From fa3003a7832a519cbe178796688f4d00aae6996a Mon Sep 17 00:00:00 2001
From: Lei Liu <lei.liu2@windriver.com>
Date: Mon, 13 Aug 2018 06:06:53 +0000
Subject: [PATCH] Restore correct x86_64 EH encodings in kernel code model

Fixes PR37524.

The exception handling encodings for x86_64 in kernel code model
has been changed with r309884.  Restore it to correct ones.  These
encodings include PersonalityEncoding, LSDAEncoding and
TTypeEncoding.

Differential Revision: https://reviews.llvm.org/D50490



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339534 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 23 +++---
 test/CodeGen/X86/code-model-kernel.ll        | 79 ++++++++++++++++++++
 2 files changed, 93 insertions(+), 9 deletions(-)
 create mode 100644 test/CodeGen/X86/code-model-kernel.ll

diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 2b571a02b4d..7a5fd2985c7 100644
--- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -96,7 +96,7 @@ void TargetLoweringObjectFileELF::Initialize(MCContext &Ctx,
   TargetLoweringObjectFile::Initialize(Ctx, TgtM);
   TM = &TgtM;
 
-  bool Large = TgtM.getCodeModel() == CodeModel::Large;
+  CodeModel::Model CM = TgtM.getCodeModel();
 
   switch (TgtM.getTargetTriple().getArch()) {
   case Triple::arm:
@@ -124,18 +124,23 @@ void TargetLoweringObjectFileELF::Initialize(MCContext &Ctx,
     break;
   case Triple::x86_64:
     if (isPositionIndependent()) {
-      PersonalityEncoding =
-          dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
-          (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
+      PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
+        ((CM == CodeModel::Small || CM == CodeModel::Medium)
+         ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
-                     (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
+        (CM == CodeModel::Small
+         ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
-                      (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
+        ((CM == CodeModel::Small || CM == CodeModel::Medium)
+         ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
     } else {
       PersonalityEncoding =
-          Large ? dwarf::DW_EH_PE_absptr : dwarf::DW_EH_PE_udata4;
-      LSDAEncoding = Large ? dwarf::DW_EH_PE_absptr : dwarf::DW_EH_PE_udata4;
-      TTypeEncoding = Large ? dwarf::DW_EH_PE_absptr : dwarf::DW_EH_PE_udata4;
+        (CM == CodeModel::Small || CM == CodeModel::Medium)
+        ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
+      LSDAEncoding = (CM == CodeModel::Small)
+        ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
+      TTypeEncoding = (CM == CodeModel::Small)
+        ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
     }
     break;
   case Triple::hexagon:
diff --git a/test/CodeGen/X86/code-model-kernel.ll b/test/CodeGen/X86/code-model-kernel.ll
new file mode 100644
index 00000000000..ba47151ac07
--- /dev/null
+++ b/test/CodeGen/X86/code-model-kernel.ll
@@ -0,0 +1,79 @@
+; RUN: llc -mtriple=x86_64-pc-linux-gnu -code-model=kernel %s -o - | FileCheck %s
+; CHECK-LABEL: main
+; CHECK: .cfi_startproc
+; CHECK: .cfi_personality 0, __gxx_personality_v0
+; CHECK: .cfi_lsda 0, [[EXCEPTION_LABEL:.L[^ ]*]]
+; CHECK: [[EXCEPTION_LABEL]]:
+; CHECK: .byte	0                       # @TType Encoding = absptr
+; CHECK: .quad	_ZTIi
+
+@_ZTIi = external constant i8*
+
+; Function Attrs: noinline norecurse optnone uwtable
+define i32 @main() #0 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
+  %1 = alloca i32, align 4
+  %2 = alloca i8*
+  %3 = alloca i32
+  %4 = alloca i32, align 4
+  store i32 0, i32* %1, align 4
+  %5 = call i8* @__cxa_allocate_exception(i64 4) #2
+  %6 = bitcast i8* %5 to i32*
+  store i32 20, i32* %6, align 16
+  invoke void @__cxa_throw(i8* %5, i8* bitcast (i8** @_ZTIi to i8*), i8* null) #3
+          to label %26 unwind label %7
+
+; <label>:7:                                      ; preds = %0
+  %8 = landingpad { i8*, i32 }
+          catch i8* bitcast (i8** @_ZTIi to i8*)
+  %9 = extractvalue { i8*, i32 } %8, 0
+  store i8* %9, i8** %2, align 8
+  %10 = extractvalue { i8*, i32 } %8, 1
+  store i32 %10, i32* %3, align 4
+  br label %11
+
+; <label>:11:                                     ; preds = %7
+  %12 = load i32, i32* %3, align 4
+  %13 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) #2
+  %14 = icmp eq i32 %12, %13
+  br i1 %14, label %15, label %21
+
+; <label>:15:                                     ; preds = %11
+  %16 = load i8*, i8** %2, align 8
+  %17 = call i8* @__cxa_begin_catch(i8* %16) #2
+  %18 = bitcast i8* %17 to i32*
+  %19 = load i32, i32* %18, align 4
+  store i32 %19, i32* %4, align 4
+  call void @__cxa_end_catch() #2
+  br label %20
+
+; <label>:20:                                     ; preds = %15
+  ret i32 0
+
+; <label>:21:                                     ; preds = %11
+  %22 = load i8*, i8** %2, align 8
+  %23 = load i32, i32* %3, align 4
+  %24 = insertvalue { i8*, i32 } undef, i8* %22, 0
+  %25 = insertvalue { i8*, i32 } %24, i32 %23, 1
+  resume { i8*, i32 } %25
+
+; <label>:26:                                     ; preds = %0
+  unreachable
+}
+
+declare i8* @__cxa_allocate_exception(i64)
+
+declare void @__cxa_throw(i8*, i8*, i8*)
+
+declare i32 @__gxx_personality_v0(...)
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.eh.typeid.for(i8*) #1
+
+declare i8* @__cxa_begin_catch(i8*)
+
+declare void @__cxa_end_catch()
+
+attributes #0 = { noinline norecurse optnone uwtable }
+attributes #1 = { nounwind readnone }
+attributes #2 = { nounwind }
+attributes #3 = { noreturn }