x86: Reduce code size of mem{move|pcpy|cpy}-ssse3

The goal is to remove most SSSE3 function as SSE4, AVX2, and EVEX are
generally preferable. memcpy/memmove is one exception where avoiding
unaligned loads with `palignr` is important for some targets.

This commit replaces memmove-ssse3 with a better optimized are lower
code footprint verion. As well it aliases memcpy to memmove.

Aside from this function all other SSSE3 functions should be safe to
remove.

The performance is not changed drastically although shows overall
improvements without any major regressions or gains.

bench-memcpy geometric_mean(N=50) New / Original: 0.957

bench-memcpy-random geometric_mean(N=50) New / Original: 0.912

bench-memcpy-large geometric_mean(N=50) New / Original: 0.892

Benchmarks where run on Zhaoxin KX-6840@2000MHz See attached numbers
for all results.

More important this saves 7246 bytes of code size in memmove an
additional 10741 bytes by reusing memmove code for memcpy (total 17987
bytes saves). As well an additional 896 bytes of rodata for the jump
table entries.
This commit is contained in:
Noah Goldstein 2022-04-14 11:47:40 -05:00
parent d85916e30a
commit 26b2478322
3 changed files with 380 additions and 3156 deletions

View File

@ -16,7 +16,6 @@ sysdep_routines += \
memcmpeq-avx2-rtm \
memcmpeq-evex \
memcmpeq-sse2 \
memcpy-ssse3 \
memmove-avx-unaligned-erms \
memmove-avx-unaligned-erms-rtm \
memmove-avx512-no-vzeroupper \

