gas/

	* config/tc-i386.c (parse_insn): Don't complain about REP prefix
	when the template has opcode_modifier.repprefixok set.
	* NEWS: Mention the change.

gas/testsuite/
	* gas/i386/rep-bsf.d: New file.
	* gas/i386/rep-bsf.s: New file.
	* gas/i386/i386.exp: Add the new test.

opcodes/
	* i386-opc.h (RepPrefixOk): New enum constant.
	(i386_opcode_modifier): New bitfield 'repprefixok'.
	* i386-gen.c (opcode_modifiers): Add RepPrefixOk.
	* i386-opc.tbl: Add RepPrefixOk to bsf, bsr, and to all
	instructions that have IsString.
	* i386-tbl.h: Regenerate.

7 files changed, 32 insertions, 3 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index aca611ea6f..5698397c20 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,9 @@
+2012-06-22  Roland McGrath  <mcgrathr@google.com>
+
+	* config/tc-i386.c (parse_insn): Don't complain about REP prefix
+	when the template has opcode_modifier.repprefixok set.
+	* NEWS: Mention the change.
+
 2012-06-18  Iain Sandoe  <iain@codesourcery.com>
 
 	* configure.in: Check DECLS for free, getenv, malloc, realloc,
diff --git a/gas/NEWS b/gas/NEWS
index 6b6dbba827..6f62b938d8 100644
--- a/gas/NEWS
+++ b/gas/NEWS
@@ -13,6 +13,8 @@
 
 * Add support for the Adapteva EPIPHANY architecture.
 
+* For x86, allow 'rep bsf' or 'rep bsr' syntax.
+
 Changes in 2.22:
 
 * Add support for the Tilera TILEPro and TILE-Gx architectures.
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index d2b492762f..4701e6dbc3 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -3528,13 +3528,13 @@ skip:
       as_warn (_("use .code16 to ensure correct addressing mode"));
     }
 
-  /* Check for rep/repne without a string instruction.  */
+  /* Check for rep/repne without a string (or other allowed) instruction.  */
   if (expecting_string_instruction)
     {
       static templates override;
 
       for (t = current_templates->start; t < current_templates->end; ++t)
-	if (t->opcode_modifier.isstring)
+	if (t->opcode_modifier.repprefixok)
 	  break;
       if (t >= current_templates->end)
 	{
@@ -3543,7 +3543,7 @@ skip:
 	  return NULL;
 	}
       for (override.start = t; t < current_templates->end; ++t)
-	if (!t->opcode_modifier.isstring)
+	if (!t->opcode_modifier.repprefixok)
 	  break;
       override.end = t;
       current_templates = &override;
diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index 1129df01bf..59916b6e07 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2012-06-22  Roland McGrath  <mcgrathr@google.com>
+
+	* gas/i386/rep-bsf.d: New file.
+	* gas/i386/rep-bsf.s: New file.
+	* gas/i386/i386.exp: Add the new test.
+
 2012-06-13  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* gas/i386/ilp32/x86-64-dc_a.d: New.
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index 89adf696a0..2f055807b0 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -264,6 +264,7 @@ if [expr ([istarget "i*86-*-*"] ||  [istarget "x86_64-*-*"]) && [gas_32_check]]
 
     # Miscellaneous tests.
     run_dump_test "pr12589-1"
+    run_dump_test "rep-bsf"
 
     set ASFLAGS "$old_ASFLAGS"
 }
diff --git a/gas/testsuite/gas/i386/rep-bsf.d b/gas/testsuite/gas/i386/rep-bsf.d
new file mode 100644
index 0000000000..c0a47ddff4
--- /dev/null
+++ b/gas/testsuite/gas/i386/rep-bsf.d
@@ -0,0 +1,11 @@
+#objdump: -d
+#name: rep prefix on bsf/bsr
+
+.*: +file format .*
+
+Disassembly of section .text:
+
+0+000 <bsf>:
+\s*[0-9]+:\s+f3 0f bc c1\s+tzcnt  %ecx,%eax
+0+004 <bsr>:
+\s*[0-9]+:\s+f3 0f bd c1\s+lzcnt  %ecx,%eax
diff --git a/gas/testsuite/gas/i386/rep-bsf.s b/gas/testsuite/gas/i386/rep-bsf.s
new file mode 100644
index 0000000000..10a12aa5e5
--- /dev/null
+++ b/gas/testsuite/gas/i386/rep-bsf.s
@@ -0,0 +1,3 @@
+	.text
+bsf:	rep bsf %ecx, %eax
+bsr:	rep bsr %ecx, %eax