35 lines
1.7 KiB
LLVM
35 lines
1.7 KiB
LLVM
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -S -passes=memcpyopt -verify-memoryssa | FileCheck %s
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target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
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declare void @llvm.memcpy.p0.p0.i64(ptr nocapture, ptr nocapture readonly, i64, i1) unnamed_addr nounwind
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declare void @llvm.memset.p0.i64(ptr nocapture, i8, i64, i1) nounwind
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; all bytes of %dst that are touch by the memset are dereferenceable
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define void @must_remove_memcpy(ptr noalias nocapture writable dereferenceable(4096) %dst) nofree nosync {
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; CHECK-LABEL: @must_remove_memcpy(
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; CHECK-NEXT: [[SRC:%.*]] = alloca [4096 x i8], align 1
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; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr [[DST:%.*]], i8 0, i64 4096, i1 false)
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; CHECK-NEXT: ret void
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;
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%src = alloca [4096 x i8], align 1
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call void @llvm.memset.p0.i64(ptr %src, i8 0, i64 4096, i1 false)
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call void @llvm.memcpy.p0.p0.i64(ptr %dst, ptr %src, i64 4096, i1 false) #2
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ret void
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}
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; memset touch more bytes than those guaranteed to be dereferenceable
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; We can't remove the memcpy, but we can turn it into an independent memset.
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define void @must_not_remove_memcpy(ptr noalias nocapture writable dereferenceable(1024) %dst) nofree nosync {
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; CHECK-LABEL: @must_not_remove_memcpy(
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; CHECK-NEXT: [[SRC:%.*]] = alloca [4096 x i8], align 1
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; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr [[SRC]], i8 0, i64 4096, i1 false)
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; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr [[DST:%.*]], i8 0, i64 4096, i1 false)
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; CHECK-NEXT: ret void
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;
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%src = alloca [4096 x i8], align 1
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call void @llvm.memset.p0.i64(ptr %src, i8 0, i64 4096, i1 false)
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call void @llvm.memcpy.p0.p0.i64(ptr %dst, ptr %src, i64 4096, i1 false) #2
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ret void
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}
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