Index: include/llvm/Analysis/TargetLibraryInfo.def
===================================================================
--- include/llvm/Analysis/TargetLibraryInfo.def
+++ include/llvm/Analysis/TargetLibraryInfo.def
@@ -616,6 +616,9 @@
 /// char *ctermid(char *s);
 TLI_DEFINE_ENUM_INTERNAL(ctermid)
 TLI_DEFINE_STRING_INTERNAL("ctermid")
+/// div_t div(int numerator, int denominator);
+TLI_DEFINE_ENUM_INTERNAL(div)
+TLI_DEFINE_STRING_INTERNAL("div")
 /// int execl(const char *path, const char *arg, ...);
 TLI_DEFINE_ENUM_INTERNAL(execl)
 TLI_DEFINE_STRING_INTERNAL("execl")
@@ -928,9 +931,15 @@
 /// long double ldexpl(long double x, int n);
 TLI_DEFINE_ENUM_INTERNAL(ldexpl)
 TLI_DEFINE_STRING_INTERNAL("ldexpl")
+/// ldiv_t ldiv(long numerator, long denominator);
+TLI_DEFINE_ENUM_INTERNAL(ldiv)
+TLI_DEFINE_STRING_INTERNAL("ldiv")
 /// long long int llabs(long long int j);
 TLI_DEFINE_ENUM_INTERNAL(llabs)
 TLI_DEFINE_STRING_INTERNAL("llabs")
+/// lldiv_t lldiv(long long numerator, long long denominator);
+TLI_DEFINE_ENUM_INTERNAL(lldiv)
+TLI_DEFINE_STRING_INTERNAL("lldiv")
 /// double log(double x);
 TLI_DEFINE_ENUM_INTERNAL(log)
 TLI_DEFINE_STRING_INTERNAL("log")
Index: include/llvm/Transforms/Utils/SimplifyLibCalls.h
===================================================================
--- include/llvm/Transforms/Utils/SimplifyLibCalls.h
+++ include/llvm/Transforms/Utils/SimplifyLibCalls.h
@@ -198,6 +198,7 @@
   Value *optimizeIsAscii(CallInst *CI, IRBuilder<> &B);
   Value *optimizeToAscii(CallInst *CI, IRBuilder<> &B);
   Value *optimizeAtoi(CallInst *CI, IRBuilder<> &B);
+  Value *optimizeDiv(CallInst *CI, IRBuilder<> &B);
   Value *optimizeStrtol(CallInst *CI, IRBuilder<> &B);
 
   // Formatting and IO Library Call Optimizations
Index: lib/Analysis/TargetLibraryInfo.cpp
===================================================================
--- lib/Analysis/TargetLibraryInfo.cpp
+++ lib/Analysis/TargetLibraryInfo.cpp
@@ -1286,6 +1286,12 @@
   case LibFunc_coshl:
   case LibFunc_coshl_finite:
   case LibFunc_cosl:
+    return (NumParams == 1 && FTy.getReturnType()->isFloatingPointTy() &&
+            FTy.getReturnType() == FTy.getParamType(0));
+  case LibFunc_div:
+    return (NumParams == 2 && FTy.getReturnType()->isIntegerTy() &&
+            FTy.getParamType(0)->isIntegerTy() &&
+            FTy.getParamType(1)->isIntegerTy());
   case LibFunc_exp10:
   case LibFunc_exp10_finite:
   case LibFunc_exp10f:
@@ -1313,6 +1319,11 @@
   case LibFunc_floor:
   case LibFunc_floorf:
   case LibFunc_floorl:
+  case LibFunc_ldiv:
+  case LibFunc_lldiv:
+    return (NumParams == 2 && FTy.getReturnType()->isAggregateType() &&
+            FTy.getParamType(0)->isIntegerTy() &&
+            FTy.getParamType(1)->isIntegerTy());
   case LibFunc_log10:
   case LibFunc_log10_finite:
   case LibFunc_log10f:
Index: lib/Transforms/Utils/BuildLibCalls.cpp
===================================================================
--- lib/Transforms/Utils/BuildLibCalls.cpp
+++ lib/Transforms/Utils/BuildLibCalls.cpp
@@ -150,6 +150,15 @@
