| // Copyright 2018 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. |
| |
| // +build ppc64le ppc64 |
| |
| #include "go_asm.h" |
| #include "textflag.h" |
| |
| TEXT ·Count(SB), NOSPLIT|NOFRAME, $0-40 |
| MOVD b_base+0(FP), R3 // R3 = byte array pointer |
| MOVD b_len+8(FP), R4 // R4 = length |
| MOVBZ c+24(FP), R5 // R5 = byte |
| MOVD $ret+32(FP), R14 // R14 = &ret |
| BR countbytebody<>(SB) |
| |
| TEXT ·CountString(SB), NOSPLIT|NOFRAME, $0-32 |
| MOVD s_base+0(FP), R3 // R3 = string |
| MOVD s_len+8(FP), R4 // R4 = length |
| MOVBZ c+16(FP), R5 // R5 = byte |
| MOVD $ret+24(FP), R14 // R14 = &ret |
| BR countbytebody<>(SB) |
| |
| // R3: addr of string |
| // R4: len of string |
| // R5: byte to count |
| // R14: addr for return value |
| // endianness shouldn't matter since we are just counting and order |
| // is irrelevant |
| TEXT countbytebody<>(SB), NOSPLIT|NOFRAME, $0-0 |
| DCBT (R3) // Prepare cache line. |
| MOVD R0, R18 // byte count |
| MOVD R3, R19 // Save base address for calculating the index later. |
| MOVD R4, R16 |
| |
| MOVD R5, R6 |
| RLDIMI $8, R6, $48, R6 |
| RLDIMI $16, R6, $32, R6 |
| RLDIMI $32, R6, $0, R6 // fill reg with the byte to count |
| |
| VSPLTISW $3, V4 // used for shift |
| MTVRD R6, V1 // move compare byte |
| VSPLTB $7, V1, V1 // replicate byte across V1 |
| |
| CMPU R4, $32 // Check if it's a small string (<32 bytes) |
| BLT tail // Jump to the small string case |
| XXLXOR VS37, VS37, VS37 // clear V5 (aka VS37) to use as accumulator |
| |
| cmploop: |
| LXVW4X (R3), VS32 // load bytes from string |
| |
| // when the bytes match, the corresponding byte contains all 1s |
| VCMPEQUB V1, V0, V2 // compare bytes |
| VPOPCNTD V2, V3 // each double word contains its count |
| VADDUDM V3, V5, V5 // accumulate bit count in each double word |
| ADD $16, R3, R3 // increment pointer |
| SUB $16, R16, R16 // remaining bytes |
| CMP R16, $16 // at least 16 remaining? |
| BGE cmploop |
| VSRD V5, V4, V5 // shift by 3 to convert bits to bytes |
| VSLDOI $8, V5, V5, V6 // get the double word values from vector |
| MFVSRD V5, R9 |
| MFVSRD V6, R10 |
| ADD R9, R10, R9 |
| ADD R9, R18, R18 |
| |
| tail: |
| CMP R16, $8 // 8 bytes left? |
| BLT small |
| |
| MOVD (R3), R12 // load 8 bytes |
| CMPB R12, R6, R17 // compare bytes |
| POPCNTD R17, R15 // bit count |
| SRD $3, R15, R15 // byte count |
| ADD R15, R18, R18 // add to byte count |
| |
| next1: |
| ADD $8, R3, R3 |
| SUB $8, R16, R16 // remaining bytes |
| BR tail |
| |
| small: |
| CMP $0, R16 // any remaining |
| BEQ done |
| MOVBZ (R3), R12 // check each remaining byte |
| CMP R12, R5 |
| BNE next2 |
| ADD $1, R18 |
| |
| next2: |
| SUB $1, R16 |
| ADD $1, R3 // inc address |
| BR small |
| |
| done: |
| MOVD R18, (R14) // return count |
| RET |
