1 // Copyright 2023 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 //go:build !purego && (386 || amd64 || arm || arm64 || ppc64 || ppc64le || riscv64 || s390x) 6 7 package bigmod 8 9 import "internal/cpu" 10 11 // amd64 assembly uses ADCX/ADOX/MULX if ADX is available to run two carry 12 // chains in the flags in parallel across the whole operation, and aggressively 13 // unrolls loops. arm64 processes four words at a time. 14 // 15 // It's unclear why the assembly for all other architectures, as well as for 16 // amd64 without ADX, perform better than the compiler output. 17 // TODO(filippo): file cmd/compile performance issue. 18 19 var supportADX = cpu.X86.HasADX && cpu.X86.HasBMI2 20 21 //go:noescape 22 func addMulVVW1024(z, x *uint, y uint) (c uint) 23 24 //go:noescape 25 func addMulVVW1536(z, x *uint, y uint) (c uint) 26 27 //go:noescape 28 func addMulVVW2048(z, x *uint, y uint) (c uint) 29