aboutsummaryrefslogtreecommitdiff
path: root/gas
diff options
context:
space:
mode:
authorJan Beulich <jbeulich@suse.com>2023-10-23 10:30:30 +0200
committerJan Beulich <jbeulich@suse.com>2023-10-23 10:30:30 +0200
commitd164359dbc14c8ae4c7a117d236f5b7de4af671a (patch)
tree8f093e045bfab0c787da700addd9d3dc0f48e53a /gas
parentd12c7ab814cdb61da22c8d362e109ed55982a74b (diff)
downloadgdb-d164359dbc14c8ae4c7a117d236f5b7de4af671a.zip
gdb-d164359dbc14c8ae4c7a117d236f5b7de4af671a.tar.gz
gdb-d164359dbc14c8ae4c7a117d236f5b7de4af671a.tar.bz2
x86: don't use 32-bit LEA as NOP surrogate in 64-bit code
Except for the shared 1- and 2-byte cases, the LEA uses corrupt %rsi (by zero-extending %esi to %rsi). Introduce separate 64-bit patterns which keep %rsi intact.
Diffstat (limited to 'gas')
-rw-r--r--gas/config/tc-i386.c31
-rw-r--r--gas/testsuite/gas/i386/ilp32/x86-64-nops-1-pentium.d164
-rw-r--r--gas/testsuite/gas/i386/x86-64-nops-1-pentium.d43
3 files changed, 41 insertions, 197 deletions
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index d7eea9d..bec6304 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -1279,6 +1279,18 @@ static const unsigned char f32_6[] =
{0x8d,0xb6,0x00,0x00,0x00,0x00}; /* leal 0L(%esi),%esi */
static const unsigned char f32_7[] =
{0x8d,0xb4,0x26,0x00,0x00,0x00,0x00}; /* leal 0L(%esi,1),%esi */
+static const unsigned char f64_3[] =
+ {0x48,0x89,0xf6}; /* mov %rsi,%rsi */
+static const unsigned char f64_4[] =
+ {0x48,0x8d,0x76,0x00}; /* lea 0(%rsi),%rsi */
+#define f64_5 (f64_6 + 1) /* lea 0(%rsi,%riz),%rsi */
+static const unsigned char f64_6[] =
+ {0x2e,0x48,0x8d,0x74,0x26,0x00}; /* lea %cs:0(%rsi,%riz),%rsi */
+static const unsigned char f64_7[] =
+ {0x48,0x8d,0xb6,0x00,0x00,0x00,0x00}; /* lea 0L(%rsi),%rsi */
+#define f64_8 (f64_9 + 1) /* lea 0L(%rsi,%riz),%rsi */
+static const unsigned char f64_9[] =
+ {0x2e,0x48,0x8d,0xb4,0x26,0x00,0x00,0x00,0x00}; /* lea %cs:0L(%rsi,%riz),%rsi */
static const unsigned char f16_3[] =
{0x8d,0x74,0x00}; /* lea 0(%si),%si */
static const unsigned char f16_4[] =
@@ -1293,6 +1305,10 @@ static const unsigned char jump16_disp32[] =
static const unsigned char *const f32_patt[] = {
f32_1, f32_2, f32_3, f32_4, NULL, f32_6, f32_7
};
+/* 64-bit NOPs patterns. */
+static const unsigned char *const f64_patt[] = {
+ f32_1, f32_2, f64_3, f64_4, f64_5, f64_6, f64_7, f64_8, f64_9
+};
/* 16-bit NOPs patterns. */
static const unsigned char *const f16_patt[] = {
f32_1, f32_2, f16_3, f16_4
@@ -1428,7 +1444,7 @@ i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit)
2. For the rest, alt_patt will be used.
When -mtune= isn't used, alt_patt will be used if
- cpu_arch_isa_flags has CpuNop. Otherwise, f32_patt will
+ cpu_arch_isa_flags has CpuNop. Otherwise, f32_patt/f64_patt will
be used.
