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ce69666273
There's no need for the 16-bit arithmetic here, and it tickles a long-standing compiler bug. Fix the exp code not to use 16-bit math and create an explicit test for the compiler bug. R=golang-dev, r CC=golang-dev https://golang.org/cl/6256048
22 lines
616 B
Go
22 lines
616 B
Go
// $G $D/$F.go && $L $F.$A && ./$A.out
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// # switch above to 'run' when bug gets fixed.
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// # right now it only breaks on 8g
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// Test for 8g register move bug. The optimizer gets confused
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// about 16- vs 32-bit moves during splitContractIndex.
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package main
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func main() {
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const c = 0x12345678
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index, n, offset := splitContractIndex(c)
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if index != int((c&0xffff)>>5) || n != int(c & (1<<5-1)) || offset != (c>>16)&(1<<14-1) {
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println("BUG", index, n, offset)
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}
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}
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func splitContractIndex(ce uint32) (index, n, offset int) {
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h := uint16(ce)
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return int(h >> 5), int(h & (1<<5 - 1)), int(ce>>16) & (1<<14 - 1)
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}
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