[v1] x86: Move strcat SSE2 implementation to multiarch/strcat-sse2.S
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Patch applied to master at the time it was sent
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| dj/TryBot-32bit |
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Build for i686
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Commit Message
This commit doesn't affect libc.so.6, its just housekeeping to prepare
for adding explicit ISA level support.
Tested build on x86_64 and x86_32 with/without multiarch.
---
sysdeps/x86_64/multiarch/strcat-sse2.S | 242 ++++++++++++++++++++++++-
sysdeps/x86_64/strcat.S | 239 +-----------------------
2 files changed, 238 insertions(+), 243 deletions(-)
Comments
On Tue, Jul 12, 2022 at 12:29 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> This commit doesn't affect libc.so.6, its just housekeeping to prepare
> for adding explicit ISA level support.
>
> Tested build on x86_64 and x86_32 with/without multiarch.
> ---
> sysdeps/x86_64/multiarch/strcat-sse2.S | 242 ++++++++++++++++++++++++-
> sysdeps/x86_64/strcat.S | 239 +-----------------------
> 2 files changed, 238 insertions(+), 243 deletions(-)
>
> diff --git a/sysdeps/x86_64/multiarch/strcat-sse2.S b/sysdeps/x86_64/multiarch/strcat-sse2.S
> index 449e102438..244c4a6d74 100644
> --- a/sysdeps/x86_64/multiarch/strcat-sse2.S
> +++ b/sysdeps/x86_64/multiarch/strcat-sse2.S
> @@ -17,12 +17,242 @@
> <https://www.gnu.org/licenses/>. */
>
> #if IS_IN (libc)
> +# ifndef STRCAT
> +# define STRCAT __strcat_sse2
> +# endif
> +#endif
>
> -# include <sysdep.h>
> -# define strcat __strcat_sse2
> +#include <sysdep.h>
> +
> + .text
> +ENTRY (STRCAT)
> + movq %rdi, %rcx /* Dest. register. */
> + andl $7, %ecx /* mask alignment bits */
> + movq %rdi, %rax /* Duplicate destination pointer. */
> + movq $0xfefefefefefefeff,%r8
> +
> + /* First step: Find end of destination. */
> + jz 4f /* aligned => start loop */
> +
> + neg %ecx /* We need to align to 8 bytes. */
> + addl $8,%ecx
> + /* Search the first bytes directly. */
> +0: cmpb $0x0,(%rax) /* is byte NUL? */
> + je 2f /* yes => start copy */
> + incq %rax /* increment pointer */
> + decl %ecx
> + jnz 0b
> +
> +
> +
> + /* Now the source is aligned. Scan for NUL byte. */
> + .p2align 4
> +4:
> + /* First unroll. */
> + movq (%rax), %rcx /* get double word (= 8 bytes) in question */
> + addq $8,%rax /* adjust pointer for next word */
> + movq %r8, %rdx /* magic value */
> + addq %rcx, %rdx /* add the magic value to the word. We get
> + carry bits reported for each byte which
> + is *not* 0 */
> + jnc 3f /* highest byte is NUL => return pointer */
> + xorq %rcx, %rdx /* (word+magic)^word */
> + orq %r8, %rdx /* set all non-carry bits */
> + incq %rdx /* add 1: if one carry bit was *not* set
> + the addition will not result in 0. */
> + jnz 3f /* found NUL => return pointer */
> +
> + /* Second unroll. */
> + movq (%rax), %rcx /* get double word (= 8 bytes) in question */
> + addq $8,%rax /* adjust pointer for next word */
> + movq %r8, %rdx /* magic value */
> + addq %rcx, %rdx /* add the magic value to the word. We get
> + carry bits reported for each byte which
> + is *not* 0 */
> + jnc 3f /* highest byte is NUL => return pointer */
> + xorq %rcx, %rdx /* (word+magic)^word */
> + orq %r8, %rdx /* set all non-carry bits */
> + incq %rdx /* add 1: if one carry bit was *not* set
> + the addition will not result in 0. */
> + jnz 3f /* found NUL => return pointer */
> +
> + /* Third unroll. */
> + movq (%rax), %rcx /* get double word (= 8 bytes) in question */
> + addq $8,%rax /* adjust pointer for next word */
> + movq %r8, %rdx /* magic value */
> + addq %rcx, %rdx /* add the magic value to the word. We get
> + carry bits reported for each byte which
> + is *not* 0 */
> + jnc 3f /* highest byte is NUL => return pointer */
> + xorq %rcx, %rdx /* (word+magic)^word */
> + orq %r8, %rdx /* set all non-carry bits */
> + incq %rdx /* add 1: if one carry bit was *not* set
> + the addition will not result in 0. */
> + jnz 3f /* found NUL => return pointer */
> +
> + /* Fourth unroll. */
> + movq (%rax), %rcx /* get double word (= 8 bytes) in question */
> + addq $8,%rax /* adjust pointer for next word */
> + movq %r8, %rdx /* magic value */
> + addq %rcx, %rdx /* add the magic value to the word. We get
> + carry bits reported for each byte which
> + is *not* 0 */
> + jnc 3f /* highest byte is NUL => return pointer */
> + xorq %rcx, %rdx /* (word+magic)^word */
> + orq %r8, %rdx /* set all non-carry bits */
> + incq %rdx /* add 1: if one carry bit was *not* set
> + the addition will not result in 0. */
> + jz 4b /* no NUL found => continue loop */