When -march= or .arch is used, we can't use anything beyond
@@ -1443,6 +1459,7 @@ i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit)
}
else
{
+ patt = fragP->tc_frag_data.code == CODE_64BIT ? f64_patt : f32_patt;
if (fragP->tc_frag_data.isa == PROCESSOR_UNKNOWN)
{
/* PROCESSOR_UNKNOWN means that all ISAs may be used. */
@@ -1453,8 +1470,6 @@ i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit)
optimize with nops. */
if (fragP->tc_frag_data.isa_flags.bitfield.cpunop)
patt = alt_patt;
- else
- patt = f32_patt;
break;
case PROCESSOR_PENTIUM4:
case PROCESSOR_NOCONA:
@@ -1477,7 +1492,6 @@ i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit)
case PROCESSOR_PENTIUMPRO:
case PROCESSOR_IAMCU:
case PROCESSOR_GENERIC32:
- patt = f32_patt;
break;
case PROCESSOR_NONE:
abort ();
@@ -1509,8 +1523,6 @@ i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit)
with nops. */
if (fragP->tc_frag_data.isa_flags.bitfield.cpunop)
patt = alt_patt;
- else
- patt = f32_patt;
break;
case PROCESSOR_PENTIUMPRO:
case PROCESSOR_PENTIUM4:
@@ -1520,8 +1532,6 @@ i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit)
case PROCESSOR_COREI7:
if (fragP->tc_frag_data.isa_flags.bitfield.cpunop)
patt = alt_patt;
- else
- patt = f32_patt;
break;
case PROCESSOR_GENERIC64:
patt = alt_patt;
@@ -1531,9 +1541,10 @@ i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit)
}
}
- if (patt == f32_patt)
+ if (patt != alt_patt)
{
- max_single_nop_size = sizeof (f32_patt) / sizeof (f32_patt[0]);
+ max_single_nop_size = patt == f32_patt ? ARRAY_SIZE (f32_patt)
+ : ARRAY_SIZE (f64_patt);
/* Limit number of NOPs to 2 for older processors. */
max_number_of_nops = 2;
}
diff --git a/gas/testsuite/gas/i386/ilp32/x86-64-nops-1-pentium.d b/gas/testsuite/gas/i386/ilp32/x86-64-nops-1-pentium.d
index c669988..b144d54 100644
--- a/gas/testsuite/gas/i386/ilp32/x86-64-nops-1-pentium.d
+++ b/gas/testsuite/gas/i386/ilp32/x86-64-nops-1-pentium.d
@@ -2,166 +2,4 @@
#as: -mtune=pentium
#objdump: -drw
#name: x86-64 (ILP32) -mtune=pentium nops 1
-
-.*: +file format .*
-
-Disassembly of section .text:
-
-0+ <nop15>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 90 nop
-
-0+10 <nop14>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-
-0+20 <nop13>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d b6 00 00 00 00 lea 0x0\(%rsi\),%esi
-
-0+30 <nop12>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d 74 26 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 90 nop
-
-0+40 <nop11>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d 74 26 00 lea 0x0\(%rsi,%riz,1\),%esi
-
-0+50 <nop10>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d 76 00 lea 0x0\(%rsi\),%esi
-
-0+60 <nop9>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 66 90 xchg %ax,%ax
-
-0+70 <nop8>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 90 nop
-
-0+80 <nop7>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-
-0+90 <nop6>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b6 00 00 00 00 lea 0x0\(%rsi\),%esi
-
-0+a0 <nop5>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d 74 26 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 90 nop
-
-0+b0 <nop4>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d 74 26 00 lea 0x0\(%rsi,%riz,1\),%esi
-
-0+c0 <nop3>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d 76 00 lea 0x0\(%rsi\),%esi
-
-0+d0 <nop2>:
