From 26cfbea73872e0553a8449bfb14e12102414185e Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Thu, 6 Nov 2014 14:39:49 +0000
Subject: [PATCH] Compute the correct jump table entries on 32 bit windows.

On 32 bit windows we use label differences and .set does not suppress
rolocations, a combination that was not used before r220256.

This fixes PR21497.

llvm-svn: 221456
---
 llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp   |  5 ++--
 llvm/test/CodeGen/X86/win32-pic-jumptable.ll | 36 ++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 2 deletions(-)
 create mode 100644 llvm/test/CodeGen/X86/win32-pic-jumptable.ll

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index ba42742..61f1d1b 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1247,8 +1247,9 @@ void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
       break;
     }
     Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
-    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
-    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
+    const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
+    const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
+    Value = MCBinaryExpr::CreateSub(Value, Base, OutContext);
     break;
   }
   }
diff --git a/llvm/test/CodeGen/X86/win32-pic-jumptable.ll b/llvm/test/CodeGen/X86/win32-pic-jumptable.ll
new file mode 100644
index 0000000..cabd36a
--- /dev/null
+++ b/llvm/test/CodeGen/X86/win32-pic-jumptable.ll
@@ -0,0 +1,36 @@
+; RUN: llc < %s -relocation-model=pic | FileCheck %s
+
+; CHECK:        calll L0$pb
+; CHECK-NEXT: L0$pb:
+; CHECK-NEXT:   popl %eax
+; CHECK-NEXT:   addl LJTI0_0(,%ecx,4), %eax
+; CHECK-NEXT:   jmpl *%eax
+
+; CHECK:      LJTI0_0:
+; CHECK-NEXT:   .long LBB0_4-L0$pb
+; CHECK-NEXT:   .long LBB0_5-L0$pb
+; CHECK-NEXT:   .long LBB0_6-L0$pb
+; CHECK-NEXT:   .long LBB0_7-L0$pb
+
+
+target triple = "i686--windows-itanium"
+define i32 @f(i64 %x) {
+bb0:
+  switch i64 %x, label %bb5 [
+    i64 1, label %bb1
+    i64 2, label %bb2
+    i64 3, label %bb3
+    i64 4, label %bb4
+  ]
+bb1:
+  br label %bb5
+bb2:
+  br label %bb5
+bb3:
+  br label %bb5
+bb4:
+  br label %bb5
+bb5:
+  %y = phi i32 [ 0, %bb0 ], [ 1, %bb1 ], [ 2, %bb2 ], [ 3, %bb3 ], [ 4, %bb4 ]
+  ret i32 %y
+}
-- 
2.7.4