diff --git a/lldb/source/Utility/DataExtractor.cpp b/lldb/source/Utility/DataExtractor.cpp
--- a/lldb/source/Utility/DataExtractor.cpp
+++ b/lldb/source/Utility/DataExtractor.cpp
@@ -931,7 +931,7 @@
 
     // Sign bit of byte is 2nd high order bit (0x40)
     if (shift < size && (byte & 0x40))
-      result |= -(1 << shift);
+      result |= -(static_cast<int64_t>(1) << shift);
 
     *offset_ptr += bytecount;
     return result;
diff --git a/lldb/test/Shell/SymbolFile/DWARF/DW_TAG_variable-DW_AT_const_value.s b/lldb/test/Shell/SymbolFile/DWARF/DW_TAG_variable-DW_AT_const_value.s
new file mode 100644
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/DW_TAG_variable-DW_AT_const_value.s
@@ -0,0 +1,85 @@
+# This tests that lldb is able to print DW_TAG_variable using DW_AT_const_value.
+
+# REQUIRES: x86
+
+# RUN: llvm-mc -triple x86_64-unknown-linux-gnu %s -filetype=obj > %t.o
+# RUN: %lldb %t.o -o "p/x magic64" -o exit | FileCheck %s
+
+# CHECK: (const long) $0 = 0xed9a924c00011151
+
+# The DW_TAG_variable using DW_AT_const_value. can be produced from:
+# static const long magic64 = 0xed9a924c00011151;
+# int main(void) { return magic64; }
+
+	.text
+	.globl	main                    # -- Begin function main
+	.type	main,@function
+main:                                   # @main
+.Lfunc_end0:
+	.size	main, .Lfunc_end0-main
+                                        # -- End function
+	.section	.debug_abbrev,"",@progbits
+	.byte	1                       # Abbreviation Code
+	.byte	17                      # DW_TAG_compile_unit
+	.byte	1                       # DW_CHILDREN_yes
+	.byte	37                      # DW_AT_producer
+	.byte	8                       # DW_FORM_string
+	.byte	19                      # DW_AT_language
+	.byte	5                       # DW_FORM_data2
+	.byte	0                       # EOM(1)
+	.byte	0                       # EOM(2)
+	.byte	2                       # Abbreviation Code
+	.byte	52                      # DW_TAG_variable
+	.byte	0                       # DW_CHILDREN_no
+	.byte	3                       # DW_AT_name
+	.byte	8                       # DW_FORM_string
+	.byte	73                      # DW_AT_type
+	.byte	19                      # DW_FORM_ref4
+	.byte	28                      # DW_AT_const_value
+#	.byte	15                      # DW_FORM_udata
+	.byte	13                      # DW_FORM_sdata
+	.byte	0                       # EOM(1)
+	.byte	0                       # EOM(2)
+	.byte	3                       # Abbreviation Code
+	.byte	38                      # DW_TAG_const_type
+	.byte	0                       # DW_CHILDREN_no
+	.byte	73                      # DW_AT_type
+	.byte	19                      # DW_FORM_ref4
+	.byte	0                       # EOM(1)
+	.byte	0                       # EOM(2)
+	.byte	4                       # Abbreviation Code
+	.byte	36                      # DW_TAG_base_type
+	.byte	0                       # DW_CHILDREN_no
+	.byte	3                       # DW_AT_name
+	.byte	8                       # DW_FORM_string
+	.byte	62                      # DW_AT_encoding
+	.byte	11                      # DW_FORM_data1
+	.byte	11                      # DW_AT_byte_size
+	.byte	11                      # DW_FORM_data1
+	.byte	0                       # EOM(1)
+	.byte	0                       # EOM(2)
+	.byte	0                       # EOM(3)
+	.section	.debug_info,"",@progbits
+.Lcu_begin0:
+	.long	.Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+	.short	4                       # DWARF version number
+	.long	.debug_abbrev           # Offset Into Abbrev. Section
+	.byte	8                       # Address Size (in bytes)
+	.byte	1                       # Abbrev [1] 0xb:0x61 DW_TAG_compile_unit
+	.asciz	"clang version 10.0.0"  # DW_AT_producer
+	.short	12                      # DW_AT_language
+	.byte	2                       # Abbrev [2] 0x2a:0x15 DW_TAG_variable
+	.asciz	"magic64"               # DW_AT_name
+	.long	.Lconst                 # DW_AT_type
+        .sleb128 0xed9a924c00011151     # DW_AT_const_value
+.Lconst:
+	.byte	3                       # Abbrev [3] 0x3f:0x5 DW_TAG_const_type
+	.long	.Lint64                 # DW_AT_type
+.Lint64:
+	.byte	4                       # Abbrev [4] 0x44:0x7 DW_TAG_base_type
+	.asciz	"long int"              # DW_AT_name
+	.byte	5                       # DW_AT_encoding
+	.byte	8                       # DW_AT_byte_size
+	.byte	0                       # End Of Children Mark
+.Ldebug_info_end0:
diff --git a/lldb/unittests/Utility/DataExtractorTest.cpp b/lldb/unittests/Utility/DataExtractorTest.cpp
--- a/lldb/unittests/Utility/DataExtractorTest.cpp
+++ b/lldb/unittests/Utility/DataExtractorTest.cpp
@@ -261,3 +261,41 @@
   EXPECT_EQ(0x0102030405060708U, BE.GetMaxU64_unchecked(&offset, 8));
   EXPECT_EQ(8U, offset);
 }
+
+TEST(DataExtractorTest, GetSLEB128_bit63) {
+  uint8_t buffer[] = {0xff, 0x80, 0xff, 0x80, 0xff, 0x80, 0xff, 0x80, 0x7f};
+
+  DataExtractor LE(buffer, sizeof(buffer), lldb::eByteOrderLittle,
+                   sizeof(void *));
+  DataExtractor BE(buffer, sizeof(buffer), lldb::eByteOrderBig, sizeof(void *));
+
+  lldb::offset_t offset;
+
+  int64_t expected =
+      0b1111111100000001111111000000011111110000000111111100000001111111;
+  offset = 0;
+  EXPECT_EQ(expected, LE.GetSLEB128(&offset));
+  EXPECT_EQ(9U, offset);
+  offset = 0;
+  EXPECT_EQ(expected, BE.GetSLEB128(&offset));
+  EXPECT_EQ(9U, offset);
+}
+
+TEST(DataExtractorTest, GetULEB128_bit63) {
+  uint8_t buffer[] = {0xff, 0x80, 0xff, 0x80, 0xff, 0x80, 0xff, 0x80, 0x7f};
+
+  DataExtractor LE(buffer, sizeof(buffer), lldb::eByteOrderLittle,
+                   sizeof(void *));
+  DataExtractor BE(buffer, sizeof(buffer), lldb::eByteOrderBig, sizeof(void *));
+
+  lldb::offset_t offset;
+
+  uint64_t expected =
+      0b0111111100000001111111000000011111110000000111111100000001111111;
+  offset = 0;
+  EXPECT_EQ(expected, LE.GetULEB128(&offset));
+  EXPECT_EQ(9U, offset);
+  offset = 0;
+  EXPECT_EQ(expected, BE.GetULEB128(&offset));
+  EXPECT_EQ(9U, offset);
+}