PATCH: Align memcmp-sse4.S and fix unwind info
H.J. Lu
hongjiu.lu@intel.com
Tue Feb 16 18:57:00 GMT 2010
Hi,
This patch alignes jump targets to 16byte and puts the table into
.rodata.sse4.2 section. It also fixes unwind info. Before the fix, I
got
Breakpoint 1, __memcmp_sse4_2 () at
../sysdeps/i386/i686/multiarch/memcmp-sse4.S:161
161 jb L(0bytesend)
(gdb) bt
#0 __memcmp_sse4_2 () at ../sysdeps/i386/i686/multiarch/memcmp-sse4.S:161
#1 0xf7ffbffd in ?? ()
#2 0xf7ff8ffd in ?? ()
#3 0x00000001 in ?? ()
#4 0x0003fadd in ?? ()
#5 0xffffd020 in ?? ()
#6 0x0000000d in ?? ()
#7 0xf7fb4000 in ?? ()
#8 0x0805cc92 in __write_nocancel () at
../sysdeps/unix/syscall-template.S:82
#9 0x00000000 in ?? ()
After the fix, I got
Breakpoint 1, __memcmp_sse4_2 ()
at ../sysdeps/i386/i686/multiarch/memcmp-sse4.S:161
161 jb L(0bytesend)
(gdb) bt
#0 __memcmp_sse4_2 () at
../sysdeps/i386/i686/multiarch/memcmp-sse4.S:161
#1 0x0804c547 in do_one_test (impl=0x80d6890, s1=0xf7ffbffd
"\001\001\245",
s2=0xf7ff8ffd "\001\001Z", len=1, exp_result=0) at test-memcmp.c:57
#2 0x0804cb43 in do_test (align1=1, align2=1, len=1, exp_result=0)
at test-memcmp.c:203
#3 0x0804d55f in main () at test-memcmp.c:447
---
2010-02-16 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/i386/i686/multiarch/memcmp-sse4.S (less8bytes): Aligned
to 16byte.
(find_16diff): Likewise.
(52bytes): Likewise.
(53bytes): Likewise.
(54bytes): Likewise.
(55bytes): Likewise.
(56bytes): Likewise.
(57bytes): Likewise.
(58bytes): Likewise.
(59bytes): Likewise.
(60bytes): Likewise.
(61bytes): Likewise.
(62bytes): Likewise.
(63bytes): Likewise.
(64bytes): Likewise.
(less16bytes): Likewise.
(less1bytes): Remove extra CFI_PUSH.
(table_64bytes): Put it in .rodata.sse4.2 section.
diff --git a/sysdeps/i386/i686/multiarch/memcmp-sse4.S b/sysdeps/i386/i686/multiarch/memcmp-sse4.S
index 71c4e1c..b799bdf 100644
--- a/sysdeps/i386/i686/multiarch/memcmp-sse4.S
+++ b/sysdeps/i386/i686/multiarch/memcmp-sse4.S
@@ -96,8 +96,9 @@ ENTRY (MEMCMP)
add %ecx, %edx
add %ecx, %eax
BRANCH_TO_JMPTBL_ENTRY(L(table_64bytes), %ecx, 4)
-L(less8bytes):
+ ALIGN (4)
+L(less8bytes):
mov (%eax), %bl
cmpb (%edx), %bl
jne L(nonzero)
@@ -154,7 +155,6 @@ L(0bytes):
POP (%ebx)
xor %eax, %eax
ret
- CFI_PUSH (%ebx)
ALIGN (4)
L(less1bytes):
@@ -207,6 +207,8 @@ L(64bytesormore_loop):
add %ecx, %edx
add %ecx, %eax
