From 67bcf74b14577b33c7a149f04bae9a203e357365 Mon Sep 17 00:00:00 2001
From: Sanjoy Das <sanjoy@playingwithpointers.com>
Date: Tue, 4 Nov 2014 00:59:21 +0000
Subject: [PATCH] The patchpoint lowering logic would crash with live constants
 equal to the tombstone or empty keys of a DenseMap<int64_t, T>.  This patch
 fixes the issue (and adds a tests case).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221214 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/CodeGen/StackMaps.h             |  2 +-
 lib/CodeGen/StackMaps.cpp                    | 10 +++
 test/CodeGen/X86/stackmap-large-constants.ll | 83 ++++++++++++++++++++
 3 files changed, 94 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/X86/stackmap-large-constants.ll

diff --git a/include/llvm/CodeGen/StackMaps.h b/include/llvm/CodeGen/StackMaps.h
index 1bcd739f552..e343980d2ab 100644
--- a/include/llvm/CodeGen/StackMaps.h
+++ b/include/llvm/CodeGen/StackMaps.h
@@ -142,7 +142,7 @@ private:
 
   typedef SmallVector<Location, 8> LocationVec;
   typedef SmallVector<LiveOutReg, 8> LiveOutVec;
-  typedef MapVector<int64_t, int64_t> ConstantPool;
+  typedef MapVector<uint64_t, uint64_t> ConstantPool;
   typedef MapVector<const MCSymbol *, uint64_t> FnStackSizeMap;
 
   struct CallsiteInfo {
diff --git a/lib/CodeGen/StackMaps.cpp b/lib/CodeGen/StackMaps.cpp
index 967cf751f36..d3791c3feb5 100644
--- a/lib/CodeGen/StackMaps.cpp
+++ b/lib/CodeGen/StackMaps.cpp
@@ -222,6 +222,16 @@ void StackMaps::recordStackMapOpers(const MachineInstr &MI, uint64_t ID,
     // -1 is directly encoded as .long 0xFFFFFFFF with no constant pool.
     if (I->LocType == Location::Constant && !isInt<32>(I->Offset)) {
       I->LocType = Location::ConstantIndex;
+      // ConstPool is intentionally a MapVector of 'uint64_t's (as
+      // opposed to 'int64_t's).  We should never be in a situation
+      // where we have to insert either the tombstone or the empty
+      // keys into a map, and for a DenseMap<uint64_t, T> these are
+      // (uint64_t)0 and (uint64_t)-1.  They can be and are
+      // represented using 32 bit integers.
+
+      assert((uint64_t)I->Offset != DenseMapInfo<uint64_t>::getEmptyKey() &&
+             (uint64_t)I->Offset != DenseMapInfo<uint64_t>::getTombstoneKey() &&
+             "empty and tombstone keys should fit in 32 bits!");
       auto Result = ConstPool.insert(std::make_pair(I->Offset, I->Offset));
       I->Offset = Result.first - ConstPool.begin();
     }
diff --git a/test/CodeGen/X86/stackmap-large-constants.ll b/test/CodeGen/X86/stackmap-large-constants.ll
new file mode 100644
index 00000000000..85e7a061ca9
--- /dev/null
+++ b/test/CodeGen/X86/stackmap-large-constants.ll
@@ -0,0 +1,83 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin | FileCheck %s
+
+; CHECK-LABEL:	.section	__LLVM_STACKMAPS,__llvm_stackmaps
+; CHECK-NEXT: __LLVM_StackMaps:
+; version
+; CHECK-NEXT: 	.byte	1
+; reserved
+; CHECK-NEXT: 	.byte	0
+; reserved
+; CHECK-NEXT: 	.short	0
+; # functions
+; CHECK-NEXT: 	.long	2
+; # constants
+; CHECK-NEXT: 	.long	2
+; # records
+; CHECK-NEXT: 	.long	2
+; function address & stack size
+; CHECK-NEXT: 	.quad	_foo
+; CHECK-NEXT: 	.quad	8
+; function address & stack size
+; CHECK-NEXT: 	.quad	_bar
+; CHECK-NEXT: 	.quad	8
+
+; Constants Array:
+; CHECK-NEXT: 	.quad	9223372036854775807
+; CHECK-NEXT: 	.quad	-9223372036854775808
+
+; Patchpoint ID
+; CHECK-NEXT: 	.quad	0
+; Instruction offset
+; CHECK-NEXT: 	.long	Ltmp3-_foo
+; reserved
+; CHECK-NEXT: 	.short	0
+; # locations
+; CHECK-NEXT: 	.short	1
+; ConstantIndex
+; CHECK-NEXT: 	.byte	5
+; reserved
+; CHECK-NEXT: 	.byte	8
+; Dwarf RegNum
+; CHECK-NEXT: 	.short	0
+; Offset
+; CHECK-NEXT: 	.long	0
+; padding
+; CHECK-NEXT: 	.short	0
+; NumLiveOuts
+; CHECK-NEXT: 	.short	0
+
+; CHECK-NEXT: 	.align	3
+
+declare void @llvm.experimental.stackmap(i64, i32, ...)
+
+define void @foo() {
+  tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 0, i32 0, i64 9223372036854775807)
+  ret void
+}
+
+; Patchpoint ID
+; CHECK-NEXT: 	.quad	0
+; Instruction Offset
+; CHECK-NEXT: 	.long	Ltmp7-_bar
+; reserved
+; CHECK-NEXT: 	.short	0
+; # locations
+; CHECK-NEXT: 	.short	1
+; ConstantIndex
+; CHECK-NEXT: 	.byte	5
+; reserved
+; CHECK-NEXT: 	.byte	8
+; Dwarf RegNum
+; CHECK-NEXT: 	.short	0
+; Offset
+; CHECK-NEXT: 	.long	1
+; padding
+; CHECK-NEXT: 	.short	0
+; NumLiveOuts
+; CHECK-NEXT: 	.short	0
+
+
+define void @bar() {
+  tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 0, i32 0, i64 -9223372036854775808)
+  ret void
+}