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https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-23 17:29:19 +00:00
teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users.
This means we can do cheap DSE for heap memory. Nothing is done if the pointer excapes or has a load. The churn in the tests is mostly due to objectsize, since we want to make sure we don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159876 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -1137,12 +1137,29 @@ static bool IsOnlyNullComparedAndFreed(Value *V, SmallVectorImpl<WeakVH> &Users,
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}
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}
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if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U)) {
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if (II->getIntrinsicID() == Intrinsic::lifetime_start ||
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II->getIntrinsicID() == Intrinsic::lifetime_end) {
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switch (II->getIntrinsicID()) {
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default: return false;
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case Intrinsic::memmove:
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case Intrinsic::memcpy:
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case Intrinsic::memset: {
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MemIntrinsic *MI = cast<MemIntrinsic>(II);
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if (MI->isVolatile() || MI->getRawDest() != V)
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return false;
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}
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// fall through
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case Intrinsic::objectsize:
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case Intrinsic::lifetime_start:
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case Intrinsic::lifetime_end:
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Users.push_back(II);
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continue;
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}
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}
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if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
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if (SI->isVolatile() || SI->getPointerOperand() != V)
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return false;
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Users.push_back(SI);
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continue;
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}
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return false;
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}
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return true;
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@ -1164,6 +1181,12 @@ Instruction *InstCombiner::visitMalloc(Instruction &MI) {
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C->isFalseWhenEqual()));
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} else if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I)) {
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ReplaceInstUsesWith(*I, UndefValue::get(I->getType()));
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} else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
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if (II->getIntrinsicID() == Intrinsic::objectsize) {
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ConstantInt *CI = cast<ConstantInt>(II->getArgOperand(1));
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uint64_t DontKnow = CI->isZero() ? -1ULL : 0;
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ReplaceInstUsesWith(*I, ConstantInt::get(I->getType(), DontKnow));
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}
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}
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EraseInstFromFunction(*I);
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}
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@ -16,5 +16,26 @@ define i1 @test1() {
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ret i1 %B
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; CHECK: @test1
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; CHECK: ret i1 %B
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; CHECK: ret i1 false
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}
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; CHECK: @test2
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define noalias i8* @test2() nounwind {
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entry:
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; CHECK: @malloc
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%A = call noalias i8* @malloc(i64 4) nounwind
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; CHECK: icmp eq
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%tobool = icmp eq i8* %A, null
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; CHECK: br i1
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br i1 %tobool, label %return, label %if.end
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if.end:
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; CHECK: store
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store i8 7, i8* %A
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br label %return
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return:
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; CHECK: phi
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%retval.0 = phi i8* [ %A, %if.end ], [ null, %entry ]
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ret i8* %retval.0
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}
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@ -4,6 +4,7 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3
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declare i32 @__gxx_personality_v0(...)
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declare void @__cxa_call_unexpected(i8*)
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declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readonly
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declare i8* @_Znwm(i64)
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; CHECK: @f1
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@ -45,3 +46,20 @@ lpad:
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tail call void @__cxa_call_unexpected(i8* %2) noreturn nounwind
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unreachable
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}
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; CHECK: @f3
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define void @f3() nounwind uwtable ssp {
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; CHECK: invoke void @llvm.donothing()
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%call = invoke noalias i8* @_Znwm(i64 13)
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to label %invoke.cont unwind label %lpad
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invoke.cont:
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ret void
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lpad:
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%1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
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filter [0 x i8*] zeroinitializer
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%2 = extractvalue { i8*, i32 } %1, 0
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tail call void @__cxa_call_unexpected(i8* %2) noreturn nounwind
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unreachable
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}
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@ -1,17 +1,17 @@
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; RUN: opt < %s -instcombine -S | FileCheck %s
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; PR1201
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define i32 @main(i32 %argc, i8** %argv) {
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; CHECK: @main
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%c_19 = alloca i8*
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%malloc_206 = tail call i8* @malloc(i32 mul (i32 ptrtoint (i8* getelementptr (i8* null, i32 1) to i32), i32 10))
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store i8* %malloc_206, i8** %c_19
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%tmp_207 = load i8** %c_19
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tail call void @free(i8* %tmp_207)
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ret i32 0
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; CHECK-NOT: malloc
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; CHECK-NOT: free
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; CHECK: ret i32 0
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; CHECK-NEXT: ret i32 0
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}
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declare noalias i8* @calloc(i32, i32) nounwind
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declare noalias i8* @malloc(i32)
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declare void @free(i8*)
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@ -26,13 +26,24 @@ define i1 @foo() {
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declare void @llvm.lifetime.start(i64, i8*)
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declare void @llvm.lifetime.end(i64, i8*)
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declare i64 @llvm.objectsize.i64(i8*, i1)
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declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
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declare void @llvm.memmove.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
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declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i32, i1) nounwind
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define void @test3() {
