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From: Jan Beulich <jbeulich@sourceware.org>
To: bfd-cvs@sourceware.org
Subject: [binutils-gdb] gas: no md_cons_align() for .nop{,s}
Date: Fri,  1 Dec 2023 07:30:01 +0000 (GMT)	[thread overview]
Message-ID: <20231201073001.A28E93858C30@sourceware.org> (raw)

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=54fc4573887bfba8bd2ac0cb2eb9259e94ba178d

commit 54fc4573887bfba8bd2ac0cb2eb9259e94ba178d
Author: Jan Beulich <jbeulich@suse.com>
Date:   Fri Dec 1 08:28:20 2023 +0100

    gas: no md_cons_align() for .nop{,s}
    
    .nop and .nops generate code, not data. Hence them invoking
    md_cons_align() is at best inappropriate. In fact it actually gets in
    the of x86'es state maintenance involving i386_cons_align().

Diff:
---
 gas/read.c                              | 8 --------
 gas/testsuite/gas/i386/align-branch-6.e | 2 +-
 gas/testsuite/gas/i386/lfence-byte.d    | 9 +++++++++
 gas/testsuite/gas/i386/lfence-byte.s    | 7 +++++++
 4 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/gas/read.c b/gas/read.c
index 826156db3fe..76ef86c523c 100644
--- a/gas/read.c
+++ b/gas/read.c
@@ -3466,10 +3466,6 @@ s_nop (int ignore ATTRIBUTE_UNUSED)
   md_flush_pending_output ();
 #endif
 
-#ifdef md_cons_align
-  md_cons_align (1);
-#endif
-
   SKIP_WHITESPACE ();
   expression (&exp);
   demand_empty_rest_of_line ();
@@ -3519,10 +3515,6 @@ s_nops (int ignore ATTRIBUTE_UNUSED)
   md_flush_pending_output ();
 #endif
 
-#ifdef md_cons_align
-  md_cons_align (1);
-#endif
-
   SKIP_WHITESPACE ();
   expression (&exp);
   /* Note - this expression is tested for an absolute value in
diff --git a/gas/testsuite/gas/i386/align-branch-6.e b/gas/testsuite/gas/i386/align-branch-6.e
index c3378353ef7..c959492cf65 100644
--- a/gas/testsuite/gas/i386/align-branch-6.e
+++ b/gas/testsuite/gas/i386/align-branch-6.e
@@ -1,2 +1,2 @@
 .*: Assembler messages:
-.*:4: Warning: `constant directive` skips -malign-branch-boundary on `jnc`
+.*:5: Warning: `constant directive` skips -malign-branch-boundary on `jnc`
diff --git a/gas/testsuite/gas/i386/lfence-byte.d b/gas/testsuite/gas/i386/lfence-byte.d
index 6d9a8893085..f0236a8278d 100644
--- a/gas/testsuite/gas/i386/lfence-byte.d
+++ b/gas/testsuite/gas/i386/lfence-byte.d
@@ -27,4 +27,13 @@ Disassembly of section .text:
  +[a-f0-9]+:	f3 c3                	repz ret
  +[a-f0-9]+:	c3                   	ret
  +[a-f0-9]+:	f3 ff d0             	repz call \*%eax
+
+[a-f0-9]+ <directive>:
+ +[a-f0-9]+:	90                   	nop
+ +[a-f0-9]+:	0f ae e8             	lfence
+ +[a-f0-9]+:	ff d0                	call   \*%eax
+ +[a-f0-9]+:	8d 76 00             	lea    (0x)?0\(%esi\),%esi
+ +[a-f0-9]+:	83 0c 24 00          	orl    \$0x0,\(%esp\)
+ +[a-f0-9]+:	0f ae e8             	lfence
+ +[a-f0-9]+:	c3                   	ret
 #pass
diff --git a/gas/testsuite/gas/i386/lfence-byte.s b/gas/testsuite/gas/i386/lfence-byte.s
index 0a05e6405b9..570a1c6ef35 100644
--- a/gas/testsuite/gas/i386/lfence-byte.s
+++ b/gas/testsuite/gas/i386/lfence-byte.s
@@ -21,3 +21,10 @@ _start:
 	call *%eax
 	.data
 	.byte 0
+
+	.text
+directive:
+	.nop
+	call	*%eax
+	.nops 3
+	ret

                 reply	other threads:[~2023-12-01  7:30 UTC|newest]

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