llvm-project/llvm/test/Transforms/InstCombine/prefetch-load.ll

35 lines
1.3 KiB
LLVM

; RUN: opt < %s -instcombine -S | FileCheck %s
%struct.C = type { %struct.C*, i32 }
; Check that we instcombine the load across the prefetch.
; CHECK-LABEL: define signext i32 @foo
define signext i32 @foo(%struct.C* %c) local_unnamed_addr #0 {
; CHECK: store i32 %dec, i32* %length_
; CHECK-NOT: load
; CHECK: llvm.prefetch
; CHECK-NEXT: ret
entry:
%next_ = getelementptr inbounds %struct.C, %struct.C* %c, i32 0, i32 0
%0 = load %struct.C*, %struct.C** %next_, align 8
%next_1 = getelementptr inbounds %struct.C, %struct.C* %0, i32 0, i32 0
%1 = load %struct.C*, %struct.C** %next_1, align 8
store %struct.C* %1, %struct.C** %next_, align 8
%length_ = getelementptr inbounds %struct.C, %struct.C* %c, i32 0, i32 1
%2 = load i32, i32* %length_, align 8
%dec = add nsw i32 %2, -1
store i32 %dec, i32* %length_, align 8
%3 = bitcast %struct.C* %1 to i8*
call void @llvm.prefetch(i8* %3, i32 0, i32 0, i32 1)
%4 = load i32, i32* %length_, align 8
ret i32 %4
}
; Function Attrs: inaccessiblemem_or_argmemonly nounwind
declare void @llvm.prefetch(i8* nocapture readonly, i32, i32, i32)
attributes #0 = { noinline nounwind }
; We've explicitly removed the function attrs from llvm.prefetch so we get the defaults.
; attributes #1 = { inaccessiblemem_or_argmemonly nounwind }