304c7425d2
Brings the TEXT() function signature closer to how the directive works in assembly. Also update almost all examples to use NOSPLIT. Closes #11
sum
Sum a slice of uint64s.
func main() {
TEXT("Sum", "func(xs []uint64) uint64")
Doc("Sum returns the sum of the elements in xs.")
ptr := Load(Param("xs").Base(), GP64())
n := Load(Param("xs").Len(), GP64())
// Initialize sum register to zero.
s := GP64()
XORQ(s, s)
// Loop until zero bytes remain.
Label("loop")
CMPQ(n, Imm(0))
JE(LabelRef("done"))
// Load from pointer and add to running sum.
ADDQ(Mem{Base: ptr}, s)
// Advance pointer, decrement byte count.
ADDQ(Imm(8), ptr)
DECQ(n)
JMP(LabelRef("loop"))
// Store sum to return value.
Label("done")
Store(s, ReturnIndex(0))
RET()
Generate()
}