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authorJan Beulich <jbeulich@suse.com>2023-12-22 09:34:10 +0100
committerJan Beulich <jbeulich@suse.com>2023-12-22 09:34:10 +0100
commit3e4a511bee874d73f9f749cc8cf3bc748b4d47b5 (patch)
treeef60a2e3f33f6e5ceabe27ffcdc316ed47d24ba9
parentce7056886a6e52a4fc91b5e3b28da2c0735d0b19 (diff)
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x86-64: refuse "high" 8-bit regs with .insn and VEX/XOP/EVEX encodings
Much like REX, those encodings - if permitting 8-bit regs at all, i.e. only starting with APX - permit use of "new" 8-bit registers only. %ah, %ch, %dh, and %bh cannot be encoded and hence should be rejected. Permit their use outside of 64-bit code though, as "new" registers simply don't exist there.
-rw-r--r--gas/config/tc-i386.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 6e2f6e5..cdd3b55 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -11485,6 +11485,16 @@ s_insn (int dummy ATTRIBUTE_UNUSED)
for (j = i.imm_operands; j < i.operands; ++j)
{
+ /* Look for 8-bit operands that use old registers. */
+ if (i.vec_encoding != vex_encoding_default
+ && flag_code == CODE_64BIT
+ && i.types[j].bitfield.class == Reg
+ && i.types[j].bitfield.byte
+ && !(i.op[j].regs->reg_flags & RegRex64)
+ && i.op[j].regs->reg_num > 3)
+ as_bad (_("can't encode register '%s%s' with VEX/XOP/EVEX"),
+ register_prefix, i.op[j].regs->reg_name);
+
i.types[j].bitfield.instance = InstanceNone;
if (operand_type_check (i.types[j], disp))