File diff suppressed because it is too large Load Diff

View File

@ -1,4 +1,380 @@
#define USE_AS_MEMMOVE
#define MEMCPY __memmove_ssse3
#define MEMCPY_CHK __memmove_chk_ssse3
#include "memcpy-ssse3.S"
#include <sysdep.h>
#ifndef MEMMOVE
# define MEMMOVE __memmove_ssse3
# define MEMMOVE_CHK __memmove_chk_ssse3
# define MEMCPY __memcpy_ssse3
# define MEMCPY_CHK __memcpy_chk_ssse3
# define MEMPCPY __mempcpy_ssse3
# define MEMPCPY_CHK __mempcpy_chk_ssse3
#endif
.section .text.ssse3, "ax", @progbits
ENTRY(MEMPCPY_CHK)
cmp %RDX_LP, %RCX_LP
jb HIDDEN_JUMPTARGET(__chk_fail)
END(MEMPCPY_CHK)
ENTRY(MEMPCPY)
mov %RDI_LP, %RAX_LP
add %RDX_LP, %RAX_LP
jmp L(start)
END(MEMPCPY)
ENTRY(MEMMOVE_CHK)
cmp %RDX_LP, %RCX_LP
jb HIDDEN_JUMPTARGET(__chk_fail)
END(MEMMOVE_CHK)
ENTRY_P2ALIGN(MEMMOVE, 6)
movq %rdi, %rax
L(start):
cmpq $16, %rdx
jb L(copy_0_15)
/* These loads are always useful. */
movups 0(%rsi), %xmm0
movups -16(%rsi, %rdx), %xmm7
cmpq $32, %rdx
ja L(more_2x_vec)
movups %xmm0, 0(%rdi)
movups %xmm7, -16(%rdi, %rdx)
ret
.p2align 4,, 4
L(copy_0_15):
cmpl $4, %edx
jb L(copy_0_3)
cmpl $8, %edx
jb L(copy_4_7)
movq 0(%rsi), %rcx
movq -8(%rsi, %rdx), %rsi
movq %rcx, 0(%rdi)
movq %rsi, -8(%rdi, %rdx)
ret
.p2align 4,, 4
L(copy_4_7):
movl 0(%rsi), %ecx
movl -4(%rsi, %rdx), %esi
movl %ecx, 0(%rdi)
movl %esi, -4(%rdi, %rdx)
ret
.p2align 4,, 4
L(copy_0_3):
decl %edx
jl L(copy_0_0)
movb (%rsi), %cl
je L(copy_1_1)
movzwl -1(%rsi, %rdx), %esi
movw %si, -1(%rdi, %rdx)
L(copy_1_1):
movb %cl, (%rdi)
L(copy_0_0):
ret
.p2align 4,, 4
L(copy_4x_vec):
movups 16(%rsi), %xmm1
movups -32(%rsi, %rdx), %xmm2
movups %xmm0, 0(%rdi)
movups %xmm1, 16(%rdi)
movups %xmm2, -32(%rdi, %rdx)
movups %xmm7, -16(%rdi, %rdx)
L(nop):
ret
.p2align 4
L(more_2x_vec):
cmpq $64, %rdx
jbe L(copy_4x_vec)
/* We use rcx later to get alignr value. */
movq %rdi, %rcx
/* Backward copy for overlap + dst > src for memmove safety. */
subq %rsi, %rcx
cmpq %rdx, %rcx
jb L(copy_backward)
/* Load tail. */
/* -16(%rsi, %rdx) already loaded into xmm7. */
movups -32(%rsi, %rdx), %xmm8
movups -48(%rsi, %rdx), %xmm9
/* Get misalignment. */
andl $0xf, %ecx
movq %rsi, %r9
addq %rcx, %rsi
andq $-16, %rsi
/* Get first vec for `palignr`. */
movaps (%rsi), %xmm1
/* We have loaded (%rsi) so safe to do this store before the
loop. */
movups %xmm0, (%rdi)
#ifdef SHARED_CACHE_SIZE_HALF
cmp $SHARED_CACHE_SIZE_HALF, %RDX_LP
#else
cmp __x86_shared_cache_size_half(%rip), %rdx
#endif
ja L(large_memcpy)
leaq -64(%rdi, %rdx), %r8
andq $-16, %rdi
movl $48, %edx
leaq L(loop_fwd_start)(%rip), %r9
sall $6, %ecx
addq %r9, %rcx
jmp * %rcx
.p2align 4,, 8
L(copy_backward):
testq %rcx, %rcx
jz L(nop)