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 66 90 xchg %ax,%ax
-#pass
+#dump: ../x86-64-nops-1-pentium.d
diff --git a/gas/testsuite/gas/i386/x86-64-nops-1-pentium.d b/gas/testsuite/gas/i386/x86-64-nops-1-pentium.d
index 4145e51..a888208 100644
--- a/gas/testsuite/gas/i386/x86-64-nops-1-pentium.d
+++ b/gas/testsuite/gas/i386/x86-64-nops-1-pentium.d
@@ -9,31 +9,29 @@ Disassembly of section .text:
0+ <nop15>:
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 90 nop
+[ ]*[a-f0-9]+: 2e 48 8d b4 26 00 00 00 00 cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ ]*[a-f0-9]+: 2e 48 8d 74 26 00 cs lea (0x)?0\(%rsi,%riz,1\),%rsi
0+10 <nop14>:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
+[ ]*[a-f0-9]+: 2e 48 8d b4 26 00 00 00 00 cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ ]*[a-f0-9]+: 48 8d 74 26 00 lea (0x)?0\(%rsi,%riz,1\),%rsi
0+20 <nop13>:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d b6 00 00 00 00 lea 0x0\(%rsi\),%esi
+[ ]*[a-f0-9]+: 2e 48 8d b4 26 00 00 00 00 cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ ]*[a-f0-9]+: 48 8d 76 00 lea (0x)?0\(%rsi\),%rsi
0+30 <nop12>:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d 74 26 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 90 nop
+[ ]*[a-f0-9]+: 2e 48 8d b4 26 00 00 00 00 cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ ]*[a-f0-9]+: 48 89 f6 mov %rsi,%rsi
0+40 <nop11>:
[ ]*[a-f0-9]+: 90 nop
@@ -41,8 +39,8 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d 74 26 00 lea 0x0\(%rsi,%riz,1\),%esi
+[ ]*[a-f0-9]+: 2e 48 8d b4 26 00 00 00 00 cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ ]*[a-f0-9]+: 66 90 xchg %ax,%ax
0+50 <nop10>:
[ ]*[a-f0-9]+: 90 nop
@@ -51,8 +49,8 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 8d 76 00 lea 0x0\(%rsi\),%esi
+[ ]*[a-f0-9]+: 2e 48 8d b4 26 00 00 00 00 cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ ]*[a-f0-9]+: 90 nop
0+60 <nop9>:
[ ]*[a-f0-9]+: 90 nop
@@ -62,8 +60,7 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 66 90 xchg %ax,%ax
+[ ]*[a-f0-9]+: 2e 48 8d b4 26 00 00 00 00 cs lea (0x)?0\(%rsi,%riz,1\),%rsi
0+70 <nop8>:
[ ]*[a-f0-9]+: 90 nop
@@ -74,8 +71,7 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 90 nop
+[ ]*[a-f0-9]+: 48 8d b4 26 00 00 00 00 lea (0x)?0\(%rsi,%riz,1\),%rsi
0+80 <nop7>:
[ ]*[a-f0-9]+: 90 nop
@@ -87,7 +83,7 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b4 26 00 00 00 00 lea 0x0\(%rsi,%riz,1\),%esi
+[ ]*[a-f0-9]+: 48 8d b6 00 00 00 00 lea (0x)?0\(%rsi\),%rsi
0+90 <nop6>:
[ ]*[a-f0-9]+: 90 nop
@@ -100,7 +96,7 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d b6 00 00 00 00 lea 0x0\(%rsi\),%esi
+[ ]*[a-f0-9]+: 2e 48 8d 74 26 00 cs lea (0x)?0\(%rsi,%riz,1\),%rsi
0+a0 <nop5>:
[ ]*[a-f0-9]+: 90 nop
@@ -114,8 +110,7 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d 74 26 00 lea 0x0\(%rsi,%riz,1\),%esi
-[ ]*[a-f0-9]+: 90 nop
+[ ]*[a-f0-9]+: 48 8d 74 26 00 lea (0x)?0\(%rsi,%riz,1\),%rsi
0+b0 <nop4>:
[ ]*[a-f0-9]+: 90 nop
@@ -130,7 +125,7 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d 74 26 00 lea 0x0\(%rsi,%riz,1\),%esi
+[ ]*[a-f0-9]+: 48 8d 76 00 lea (0x)?0\(%rsi\),%rsi
0+c0 <nop3>:
[ ]*[a-f0-9]+: 90 nop
@@ -146,7 +141,7 @@ Disassembly of section .text:
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
[ ]*[a-f0-9]+: 90 nop
-[ ]*[a-f0-9]+: 8d 76 00 lea 0x0\(%rsi\),%esi
+[ ]*[a-f0-9]+: 48 89 f6 mov %rsi,%rsi
0+d0 <nop2>:
[ ]*[a-f0-9]+: 90 nop