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// 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.
//go:build ppc64 || ppc64le
#include "go_asm.h"
#include "textflag.h"
TEXT ·Compare<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-56
// incoming:
// R3 a addr -> R5
// R4 a len -> R3
// R5 a cap unused
// R6 b addr -> R6
// R7 b len -> R4
// R8 b cap unused
MOVD R3, R5
MOVD R4, R3
MOVD R7, R4
CMP R5,R6,CR7
CMP R3,R4,CR6
BEQ CR7,equal
#ifdef GOARCH_ppc64le
BR cmpbodyLE<>(SB)
#else
BR cmpbodyBE<>(SB)
#endif
equal:
BEQ CR6,done
MOVD $1, R8
BGT CR6,greater
NEG R8
greater:
MOVD R8, R3
RET
done:
MOVD $0, R3
RET
TEXT runtime·cmpstring<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-40
// incoming:
// R3 a addr -> R5
// R4 a len -> R3
// R5 b addr -> R6
// R6 b len -> R4
MOVD R6, R7
MOVD R5, R6
MOVD R3, R5
MOVD R4, R3
MOVD R7, R4
CMP R5,R6,CR7
CMP R3,R4,CR6
BEQ CR7,equal
#ifdef GOARCH_ppc64le
BR cmpbodyLE<>(SB)
#else
BR cmpbodyBE<>(SB)
#endif
equal:
BEQ CR6,done
MOVD $1, R8
BGT CR6,greater
NEG R8
greater:
MOVD R8, R3
RET
done:
MOVD $0, R3
RET
// Do an efficient memcmp for ppc64le
// R3 = a len
// R4 = b len
// R5 = a addr
// R6 = b addr
// On exit:
// R3 = return value
TEXT cmpbodyLE<>(SB),NOSPLIT|NOFRAME,$0-0
MOVD R3,R8 // set up length
CMP R3,R4,CR2 // unequal?
BC 12,8,setuplen // BLT CR2
MOVD R4,R8 // use R4 for comparison len
setuplen:
MOVD R8,CTR // set up loop counter
CMP R8,$8 // only optimize >=8
BLT simplecheck
DCBT (R5) // cache hint
DCBT (R6)
CMP R8,$32 // optimize >= 32
MOVD R8,R9
BLT setup8a // 8 byte moves only
setup32a:
SRADCC $5,R8,R9 // number of 32 byte chunks
MOVD R9,CTR
// Special processing for 32 bytes or longer.
// Loading this way is faster and correct as long as the
// doublewords being compared are equal. Once they
// are found unequal, reload them in proper byte order
// to determine greater or less than.
loop32a:
MOVD 0(R5),R9 // doublewords to compare
MOVD 0(R6),R10 // get 4 doublewords
MOVD 8(R5),R14
MOVD 8(R6),R15
CMPU R9,R10 // bytes equal?
MOVD $0,R16 // set up for cmpne
BNE cmpne // further compare for LT or GT
MOVD 16(R5),R9 // get next pair of doublewords
MOVD 16(R6),R10
CMPU R14,R15 // bytes match?
MOVD $8,R16 // set up for cmpne
BNE cmpne // further compare for LT or GT
MOVD 24(R5),R14 // get next pair of doublewords
MOVD 24(R6),R15
CMPU R9,R10 // bytes match?
MOVD $16,R16 // set up for cmpne
BNE cmpne // further compare for LT or GT
MOVD $-8,R16 // for cmpne, R5,R6 already inc by 32
ADD $32,R5 // bump up to next 32
ADD $32,R6
CMPU R14,R15 // bytes match?
BC 8,2,loop32a // br ctr and cr
BNE cmpne
ANDCC $24,R8,R9 // Any 8 byte chunks?
BEQ leftover // and result is 0
setup8a:
SRADCC $3,R9,R9 // get the 8 byte count
BEQ leftover // shifted value is 0
MOVD R9,CTR // loop count for doublewords
loop8:
MOVDBR (R5+R0),R9 // doublewords to compare
MOVDBR (R6+R0),R10 // LE compare order
ADD $8,R5
ADD $8,R6
CMPU R9,R10 // match?
