x86: x87-related adjustments

Neither 287 wrt 8087 nor 387 wrt 287 are proper supersets - in each case
some insns get removed from the ISA (they become NOPs, but code intended
for newer co-processors should not use them).

Furthermore with .no87, ST should not be recognized as a register name.

7 files changed, 55 insertions, 6 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index c1109a7..3131982 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,5 +1,13 @@
 2018-04-26  Jan Beulich  <jbeulich@suse.com>
 
+	* config/tc-i386.c (parse_real_register): Check FPU register
+	earlier.
+	* testsuite/gas/i386/fpu.s, testsuite/gas/i386/fpu.l,
+	testsuite/gas/i386/stN.s, testsuite/gas/i386/stN.l: New.
+	* testsuite/gas/i386/i386.exp: Run new tests.
+
+2018-04-26  Jan Beulich  <jbeulich@suse.com>
+
 	* config/tc-i386.c (build_modrm_byte): Use tabs for indentation.
 
 2018-04-26  Jan Beulich  <jbeulich@suse.com>
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 42186ff..fcd40e2 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -10109,6 +10109,11 @@ parse_real_register (char *reg_string, char **end_op)
   /* Handle floating point regs, allowing spaces in the (i) part.  */
   if (r == i386_regtab /* %st is first entry of table  */)
     {
+      if (!cpu_arch_flags.bitfield.cpu8087
+	  && !cpu_arch_flags.bitfield.cpu287
+	  && !cpu_arch_flags.bitfield.cpu387)
+	return (const reg_entry *) NULL;
+
       if (is_space_char (*s))
 	++s;
       if (*s == '(')
@@ -10149,12 +10154,6 @@ parse_real_register (char *reg_string, char **end_op)
       && !cpu_arch_flags.bitfield.cpui386)
     return (const reg_entry *) NULL;
 
-  if (r->reg_type.bitfield.tbyte
-      && !cpu_arch_flags.bitfield.cpu8087
-      && !cpu_arch_flags.bitfield.cpu287
-      && !cpu_arch_flags.bitfield.cpu387)
-    return (const reg_entry *) NULL;
-
   if (r->reg_type.bitfield.regmmx && !cpu_arch_flags.bitfield.cpuregmmx)
     return (const reg_entry *) NULL;
 
diff --git a/gas/testsuite/gas/i386/fpu.l b/gas/testsuite/gas/i386/fpu.l
new file mode 100644
index 0000000..531884c
--- /dev/null
+++ b/gas/testsuite/gas/i386/fpu.l
@@ -0,0 +1,4 @@
+.*: Assembler messages:
+.*:6: Error: .*`fneni'.*
+.*:11: Error: .*`fneni'.*
+.*:12: Error: .*`fnsetpm'.*
diff --git a/gas/testsuite/gas/i386/fpu.s b/gas/testsuite/gas/i386/fpu.s
new file mode 100644
index 0000000..4ddcb33
--- /dev/null
+++ b/gas/testsuite/gas/i386/fpu.s
@@ -0,0 +1,12 @@
+	.text
+	.intel_syntax noprefix
+	.arch generic32
+fpu:
+	.arch .287
+	fneni
+	fnsetpm
+
+	.arch .no287
+	.arch .387
+	fneni
+	fnsetpm
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index 91d91d6..95e3469 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -170,6 +170,8 @@ if [expr ([istarget "i*86-*-*"] ||  [istarget "x86_64-*-*"]) && [gas_32_check]]
     run_list_test "no87" "-al"
     run_list_test "no87-2" "-march=i686+no87 -al"
     run_list_test "no87-3" "-al"
+    run_list_test "stN" "-al"
+    run_list_test "fpu"
     run_list_test "nommx-1" "-al"
     run_list_test "nommx-2" "-march=core+nommx -al"
     run_list_test "nommx-3" "-march=+nommx -al"
diff --git a/gas/testsuite/gas/i386/stN.l b/gas/testsuite/gas/i386/stN.l
new file mode 100644
index 0000000..5885686
--- /dev/null
+++ b/gas/testsuite/gas/i386/stN.l
@@ -0,0 +1,16 @@
+.*: Assembler messages:
+.*:6: Error: .*junk.*
+.*:7: Error: .*junk.*
+.*:8: Error: .*junk.*
+GAS LISTING .*
+
+
+[ 	]*1[ 	]+\.text
+[ 	]*2[ 	]+\.intel_syntax noprefix
+[ 	]*3[ 	]+\.arch \.no87
+[ 	]*4[ 	]+stN:
+[ 	]*5[ 	]+\?\?\?\? A1000000[ 	]+mov	eax, st
+[ 	]*5[ 	]+00
+[ 	]*6[ 	]+mov	eax, st\(7\)
+[ 	]*7[ 	]+mov	eax, st \( 7 \)
+[ 	]*8[ 	]+mov	eax, x\(7\)
diff --git a/gas/testsuite/gas/i386/stN.s b/gas/testsuite/gas/i386/stN.s
new file mode 100644
index 0000000..6a1512e
--- /dev/null
+++ b/gas/testsuite/gas/i386/stN.s
@@ -0,0 +1,8 @@
+	.text
+	.intel_syntax noprefix
+	.arch .no87
+stN:
+	mov	eax, st
+	mov	eax, st(7)
+	mov	eax, st ( 7 )
+	mov	eax, x(7)