27 lines
527 B
Markdown
27 lines
527 B
Markdown
# sum
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Sum a slice of `uint64`s.
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[embedmd]:# (asm.go go /func main/ /^}/)
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```go
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func main() {
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TEXT("Sum", "func(xs []uint64) uint64")
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Doc("Sum returns the sum of the elements in xs.")
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ptr := Load(Param("xs").Base(), GP64())
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n := Load(Param("xs").Len(), GP64())
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s := GP64()
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XORQ(s, s)
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LABEL("loop")
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CMPQ(n, operand.Imm(0))
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JE(operand.LabelRef("done"))
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ADDQ(operand.Mem{Base: ptr}, s)
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ADDQ(operand.Imm(8), ptr)
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DECQ(n)
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JMP(operand.LabelRef("loop"))
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LABEL("done")
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Store(s, ReturnIndex(0))
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RET()
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Generate()
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}
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```
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