Print properly signed displacement in disassembler.

src/x64/disasm-x64.cc

Index: src/x64/disasm-x64.cc
diff --git a/src/x64/disasm-x64.cc b/src/x64/disasm-x64.cc
index dd64d3f5ee4b3a501a850a4b7591c42b7cece2bc..f0f399ec0a73f0a0142f1f4c87e6d19a201bb853 100644
--- a/src/x64/disasm-x64.cc
+++ b/src/x64/disasm-x64.cc
@@ -485,9 +485,11 @@ int DisassemblerX64::PrintRightOperandHelper(
         } else if (base == 5) {
           // base == rbp means no base register (when mod == 0).
           int32_t disp = *reinterpret_cast<int32_t*>(modrmp + 2);
-          AppendToBuffer("[%s*%d+0x%x]",
+          AppendToBuffer("[%s*%d%s0x%x]",
                          NameOfCPURegister(index),
-                         1 << scale, disp);
+                         1 << scale,
+                         disp < 0 ? "-" : "+",
+                         disp < 0 ? -disp : disp);
           return 6;
         } else if (index != 4 && base != 5) {
           // [base+index*scale]
@@ -512,38 +514,29 @@ int DisassemblerX64::PrintRightOperandHelper(
         int scale, index, base;
         get_sib(sib, &scale, &index, &base);
         int disp = (mod == 2) ? *reinterpret_cast<int32_t*>(modrmp + 2)
-                              : *reinterpret_cast<char*>(modrmp + 2);
+                              : *reinterpret_cast<int8_t*>(modrmp + 2);
         if (index == 4 && (base & 7) == 4 && scale == 0 /*times_1*/) {
-          if (-disp > 0) {
-            AppendToBuffer("[%s-0x%x]", NameOfCPURegister(base), -disp);
-          } else {
-            AppendToBuffer("[%s+0x%x]", NameOfCPURegister(base), disp);
-          }
+          AppendToBuffer("[%s%s0x%x]",
+                         NameOfCPURegister(base),
+                         disp < 0 ? "-" : "+",
+                         disp < 0 ? -disp : disp);
         } else {
-          if (-disp > 0) {
-            AppendToBuffer("[%s+%s*%d-0x%x]",
-                           NameOfCPURegister(base),
-                           NameOfCPURegister(index),
-                           1 << scale,
-                           -disp);
-          } else {
-            AppendToBuffer("[%s+%s*%d+0x%x]",
-                           NameOfCPURegister(base),
-                           NameOfCPURegister(index),
-                           1 << scale,
-                           disp);
-          }
+          AppendToBuffer("[%s+%s*%d%s0x%x]",
+                         NameOfCPURegister(base),
+                         NameOfCPURegister(index),
+                         1 << scale,
+                         disp < 0 ? "-" : "+",
+                         disp < 0 ? -disp : disp);
         }
         return mod == 2 ? 6 : 3;
       } else {
         // No sib.
         int disp = (mod == 2) ? *reinterpret_cast<int32_t*>(modrmp + 1)
-                              : *reinterpret_cast<char*>(modrmp + 1);
-        if (-disp > 0) {
-        AppendToBuffer("[%s-0x%x]", NameOfCPURegister(rm), -disp);
-        } else {
-        AppendToBuffer("[%s+0x%x]", NameOfCPURegister(rm), disp);
-        }
+                              : *reinterpret_cast<int8_t*>(modrmp + 1);
+        AppendToBuffer("[%s%s0x%x]",
+                       NameOfCPURegister(rm),
+                       disp < 0 ? "-" : "+",
+                       disp < 0 ? -disp : disp);
         return (mod == 2) ? 5 : 2;
       }
       break;