mozilla/rust — pull request #9656 by thestinger (2013-10-01 06:56:58+00:00)
Title: make small (<= size_of::<int>()) tuples immediate

fn foo() -> (u32, u8, u8, u8, u8) {
(4, 5, 6, 7, 8)
}

Before:

; Function Attrs: nounwind uwtable
define void @_ZN3foo18hbb616262f874f8daf4v0.0E({ i32, i8, i8, i8, i8 }* noalias nocapture sret, { i64, %tydesc*, i8*, i8*, i8 }* nocapture readnone) #0 {
"function top level":
%2 = getelementptr inbounds { i32, i8, i8, i8, i8 }* %0, i64 0, i32 0
store i32 4, i32* %2, align 4
%3 = getelementptr inbounds { i32, i8, i8, i8, i8 }* %0, i64 0, i32 1
store i8 5, i8* %3, align 4
%4 = getelementptr inbounds { i32, i8, i8, i8, i8 }* %0, i64 0, i32 2
store i8 6, i8* %4, align 1
%5 = getelementptr inbounds { i32, i8, i8, i8, i8 }* %0, i64 0, i32 3
store i8 7, i8* %5, align 2
%6 = getelementptr inbounds { i32, i8, i8, i8, i8 }* %0, i64 0, i32 4
store i8 8, i8* %6, align 1
ret void
}

After:

; Function Attrs: nounwind readnone uwtable
define { i32, i8, i8, i8, i8 } @_ZN3foo18hbb616262f874f8daf4v0.0E({ i64, %tydesc*, i8*, i8*, i8 }* nocapture readnone) #0 {
"function top level":
ret { i32, i8, i8, i8, i8 } { i32 4, i8 5, i8 6, i8 7, i8 8 }
}