forked from OSchip/llvm-project
53 lines
1.2 KiB
LLVM
53 lines
1.2 KiB
LLVM
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; RUN: llc -mtriple=x86_64-apple-macosx -O3 -debug-only=faultmaps -enable-implicit-null-checks < %s | FileCheck %s
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; List cases where we should *not* be emitting implicit null checks.
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; CHECK-NOT: Fault Map Output
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define i32 @imp_null_check_load(i32* %x, i32* %y) {
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entry:
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%c = icmp eq i32* %x, null
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; It isn't legal to move the load from %x from "not_null" to here --
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; the store to %y could be aliasing it.
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br i1 %c, label %is_null, label %not_null
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is_null:
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ret i32 42
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not_null:
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store i32 0, i32* %y
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%t = load i32, i32* %x
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ret i32 %t
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}
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define i32 @imp_null_check_gep_load(i32* %x) {
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entry:
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%c = icmp eq i32* %x, null
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br i1 %c, label %is_null, label %not_null
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is_null:
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ret i32 42
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not_null:
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; null + 5000 * sizeof(i32) lies outside the null page and hence the
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; load to %t cannot be assumed to be reliably faulting.
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%x.gep = getelementptr i32, i32* %x, i32 5000
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%t = load i32, i32* %x.gep
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ret i32 %t
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}
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define i32 @imp_null_check_load_no_md(i32* %x) {
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; Everything is okay except that the !never.executed metadata is
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; missing.
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entry:
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%c = icmp eq i32* %x, null
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br i1 %c, label %is_null, label %not_null
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is_null:
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ret i32 42
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not_null:
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%t = load i32, i32* %x
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ret i32 %t
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}
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