nosplit: Generate index-only EA only when a multiplier is used.

[nosplit eax] has been encoded as [eax*1+0] since 0.98.34.
But this seems like unexpected behavior.
So only when a register is multiplied, that will be treated
as an index. ([nosplit eax*1] -> [eax*1+0])
Document is updated accordingly.

Signed-off-by: Jin Kyu Song <jin.kyu.song@intel.com>

2 files changed, 5 insertions, 3 deletions

diff --git a/assemble.c b/assemble.c
index fbd7caf0..eeab9bbc 100644
--- a/assemble.c
+++ b/assemble.c
@@ -2635,9 +2635,10 @@ static enum ea_type process_ea(operand *input, ea *output, int bits,
                         bt = it, bx = ix, s--;
                     }
                     if (it == -1 && (bt & 7) != REG_NUM_ESP &&
-                        (eaflags & EAF_TIMESTWO)) {
+                        (eaflags & EAF_TIMESTWO) &&
+                        (hb == b && ht == EAH_NOTBASE)) {
                         /*
-                         * convert [NOSPLIT EAX]
+                         * convert [NOSPLIT EAX*1]
                          * to sib format with 0x0 displacement - [EAX*1+0].
                          */
                         it = bt, ix = bx, bt = -1, bx = 0, s = 1;
diff --git a/doc/nasmdoc.src b/doc/nasmdoc.src
index 8554a341..dbf8e70f 100644
--- a/doc/nasmdoc.src
+++ b/doc/nasmdoc.src
@@ -1459,7 +1459,8 @@ that allows the offset field to be absent and space to be saved; in
 fact, it will also split \c{[eax*2+offset]} into
 \c{[eax+eax+offset]}. You can combat this behaviour by the use of
 the \c{NOSPLIT} keyword: \c{[nosplit eax*2]} will force
-\c{[eax*2+0]} to be generated literally.
+\c{[eax*2+0]} to be generated literally. \c{[nosplit eax*1]} also has the
+same effect. In another way, a split EA form \c{[0, eax*2]} can be used, too.
 However, \c{NOSPLIT} in \c{[nosplit eax+eax]} will be ignored because user's
 intention here is considered as \c{[eax+eax]}.