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target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64--linux"
@str = constant [6 x i8] c"foobar"
declare { ptr, i64, i64 } @runtime.stringToBytes(ptr, i64)
declare void @printSlice(ptr nocapture readonly, i64, i64)
declare void @writeToSlice(ptr nocapture, i64, i64)
; Test that runtime.stringToBytes can be fully optimized away.
define void @testReadOnly() {
entry:
%0 = call fastcc { ptr, i64, i64 } @runtime.stringToBytes(ptr @str, i64 6)
%1 = extractvalue { ptr, i64, i64 } %0, 0
%2 = extractvalue { ptr, i64, i64 } %0, 1
%3 = extractvalue { ptr, i64, i64 } %0, 2
call fastcc void @printSlice(ptr %1, i64 %2, i64 %3)
ret void
}
; Test that even though the slice is written to, some values can be propagated.
define void @testReadWrite() {
entry:
%0 = call fastcc { ptr, i64, i64 } @runtime.stringToBytes(ptr @str, i64 6)
%1 = extractvalue { ptr, i64, i64 } %0, 0
%2 = extractvalue { ptr, i64, i64 } %0, 1
%3 = extractvalue { ptr, i64, i64 } %0, 2
call fastcc void @writeToSlice(ptr %1, i64 %2, i64 %3)
ret void
}
; Test that pointer values are never propagated if there is even a single write
; to the pointer value (but len/cap values still can be).
define void @testReadSome() {
entry:
%s = call fastcc { ptr, i64, i64 } @runtime.stringToBytes(ptr @str, i64 6)
%s.ptr = extractvalue { ptr, i64, i64 } %s, 0
%s.len = extractvalue { ptr, i64, i64 } %s, 1
%s.cap = extractvalue { ptr, i64, i64 } %s, 2
call fastcc void @writeToSlice(ptr %s.ptr, i64 %s.len, i64 %s.cap)
%s.ptr2 = extractvalue { ptr, i64, i64 } %s, 0
%s.len2 = extractvalue { ptr, i64, i64 } %s, 1
%s.cap2 = extractvalue { ptr, i64, i64 } %s, 2
call fastcc void @printSlice(ptr %s.ptr2, i64 %s.len2, i64 %s.cap2)
ret void
}
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