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Diffstat (limited to '')
| -rw-r--r-- | src/runtime/memclr_ppc64x.s | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/runtime/memclr_ppc64x.s b/src/runtime/memclr_ppc64x.s new file mode 100644 index 0000000..64132ce --- /dev/null +++ b/src/runtime/memclr_ppc64x.s @@ -0,0 +1,167 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build ppc64 || ppc64le + +#include "textflag.h" + +// See memclrNoHeapPointers Go doc for important implementation constraints. + +// func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr) +TEXT runtime·memclrNoHeapPointers<ABIInternal>(SB), NOSPLIT|NOFRAME, $0-16 +#ifndef GOEXPERIMENT_regabiargs + MOVD ptr+0(FP), R3 + MOVD n+8(FP), R4 +#endif + + // Determine if there are doublewords to clear +check: + ANDCC $7, R4, R5 // R5: leftover bytes to clear + SRD $3, R4, R6 // R6: double words to clear + CMP R6, $0, CR1 // CR1[EQ] set if no double words + + BC 12, 6, nozerolarge // only single bytes + CMP R4, $512 + BLT under512 // special case for < 512 + ANDCC $127, R3, R8 // check for 128 alignment of address + BEQ zero512setup + + ANDCC $7, R3, R15 + BEQ zero512xsetup // at least 8 byte aligned + + // zero bytes up to 8 byte alignment + + ANDCC $1, R3, R15 // check for byte alignment + BEQ byte2 + MOVB R0, 0(R3) // zero 1 byte + ADD $1, R3 // bump ptr by 1 + ADD $-1, R4 + +byte2: + ANDCC $2, R3, R15 // check for 2 byte alignment + BEQ byte4 + MOVH R0, 0(R3) // zero 2 bytes + ADD $2, R3 // bump ptr by 2 + ADD $-2, R4 + +byte4: + ANDCC $4, R3, R15 // check for 4 byte alignment + BEQ zero512xsetup + MOVW R0, 0(R3) // zero 4 bytes + ADD $4, R3 // bump ptr by 4 + ADD $-4, R4 + BR zero512xsetup // ptr should now be 8 byte aligned + +under512: + MOVD R6, CTR // R6 = number of double words + SRDCC $2, R6, R7 // 32 byte chunks? + BNE zero32setup + + // Clear double words + +zero8: + MOVD R0, 0(R3) // double word + ADD $8, R3 + ADD $-8, R4 + BC 16, 0, zero8 // dec ctr, br zero8 if ctr not 0 + BR nozerolarge // handle leftovers + + // Prepare to clear 32 bytes at a time. + +zero32setup: + DCBTST (R3) // prepare data cache + XXLXOR VS32, VS32, VS32 // clear VS32 (V0) + MOVD R7, CTR // number of 32 byte chunks + MOVD $16, R8 + +zero32: + STXVD2X VS32, (R3+R0) // store 16 bytes + STXVD2X VS32, (R3+R8) + ADD $32, R3 + ADD $-32, R4 + BC 16, 0, zero32 // dec ctr, br zero32 if ctr not 0 + RLDCLCC $61, R4, $3, R6 // remaining doublewords + BEQ nozerolarge + MOVD R6, CTR // set up the CTR for doublewords + BR zero8 + +nozerolarge: + ANDCC $7, R4, R5 // any remaining bytes + BC 4, 1, LR // ble lr + +zerotail: + MOVD R5, CTR // set up to clear tail bytes + +zerotailloop: + MOVB R0, 0(R3) // clear single bytes + ADD $1, R3 + BC 16, 0, zerotailloop // dec ctr, br zerotailloop if ctr not 0 + RET + +zero512xsetup: // 512 chunk with extra needed + ANDCC $8, R3, R11 // 8 byte alignment? + BEQ zero512setup16 + MOVD R0, 0(R3) // clear 8 bytes + ADD $8, R3 // update ptr to next 8 + ADD $-8, R4 // dec count by 8 + +zero512setup16: + ANDCC $127, R3, R14 // < 128 byte alignment + BEQ zero512setup // handle 128 byte alignment + MOVD $128, R15 + SUB R14, R15, R14 // find increment to 128 alignment + SRD $4, R14, R15 // number of 16 byte chunks + +zero512presetup: + MOVD R15, CTR // loop counter of 16 bytes + XXLXOR VS32, VS32, VS32 // clear VS32 (V0) + +zero512preloop: // clear up to 128 alignment + STXVD2X VS32, (R3+R0) // clear 16 bytes + ADD $16, R3 // update ptr + ADD $-16, R4 // dec count + BC 16, 0, zero512preloop + +zero512setup: // setup for dcbz loop + CMP R4, $512 // check if at least 512 + BLT remain + SRD $9, R4, R8 // loop count for 512 chunks + MOVD R8, CTR // set up counter + MOVD $128, R9 // index regs for 128 bytes + MOVD $256, R10 + MOVD $384, R11 + +zero512: + DCBZ (R3+R0) // clear first chunk + DCBZ (R3+R9) // clear second chunk + DCBZ (R3+R10) // clear third chunk + DCBZ (R3+R11) // clear fourth chunk + ADD $512, R3 + ADD $-512, R4 + BC 16, 0, zero512 + +remain: + CMP R4, $128 // check if 128 byte chunks left + BLT smaller + DCBZ (R3+R0) // clear 128 + ADD $128, R3 + ADD $-128, R4 + BR remain + +smaller: + ANDCC $127, R4, R7 // find leftovers + BEQ done + CMP R7, $64 // more than 64, do 32 at a time + BLT zero8setup // less than 64, do 8 at a time + SRD $5, R7, R7 // set up counter for 32 + BR zero32setup + +zero8setup: + SRDCC $3, R7, R7 // less than 8 bytes + BEQ nozerolarge + MOVD R7, CTR + BR zero8 + +done: + RET |