> +
> + .p2align 4 /* Align, it's a jump target. */
> +3: subq $8,%rax /* correct pointer increment. */
> +
> + testb %cl, %cl /* is first byte NUL? */
> + jz 2f /* yes => return */
> + incq %rax /* increment pointer */
> +
> + testb %ch, %ch /* is second byte NUL? */
> + jz 2f /* yes => return */
> + incq %rax /* increment pointer */
> +
> + testl $0x00ff0000, %ecx /* is third byte NUL? */
> + jz 2f /* yes => return pointer */
> + incq %rax /* increment pointer */
> +
> + testl $0xff000000, %ecx /* is fourth byte NUL? */
> + jz 2f /* yes => return pointer */
> + incq %rax /* increment pointer */
> +
> + shrq $32, %rcx /* look at other half. */
> +
> + testb %cl, %cl /* is first byte NUL? */
> + jz 2f /* yes => return */
> + incq %rax /* increment pointer */
> +
> + testb %ch, %ch /* is second byte NUL? */
> + jz 2f /* yes => return */
> + incq %rax /* increment pointer */
> +
> + testl $0xff0000, %ecx /* is third byte NUL? */
> + jz 2f /* yes => return pointer */
> + incq %rax /* increment pointer */
> +
> +2:
> + /* Second step: Copy source to destination. */
> +
> + movq %rsi, %rcx /* duplicate */
> + andl $7,%ecx /* mask alignment bits */
> + movq %rax, %rdx /* move around */
> + jz 22f /* aligned => start loop */
> +
> + neg %ecx /* align to 8 bytes. */
> + addl $8, %ecx
> + /* Align the source pointer. */
> +21:
> + movb (%rsi), %al /* Fetch a byte */
> + testb %al, %al /* Is it NUL? */
> + movb %al, (%rdx) /* Store it */
> + jz 24f /* If it was NUL, done! */
> + incq %rsi
> + incq %rdx
> + decl %ecx
> + jnz 21b
> +
> + /* Now the sources is aligned. Unfortunatly we cannot force
> + to have both source and destination aligned, so ignore the
> + alignment of the destination. */
> + .p2align 4
> +22:
> + /* 1st unroll. */
> + movq (%rsi), %rax /* Read double word (8 bytes). */
> + addq $8, %rsi /* Adjust pointer for next word. */
> + movq %rax, %r9 /* Save a copy for NUL finding. */
> + addq %r8, %r9 /* add the magic value to the word. We get
> + carry bits reported for each byte which
> + is *not* 0 */
> + jnc 23f /* highest byte is NUL => return pointer */
> + xorq %rax, %r9 /* (word+magic)^word */
> + orq %r8, %r9 /* set all non-carry bits */
> + incq %r9 /* add 1: if one carry bit was *not* set
> + the addition will not result in 0. */
> +
> + jnz 23f /* found NUL => return pointer */
> +
> + movq %rax, (%rdx) /* Write value to destination. */
> + addq $8, %rdx /* Adjust pointer. */
> +
> + /* 2nd unroll. */
> + movq (%rsi), %rax /* Read double word (8 bytes). */
> + addq $8, %rsi /* Adjust pointer for next word. */
> + movq %rax, %r9 /* Save a copy for NUL finding. */
> + addq %r8, %r9 /* add the magic value to the word. We get
> + carry bits reported for each byte which
> + is *not* 0 */
> + jnc 23f /* highest byte is NUL => return pointer */
> + xorq %rax, %r9 /* (word+magic)^word */
> + orq %r8, %r9 /* set all non-carry bits */
> + incq %r9 /* add 1: if one carry bit was *not* set
> + the addition will not result in 0. */
> +
> + jnz 23f /* found NUL => return pointer */
> +
> + movq %rax, (%rdx) /* Write value to destination. */
> + addq $8, %rdx /* Adjust pointer. */
> +
> + /* 3rd unroll. */
> + movq (%rsi), %rax /* Read double word (8 bytes). */
> + addq $8, %rsi /* Adjust pointer for next word. */
> + movq %rax, %r9 /* Save a copy for NUL finding. */
> + addq %r8, %r9 /* add the magic value to the word. We get
> + carry bits reported for each byte which
> + is *not* 0 */
> + jnc 23f /* highest byte is NUL => return pointer */
> + xorq %rax, %r9 /* (word+magic)^word */
> + orq %r8, %r9 /* set all non-carry bits */
> + incq %r9 /* add 1: if one carry bit was *not* set
> + the addition will not result in 0. */
> +
> + jnz 23f /* found NUL => return pointer */
> +
> + movq %rax, (%rdx) /* Write value to destination. */
> + addq $8, %rdx /* Adjust pointer. */
> +
> + /* 4th unroll. */
> + movq (%rsi), %rax /* Read double word (8 bytes). */
> + addq $8, %rsi /* Adjust pointer for next word. */
> + movq %rax, %r9 /* Save a copy for NUL finding. */
> + addq %r8, %r9 /* add the magic value to the word. We get
> + carry bits reported for each byte which
> + is *not* 0 */
> + jnc 23f /* highest byte is NUL => return pointer */
> + xorq %rax, %r9 /* (word+magic)^word */
> + orq %r8, %r9 /* set all non-carry bits */
> + incq %r9 /* add 1: if one carry bit was *not* set
> + the addition will not result in 0. */
> +
> + jnz 23f /* found NUL => return pointer */
> +
> + movq %rax, (%rdx) /* Write value to destination. */
> + addq $8, %rdx /* Adjust pointer. */
> + jmp 22b /* Next iteration. */
> +
> + /* Do the last few bytes. %rax contains the value to write.
