From 009c4d86c14bb2f46f9473f8f517393dabab7e9e Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <samsonov@google.com>
Date: Tue, 13 Nov 2012 07:15:32 +0000
Subject: [PATCH] Figure out <size> argument of llvm.lifetime intrinsics at the
 moment they are created (during function inlining)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167821 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Utils/InlineFunction.cpp       | 23 +++++++++-
 .../Inline/lifetime-no-datalayout.ll          | 23 ++++++++++
 test/Transforms/Inline/lifetime.ll            | 44 ++++++++++++++-----
 3 files changed, 77 insertions(+), 13 deletions(-)
 create mode 100644 test/Transforms/Inline/lifetime-no-datalayout.ll

diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index 009847f87bc..303de56d95c 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -668,10 +668,29 @@ bool llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
       if (hasLifetimeMarkers(AI))
         continue;
 
-      builder.CreateLifetimeStart(AI);
+      // Try to determine the size of the allocation.
+      ConstantInt *AllocaSize = 0;
+      if (ConstantInt *AIArraySize =
+          dyn_cast<ConstantInt>(AI->getArraySize())) {
+        if (IFI.TD) {
+          Type *AllocaType = AI->getAllocatedType();
+          uint64_t AllocaTypeSize = IFI.TD->getTypeAllocSize(AllocaType);
+          uint64_t AllocaArraySize = AIArraySize->getLimitedValue();
+          assert(AllocaArraySize > 0 && "array size of AllocaInst is zero");
+          // Check that array size doesn't saturate uint64_t and doesn't
+          // overflow when it's multiplied by type size.
+          if (AllocaArraySize != ~0ULL &&
+              UINT64_MAX / AllocaArraySize >= AllocaTypeSize) {
+            AllocaSize = ConstantInt::get(Type::getInt64Ty(AI->getContext()),
+                                          AllocaArraySize * AllocaTypeSize);
+          }
+        }
+      }
+
+      builder.CreateLifetimeStart(AI, AllocaSize);
       for (unsigned ri = 0, re = Returns.size(); ri != re; ++ri) {
         IRBuilder<> builder(Returns[ri]);
-        builder.CreateLifetimeEnd(AI);
+        builder.CreateLifetimeEnd(AI, AllocaSize);
       }
     }
   }
diff --git a/test/Transforms/Inline/lifetime-no-datalayout.ll b/test/Transforms/Inline/lifetime-no-datalayout.ll
new file mode 100644
index 00000000000..9ad14282f98
--- /dev/null
+++ b/test/Transforms/Inline/lifetime-no-datalayout.ll
@@ -0,0 +1,23 @@
+; RUN: opt -inline %s -S -o - | FileCheck %s
+
+declare void @use(i8* %a)
+
+define void @helper() {
+  %a = alloca i8
+  call void @use(i8* %a)
+  ret void
+}
+
+; Size in llvm.lifetime.X should be -1 (unknown).
+define void @test() {
+; CHECK: @test
+; CHECK-NOT: lifetime
+; CHECK: llvm.lifetime.start(i64 -1
+; CHECK-NOT: lifetime
+; CHECK: llvm.lifetime.end(i64 -1
+  call void @helper()
+; CHECK-NOT: lifetime
+; CHECK: ret void
+  ret void
+}
+
diff --git a/test/Transforms/Inline/lifetime.ll b/test/Transforms/Inline/lifetime.ll
index a95c836b77d..fb520498c43 100644
--- a/test/Transforms/Inline/lifetime.ll
+++ b/test/Transforms/Inline/lifetime.ll
@@ -1,22 +1,25 @@
 ; RUN: opt -inline %s -S -o - | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
 
 declare void @llvm.lifetime.start(i64, i8*)
 declare void @llvm.lifetime.end(i64, i8*)
 
 define void @helper_both_markers() {
   %a = alloca i8
-  call void @llvm.lifetime.start(i64 1, i8* %a)
-  call void @llvm.lifetime.end(i64 1, i8* %a)
+  ; Size in llvm.lifetime.start / llvm.lifetime.end differs from
+  ; allocation size. We should use the former.
+  call void @llvm.lifetime.start(i64 2, i8* %a)
+  call void @llvm.lifetime.end(i64 2, i8* %a)
   ret void
 }
 
 define void @test_both_markers() {
 ; CHECK: @test_both_markers
-; CHECK: llvm.lifetime.start(i64 1
-; CHECK-NEXT: llvm.lifetime.end(i64 1
+; CHECK: llvm.lifetime.start(i64 2
+; CHECK-NEXT: llvm.lifetime.end(i64 2
   call void @helper_both_markers()
-; CHECK-NEXT: llvm.lifetime.start(i64 1
-; CHECK-NEXT: llvm.lifetime.end(i64 1
+; CHECK-NEXT: llvm.lifetime.start(i64 2
+; CHECK-NEXT: llvm.lifetime.end(i64 2
   call void @helper_both_markers()
 ; CHECK-NEXT: ret void
   ret void
@@ -27,7 +30,7 @@ define void @test_both_markers() {
 declare void @use(i8* %a)
 
 define void @helper_no_markers() {
-  %a = alloca i8
+  %a = alloca i8 ; Allocation size is 1 byte.
   call void @use(i8* %a)
   ret void
 }
@@ -37,14 +40,14 @@ define void @helper_no_markers() {
 define void @test_no_marker() {
 ; CHECK: @test_no_marker
 ; CHECK-NOT: lifetime
-; CHECK: llvm.lifetime.start(i64 -1
+; CHECK: llvm.lifetime.start(i64 1
 ; CHECK-NOT: lifetime
-; CHECK: llvm.lifetime.end(i64 -1
+; CHECK: llvm.lifetime.end(i64 1
   call void @helper_no_markers()
 ; CHECK-NOT: lifetime
-; CHECK: llvm.lifetime.start(i64 -1
+; CHECK: llvm.lifetime.start(i64 1
 ; CHECK-NOT: lifetime
-; CHECK: llvm.lifetime.end(i64 -1
+; CHECK: llvm.lifetime.end(i64 1
   call void @helper_no_markers()
 ; CHECK-NOT: lifetime
 ; CHECK: ret void
@@ -76,3 +79,22 @@ define void @test_two_casts() {
 ; CHECK: ret void
   ret void
 }
+
+define void @helper_arrays_alloca() {
+  %a = alloca [10 x i32], align 16
+  %1 = bitcast [10 x i32]* %a to i8*
+  call void @use(i8* %1)
+  ret void
+}
+
+define void @test_arrays_alloca() {
+; CHECK: @test_arrays_alloca
+; CHECK-NOT: lifetime
+; CHECK: llvm.lifetime.start(i64 40,
+; CHECK-NOT: lifetime
+; CHECK: llvm.lifetime.end(i64 40,
+  call void @helper_arrays_alloca()
+; CHECK-NOT: lifetime
+; CHECK: ret void
+  ret void
+}