diff --git a/include/llvm/CodeGen/FastISel.h b/include/llvm/CodeGen/FastISel.h
index 00634745347..1e0ef6b545e 100644
--- a/include/llvm/CodeGen/FastISel.h
+++ b/include/llvm/CodeGen/FastISel.h
@@ -358,6 +358,15 @@ protected:
     return 0;
   }
 
+  /// \brief Check if \c Add is an add that can be safely folded into \c GEP.
+  ///
+  /// \c Add can be folded into \c GEP if:
+  /// - \c Add is an add,
+  /// - \c Add's size matches \c GEP's,
+  /// - \c Add is in the same basic block as \c GEP, and
+  /// - \c Add has a constant operand.
+  bool canFoldAddIntoGEP(const User *GEP, const Value *Add);
+
 private:
   bool SelectBinaryOp(const User *I, unsigned ISDOpcode);
 
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index fb798c1f09b..a6f746140dd 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -1571,4 +1571,19 @@ bool FastISel::tryToFoldLoad(const LoadInst *LI, const Instruction *FoldInst) {
   return tryToFoldLoadIntoMI(User, RI.getOperandNo(), LI);
 }
 
+bool FastISel::canFoldAddIntoGEP(const User *GEP, const Value *Add) {
+  // Must be an add.
+  if (!isa<AddOperator>(Add))
+    return false;
+  // Type size needs to match.
+  if (TD.getTypeSizeInBits(GEP->getType()) !=
+      TD.getTypeSizeInBits(Add->getType()))
+    return false;
+  // Must be in the same basic block.
+  if (isa<Instruction>(Add) &&
+      FuncInfo.MBBMap[cast<Instruction>(Add)->getParent()] != FuncInfo.MBB)
+    return false;
+  // Must have a constant operand.
+  return isa<ConstantInt>(cast<AddOperator>(Add)->getOperand(1));
+}
 
diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index f3a74c7109e..a4004f32db3 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -900,13 +900,8 @@ bool ARMFastISel::ARMComputeAddress(const Value *Obj, Address &Addr) {
               TmpOffset += CI->getSExtValue() * S;
               break;
             }
-            if (isa<AddOperator>(Op) &&
-                (!isa<Instruction>(Op) ||
-                 FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()]
-                 == FuncInfo.MBB) &&
-                isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
-              // An add (in the same block) with a constant operand. Fold the
-              // constant.
+            if (canFoldAddIntoGEP(U, Op)) {
+              // A compatible add with a constant operand. Fold the constant.
               ConstantInt *CI =
               cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
               TmpOffset += CI->getSExtValue() * S;
diff --git a/lib/Target/PowerPC/PPCFastISel.cpp b/lib/Target/PowerPC/PPCFastISel.cpp
index 4f8e6c1a101..09117e7ded4 100644
--- a/lib/Target/PowerPC/PPCFastISel.cpp
+++ b/lib/Target/PowerPC/PPCFastISel.cpp
@@ -336,13 +336,8 @@ bool PPCFastISel::PPCComputeAddress(const Value *Obj, Address &Addr) {
               TmpOffset += CI->getSExtValue() * S;
               break;
             }
-            if (isa<AddOperator>(Op) &&
-                (!isa<Instruction>(Op) ||
-                 FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()]
-                 == FuncInfo.MBB) &&
-                isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
-              // An add (in the same block) with a constant operand. Fold the
-              // constant.
+            if (canFoldAddIntoGEP(U, Op)) {
+              // A compatible add with a constant operand. Fold the constant.
               ConstantInt *CI =
               cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
               TmpOffset += CI->getSExtValue() * S;
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 928dea91b4f..97f96ab72c2 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -561,13 +561,8 @@ redo_gep:
           Disp += CI->getSExtValue() * S;
           break;
         }
-        if (isa<AddOperator>(Op) &&
-            (!isa<Instruction>(Op) ||
-             FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()]
-               == FuncInfo.MBB) &&
-            isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {
-          // An add (in the same block) with a constant operand. Fold the
-          // constant.
+        if (canFoldAddIntoGEP(U, Op)) {
+          // A compatible add with a constant operand. Fold the constant.
           ConstantInt *CI =
             cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));
           Disp += CI->getSExtValue() * S;
diff --git a/test/CodeGen/ARM/fastisel-gep-promote-before-add.ll b/test/CodeGen/ARM/fastisel-gep-promote-before-add.ll
new file mode 100644
index 00000000000..a32ab6d0931
--- /dev/null
+++ b/test/CodeGen/ARM/fastisel-gep-promote-before-add.ll
@@ -0,0 +1,18 @@
+; fastisel should not fold add with non-pointer bitwidth
+; sext(a) + sext(b) != sext(a + b)
+; RUN: llc -mtriple=armv7-apple-ios %s -O0 -o - | FileCheck %s
+
+define zeroext i8 @gep_promotion(i8* %ptr) nounwind uwtable ssp {
+entry:
+  %ptr.addr = alloca i8*, align 8
+  %add = add i8 64, 64 ; 0x40 + 0x40
+  %0 = load i8** %ptr.addr, align 8
+
+  ; CHECK-LABEL: _gep_promotion:
+  ; CHECK: ldrb {{r[0-9]+}}, {{\[r[0-9]+\]}}
+  %arrayidx = getelementptr inbounds i8* %0, i8 %add
+
+  %1 = load i8* %arrayidx, align 1
+  ret i8 %1
+}
+
diff --git a/test/CodeGen/PowerPC/fastisel-gep-promote-before-add.ll b/test/CodeGen/PowerPC/fastisel-gep-promote-before-add.ll
new file mode 100644
index 00000000000..4bcacf00974
--- /dev/null
+++ b/test/CodeGen/PowerPC/fastisel-gep-promote-before-add.ll
@@ -0,0 +1,17 @@
+; fastisel should not fold add with non-pointer bitwidth
+; sext(a) + sext(b) != sext(a + b)
+; RUN: llc -mtriple=powerpc64-unknown-freebsd10.0 %s -O0 -o - | FileCheck %s
+
+define zeroext i8 @gep_promotion(i8* %ptr) nounwind uwtable ssp {
+entry:
+  %ptr.addr = alloca i8*, align 8
+  %add = add i8 64, 64 ; 0x40 + 0x40
+  %0 = load i8** %ptr.addr, align 8
+
+  ; CHECK-LABEL: gep_promotion:
+  ; CHECK: lbz {{[0-9]+}}, 0({{.*}})
+  %arrayidx = getelementptr inbounds i8* %0, i8 %add
+
+  %1 = load i8* %arrayidx, align 1
+  ret i8 %1
+}
diff --git a/test/CodeGen/X86/fastisel-gep-promote-before-add.ll b/test/CodeGen/X86/fastisel-gep-promote-before-add.ll
new file mode 100644
index 00000000000..f87a34c4abd
--- /dev/null
+++ b/test/CodeGen/X86/fastisel-gep-promote-before-add.ll
@@ -0,0 +1,37 @@
+; fastisel should not fold add with non-pointer bitwidth
+; sext(a) + sext(b) != sext(a + b)
+; RUN: llc -mtriple=x86_64-apple-darwin %s -O0 -o - | FileCheck %s
+
+define zeroext i8 @gep_promotion(i8* %ptr) nounwind uwtable ssp {
+entry:
+  %ptr.addr = alloca i8*, align 8
+  %add = add i8 64, 64 ; 0x40 + 0x40
+  %0 = load i8** %ptr.addr, align 8
+
+  ; CHECK-LABEL: _gep_promotion:
+  ; CHECK: movzbl ({{.*}})
+  %arrayidx = getelementptr inbounds i8* %0, i8 %add
+
+  %1 = load i8* %arrayidx, align 1
+  ret i8 %1
+}
+
+define zeroext i8 @gep_promotion_nonconst(i8 %i, i8* %ptr) nounwind uwtable ssp {
+entry:
+  %i.addr = alloca i8, align 4
+  %ptr.addr = alloca i8*, align 8
+  store i8 %i, i8* %i.addr, align 4
+  store i8* %ptr, i8** %ptr.addr, align 8
+  %0 = load i8* %i.addr, align 4
+  ; CHECK-LABEL: _gep_promotion_nonconst:
+  ; CHECK: movzbl ({{.*}})
+  %xor = xor i8 %0, -128   ; %0   ^ 0x80
+  %add = add i8 %xor, -127 ; %xor + 0x81
+  %1 = load i8** %ptr.addr, align 8
+
+  %arrayidx = getelementptr inbounds i8* %1, i8 %add
+
+  %2 = load i8* %arrayidx, align 1
+  ret i8 %2
+}
+