> + The loop is unrolled twice. */
> + .p2align 4
> +23:
> + movb %al, (%rdx) /* 1st byte. */
> + testb %al, %al /* Is it NUL. */
> + jz 24f /* yes, finish. */
> + incq %rdx /* Increment destination. */
> + movb %ah, (%rdx) /* 2nd byte. */
> + testb %ah, %ah /* Is it NUL?. */
> + jz 24f /* yes, finish. */
> + incq %rdx /* Increment destination. */
> + shrq $16, %rax /* Shift... */
> + jmp 23b /* and look at next two bytes in %rax. */
>
> -# undef libc_hidden_builtin_def
> -# define libc_hidden_builtin_def(strcat)
> -#endif
>
> -#include <sysdeps/x86_64/strcat.S>
> +24:
> + movq %rdi, %rax /* Source is return value. */
> + retq
> +END (STRCAT)
> diff --git a/sysdeps/x86_64/strcat.S b/sysdeps/x86_64/strcat.S
> index 565a9c785a..fc3e8a9bcf 100644
> --- a/sysdeps/x86_64/strcat.S
> +++ b/sysdeps/x86_64/strcat.S
> @@ -17,241 +17,6 @@
> License along with the GNU C Library; if not, see
> <https://www.gnu.org/licenses/>. */
>
> -#include <sysdep.h>
> -#include "asm-syntax.h"
> -
> -/* Will be removed when new strcpy implementation gets merged. */
> -
> - .text
> -ENTRY (strcat)
> - movq %rdi, %rcx /* Dest. register. */
> - andl $7, %ecx /* mask alignment bits */
> - movq %rdi, %rax /* Duplicate destination pointer. */
> - movq $0xfefefefefefefeff,%r8
> -
> - /* First step: Find end of destination. */
> - jz 4f /* aligned => start loop */
> -
> - neg %ecx /* We need to align to 8 bytes. */
> - addl $8,%ecx
> - /* Search the first bytes directly. */
> -0: cmpb $0x0,(%rax) /* is byte NUL? */
> - je 2f /* yes => start copy */
> - incq %rax /* increment pointer */
> - decl %ecx
> - jnz 0b
> -
> -
> -
> - /* Now the source is aligned. Scan for NUL byte. */
> - .p2align 4
> -4:
> - /* First unroll. */
> - movq (%rax), %rcx /* get double word (= 8 bytes) in question */
> - addq $8,%rax /* adjust pointer for next word */
> - movq %r8, %rdx /* magic value */
> - addq %rcx, %rdx /* add the magic value to the word. We get
> - carry bits reported for each byte which
> - is *not* 0 */
> - jnc 3f /* highest byte is NUL => return pointer */
> - xorq %rcx, %rdx /* (word+magic)^word */
> - orq %r8, %rdx /* set all non-carry bits */
> - incq %rdx /* add 1: if one carry bit was *not* set
> - the addition will not result in 0. */
> - jnz 3f /* found NUL => return pointer */
> -
> - /* Second unroll. */
> - movq (%rax), %rcx /* get double word (= 8 bytes) in question */
> - addq $8,%rax /* adjust pointer for next word */
> - movq %r8, %rdx /* magic value */
> - addq %rcx, %rdx /* add the magic value to the word. We get
> - carry bits reported for each byte which
> - is *not* 0 */
> - jnc 3f /* highest byte is NUL => return pointer */
> - xorq %rcx, %rdx /* (word+magic)^word */
> - orq %r8, %rdx /* set all non-carry bits */
> - incq %rdx /* add 1: if one carry bit was *not* set
> - the addition will not result in 0. */
> - jnz 3f /* found NUL => return pointer */
> -
> - /* Third unroll. */
> - movq (%rax), %rcx /* get double word (= 8 bytes) in question */
> - addq $8,%rax /* adjust pointer for next word */
> - movq %r8, %rdx /* magic value */
> - addq %rcx, %rdx /* add the magic value to the word. We get
> - carry bits reported for each byte which
> - is *not* 0 */
> - jnc 3f /* highest byte is NUL => return pointer */
> - xorq %rcx, %rdx /* (word+magic)^word */
> - orq %r8, %rdx /* set all non-carry bits */
> - incq %rdx /* add 1: if one carry bit was *not* set
> - the addition will not result in 0. */
> - jnz 3f /* found NUL => return pointer */
> -
> - /* Fourth unroll. */
> - movq (%rax), %rcx /* get double word (= 8 bytes) in question */
> - addq $8,%rax /* adjust pointer for next word */
> - movq %r8, %rdx /* magic value */
> - addq %rcx, %rdx /* add the magic value to the word. We get
> - carry bits reported for each byte which
> - is *not* 0 */
> - jnc 3f /* highest byte is NUL => return pointer */
> - xorq %rcx, %rdx /* (word+magic)^word */
> - orq %r8, %rdx /* set all non-carry bits */
> - incq %rdx /* add 1: if one carry bit was *not* set
> - the addition will not result in 0. */
> - jz 4b /* no NUL found => continue loop */
> -
> - .p2align 4 /* Align, it's a jump target. */
> -3: subq $8,%rax /* correct pointer increment. */
> -
> - testb %cl, %cl /* is first byte NUL? */
> - jz 2f /* yes => return */
> - incq %rax /* increment pointer */
> -
> - testb %ch, %ch /* is second byte NUL? */
