llvm/test/Transforms/ArgumentPromotion/byval.ll
Chris Lattner 10603e0c84 Teach argpromote to ruthlessly hack small byval structs when it can
get away with it, which exposes opportunities to eliminate the memory
objects entirely.  For example, we now compile byval.ll to:

define internal void @f1(i32 %b.0, i64 %b.1) {
entry:
	%tmp2 = add i32 %b.0, 1		; <i32> [#uses=0]
	ret void
}

define i32 @main() nounwind  {
entry:
	call void @f1( i32 1, i64 2 )
	ret i32 0
}

This seems like it would trigger a lot for code that passes around small
structs (e.g. SDOperand's or _Complex)...



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45886 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-11 22:31:41 +00:00

25 lines
843 B
LLVM

; RUN: llvm-as < %s | opt -argpromotion -scalarrepl | llvm-dis | not grep load
; Argpromote + scalarrepl should change this to passing the two integers by value.
%struct.ss = type { i32, i64 }
define internal void @f(%struct.ss* byval %b) nounwind {
entry:
%tmp = getelementptr %struct.ss* %b, i32 0, i32 0 ; <i32*> [#uses=2]
%tmp1 = load i32* %tmp, align 4 ; <i32> [#uses=1]
%tmp2 = add i32 %tmp1, 1 ; <i32> [#uses=1]
store i32 %tmp2, i32* %tmp, align 4
ret void
}
define i32 @main() nounwind {
entry:
%S = alloca %struct.ss ; <%struct.ss*> [#uses=4]
%tmp1 = getelementptr %struct.ss* %S, i32 0, i32 0 ; <i32*> [#uses=1]
store i32 1, i32* %tmp1, align 8
%tmp4 = getelementptr %struct.ss* %S, i32 0, i32 1 ; <i64*> [#uses=1]
store i64 2, i64* %tmp4, align 4
call void @f( %struct.ss* byval %S ) nounwind
ret i32 0
}