83 lines
2.1 KiB
LLVM
83 lines
2.1 KiB
LLVM
; RUN: opt -S -licm < %s | FileCheck %s
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; Note: the !invariant.load is there just solely to let us call @use()
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; to add a fake use, and still have the aliasing work out. The call
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; to @use(0) is just to provide a may-unwind exit out of the loop, so
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; that LICM cannot hoist out the load simply because it is guaranteed
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; to execute.
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declare void @use(i32)
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define void @f_0(i8* align 4 dereferenceable(1024) %ptr) {
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; CHECK-LABEL: @f_0(
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; CHECK: entry:
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; CHECK: %val = load i32, i32* %ptr.i32
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; CHECK: br label %loop
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; CHECK: loop:
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; CHECK: call void @use(i32 0)
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; CHECK-NEXT: call void @use(i32 %val)
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entry:
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%ptr.gep = getelementptr i8, i8* %ptr, i32 32
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%ptr.i32 = bitcast i8* %ptr.gep to i32*
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br label %loop
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loop:
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call void @use(i32 0)
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%val = load i32, i32* %ptr.i32, !invariant.load !{}
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call void @use(i32 %val)
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br label %loop
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}
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define void @f_1(i8* align 4 dereferenceable_or_null(1024) %ptr) {
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; CHECK-LABEL: @f_1(
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entry:
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%ptr.gep = getelementptr i8, i8* %ptr, i32 32
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%ptr.i32 = bitcast i8* %ptr.gep to i32*
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%ptr_is_null = icmp eq i8* %ptr, null
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br i1 %ptr_is_null, label %leave, label %loop
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; CHECK: loop.preheader:
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; CHECK: %val = load i32, i32* %ptr.i32
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; CHECK: br label %loop
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; CHECK: loop:
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; CHECK: call void @use(i32 0)
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; CHECK-NEXT: call void @use(i32 %val)
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loop:
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call void @use(i32 0)
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%val = load i32, i32* %ptr.i32, !invariant.load !{}
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call void @use(i32 %val)
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br label %loop
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leave:
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ret void
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}
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define void @f_2(i8* align 4 dereferenceable_or_null(1024) %ptr) {
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; CHECK-LABEL: @f_2(
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; CHECK-NOT: load
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; CHECK: call void @use(i32 0)
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; CHECK-NEXT: %val = load i32, i32* %ptr.i32, !invariant.load !0
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; CHECK-NEXT: call void @use(i32 %val)
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entry:
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;; Can't hoist, since the alignment does not work out -- (<4 byte
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;; aligned> + 30) is not necessarily 4 byte aligned.
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%ptr.gep = getelementptr i8, i8* %ptr, i32 30
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%ptr.i32 = bitcast i8* %ptr.gep to i32*
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%ptr_is_null = icmp eq i8* %ptr, null
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br i1 %ptr_is_null, label %leave, label %loop
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loop:
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call void @use(i32 0)
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%val = load i32, i32* %ptr.i32, !invariant.load !{}
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call void @use(i32 %val)
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br label %loop
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leave:
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ret void
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}
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