BRANCH_TO_JMPTBL_ENTRY(L(table_64bytes), %ecx, 4)
+
+ ALIGN (4)
L(find_16diff):
sub $16, %ecx
L(find_32diff):
@@ -217,8 +219,8 @@ L(find_64diff):
add %ecx, %edx
add %ecx, %eax
jmp L(16bytes)
- ALIGN (4)
+ ALIGN (4)
L(16bytes):
mov -16(%eax), %ecx
mov -16(%edx), %ebx
@@ -377,7 +379,7 @@ L(1bytes):
jne L(end)
RETURN
-
+ ALIGN (4)
L(52bytes):
movdqu -52(%eax), %xmm1
movdqu -52(%edx), %xmm2
@@ -406,6 +408,7 @@ L(20bytes):
jne L(find_diff)
RETURN
+ ALIGN (4)
L(53bytes):
movdqu -53(%eax), %xmm1
movdqu -53(%edx), %xmm2
@@ -437,6 +440,7 @@ L(21bytes):
jne L(end)
RETURN
+ ALIGN (4)
L(54bytes):
movdqu -54(%eax), %xmm1
movdqu -54(%edx), %xmm2
@@ -472,6 +476,7 @@ L(22bytes):
jne L(end)
RETURN
+ ALIGN (4)
L(55bytes):
movdqu -55(%eax), %xmm1
movdqu -55(%edx), %xmm2
@@ -509,6 +514,7 @@ L(23bytes):
jne L(end)
RETURN
+ ALIGN (4)
L(56bytes):
movdqu -56(%eax), %xmm1
movdqu -56(%edx), %xmm2
@@ -543,6 +549,7 @@ L(24bytes):
jne L(find_diff)
RETURN
+ ALIGN (4)
L(57bytes):
movdqu -57(%eax), %xmm1
movdqu -57(%edx), %xmm2
@@ -578,6 +585,7 @@ L(25bytes):
jne L(end)
RETURN
+ ALIGN (4)
L(58bytes):
movdqu -58(%eax), %xmm1
movdqu -58(%edx), %xmm2
@@ -619,6 +627,7 @@ L(26bytes):
jne L(end)
RETURN
+ ALIGN (4)
L(59bytes):
movdqu -59(%eax), %xmm1
movdqu -59(%edx), %xmm2
@@ -660,6 +669,7 @@ L(27bytes):
jne L(end)
RETURN
+ ALIGN (4)
L(60bytes):
movdqu -60(%eax), %xmm1
movdqu -60(%edx), %xmm2
@@ -696,6 +706,7 @@ L(28bytes):
jne L(find_diff)
RETURN
+ ALIGN (4)
L(61bytes):
movdqu -61(%eax), %xmm1
movdqu -61(%edx), %xmm2
@@ -738,6 +749,7 @@ L(29bytes):
jne L(end)
RETURN
+ ALIGN (4)
L(62bytes):
movdqu -62(%eax), %xmm1
movdqu -62(%edx), %xmm2
@@ -780,6 +792,7 @@ L(30bytes):
jne L(end)
RETURN
+ ALIGN (4)
L(63bytes):
movdqu -63(%eax), %xmm1
movdqu -63(%edx), %xmm2
@@ -826,6 +839,7 @@ L(31bytes):
jne L(end)
RETURN
+ ALIGN (4)
L(64bytes):
movdqu -64(%eax), %xmm1
movdqu -64(%edx), %xmm2
@@ -870,6 +884,7 @@ L(32bytes):
jne L(find_diff)
RETURN
+ ALIGN (4)
L(less16bytes):
add %ebx, %eax
add %ebx, %edx
@@ -914,7 +929,9 @@ L(end):
neg %eax
L(bigger):
ret
+END (MEMCMP)
+ .section .rodata.sse4.2,"a",@progbits
ALIGN (2)
L(table_64bytes):
.int JMPTBL (L(0bytes), L(table_64bytes))
@@ -983,6 +1000,4 @@ L(table_64bytes):
.int JMPTBL (L(63bytes), L(table_64bytes))
.int JMPTBL (L(64bytes), L(table_64bytes))
-END (MEMCMP)
-
#endif
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