Index: llvm/lib/Analysis/ConstantFolding.cpp
===================================================================
--- llvm/lib/Analysis/ConstantFolding.cpp
+++ llvm/lib/Analysis/ConstantFolding.cpp
@@ -429,18 +429,17 @@
     return true;
 
   if (auto *CI = dyn_cast<ConstantInt>(C)) {
-    if (CI->getBitWidth() > 64 ||
-        (CI->getBitWidth() & 7) != 0)
+    // TODO: Adjust non-byte-sized integer
+    if ((CI->getBitWidth() & 7) != 0)
       return false;
-
-    uint64_t Val = CI->getZExtValue();
+    APInt Val = CI->getValue();
     unsigned IntBytes = unsigned(CI->getBitWidth()/8);
 
     for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) {
-      int n = ByteOffset;
+      unsigned n = ByteOffset;
       if (!DL.isLittleEndian())
         n = IntBytes - n - 1;
-      CurPtr[i] = (unsigned char)(Val >> (n * 8));
+      CurPtr[i] = Val.extractBits(8, n * 8).getZExtValue();
       ++ByteOffset;
     }
     return true;
Index: llvm/test/Transforms/InstCombine/constant-fold.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/InstCombine/constant-fold.ll
@@ -0,0 +1,20 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+@global128 = internal constant i128 1125899906842625
+@global125 = internal constant i125 1125899906842625
+define i128 @load-128bit(){
+; CHECK-LABEL: define i128 @load-128bit() {
+; CHECK-NEXT:    ret i128 1125899906842625
+;
+  %1 = load i128, ptr @global128, align 4
+  ret i128 %1
+}
+
+; TODO: Current ReadDataFromGlobal assumes only byte-sized integer
+define i125 @load-125bit(){
+; CHECK-LABEL: define i125 @load-125bit() {
+; CHECK-NEXT:    ret i125 1125899906842625
+;
+  %1 = load i125, ptr @global125, align 4
+  ret i125 %1
+}