> - jz 2f /* yes => return */
> - incq %rax /* increment pointer */
> -
> - testl $0x00ff0000, %ecx /* is third byte NUL? */
> - jz 2f /* yes => return pointer */
> - incq %rax /* increment pointer */
> -
> - testl $0xff000000, %ecx /* is fourth byte NUL? */
> - jz 2f /* yes => return pointer */
> - incq %rax /* increment pointer */
> -
> - shrq $32, %rcx /* look at other half. */
> -
> - testb %cl, %cl /* is first byte NUL? */
> - jz 2f /* yes => return */
> - incq %rax /* increment pointer */
> -
> - testb %ch, %ch /* is second byte NUL? */
> - jz 2f /* yes => return */
> - incq %rax /* increment pointer */
> -
> - testl $0xff0000, %ecx /* is third byte NUL? */
> - jz 2f /* yes => return pointer */
> - incq %rax /* increment pointer */
> -
> -2:
> - /* Second step: Copy source to destination. */
> -
> - movq %rsi, %rcx /* duplicate */
> - andl $7,%ecx /* mask alignment bits */
> - movq %rax, %rdx /* move around */
> - jz 22f /* aligned => start loop */
> -
> - neg %ecx /* align to 8 bytes. */
> - addl $8, %ecx
> - /* Align the source pointer. */
> -21:
> - movb (%rsi), %al /* Fetch a byte */
> - testb %al, %al /* Is it NUL? */
> - movb %al, (%rdx) /* Store it */
> - jz 24f /* If it was NUL, done! */
> - incq %rsi
> - incq %rdx
> - decl %ecx
> - jnz 21b
> -
> - /* Now the sources is aligned. Unfortunatly we cannot force
> - to have both source and destination aligned, so ignore the
> - alignment of the destination. */
> - .p2align 4
> -22:
> - /* 1st unroll. */
> - movq (%rsi), %rax /* Read double word (8 bytes). */
> - addq $8, %rsi /* Adjust pointer for next word. */
> - movq %rax, %r9 /* Save a copy for NUL finding. */
> - addq %r8, %r9 /* add the magic value to the word. We get
> - carry bits reported for each byte which
> - is *not* 0 */
> - jnc 23f /* highest byte is NUL => return pointer */
> - xorq %rax, %r9 /* (word+magic)^word */
> - orq %r8, %r9 /* set all non-carry bits */
> - incq %r9 /* add 1: if one carry bit was *not* set
> - the addition will not result in 0. */
> -
> - jnz 23f /* found NUL => return pointer */
> -
> - movq %rax, (%rdx) /* Write value to destination. */
> - addq $8, %rdx /* Adjust pointer. */
> -
> - /* 2nd unroll. */
> - movq (%rsi), %rax /* Read double word (8 bytes). */
> - addq $8, %rsi /* Adjust pointer for next word. */
> - movq %rax, %r9 /* Save a copy for NUL finding. */
> - addq %r8, %r9 /* add the magic value to the word. We get
> - carry bits reported for each byte which
> - is *not* 0 */
> - jnc 23f /* highest byte is NUL => return pointer */
> - xorq %rax, %r9 /* (word+magic)^word */
> - orq %r8, %r9 /* set all non-carry bits */
> - incq %r9 /* add 1: if one carry bit was *not* set
> - the addition will not result in 0. */
> -
> - jnz 23f /* found NUL => return pointer */
> -
> - movq %rax, (%rdx) /* Write value to destination. */
> - addq $8, %rdx /* Adjust pointer. */
> -
> - /* 3rd unroll. */
> - movq (%rsi), %rax /* Read double word (8 bytes). */
> - addq $8, %rsi /* Adjust pointer for next word. */
> - movq %rax, %r9 /* Save a copy for NUL finding. */
> - addq %r8, %r9 /* add the magic value to the word. We get
> - carry bits reported for each byte which
> - is *not* 0 */
> - jnc 23f /* highest byte is NUL => return pointer */
> - xorq %rax, %r9 /* (word+magic)^word */
> - orq %r8, %r9 /* set all non-carry bits */
> - incq %r9 /* add 1: if one carry bit was *not* set
> - the addition will not result in 0. */
> -
> - jnz 23f /* found NUL => return pointer */
> -
> - movq %rax, (%rdx) /* Write value to destination. */
> - addq $8, %rdx /* Adjust pointer. */
> -
> - /* 4th unroll. */
> - movq (%rsi), %rax /* Read double word (8 bytes). */
> - addq $8, %rsi /* Adjust pointer for next word. */
> - movq %rax, %r9 /* Save a copy for NUL finding. */
> - addq %r8, %r9 /* add the magic value to the word. We get
> - carry bits reported for each byte which
> - is *not* 0 */
> - jnc 23f /* highest byte is NUL => return pointer */
> - xorq %rax, %r9 /* (word+magic)^word */
> - orq %r8, %r9 /* set all non-carry bits */
> - incq %r9 /* add 1: if one carry bit was *not* set
> - the addition will not result in 0. */
> -
> - jnz 23f /* found NUL => return pointer */
> -
> - movq %rax, (%rdx) /* Write value to destination. */
> - addq $8, %rdx /* Adjust pointer. */
> - jmp 22b /* Next iteration. */
> -
> - /* Do the last few bytes. %rax contains the value to write.