/* Preload tail. */
/* (%rsi) already loaded into xmm0. */
movups 16(%rsi), %xmm4
movups 32(%rsi), %xmm5
movq %rdi, %r8
subq %rdi, %rsi
leaq -49(%rdi, %rdx), %rdi
andq $-16, %rdi
addq %rdi, %rsi
andq $-16, %rsi
movaps 48(%rsi), %xmm6
leaq L(loop_bkwd_start)(%rip), %r9
andl $0xf, %ecx
sall $6, %ecx
addq %r9, %rcx
jmp * %rcx
.p2align 4,, 8
L(large_memcpy):
movups -64(%r9, %rdx), %xmm10
movups -80(%r9, %rdx), %xmm11
sall $5, %ecx
leal (%rcx, %rcx, 2), %r8d
leaq -96(%rdi, %rdx), %rcx
andq $-16, %rdi
leaq L(large_loop_fwd_start)(%rip), %rdx
addq %r8, %rdx
jmp * %rdx
/* Instead of a typical jump table all 16 loops are exactly
64-bytes in size. So, we can just jump to first loop + r8 *
64. Before modifying any loop ensure all their sizes match!
*/
.p2align 6
L(loop_fwd_start):
L(loop_fwd_0x0):
movaps 16(%rsi), %xmm1
movaps 32(%rsi), %xmm2
movaps 48(%rsi), %xmm3
movaps %xmm1, 16(%rdi)
movaps %xmm2, 32(%rdi)
movaps %xmm3, 48(%rdi)
addq %rdx, %rdi
addq %rdx, %rsi
cmpq %rdi, %r8
ja L(loop_fwd_0x0)
L(end_loop_fwd):
movups %xmm9, 16(%r8)
movups %xmm8, 32(%r8)
movups %xmm7, 48(%r8)
ret
/* Extactly 64 bytes if `jmp L(end_loop_fwd)` is long encoding.
60 bytes otherwise. */
#define ALIGNED_LOOP_FWD(align_by); \
.p2align 6; \
L(loop_fwd_ ## align_by): \
movaps 16(%rsi), %xmm0; \
movaps 32(%rsi), %xmm2; \
movaps 48(%rsi), %xmm3; \
movaps %xmm3, %xmm4; \
palignr $align_by, %xmm2, %xmm3; \
palignr $align_by, %xmm0, %xmm2; \
palignr $align_by, %xmm1, %xmm0; \
movaps %xmm4, %xmm1; \
movaps %xmm0, 16(%rdi); \
movaps %xmm2, 32(%rdi); \
movaps %xmm3, 48(%rdi); \
addq %rdx, %rdi; \
addq %rdx, %rsi; \
cmpq %rdi, %r8; \
ja L(loop_fwd_ ## align_by); \
jmp L(end_loop_fwd);
/* Must be in descending order. */
ALIGNED_LOOP_FWD (0xf)
ALIGNED_LOOP_FWD (0xe)
ALIGNED_LOOP_FWD (0xd)
ALIGNED_LOOP_FWD (0xc)
ALIGNED_LOOP_FWD (0xb)
ALIGNED_LOOP_FWD (0xa)
ALIGNED_LOOP_FWD (0x9)
ALIGNED_LOOP_FWD (0x8)
ALIGNED_LOOP_FWD (0x7)
ALIGNED_LOOP_FWD (0x6)
ALIGNED_LOOP_FWD (0x5)
ALIGNED_LOOP_FWD (0x4)
ALIGNED_LOOP_FWD (0x3)
ALIGNED_LOOP_FWD (0x2)
ALIGNED_LOOP_FWD (0x1)
.p2align 6
L(large_loop_fwd_start):
L(large_loop_fwd_0x0):
movaps 16(%rsi), %xmm1
movaps 32(%rsi), %xmm2
movaps 48(%rsi), %xmm3
movaps 64(%rsi), %xmm4
movaps 80(%rsi), %xmm5
movntps %xmm1, 16(%rdi)
movntps %xmm2, 32(%rdi)
movntps %xmm3, 48(%rdi)
movntps %xmm4, 64(%rdi)
movntps %xmm5, 80(%rdi)
addq $80, %rdi
addq $80, %rsi
cmpq %rdi, %rcx
ja L(large_loop_fwd_0x0)
/* Ensure no icache line split on tail. */
.p2align 4
L(end_large_loop_fwd):
sfence
movups %xmm11, 16(%rcx)
movups %xmm10, 32(%rcx)
movups %xmm9, 48(%rcx)
movups %xmm8, 64(%rcx)
movups %xmm7, 80(%rcx)
ret
