| /* |
| * SPDX-License-Identifier: GPL-2.0-or-later |
| * buffer_is_zero acceleration, loongarch64 version. |
| */ |
| |
| /* |
| * Builtins for LSX and LASX are introduced by gcc 14 and llvm 18, |
| * but as yet neither has support for attribute target, so neither |
| * is able to enable the optimization without globally enabling |
| * vector support. Since we want runtime detection, use assembly. |
| */ |
| |
| static bool buffer_is_zero_lsx(const void *buf, size_t len) |
| { |
| const void *p = QEMU_ALIGN_PTR_DOWN(buf + 16, 16); |
| const void *e = QEMU_ALIGN_PTR_DOWN(buf + len - 1, 16) - (7 * 16); |
| const void *l = buf + len; |
| bool ret; |
| |
| asm("vld $vr0,%2,0\n\t" /* first: buf + 0 */ |
| "vld $vr1,%4,-16\n\t" /* last: buf + len - 16 */ |
| "vld $vr2,%3,0\n\t" /* e[0] */ |
| "vld $vr3,%3,16\n\t" /* e[1] */ |
| "vld $vr4,%3,32\n\t" /* e[2] */ |
| "vld $vr5,%3,48\n\t" /* e[3] */ |
| "vld $vr6,%3,64\n\t" /* e[4] */ |
| "vld $vr7,%3,80\n\t" /* e[5] */ |
| "vld $vr8,%3,96\n\t" /* e[6] */ |
| "vor.v $vr0,$vr0,$vr1\n\t" |
| "vor.v $vr2,$vr2,$vr3\n\t" |
| "vor.v $vr4,$vr4,$vr5\n\t" |
| "vor.v $vr6,$vr6,$vr7\n\t" |
| "vor.v $vr0,$vr0,$vr2\n\t" |
| "vor.v $vr4,$vr4,$vr6\n\t" |
| "vor.v $vr0,$vr0,$vr4\n\t" |
| "vor.v $vr0,$vr0,$vr8\n\t" |
| "or %0,$r0,$r0\n" /* prepare return false */ |
| "1:\n\t" |
| "vsetnez.v $fcc0,$vr0\n\t" |
| "bcnez $fcc0,2f\n\t" |
| "vld $vr0,%1,0\n\t" /* p[0] */ |
| "vld $vr1,%1,16\n\t" /* p[1] */ |
| "vld $vr2,%1,32\n\t" /* p[2] */ |
| "vld $vr3,%1,48\n\t" /* p[3] */ |
| "vld $vr4,%1,64\n\t" /* p[4] */ |
| "vld $vr5,%1,80\n\t" /* p[5] */ |
| "vld $vr6,%1,96\n\t" /* p[6] */ |
| "vld $vr7,%1,112\n\t" /* p[7] */ |
| "addi.d %1,%1,128\n\t" |
| "vor.v $vr0,$vr0,$vr1\n\t" |
| "vor.v $vr2,$vr2,$vr3\n\t" |
| "vor.v $vr4,$vr4,$vr5\n\t" |
| "vor.v $vr6,$vr6,$vr7\n\t" |
| "vor.v $vr0,$vr0,$vr2\n\t" |
| "vor.v $vr4,$vr4,$vr6\n\t" |
| "vor.v $vr0,$vr0,$vr4\n\t" |
| "bltu %1,%3,1b\n\t" |
| "vsetnez.v $fcc0,$vr0\n\t" |
| "bcnez $fcc0,2f\n\t" |
| "ori %0,$r0,1\n" |
| "2:" |
| : "=&r"(ret), "+r"(p) |
| : "r"(buf), "r"(e), "r"(l) |
| : "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", "f8", "fcc0"); |
| |
| return ret; |
| } |
| |
| static bool buffer_is_zero_lasx(const void *buf, size_t len) |
| { |
| const void *p = QEMU_ALIGN_PTR_DOWN(buf + 32, 32); |
| const void *e = QEMU_ALIGN_PTR_DOWN(buf + len - 1, 32) - (7 * 32); |
| const void *l = buf + len; |
| bool ret; |
| |
| asm("xvld $xr0,%2,0\n\t" /* first: buf + 0 */ |
| "xvld $xr1,%4,-32\n\t" /* last: buf + len - 32 */ |
| "xvld $xr2,%3,0\n\t" /* e[0] */ |
| "xvld $xr3,%3,32\n\t" /* e[1] */ |
| "xvld $xr4,%3,64\n\t" /* e[2] */ |
| "xvld $xr5,%3,96\n\t" /* e[3] */ |
| "xvld $xr6,%3,128\n\t" /* e[4] */ |
| "xvld $xr7,%3,160\n\t" /* e[5] */ |
| "xvld $xr8,%3,192\n\t" /* e[6] */ |
| "xvor.v $xr0,$xr0,$xr1\n\t" |
| "xvor.v $xr2,$xr2,$xr3\n\t" |
| "xvor.v $xr4,$xr4,$xr5\n\t" |
| "xvor.v $xr6,$xr6,$xr7\n\t" |
| "xvor.v $xr0,$xr0,$xr2\n\t" |
| "xvor.v $xr4,$xr4,$xr6\n\t" |
| "xvor.v $xr0,$xr0,$xr4\n\t" |
| "xvor.v $xr0,$xr0,$xr8\n\t" |
| "or %0,$r0,$r0\n\t" /* prepare return false */ |
| "bgeu %1,%3,2f\n" |
| "1:\n\t" |
| "xvsetnez.v $fcc0,$xr0\n\t" |
| "bcnez $fcc0,3f\n\t" |
| "xvld $xr0,%1,0\n\t" /* p[0] */ |
| "xvld $xr1,%1,32\n\t" /* p[1] */ |
| "xvld $xr2,%1,64\n\t" /* p[2] */ |
| "xvld $xr3,%1,96\n\t" /* p[3] */ |
| "xvld $xr4,%1,128\n\t" /* p[4] */ |
| "xvld $xr5,%1,160\n\t" /* p[5] */ |
| "xvld $xr6,%1,192\n\t" /* p[6] */ |
| "xvld $xr7,%1,224\n\t" /* p[7] */ |
| "addi.d %1,%1,256\n\t" |
| "xvor.v $xr0,$xr0,$xr1\n\t" |
| "xvor.v $xr2,$xr2,$xr3\n\t" |
| "xvor.v $xr4,$xr4,$xr5\n\t" |
| "xvor.v $xr6,$xr6,$xr7\n\t" |
| "xvor.v $xr0,$xr0,$xr2\n\t" |
| "xvor.v $xr4,$xr4,$xr6\n\t" |
| "xvor.v $xr0,$xr0,$xr4\n\t" |
| "bltu %1,%3,1b\n" |
| "2:\n\t" |
| "xvsetnez.v $fcc0,$xr0\n\t" |
| "bcnez $fcc0,3f\n\t" |
| "ori %0,$r0,1\n" |
| "3:" |
| : "=&r"(ret), "+r"(p) |
| : "r"(buf), "r"(e), "r"(l) |
| : "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", "f8", "fcc0"); |
| |
| return ret; |
| } |
| |
| static biz_accel_fn const accel_table[] = { |
| buffer_is_zero_int_ge256, |
| buffer_is_zero_lsx, |
| buffer_is_zero_lasx, |
| }; |
| |
| static unsigned best_accel(void) |
| { |
| unsigned info = cpuinfo_init(); |
| if (info & CPUINFO_LASX) { |
| return 2; |
| } |
| if (info & CPUINFO_LSX) { |
| return 1; |
| } |
| return 0; |
| } |