> - The loop is unrolled twice. */
> - .p2align 4
> -23:
> - movb %al, (%rdx) /* 1st byte. */
> - testb %al, %al /* Is it NUL. */
> - jz 24f /* yes, finish. */
> - incq %rdx /* Increment destination. */
> - movb %ah, (%rdx) /* 2nd byte. */
> - testb %ah, %ah /* Is it NUL?. */
> - jz 24f /* yes, finish. */
> - incq %rdx /* Increment destination. */
> - shrq $16, %rax /* Shift... */
> - jmp 23b /* and look at next two bytes in %rax. */
> -
> -
> -24:
> - movq %rdi, %rax /* Source is return value. */
> - retq
> -END (strcat)
> +#define STRCAT strcat
> +#include "multiarch/strcat-sse2.S"
> libc_hidden_builtin_def (strcat)
> --
> 2.34.1
>
LGTM.
Thanks.
@@ -17,12 +17,242 @@
<https://www.gnu.org/licenses/>. */
#if IS_IN (libc)
+# ifndef STRCAT
+# define STRCAT __strcat_sse2
+# endif
+#endif
-# include <sysdep.h>
-# define strcat __strcat_sse2
+#include <sysdep.h>
+
+ .text
+ENTRY (STRCAT)
+ movq %rdi, %rcx /* Dest. register. */
+ andl $7, %ecx /* mask alignment bits */
+ movq %rdi, %rax /* Duplicate destination pointer. */
+ movq $0xfefefefefefefeff,%r8
+
+ /* First step: Find end of destination. */
+ jz 4f /* aligned => start loop */
+
+ neg %ecx /* We need to align to 8 bytes. */
+ addl $8,%ecx
+ /* Search the first bytes directly. */
+0: cmpb $0x0,(%rax) /* is byte NUL? */
+ je 2f /* yes => start copy */
+ incq %rax /* increment pointer */
+ decl %ecx
+ jnz 0b
+
+
+
+ /* Now the source is aligned. Scan for NUL byte. */
+ .p2align 4
+4:
+ /* First unroll. */
+ movq (%rax), %rcx /* get double word (= 8 bytes) in question */
+ addq $8,%rax /* adjust pointer for next word */
+ movq %r8, %rdx /* magic value */
+ addq %rcx, %rdx /* add the magic value to the word. We get
+ carry bits reported for each byte which
+ is *not* 0 */
+ jnc 3f /* highest byte is NUL => return pointer */
+ xorq %rcx, %rdx /* (word+magic)^word */
+ orq %r8, %rdx /* set all non-carry bits */
+ incq %rdx /* add 1: if one carry bit was *not* set
+ the addition will not result in 0. */
+ jnz 3f /* found NUL => return pointer */
+
+ /* Second unroll. */
+ movq (%rax), %rcx /* get double word (= 8 bytes) in question */
+ addq $8,%rax /* adjust pointer for next word */
+ movq %r8, %rdx /* magic value */
+ addq %rcx, %rdx /* add the magic value to the word. We get
+ carry bits reported for each byte which
+ is *not* 0 */
+ jnc 3f /* highest byte is NUL => return pointer */
+ xorq %rcx, %rdx /* (word+magic)^word */
+ orq %r8, %rdx /* set all non-carry bits */
+ incq %rdx /* add 1: if one carry bit was *not* set
+ the addition will not result in 0. */
+ jnz 3f /* found NUL => return pointer */
+
+ /* Third unroll. */
+ movq (%rax), %rcx /* get double word (= 8 bytes) in question */
+ addq $8,%rax /* adjust pointer for next word */
+ movq %r8, %rdx /* magic value */
+ addq %rcx, %rdx /* add the magic value to the word. We get
+ carry bits reported for each byte which
+ is *not* 0 */
+ jnc 3f /* highest byte is NUL => return pointer */
+ xorq %rcx, %rdx /* (word+magic)^word */
+ orq %r8, %rdx /* set all non-carry bits */
+ incq %rdx /* add 1: if one carry bit was *not* set
+ the addition will not result in 0. */
+ jnz 3f /* found NUL => return pointer */
+
+ /* Fourth unroll. */
+ movq (%rax), %rcx /* get double word (= 8 bytes) in question */
+ addq $8,%rax /* adjust pointer for next word */
+ movq %r8, %rdx /* magic value */
+ addq %rcx, %rdx /* add the magic value to the word. We get
+ carry bits reported for each byte which
+ is *not* 0 */
+ jnc 3f /* highest byte is NUL => return pointer */
+ xorq %rcx, %rdx /* (word+magic)^word */
+ orq %r8, %rdx /* set all non-carry bits */
+ incq %rdx /* add 1: if one carry bit was *not* set
+ the addition will not result in 0. */
+ jz 4b /* no NUL found => continue loop */
+
+ .p2align 4 /* Align, it's a jump target. */
+3: subq $8,%rax /* correct pointer increment. */
+
+ testb %cl, %cl /* is first byte NUL? */
+ jz 2f /* yes => return */
+ incq %rax /* increment pointer */
+
+ testb %ch, %ch /* is second byte NUL? */
+ jz 2f /* yes => return */
+ incq %rax /* increment pointer */
+
