x86/ELF: fix .ds.x output

The ELF psABI-s are quite clear here: On 32-bit the underlying data type
is 12 bytes long (with 2 bytes of trailing padding), while on 64-bit it
is 16 bytes long (with 6 bytes of padding). Make s_space() capable of
handling 'x' (and 'p') type floating point being other than 12 bytes
wide (also adjusting documentation). This requires duplicating the
definition of X_PRECISION in the target speciifc header; the compiler
would complain if this was out of sync with config/atof-ieee.c.

Note that for now padding space doesn't get separated from actual
storage, which means that things will work correctly only for little-
endian cases, and which also means that by specifying large enough
numbers padding space can be set to non-zero. Since the logic is needed
for a single little-endian architecture only for now, I'm hoping that
this might be acceptable for the time being; otherwise the change will
become more intrusive.

Note also that this brings the emitted data size of .ds.x vs .tfloat in
line for non-ELF targets as well; the issue will be even more obvious
when further taking into account a subsequent patch fixing .dc.x/.dcb.x
(where output sizes currently differ depending on input format).

Extend existing x86 testcases.

1 files changed, 25 insertions, 2 deletions

diff --git a/gas/read.c b/gas/read.c
index ea9261e..6bba696 100644
--- a/gas/read.c
+++ b/gas/read.c
@@ -382,10 +382,10 @@ static const pseudo_typeS potable[] = {
   {"ds.b", s_space, 1},
   {"ds.d", s_space, 8},
   {"ds.l", s_space, 4},
-  {"ds.p", s_space, 12},
+  {"ds.p", s_space, 'p'},
   {"ds.s", s_space, 4},
   {"ds.w", s_space, 2},
-  {"ds.x", s_space, 12},
+  {"ds.x", s_space, 'x'},
   {"debug", s_ignore, 0},
 #ifdef S_SET_DESC
   {"desc", s_desc, 0},
@@ -3327,6 +3327,29 @@ s_space (int mult)
   md_flush_pending_output ();
 #endif
 
+  switch (mult)
+    {
+    case 'x':
+#ifdef X_PRECISION
+# ifndef P_PRECISION
+#  define P_PRECISION     X_PRECISION
+#  define P_PRECISION_PAD X_PRECISION_PAD
+# endif
+      mult = (X_PRECISION + X_PRECISION_PAD) * sizeof (LITTLENUM_TYPE);
+      if (!mult)
+#endif
+	mult = 12;
+      break;
+
+    case 'p':
+#ifdef P_PRECISION
+      mult = (P_PRECISION + P_PRECISION_PAD) * sizeof (LITTLENUM_TYPE);
+      if (!mult)
+#endif
+	mult = 12;
+      break;
+    }
+
 #ifdef md_cons_align
   md_cons_align (1);
 #endif