0x8e, None, 0, Modrm|IgnoreSize|No_bSuf|No_sSuf|No_qSuf|No_ldSuf|NoRex64, { Reg16|Reg32|Reg64, SReg }
// Move to/from control debug registers. In the 16 or 32bit modes
// they are 32bit. In the 64bit mode they are 64bit.
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