+ testl $0x00ff0000, %ecx /* is third byte NUL? */
+ jz 2f /* yes => return pointer */
+ incq %rax /* increment pointer */
+
+ testl $0xff000000, %ecx /* is fourth byte NUL? */
+ jz 2f /* yes => return pointer */
+ incq %rax /* increment pointer */
+
+ shrq $32, %rcx /* look at other half. */
+
+ testb %cl, %cl /* is first byte NUL? */
+ jz 2f /* yes => return */
+ incq %rax /* increment pointer */
+
+ testb %ch, %ch /* is second byte NUL? */
+ jz 2f /* yes => return */
+ incq %rax /* increment pointer */
+
+ testl $0xff0000, %ecx /* is third byte NUL? */
+ jz 2f /* yes => return pointer */
+ incq %rax /* increment pointer */
+
+2:
+ /* Second step: Copy source to destination. */
+
+ movq %rsi, %rcx /* duplicate */
+ andl $7,%ecx /* mask alignment bits */
+ movq %rax, %rdx /* move around */
+ jz 22f /* aligned => start loop */
+
+ neg %ecx /* align to 8 bytes. */
+ addl $8, %ecx
+ /* Align the source pointer. */
+21:
+ movb (%rsi), %al /* Fetch a byte */
+ testb %al, %al /* Is it NUL? */
+ movb %al, (%rdx) /* Store it */
+ jz 24f /* If it was NUL, done! */
+ incq %rsi
+ incq %rdx
+ decl %ecx
+ jnz 21b
+
+ /* Now the sources is aligned. Unfortunatly we cannot force
+ to have both source and destination aligned, so ignore the
+ alignment of the destination. */
+ .p2align 4
+22:
+ /* 1st unroll. */
+ movq (%rsi), %rax /* Read double word (8 bytes). */
+ addq $8, %rsi /* Adjust pointer for next word. */
+ movq %rax, %r9 /* Save a copy for NUL finding. */
+ addq %r8, %r9 /* add the magic value to the word. We get
+ carry bits reported for each byte which
+ is *not* 0 */
+ jnc 23f /* highest byte is NUL => return pointer */
+ xorq %rax, %r9 /* (word+magic)^word */
+ orq %r8, %r9 /* set all non-carry bits */
+ incq %r9 /* add 1: if one carry bit was *not* set
+ the addition will not result in 0. */
+
+ jnz 23f /* found NUL => return pointer */
+
+ movq %rax, (%rdx) /* Write value to destination. */
+ addq $8, %rdx /* Adjust pointer. */
+
+ /* 2nd unroll. */
+ movq (%rsi), %rax /* Read double word (8 bytes). */
+ addq $8, %rsi /* Adjust pointer for next word. */
+ movq %rax, %r9 /* Save a copy for NUL finding. */
+ addq %r8, %r9 /* add the magic value to the word. We get
+ carry bits reported for each byte which
+ is *not* 0 */
+ jnc 23f /* highest byte is NUL => return pointer */
+ xorq %rax, %r9 /* (word+magic)^word */
+ orq %r8, %r9 /* set all non-carry bits */
+ incq %r9 /* add 1: if one carry bit was *not* set
+ the addition will not result in 0. */
+
+ jnz 23f /* found NUL => return pointer */
+
+ movq %rax, (%rdx) /* Write value to destination. */
+ addq $8, %rdx /* Adjust pointer. */
+
+ /* 3rd unroll. */
+ movq (%rsi), %rax /* Read double word (8 bytes). */
+ addq $8, %rsi /* Adjust pointer for next word. */
+ movq %rax, %r9 /* Save a copy for NUL finding. */
+ addq %r8, %r9 /* add the magic value to the word. We get
+ carry bits reported for each byte which
+ is *not* 0 */
+ jnc 23f /* highest byte is NUL => return pointer */
+ xorq %rax, %r9 /* (word+magic)^word */
+ orq %r8, %r9 /* set all non-carry bits */
+ incq %r9 /* add 1: if one carry bit was *not* set
+ the addition will not result in 0. */
+
+ jnz 23f /* found NUL => return pointer */
+
+ movq %rax, (%rdx) /* Write value to destination. */
+ addq $8, %rdx /* Adjust pointer. */
+
+ /* 4th unroll. */
+ movq (%rsi), %rax /* Read double word (8 bytes). */
+ addq $8, %rsi /* Adjust pointer for next word. */
+ movq %rax, %r9 /* Save a copy for NUL finding. */
+ addq %r8, %r9 /* add the magic value to the word. We get
+ carry bits reported for each byte which
+ is *not* 0 */
+ jnc 23f /* highest byte is NUL => return pointer */
+ xorq %rax, %r9 /* (word+magic)^word */
+ orq %r8, %r9 /* set all non-carry bits */
+ incq %r9 /* add 1: if one carry bit was *not* set
+ the addition will not result in 0. */
+
+ jnz 23f /* found NUL => return pointer */
+
+ movq %rax, (%rdx) /* Write value to destination. */
+ addq $8, %rdx /* Adjust pointer. */
+ jmp 22b /* Next iteration. */
+
+ /* Do the last few bytes. %rax contains the value to write.
