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[Function Specialisation] Fix use after free
This is a fix for a use-after-free found by the address sanitizer when compiling GCC: #52821 The Function Specialization pass may remove instructions, cached inside the PredicateBase class, which are later being dereferenced from the SCCPInstVisitor class. To prevent the dangling references I am lazily deleting the dead instructions after the Solver has run. Differential Revision: https://reviews.llvm.org/D118591
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llvm/test/Transforms/FunctionSpecialization/bug52821-use-after-free.ll
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py | ||
; RUN: opt -function-specialization -S < %s | FileCheck %s | ||
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%mystruct = type { i32, [2 x i64] } | ||
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define internal %mystruct* @myfunc(%mystruct* %arg) { | ||
; CHECK-LABEL: @myfunc( | ||
; CHECK-NEXT: entry: | ||
; CHECK-NEXT: br label [[FOR_COND:%.*]] | ||
; CHECK: for.cond: | ||
; CHECK-NEXT: br i1 true, label [[FOR_COND2:%.*]], label [[FOR_BODY:%.*]] | ||
; CHECK: for.body: | ||
; CHECK-NEXT: call void @callee(%mystruct* nonnull null) | ||
; CHECK-NEXT: br label [[FOR_COND]] | ||
; CHECK: for.cond2: | ||
; CHECK-NEXT: br i1 false, label [[FOR_END:%.*]], label [[FOR_BODY2:%.*]] | ||
; CHECK: for.body2: | ||
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [[MYSTRUCT:%.*]], %mystruct* null, i64 0, i32 1, i64 3 | ||
; CHECK-NEXT: br label [[FOR_COND2]] | ||
; CHECK: for.end: | ||
; CHECK-NEXT: ret %mystruct* [[ARG:%.*]] | ||
; | ||
entry: | ||
br label %for.cond | ||
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for.cond: ; preds = %for.body, %entry | ||
%phi = phi %mystruct* [ undef, %for.body ], [ null, %entry ] | ||
%cond = icmp eq %mystruct* %phi, null | ||
br i1 %cond, label %for.cond2, label %for.body | ||
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for.body: ; preds = %for.cond | ||
call void @callee(%mystruct* nonnull %phi) | ||
br label %for.cond | ||
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for.cond2: ; preds = %for.body2, %for.cond | ||
%phi2 = phi %mystruct* [ undef, %for.body2 ], [ null, %for.cond ] | ||
br i1 undef, label %for.end, label %for.body2 | ||
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for.body2: ; preds = %for.cond2 | ||
%arrayidx = getelementptr inbounds %mystruct, %mystruct* %phi2, i64 0, i32 1, i64 3 | ||
br label %for.cond2 | ||
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for.end: ; preds = %for.cond2 | ||
ret %mystruct* %arg | ||
} | ||
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define %mystruct* @caller() { | ||
; CHECK-LABEL: @caller( | ||
; CHECK-NEXT: entry: | ||
; CHECK-NEXT: [[CALL:%.*]] = call %mystruct* @myfunc(%mystruct* undef) | ||
; CHECK-NEXT: ret %mystruct* [[CALL]] | ||
; | ||
entry: | ||
%call = call %mystruct* @myfunc(%mystruct* undef) | ||
ret %mystruct* %call | ||
} | ||
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declare void @callee(%mystruct*) |