/* Size > 64 bytes and <= 96 bytes. 32-byte align between ensure
96-byte spacing between each. */
#define ALIGNED_LARGE_LOOP_FWD(align_by); \
.p2align 5; \
L(large_loop_fwd_ ## align_by): \
movaps 16(%rsi), %xmm0; \
movaps 32(%rsi), %xmm2; \
movaps 48(%rsi), %xmm3; \
movaps 64(%rsi), %xmm4; \
movaps 80(%rsi), %xmm5; \
movaps %xmm5, %xmm6; \
palignr $align_by, %xmm4, %xmm5; \
palignr $align_by, %xmm3, %xmm4; \
palignr $align_by, %xmm2, %xmm3; \
palignr $align_by, %xmm0, %xmm2; \
palignr $align_by, %xmm1, %xmm0; \
movaps %xmm6, %xmm1; \
movntps %xmm0, 16(%rdi); \
movntps %xmm2, 32(%rdi); \
movntps %xmm3, 48(%rdi); \
movntps %xmm4, 64(%rdi); \
movntps %xmm5, 80(%rdi); \
addq $80, %rdi; \
addq $80, %rsi; \
cmpq %rdi, %rcx; \
ja L(large_loop_fwd_ ## align_by); \
jmp L(end_large_loop_fwd);
/* Must be in descending order. */
ALIGNED_LARGE_LOOP_FWD (0xf)
ALIGNED_LARGE_LOOP_FWD (0xe)
ALIGNED_LARGE_LOOP_FWD (0xd)
ALIGNED_LARGE_LOOP_FWD (0xc)
ALIGNED_LARGE_LOOP_FWD (0xb)
ALIGNED_LARGE_LOOP_FWD (0xa)
ALIGNED_LARGE_LOOP_FWD (0x9)
ALIGNED_LARGE_LOOP_FWD (0x8)
ALIGNED_LARGE_LOOP_FWD (0x7)
ALIGNED_LARGE_LOOP_FWD (0x6)
ALIGNED_LARGE_LOOP_FWD (0x5)
ALIGNED_LARGE_LOOP_FWD (0x4)
ALIGNED_LARGE_LOOP_FWD (0x3)
ALIGNED_LARGE_LOOP_FWD (0x2)
ALIGNED_LARGE_LOOP_FWD (0x1)
.p2align 6
L(loop_bkwd_start):
L(loop_bkwd_0x0):
movaps 32(%rsi), %xmm1
movaps 16(%rsi), %xmm2
movaps 0(%rsi), %xmm3
movaps %xmm1, 32(%rdi)
movaps %xmm2, 16(%rdi)
movaps %xmm3, 0(%rdi)
subq $48, %rdi
subq $48, %rsi
cmpq %rdi, %r8
jb L(loop_bkwd_0x0)
L(end_loop_bkwd):
movups %xmm7, -16(%r8, %rdx)
movups %xmm0, 0(%r8)
movups %xmm4, 16(%r8)
movups %xmm5, 32(%r8)
ret
/* Extactly 64 bytes if `jmp L(end_loop_bkwd)` is long encoding.
60 bytes otherwise. */
#define ALIGNED_LOOP_BKWD(align_by); \
.p2align 6; \
L(loop_bkwd_ ## align_by): \
movaps 32(%rsi), %xmm1; \
movaps 16(%rsi), %xmm2; \
movaps 0(%rsi), %xmm3; \
palignr $align_by, %xmm1, %xmm6; \
palignr $align_by, %xmm2, %xmm1; \
palignr $align_by, %xmm3, %xmm2; \
movaps %xmm6, 32(%rdi); \
movaps %xmm1, 16(%rdi); \
movaps %xmm2, 0(%rdi); \
subq $48, %rdi; \
subq $48, %rsi; \
movaps %xmm3, %xmm6; \
cmpq %rdi, %r8; \
jb L(loop_bkwd_ ## align_by); \
jmp L(end_loop_bkwd);
/* Must be in descending order. */
ALIGNED_LOOP_BKWD (0xf)
ALIGNED_LOOP_BKWD (0xe)
ALIGNED_LOOP_BKWD (0xd)
ALIGNED_LOOP_BKWD (0xc)
ALIGNED_LOOP_BKWD (0xb)
ALIGNED_LOOP_BKWD (0xa)
ALIGNED_LOOP_BKWD (0x9)
ALIGNED_LOOP_BKWD (0x8)
ALIGNED_LOOP_BKWD (0x7)
ALIGNED_LOOP_BKWD (0x6)
ALIGNED_LOOP_BKWD (0x5)
ALIGNED_LOOP_BKWD (0x4)
ALIGNED_LOOP_BKWD (0x3)
ALIGNED_LOOP_BKWD (0x2)
ALIGNED_LOOP_BKWD (0x1)
END(MEMMOVE)
strong_alias (MEMMOVE, MEMCPY)
strong_alias (MEMMOVE_CHK, MEMCPY_CHK)