+ The loop is unrolled twice. */
+ .p2align 4
+23:
+ movb %al, (%rdx) /* 1st byte. */
+ testb %al, %al /* Is it NUL. */
+ jz 24f /* yes, finish. */
+ incq %rdx /* Increment destination. */
+ movb %ah, (%rdx) /* 2nd byte. */
+ testb %ah, %ah /* Is it NUL?. */
+ jz 24f /* yes, finish. */
+ incq %rdx /* Increment destination. */
+ shrq $16, %rax /* Shift... */
+ jmp 23b /* and look at next two bytes in %rax. */
-# undef libc_hidden_builtin_def
-# define libc_hidden_builtin_def(strcat)
-#endif
-#include <sysdeps/x86_64/strcat.S>
+24:
+ movq %rdi, %rax /* Source is return value. */
+ retq
+END (STRCAT)
@@ -17,241 +17,6 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-#include <sysdep.h>
-#include "asm-syntax.h"
-
-/* Will be removed when new strcpy implementation gets merged. */
-
- .text
-ENTRY (strcat)
- movq %rdi, %rcx /* Dest. register. */
- andl $7, %ecx /* mask alignment bits */
- movq %rdi, %rax /* Duplicate destination pointer. */
- movq $0xfefefefefefefeff,%r8
-
- /* First step: Find end of destination. */
- jz 4f /* aligned => start loop */
-
- neg %ecx /* We need to align to 8 bytes. */
- addl $8,%ecx
- /* Search the first bytes directly. */
-0: cmpb $0x0,(%rax) /* is byte NUL? */
- je 2f /* yes => start copy */
- incq %rax /* increment pointer */
- decl %ecx
- jnz 0b
-
-
-
- /* Now the source is aligned. Scan for NUL byte. */
- .p2align 4
-4:
- /* First unroll. */
- movq (%rax), %rcx /* get double word (= 8 bytes) in question */
- addq $8,%rax /* adjust pointer for next word */
- movq %r8, %rdx /* magic value */
- addq %rcx, %rdx /* add the magic value to the word. We get
- carry bits reported for each byte which
- is *not* 0 */
- jnc 3f /* highest byte is NUL => return pointer */
- xorq %rcx, %rdx /* (word+magic)^word */
- orq %r8, %rdx /* set all non-carry bits */
- incq %rdx /* add 1: if one carry bit was *not* set
- the addition will not result in 0. */
- jnz 3f /* found NUL => return pointer */
-
- /* Second unroll. */
- movq (%rax), %rcx /* get double word (= 8 bytes) in question */
- addq $8,%rax /* adjust pointer for next word */
- movq %r8, %rdx /* magic value */
- addq %rcx, %rdx /* add the magic value to the word. We get
- carry bits reported for each byte which
- is *not* 0 */
- jnc 3f /* highest byte is NUL => return pointer */
- xorq %rcx, %rdx /* (word+magic)^word */
- orq %r8, %rdx /* set all non-carry bits */
- incq %rdx /* add 1: if one carry bit was *not* set
- the addition will not result in 0. */
- jnz 3f /* found NUL => return pointer */
-
- /* Third unroll. */
- movq (%rax), %rcx /* get double word (= 8 bytes) in question */
- addq $8,%rax /* adjust pointer for next word */
- movq %r8, %rdx /* magic value */
- addq %rcx, %rdx /* add the magic value to the word. We get
- carry bits reported for each byte which
- is *not* 0 */
- jnc 3f /* highest byte is NUL => return pointer */
- xorq %rcx, %rdx /* (word+magic)^word */
- orq %r8, %rdx /* set all non-carry bits */
- incq %rdx /* add 1: if one carry bit was *not* set
- the addition will not result in 0. */
- jnz 3f /* found NUL => return pointer */
-
- /* Fourth unroll. */
- movq (%rax), %rcx /* get double word (= 8 bytes) in question */
- addq $8,%rax /* adjust pointer for next word */
- movq %r8, %rdx /* magic value */
- addq %rcx, %rdx /* add the magic value to the word. We get
- carry bits reported for each byte which
- is *not* 0 */
- jnc 3f /* highest byte is NUL => return pointer */
- xorq %rcx, %rdx /* (word+magic)^word */
- orq %r8, %rdx /* set all non-carry bits */
- incq %rdx /* add 1: if one carry bit was *not* set
- the addition will not result in 0. */
- jz 4b /* no NUL found => continue loop */
-
- .p2align 4 /* Align, it's a jump target. */
-3: subq $8,%rax /* correct pointer increment. */
-
- testb %cl, %cl /* is first byte NUL? */
- jz 2f /* yes => return */
- incq %rax /* increment pointer */
-
- testb %ch, %ch /* is second byte NUL? */
- jz 2f /* yes => return */
- incq %rax /* increment pointer */
-
- testl $0x00ff0000, %ecx /* is third byte NUL? */
- jz 2f /* yes => return pointer */
- incq %rax /* increment pointer */
-
- testl $0xff000000, %ecx /* is fourth byte NUL? */
- jz 2f /* yes => return pointer */
- incq %rax /* increment pointer */
-
- shrq $32, %rcx /* look at other half. */
-
- testb %cl, %cl /* is first byte NUL? */
