From: Jan Beulich <jbeulich@suse.com>
Date: Mon, 23 Oct 2023 08:29:54 +0000 (+0200)
Subject: x86: i386_generate_nops() may not derive decisions from global variables
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d12c7ab814cdb61da22c8d362e109ed55982a74b;p=binutils-gdb.git

x86: i386_generate_nops() may not derive decisions from global variables

What matters is what was in effect at the time the original directive
was issued. Later changes to global state (bitness or ISA) must not
affect what code is generated.
---

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index d54e9dfdbd6..d7eea9d33d4 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -1434,7 +1434,7 @@ i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit)
      When -march= or .arch is used, we can't use anything beyond
      cpu_arch_isa_flags.   */
 
-  if (flag_code == CODE_16BIT)
+  if (fragP->tc_frag_data.code == CODE_16BIT)
     {
       patt = f16_patt;
       max_single_nop_size = sizeof (f16_patt) / sizeof (f16_patt[0]);
@@ -1446,7 +1446,7 @@ i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit)
       if (fragP->tc_frag_data.isa == PROCESSOR_UNKNOWN)
 	{
 	  /* PROCESSOR_UNKNOWN means that all ISAs may be used.  */
-	  switch (cpu_arch_tune)
+	  switch (fragP->tc_frag_data.tune)
 	    {
 	    case PROCESSOR_UNKNOWN:
 	      /* We use cpu_arch_isa_flags to check if we SHOULD
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index ee74bcd4615..1072c07e4c7 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -148,6 +148,7 @@ if [gas_32_check] then {
     run_dump_test "nops-7"
     run_dump_test "nops-8"
     run_dump_test "nops-9"
+    run_dump_test "nops-10"
     run_dump_test "noreg16"
     run_list_test "noreg16"
     run_dump_test "noreg16-data32"
diff --git a/gas/testsuite/gas/i386/nops-10.d b/gas/testsuite/gas/i386/nops-10.d
new file mode 100644
index 00000000000..b4642753945
--- /dev/null
+++ b/gas/testsuite/gas/i386/nops-10.d
@@ -0,0 +1,13 @@
+#objdump: -drw
+#name: nops 10
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <default>:
+[ 	]*[a-f0-9]+:	0f be f0             	movsbl %al,%esi
+[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%esi,%eiz,1\),%esi
+[ 	]*[a-f0-9]+:	8d b6 00 00 00 00    	lea    0x0\(%esi\),%esi
+#pass
diff --git a/gas/testsuite/gas/i386/nops-10.s b/gas/testsuite/gas/i386/nops-10.s
new file mode 100644
index 00000000000..35a300a73fc
--- /dev/null
+++ b/gas/testsuite/gas/i386/nops-10.s
@@ -0,0 +1,6 @@
+	.text
+default:
+	movsbl %al,%esi
+	.p2align 4
+
+	.code16
diff --git a/gas/testsuite/gas/i386/x86-64-nops-6.d b/gas/testsuite/gas/i386/x86-64-nops-6.d
new file mode 100644
index 00000000000..e9623501330
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-nops-6.d
@@ -0,0 +1,13 @@
+#objdump: -drw
+#name: x86-64 nops 6
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <default>:
+[ 	]*[a-f0-9]+:	0f be f0             	movsbl %al,%esi
+[ 	]*[a-f0-9]+:	66 66 2e 0f 1f 84 00 00 00 00 00 	data16 cs nopw (0x)?0\(%rax,%rax,1\)
+[ 	]*[a-f0-9]+:	66 90                	xchg   %ax,%ax
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-nops-6.s b/gas/testsuite/gas/i386/x86-64-nops-6.s
new file mode 100644
index 00000000000..b6dc7ad1682
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-nops-6.s
@@ -0,0 +1,7 @@
+	.text
+default:
+	movsbl %al,%esi
+	.p2align 4
+
+	.code32
+	.arch generic32
diff --git a/gas/testsuite/gas/i386/x86-64.exp b/gas/testsuite/gas/i386/x86-64.exp
index 52711cdcf6f..3d521f66e35 100644
--- a/gas/testsuite/gas/i386/x86-64.exp
+++ b/gas/testsuite/gas/i386/x86-64.exp
@@ -116,6 +116,7 @@ run_dump_test "x86-64-nops-4-core2"
 run_dump_test "x86-64-nops-4-k8"
 run_dump_test "x86-64-nops-5"
 run_dump_test "x86-64-nops-5-k8"
+run_dump_test "x86-64-nops-6"
 run_dump_test "x86-64-nops-7"
 run_dump_test "x86-64-sysenter"
 run_dump_test "x86-64-sysenter-intel"