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define void @test3(i8* %src) {
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; CHECK: @test3
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; CHECK-NEXT: ret void
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%a = call noalias i8* @malloc(i32 10)
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call void @llvm.lifetime.start(i64 10, i8* %a)
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call void @llvm.lifetime.end(i64 10, i8* %a)
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%size = call i64 @llvm.objectsize.i64(i8* %a, i1 true)
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store i8 42, i8* %a
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call void @llvm.memcpy.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i32 1, i1 false)
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call void @llvm.memmove.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i32 1, i1 false)
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call void @llvm.memset.p0i8.i32(i8* %a, i8 5, i32 32, i32 1, i1 false)
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%alloc2 = call noalias i8* @calloc(i32 5, i32 7) nounwind
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%z = icmp ne i8* %alloc2, null
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ret void
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}
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@ -46,3 +57,37 @@ define void @test4() {
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call void @free(i8* %C)
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ret void
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}
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; CHECK: @test5
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define void @test5(i8* %ptr, i8** %esc) {
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; CHECK-NEXT: call i8* @malloc
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; CHECK-NEXT: call i8* @malloc
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; CHECK-NEXT: call i8* @malloc
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; CHECK-NEXT: call i8* @malloc
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; CHECK-NEXT: call i8* @malloc
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; CHECK-NEXT: call i8* @malloc
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; CHECK-NEXT: call i8* @malloc
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; CHECK-NEXT: call void @llvm.memcpy
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; CHECK-NEXT: call void @llvm.memmove
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; CHECK-NEXT: store
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; CHECK-NEXT: call void @llvm.memcpy
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; CHECK-NEXT: call void @llvm.memmove
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; CHECK-NEXT: call void @llvm.memset
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; CHECK-NEXT: store volatile
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; CHECK-NEXT: ret
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%a = call i8* @malloc(i32 700)
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%b = call i8* @malloc(i32 700)
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%c = call i8* @malloc(i32 700)
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%d = call i8* @malloc(i32 700)
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%e = call i8* @malloc(i32 700)
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%f = call i8* @malloc(i32 700)
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%g = call i8* @malloc(i32 700)
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call void @llvm.memcpy.p0i8.p0i8.i32(i8* %ptr, i8* %a, i32 32, i32 1, i1 false)
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call void @llvm.memmove.p0i8.p0i8.i32(i8* %ptr, i8* %b, i32 32, i32 1, i1 false)
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store i8* %c, i8** %esc
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call void @llvm.memcpy.p0i8.p0i8.i32(i8* %d, i8* %ptr, i32 32, i32 1, i1 true)
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call void @llvm.memmove.p0i8.p0i8.i32(i8* %e, i8* %ptr, i32 32, i32 1, i1 true)
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call void @llvm.memset.p0i8.i32(i8* %f, i8 5, i32 32, i32 1, i1 true)
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store volatile i8 4, i8* %g
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ret void
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}
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@ -8,23 +8,25 @@ declare void @__cxa_call_unexpected(i8*)
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declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readonly
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; CHECK: @f1
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define i64 @f1() {
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define i64 @f1(i8 **%esc) {
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%call = call i8* @malloc(i32 4)
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store i8* %call, i8** %esc
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%size = call i64 @llvm.objectsize.i64(i8* %call, i1 false)
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; CHECK-NEXT: ret i64 4
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; CHECK: ret i64 4
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ret i64 %size
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}
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; CHECK: @f2
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define i64 @f2() nounwind uwtable ssp {
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define i64 @f2(i8** %esc) nounwind uwtable ssp {
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entry:
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; CHECK: invoke void @llvm.donothing()
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; CHECK: invoke noalias i8* @_Znwm(i64 13)
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%call = invoke noalias i8* @_Znwm(i64 13)
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to label %invoke.cont unwind label %lpad
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invoke.cont:
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; CHECK: ret i64 13
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store i8* %call, i8** %esc
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%0 = tail call i64 @llvm.objectsize.i64(i8* %call, i1 false)
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ret i64 %0
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@ -121,7 +121,7 @@ entry:
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; rdar://7782496
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@s = external global i8*
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define void @test5(i32 %n) nounwind ssp {
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define i8* @test5(i32 %n) nounwind ssp {
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; CHECK: @test5
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entry:
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%0 = tail call noalias i8* @malloc(i32 20) nounwind
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@ -130,7 +130,7 @@ entry:
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; CHECK-NOT: @llvm.objectsize
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; CHECK: @llvm.memcpy.p0i8.p0i8.i32(i8* %0, i8* %1, i32 10, i32 1, i1 false)
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%3 = tail call i8* @__memcpy_chk(i8* %0, i8* %2, i32 10, i32 %1) nounwind
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ret void
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ret i8* %0
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}
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define void @test6(i32 %n) nounwind ssp {
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@ -149,22 +149,24 @@ declare i8* @__memset_chk(i8*, i32, i32, i32) nounwind
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declare noalias i8* @malloc(i32) nounwind
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define i32 @test7() {
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define i32 @test7(i8** %esc) {
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; CHECK: @test7
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%alloc = call noalias i8* @malloc(i32 48) nounwind
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store i8* %alloc, i8** %esc
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%gep = getelementptr inbounds i8* %alloc, i32 16
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%objsize = call i32 @llvm.objectsize.i32(i8* %gep, i1 false) nounwind readonly
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; CHECK-NEXT: ret i32 32
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; CHECK: ret i32 32
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ret i32 %objsize
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}
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declare noalias i8* @calloc(i32, i32) nounwind
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define i32 @test8() {
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define i32 @test8(i8** %esc) {
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; CHECK: @test8
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%alloc = call noalias i8* @calloc(i32 5, i32 7) nounwind
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store i8* %alloc, i8** %esc
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%gep = getelementptr inbounds i8* %alloc, i32 5
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%objsize = call i32 @llvm.objectsize.i32(i8* %gep, i1 false) nounwind readonly
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; CHECK-NEXT: ret i32 30
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; CHECK: ret i32 30
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ret i32 %objsize
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}
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