asm: add some f80 tests

tests/asm/f80/fxaddxx-1.S

@@ -0,0 +1,14 @@
+#include "test_start.S"
+
+        setwd wsz=8, nfx=0
+        shld,0 1, 63, %r0
+    {
+        movif,0 %r0, 0x4000, %r0
+        movif,1 %r0, 0x4001, %r1
+    }
+        fxaddxx,0 %r0, %r1, %r2
+        movfi,0 %r2, %r3
+        assert_eq_i64(%r2, 0xc000000000000000)
+        assert_eq_i32(%r3, 0x4001)
+
+#include "test_end.S"

tests/asm/f80/fxmulxx-1.S

@@ -0,0 +1,14 @@
+#include "test_start.S"
+
+        setwd wsz=8, nfx=0
+        shld,0 1, 63, %r0
+    {
+        movif,0 %r0, 0x4000, %r0
+        movif,1 %r0, 0x4001, %r1
+    }
+        fxmulxx,0 %r0, %r1, %r2
+        movfi,0 %r2, %r3
+        assert_eq_i64(%r2, 0x8000000000000000)
+        assert_eq_i32(%r3, 0x4002)
+
+#include "test_end.S"

tests/asm/f80/fxsubxx-1.S

@@ -0,0 +1,14 @@
+#include "test_start.S"
+
+        setwd wsz=8, nfx=0
+        shld,0 1, 63, %r0
+    {
+        movif,0 %r0, 0x4000, %r0
+        movif,1 %r0, 0x4001, %r1
+    }
+        fxsubxx,0 %r0, %r1, %r2
+        movfi,0 %r2, %r3
+        assert_eq_i64(%r2, 0x8000000000000000)
+        assert_eq_i32(%r3, 0xc000)
+
+#include "test_end.S"

tests/asm/f80/movif-movfi-1.S

@@ -0,0 +1,10 @@
+#include "test_start.S"
+
+        setwd wsz=8, nfx=0
+        addd,0 0, 0xaaaaaaaa, %g16
+        movif %g16, 0xbeef, %g17
+        movfi %g17, %g18
+        assert_eq_i64(%g17, 0xaaaaaaaa)
+        assert_eq_i32(%g18, 0xbeef)
+
+#include "test_end.S"

tests/asm/meson.build

@@ -190,6 +190,12 @@ asm_tests = {
     'invalid-arg-1': {},
     'invalid-arg-hi-1': {},
   },
+  'f80': {
+    'movif-movfi-1': {},
+    'fxaddxx-1': {},
+    'fxsubxx-1': {},
+    'fxmulxx-1': {},
+  },
 }
 
 foreach suite, tests : asm_tests