     Changed |= setNonLazyBind(F);
 
   switch (TheLibFunc) {
+  case LibFunc_div:
+  case LibFunc_ldiv:
+  case LibFunc_lldiv:
+    Changed |= setDoesNotThrow(F);
+    Changed |= setDoesNotCapture(F, 0);
+    Changed |= setOnlyReadsMemory(F, 0);
+    Changed |= setDoesNotCapture(F, 1);
+    Changed |= setOnlyReadsMemory(F, 1);
+    return Changed;
   case LibFunc_strlen:
   case LibFunc_wcslen:
     Changed |= setOnlyReadsMemory(F);
Index: lib/Transforms/Utils/SimplifyLibCalls.cpp
===================================================================
--- lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -1990,6 +1990,16 @@
   return convertStrToNumber(CI, Str, 10);
 }
 
+Value *LibCallSimplifier::optimizeDiv(CallInst *CI, IRBuilder<> &B) {
+  // TODO handle div
+  Value *Op0 = CI->getArgOperand(0);
+  Value *Op1 = CI->getArgOperand(1);
+  Value *V = B.CreateInsertValue(UndefValue::get(CI->getType()),
+                                 B.CreateSDiv(Op0, Op1), 0);
+  V = B.CreateInsertValue(V, B.CreateSRem(Op0, Op1), 1);
+  return V;
+}
+
 Value *LibCallSimplifier::optimizeStrtol(CallInst *CI, IRBuilder<> &B) {
   StringRef Str;
   if (!getConstantStringInfo(CI->getArgOperand(0), Str))
@@ -2780,6 +2790,11 @@
     case LibFunc_atol:
     case LibFunc_atoll:
       return optimizeAtoi(CI, Builder);
+    // TODO
+    // case LibFunc_div:
+    case LibFunc_ldiv:
+    case LibFunc_lldiv:
+      return optimizeDiv(CI, Builder);
     case LibFunc_strtol:
     case LibFunc_strtoll:
       return optimizeStrtol(CI, Builder);
Index: test/Transforms/InstCombine/div-call.ll
===================================================================
--- test/Transforms/InstCombine/div-call.ll
+++ test/Transforms/InstCombine/div-call.ll
@@ -0,0 +1,115 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+declare i64 @div(i32, i32)
+declare { i64, i64 } @ldiv(i64, i64)
+declare { i64, i64 } @lldiv(i64, i64)
+declare void @use(i64)
+
+define i64 @div_qout_rem(i32 %x, i32 %y) {
+; CHECK-LABEL: @div_qout_rem(
+; CHECK-NEXT:    [[DIVREM:%.*]] = tail call i64 @div(i32 [[X:%.*]], i32 [[Y:%.*]])
+; CHECK-NEXT:    ret i64 [[DIVREM]]
+;
+  %divrem = tail call i64 @div(i32 %x, i32 %y)
+  ret i64 %divrem
+}
+
+define i64 @div_qout_rem_multiuse(i32 %x, i32 %y) {
+; CHECK-LABEL: @div_qout_rem_multiuse(
+; CHECK-NEXT:    [[DIVREM:%.*]] = tail call i64 @div(i32 [[X:%.*]], i32 [[Y:%.*]])
+; CHECK-NEXT:    tail call void @use(i64 [[DIVREM]])
+; CHECK-NEXT:    ret i64 [[DIVREM]]
+;
+  %divrem = tail call i64 @div(i32 %x, i32 %y)
+  tail call void @use(i64 %divrem)
+  ret i64 %divrem
+}
+
+define i32 @div_qout(i32 %x, i32 %y) {
+; CHECK-LABEL: @div_qout(
+; CHECK-NEXT:    [[DIVREM:%.*]] = tail call i64 @div(i32 [[X:%.*]], i32 [[Y:%.*]])
+; CHECK-NEXT:    [[QUOT:%.*]] = trunc i64 [[DIVREM]] to i32
+; CHECK-NEXT:    ret i32 [[QUOT]]
+;
+  %divrem = tail call i64 @div(i32 %x, i32 %y)
+  %quot = trunc i64 %divrem to i32
+  ret i32 %quot
+}
+
+define i32 @div_rem(i32 %x, i32 %y) {
+; CHECK-LABEL: @div_rem(
+; CHECK-NEXT:    [[DIVREM:%.*]] = tail call i64 @div(i32 [[X:%.*]], i32 [[Y:%.*]])