- jz 2f /* yes => return */
- incq %rax /* increment pointer */
-
- testb %ch, %ch /* is second byte NUL? */
- jz 2f /* yes => return */
- incq %rax /* increment pointer */
-
- testl $0xff0000, %ecx /* is third byte NUL? */
- jz 2f /* yes => return pointer */
- incq %rax /* increment pointer */
-
-2:
- /* Second step: Copy source to destination. */
-
- movq %rsi, %rcx /* duplicate */
- andl $7,%ecx /* mask alignment bits */
- movq %rax, %rdx /* move around */
- jz 22f /* aligned => start loop */
-
- neg %ecx /* align to 8 bytes. */
- addl $8, %ecx
- /* Align the source pointer. */
-21:
- movb (%rsi), %al /* Fetch a byte */
- testb %al, %al /* Is it NUL? */
- movb %al, (%rdx) /* Store it */
- jz 24f /* If it was NUL, done! */
- incq %rsi
- incq %rdx
- decl %ecx
- jnz 21b
-
- /* Now the sources is aligned. Unfortunatly we cannot force
- to have both source and destination aligned, so ignore the
- alignment of the destination. */
- .p2align 4
-22:
- /* 1st unroll. */
- movq (%rsi), %rax /* Read double word (8 bytes). */
- addq $8, %rsi /* Adjust pointer for next word. */
- movq %rax, %r9 /* Save a copy for NUL finding. */
- addq %r8, %r9 /* add the magic value to the word. We get
- carry bits reported for each byte which
- is *not* 0 */
- jnc 23f /* highest byte is NUL => return pointer */
- xorq %rax, %r9 /* (word+magic)^word */
- orq %r8, %r9 /* set all non-carry bits */
- incq %r9 /* add 1: if one carry bit was *not* set
- the addition will not result in 0. */
-
- jnz 23f /* found NUL => return pointer */
-
- movq %rax, (%rdx) /* Write value to destination. */
- addq $8, %rdx /* Adjust pointer. */
-
- /* 2nd unroll. */
- movq (%rsi), %rax /* Read double word (8 bytes). */
- addq $8, %rsi /* Adjust pointer for next word. */
- movq %rax, %r9 /* Save a copy for NUL finding. */
- addq %r8, %r9 /* add the magic value to the word. We get
- carry bits reported for each byte which
- is *not* 0 */
- jnc 23f /* highest byte is NUL => return pointer */
- xorq %rax, %r9 /* (word+magic)^word */
- orq %r8, %r9 /* set all non-carry bits */
- incq %r9 /* add 1: if one carry bit was *not* set
- the addition will not result in 0. */
-
- jnz 23f /* found NUL => return pointer */
-
- movq %rax, (%rdx) /* Write value to destination. */
- addq $8, %rdx /* Adjust pointer. */
-
- /* 3rd unroll. */
- movq (%rsi), %rax /* Read double word (8 bytes). */
- addq $8, %rsi /* Adjust pointer for next word. */
- movq %rax, %r9 /* Save a copy for NUL finding. */
- addq %r8, %r9 /* add the magic value to the word. We get
- carry bits reported for each byte which
- is *not* 0 */
- jnc 23f /* highest byte is NUL => return pointer */
- xorq %rax, %r9 /* (word+magic)^word */
- orq %r8, %r9 /* set all non-carry bits */
- incq %r9 /* add 1: if one carry bit was *not* set
- the addition will not result in 0. */
-
- jnz 23f /* found NUL => return pointer */
-
- movq %rax, (%rdx) /* Write value to destination. */
- addq $8, %rdx /* Adjust pointer. */
-
- /* 4th unroll. */
- movq (%rsi), %rax /* Read double word (8 bytes). */
- addq $8, %rsi /* Adjust pointer for next word. */
- movq %rax, %r9 /* Save a copy for NUL finding. */
- addq %r8, %r9 /* add the magic value to the word. We get
- carry bits reported for each byte which
- is *not* 0 */
- jnc 23f /* highest byte is NUL => return pointer */
- xorq %rax, %r9 /* (word+magic)^word */
- orq %r8, %r9 /* set all non-carry bits */
- incq %r9 /* add 1: if one carry bit was *not* set
- the addition will not result in 0. */
-
- jnz 23f /* found NUL => return pointer */
-
- movq %rax, (%rdx) /* Write value to destination. */
- addq $8, %rdx /* Adjust pointer. */
- jmp 22b /* Next iteration. */
-
- /* Do the last few bytes. %rax contains the value to write.
- The loop is unrolled twice. */
- .p2align 4
-23:
- movb %al, (%rdx) /* 1st byte. */
- testb %al, %al /* Is it NUL. */
- jz 24f /* yes, finish. */
- incq %rdx /* Increment destination. */
- movb %ah, (%rdx) /* 2nd byte. */
- testb %ah, %ah /* Is it NUL?. */
- jz 24f /* yes, finish. */
- incq %rdx /* Increment destination. */
- shrq $16, %rax /* Shift... */
- jmp 23b /* and look at next two bytes in %rax. */
-
-
-24:
- movq %rdi, %rax /* Source is return value. */
- retq
-END (strcat)
+#define STRCAT strcat
+#include "multiarch/strcat-sse2.S"
libc_hidden_builtin_def (strcat)