[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
yws · Jun 26, 2015 · cd39f3c · cd39f3c
1 parent 064274d
commit cd39f3c
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Showing 4 changed files with 18 additions and 1 deletion.
diff --git 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
@@ -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
@@ -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
@@ -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