1469d82e1c
As defined in LangRef, branching on `undef` is undefined behavior. This PR aims to remove undefined behavior from tests. As UB tests break Alive2 and may be the root cause of breaking future optimizations. Here's an Alive2 proof for one of the examples: https://alive2.llvm.org/ce/z/TncxhP
73 lines
2.3 KiB
LLVM
73 lines
2.3 KiB
LLVM
; RUN: opt -debug-pass-manager -aa-pipeline=basic-aa -passes='require<phi-values>,memcpyopt,instcombine' -disable-output < %s 2>&1 | FileCheck %s
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; Check that phi values is not run when it's not already available, and that
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; basicaa is not freed after a pass that preserves CFG, as it preserves CFG.
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; CHECK-DAG: Running analysis: PhiValuesAnalysis
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; CHECK-DAG: Running analysis: BasicAA
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; CHECK-DAG: Running analysis: MemorySSA
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; CHECK: Running pass: MemCpyOptPass
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; CHECK-NOT: Invalidating analysis
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; CHECK: Running pass: InstCombinePass
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target datalayout = "p:8:8-n8"
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declare void @otherfn(ptr)
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declare i32 @__gxx_personality_v0(...)
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declare void @llvm.lifetime.end.p0(i64, ptr nocapture)
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@c = external global ptr, align 1
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; This function is one where if we didn't free basicaa after memcpyopt then the
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; usage of basicaa in instcombine would cause a segfault due to stale phi-values
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; results being used.
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define void @fn(ptr %this, ptr %ptr, i1 %arg) personality ptr @__gxx_personality_v0 {
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entry:
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%arr = alloca [4 x i8], align 8
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br i1 %arg, label %then, label %if
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if:
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br label %then
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then:
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%phi = phi ptr [ %ptr, %if ], [ null, %entry ]
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store i8 1, ptr %arr, align 8
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%load = load i64, ptr %phi, align 8
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%gep2 = getelementptr inbounds i8, ptr undef, i64 %load
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%gep3 = getelementptr inbounds i8, ptr %gep2, i64 40
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invoke i32 undef(ptr undef)
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to label %invoke unwind label %lpad
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invoke:
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unreachable
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lpad:
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landingpad { ptr, i32 }
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catch ptr null
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call void @otherfn(ptr nonnull %arr)
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unreachable
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}
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; When running instcombine after memdep, the basicaa used by instcombine uses
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; the phivalues that memdep used. This would then cause a segfault due to
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; instcombine deleting a phi whose values had been cached.
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define void @fn2(i1 %arg) {
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entry:
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%a = alloca i8, align 1
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%0 = load ptr, ptr @c, align 1
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br label %for.cond
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for.cond: ; preds = %for.body, %entry
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%d.0 = phi ptr [ %0, %entry ], [ null, %for.body ]
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br i1 %arg, label %for.body, label %for.cond.cleanup
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for.body: ; preds = %for.cond
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store volatile i8 undef, ptr %a, align 1
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br label %for.cond
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for.cond.cleanup: ; preds = %for.cond
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call void @llvm.lifetime.end.p0(i64 1, ptr %a)
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%1 = load ptr, ptr %d.0, align 1
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store ptr %1, ptr @c, align 1
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ret void
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}
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