+; CHECK-NEXT:    [[L:%.*]] = lshr i64 [[DIVREM]], 32
+; CHECK-NEXT:    [[REM:%.*]] = trunc i64 [[L]] to i32
+; CHECK-NEXT:    ret i32 [[REM]]
+;
+  %divrem = tail call i64 @div(i32 %x, i32 %y)
+  %l = lshr i64 %divrem, 32
+  %rem = trunc i64 %l to i32
+  ret i32 %rem
+}
+
+define { i64, i64 } @ldiv_qout_rem(i64 %x, i64 %y) {
+; CHECK-LABEL: @ldiv_qout_rem(
+; CHECK-NEXT:    [[TMP1:%.*]] = sdiv i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = insertvalue { i64, i64 } undef, i64 [[TMP1]], 0
+; CHECK-NEXT:    [[TMP3:%.*]] = srem i64 [[X]], [[Y]]
+; CHECK-NEXT:    [[TMP4:%.*]] = insertvalue { i64, i64 } [[TMP2]], i64 [[TMP3]], 1
+; CHECK-NEXT:    ret { i64, i64 } [[TMP4]]
+;
+  %divrem = tail call { i64, i64 } @ldiv(i64 %x, i64 %y)
+  ret { i64, i64 } %divrem
+}
+
+define i64 @ldiv_qout(i64 %x, i64 %y) {
+; CHECK-LABEL: @ldiv_qout(
+; CHECK-NEXT:    [[TMP1:%.*]] = sdiv i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i64 [[TMP1]]
+;
+  %divrem = tail call { i64, i64 } @ldiv(i64 %x, i64 %y)
+  %quot = extractvalue { i64, i64 } %divrem, 0
+  ret i64 %quot
+}
+
+define i64 @ldiv_rem(i64 %x, i64 %y) {
+; CHECK-LABEL: @ldiv_rem(
+; CHECK-NEXT:    [[TMP1:%.*]] = srem i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i64 [[TMP1]]
+;
+  %divrem = tail call { i64, i64 } @ldiv(i64 %x, i64 %y)
+  %rem = extractvalue { i64, i64 } %divrem, 1
+  ret i64 %rem
+}
+
+define { i64, i64 } @lldiv_qout_rem(i64 %x, i64 %y) {
+; CHECK-LABEL: @lldiv_qout_rem(
+; CHECK-NEXT:    [[TMP1:%.*]] = sdiv i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = insertvalue { i64, i64 } undef, i64 [[TMP1]], 0
+; CHECK-NEXT:    [[TMP3:%.*]] = srem i64 [[X]], [[Y]]
+; CHECK-NEXT:    [[TMP4:%.*]] = insertvalue { i64, i64 } [[TMP2]], i64 [[TMP3]], 1
+; CHECK-NEXT:    ret { i64, i64 } [[TMP4]]
+;
+  %divrem = tail call { i64, i64 } @lldiv(i64 %x, i64 %y)
+  ret { i64, i64 } %divrem
+}
+
+define i64 @lldiv_qout(i64 %x, i64 %y) {
+; CHECK-LABEL: @lldiv_qout(
+; CHECK-NEXT:    [[TMP1:%.*]] = sdiv i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i64 [[TMP1]]
+;
+  %divrem = tail call { i64, i64 } @lldiv(i64 %x, i64 %y)
+  %quot = extractvalue { i64, i64 } %divrem, 0
+  ret i64 %quot
+}
+
+define i64 @lldiv_rem(i64 %x, i64 %y) {
+; CHECK-LABEL: @lldiv_rem(
+; CHECK-NEXT:    [[TMP1:%.*]] = srem i64 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i64 [[TMP1]]
+;
+  %divrem = tail call { i64, i64 } @lldiv(i64 %x, i64 %y)
+  %rem = extractvalue { i64, i64 } %divrem, 1
+  ret i64 %rem
+}
Index: unittests/Analysis/TargetLibraryInfoTest.cpp
===================================================================
--- unittests/Analysis/TargetLibraryInfoTest.cpp
+++ unittests/Analysis/TargetLibraryInfoTest.cpp
@@ -139,6 +139,7 @@
       "declare float @coshf(float)\n"
       "declare x86_fp80 @coshl(x86_fp80)\n"
       "declare x86_fp80 @cosl(x86_fp80)\n"
+      "declare i64 @div(i32, i32)\n"
       "declare i8* @ctermid(i8*)\n"
       "declare double @exp(double)\n"
       "declare double @exp2(double)\n"