From cd39f3c6cb0dfa7247b0ca71cd08ce8661ee8207 Mon Sep 17 00:00:00 2001
From: Douglas Katzman <dougk@google.com>
Date: Fri, 26 Jun 2015 16:58:59 +0000
Subject: [PATCH] [X86]: Correctly sign-extend 16-bit immediate in CALL
 instruction.

Patch by Matthew Barney. Thanks!

Differential Revision: http://reviews.llvm.org/D9514

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240795 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/Disassembler/X86Disassembler.cpp | 8 +++++++-
 test/MC/Disassembler/X86/x86-16.txt             | 2 ++
 test/MC/Disassembler/X86/x86-32.txt             | 3 +++
 test/MC/Disassembler/X86/x86-64.txt             | 6 ++++++
 4 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/lib/Target/X86/Disassembler/X86Disassembler.cpp b/lib/Target/X86/Disassembler/X86Disassembler.cpp
index 6e99c37c2bc..cfc3ee2fb08 100644
--- a/lib/Target/X86/Disassembler/X86Disassembler.cpp
+++ b/lib/Target/X86/Disassembler/X86Disassembler.cpp
@@ -551,9 +551,15 @@ static void translateImmediate(MCInst &mcInst, uint64_t immediate,
   case TYPE_REL8:
     isBranch = true;
     pcrel = insn.startLocation + insn.immediateOffset + insn.immediateSize;
-    if(immediate & 0x80)
+    if (immediate & 0x80)
       immediate |= ~(0xffull);
     break;
+  case TYPE_REL16:
+    isBranch = true;
+    pcrel = insn.startLocation + insn.immediateOffset + insn.immediateSize;
+    if (immediate & 0x8000)
+      immediate |= ~(0xffffull);
+    break;
   case TYPE_REL32:
   case TYPE_REL64:
     isBranch = true;
diff --git a/test/MC/Disassembler/X86/x86-16.txt b/test/MC/Disassembler/X86/x86-16.txt
index c6844cd3cef..021cb237181 100644
--- a/test/MC/Disassembler/X86/x86-16.txt
+++ b/test/MC/Disassembler/X86/x86-16.txt
@@ -786,3 +786,5 @@
 # CHECK: lretl
 0x66 0xcb
 
+# CHECK: callw	-1
+0xe8 0xff 0xff
diff --git a/test/MC/Disassembler/X86/x86-32.txt b/test/MC/Disassembler/X86/x86-32.txt
index 830b8306630..c51e0a3dc37 100644
--- a/test/MC/Disassembler/X86/x86-32.txt
+++ b/test/MC/Disassembler/X86/x86-32.txt
@@ -54,6 +54,9 @@
 # CHECK: calll	-1234
 0xe8 0x2e 0xfb 0xff 0xff
 
+# CHECK: callw	-1
+0x66 0xe8 0xff 0xff
+
 # CHECK: lfence
 0x0f 0xae 0xe8
 
diff --git a/test/MC/Disassembler/X86/x86-64.txt b/test/MC/Disassembler/X86/x86-64.txt
index 5699f40d2d3..065b2a57c84 100644
--- a/test/MC/Disassembler/X86/x86-64.txt
+++ b/test/MC/Disassembler/X86/x86-64.txt
@@ -339,3 +339,9 @@
 # CHECK: vaddps (%rdx,%xmm1), %zmm20, %zmm15
 # FIXME: vaddps (%rdx,%rcx), %zmm20, %zmm15
 0x62 0x71 0x5c 0x40 0x58 0x3c 0x0a
+
+# CHECK: callq 32767
+0xe8 0xff 0x7f 0x00 0x00
+
+# CHECK: callq -32769
+0xe8 0xff 0x7f 0xff 0xff
-- 
2.34.1