BC 8,2,loop8 // bt ctr <> 0 && cr
BGT greater
BLT less
leftover:
ANDCC $7,R8,R9 // check for leftover bytes
MOVD R9,CTR // save the ctr
BNE simple // leftover bytes
BC 12,10,equal // test CR2 for length comparison
BC 12,8,less
BR greater
simplecheck:
CMP R8,$0 // remaining compare length 0
BNE simple // do simple compare
BC 12,10,equal // test CR2 for length comparison
BC 12,8,less // 1st len < 2nd len, result less
BR greater // 1st len > 2nd len must be greater
simple:
MOVBZ 0(R5), R9 // get byte from 1st operand
ADD $1,R5
MOVBZ 0(R6), R10 // get byte from 2nd operand
ADD $1,R6
CMPU R9, R10
BC 8,2,simple // bc ctr <> 0 && cr
BGT greater // 1st > 2nd
BLT less // 1st < 2nd
BC 12,10,equal // test CR2 for length comparison
BC 12,9,greater // 2nd len > 1st len
BR less // must be less
cmpne: // only here is not equal
MOVDBR (R5+R16),R8 // reload in reverse order
MOVDBR (R6+R16),R9
CMPU R8,R9 // compare correct endianness
BGT greater // here only if NE
less:
MOVD $-1, R3 // return value if A < B
RET
equal:
MOVD $0, R3 // return value if A == B
RET
greater:
MOVD $1, R3 // return value if A > B
RET
// Do an efficient memcmp for ppc64 (BE)
// R3 = a len
// R4 = b len
// R5 = a addr
// R6 = b addr
// On exit:
// R3 = return value
TEXT cmpbodyBE<>(SB),NOSPLIT|NOFRAME,$0-0
MOVD R3,R8 // set up length
CMP R3,R4,CR2 // unequal?
BC 12,8,setuplen // BLT CR2
MOVD R4,R8 // use R4 for comparison len
setuplen:
MOVD R8,CTR // set up loop counter
CMP R8,$8 // only optimize >=8
BLT simplecheck
DCBT (R5) // cache hint
DCBT (R6)
CMP R8,$32 // optimize >= 32
MOVD R8,R9
BLT setup8a // 8 byte moves only
setup32a:
SRADCC $5,R8,R9 // number of 32 byte chunks
MOVD R9,CTR
loop32a:
MOVD 0(R5),R9 // doublewords to compare
MOVD 0(R6),R10 // get 4 doublewords
MOVD 8(R5),R14
MOVD 8(R6),R15
CMPU R9,R10 // bytes equal?
BLT less // found to be less
BGT greater // found to be greater
MOVD 16(R5),R9 // get next pair of doublewords
MOVD 16(R6),R10
CMPU R14,R15 // bytes match?
BLT less // found less
BGT greater // found greater
MOVD 24(R5),R14 // get next pair of doublewords
MOVD 24(R6),R15
CMPU R9,R10 // bytes match?
BLT less // found to be less
BGT greater // found to be greater
ADD $32,R5 // bump up to next 32
ADD $32,R6
CMPU R14,R15 // bytes match?
BC 8,2,loop32a // br ctr and cr
BLT less // with BE, byte ordering is
BGT greater // good for compare
ANDCC $24,R8,R9 // Any 8 byte chunks?
BEQ leftover // and result is 0
setup8a:
SRADCC $3,R9,R9 // get the 8 byte count
BEQ leftover // shifted value is 0
MOVD R9,CTR // loop count for doublewords
loop8:
MOVD (R5),R9
MOVD (R6),R10
ADD $8,R5
ADD $8,R6
CMPU R9,R10 // match?
BC 8,2,loop8 // bt ctr <> 0 && cr
BGT greater
BLT less
leftover:
ANDCC $7,R8,R9 // check for leftover bytes
MOVD R9,CTR // save the ctr
BNE simple // leftover bytes
BC 12,10,equal // test CR2 for length comparison
BC 12,8,less
BR greater
simplecheck:
CMP R8,$0 // remaining compare length 0
BNE simple // do simple compare
BC 12,10,equal // test CR2 for length comparison
BC 12,8,less // 1st len < 2nd len, result less
BR greater // same len, must be equal
simple:
MOVBZ 0(R5),R9 // get byte from 1st operand
ADD $1,R5
MOVBZ 0(R6),R10 // get byte from 2nd operand
ADD $1,R6
CMPU R9,R10
BC 8,2,simple // bc ctr <> 0 && cr
BGT greater // 1st > 2nd
BLT less // 1st < 2nd
BC 12,10,equal // test CR2 for length comparison
BC 12,9,greater // 2nd len > 1st len
less:
MOVD $-1, R3 // return value if A < B
RET
equal:
MOVD $0, R3 // return value if A == B
RET
greater:
MOVD $1, R3 // return value if A > B
RET
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