Index: lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -701,6 +701,37 @@
     }
   }
 
+  if (AllowReassociate) {
+    Value *A, *B, *C;
+    BuilderTy::FastMathFlagGuard Guard(Builder);
+    Builder.setFastMathFlags(I.getFastMathFlags());
+    Value *Pow = Intrinsic::getDeclaration(I.getModule(),
+                                           Intrinsic::pow, I.getType());
+    // pow(A, B) * A -> pow(A, B+1)
+    if (match(Op0, m_Intrinsic<Intrinsic::pow>(m_Specific(Op1), m_Value(B)))) {
+      Value *One = ConstantFP::get(Op0->getType(), 1.0);
+      Value *FAdd = Builder.CreateFAdd(B, One);
+      Value *PowCall = Builder.CreateCall(Pow, { Op1, FAdd });
+      return replaceInstUsesWith(I, PowCall);
+    }
+
+    // pow(A, B) * pow(C, B) -> pow(A*C, B)
+    if (match(Op0, m_Intrinsic<Intrinsic::pow>(m_Value(A), m_Value(B))) &&
+        match(Op1, m_Intrinsic<Intrinsic::pow>(m_Value(C), m_Specific(B)))) {
+      Value *AC = Builder.CreateFMul(A, C);
+      Value *PowCall = Builder.CreateCall(Pow, { AC, B });
+      return replaceInstUsesWith(I, PowCall);
+    }
+
+    // pow(A, B) * pow(A, C) -> pow(A, B+C)
+    if (match(Op0, m_Intrinsic<Intrinsic::pow>(m_Value(A), m_Value(B))) &&
+        match(Op1, m_Intrinsic<Intrinsic::pow>(m_Specific(A), m_Value(C)))) {
+      Value *BC = Builder.CreateFAdd(B, C);
+      Value *PowCall = Builder.CreateCall(Pow, { A, BC });
+      return replaceInstUsesWith(I, PowCall);
+    }
+  }
+
   // Under unsafe algebra do:
   // X * log2(0.5*Y) = X*log2(Y) - X
   if (AllowReassociate) {
@@ -1478,6 +1509,37 @@
     return &I;
   }
 
+  if (AllowReassociate) {
+    Value *A, *B, *C;
+    BuilderTy::FastMathFlagGuard Guard(Builder);
+    Builder.setFastMathFlags(I.getFastMathFlags());
+    Value *Pow = Intrinsic::getDeclaration(I.getModule(),
+                                           Intrinsic::pow, I.getType());
+    // pow(A, B) / A -> pow(A, B-1)
+    if (match(Op0, m_Intrinsic<Intrinsic::pow>(m_Specific(Op1), m_Value(B)))) {
+      Value *One = ConstantFP::get(Op0->getType(), 1.0);
+      Value *FSub = Builder.CreateFSub(B, One);
+      Value *PowCall = Builder.CreateCall(Pow, { Op1, FSub });
+      return replaceInstUsesWith(I, PowCall);
+    }
+
+    // pow(A, B) / pow(C, B) -> pow(A/C, B)
+    if (match(Op0, m_Intrinsic<Intrinsic::pow>(m_Value(A), m_Value(B))) &&
+        match(Op1, m_Intrinsic<Intrinsic::pow>(m_Value(C), m_Specific(B)))) {
+      Value *AC = Builder.CreateFDiv(A, C);
+      Value *PowCall = Builder.CreateCall(Pow, { AC, B });
+      return replaceInstUsesWith(I, PowCall);
+    }
+
+    // pow(A, B) / pow(A, C) -> pow(A, B-C)
+    if (match(Op0, m_Intrinsic<Intrinsic::pow>(m_Value(A), m_Value(B))) &&
+        match(Op1, m_Intrinsic<Intrinsic::pow>(m_Specific(A), m_Value(C)))) {
+      Value *BC = Builder.CreateFSub(B, C);
+      Value *PowCall = Builder.CreateCall(Pow, { A, BC });
+      return replaceInstUsesWith(I, PowCall);
+    }
+  }
+
   return nullptr;
 }
 
Index: test/Transforms/InstCombine/fdiv-pow.ll
===================================================================
--- /dev/null
+++ test/Transforms/InstCombine/fdiv-pow.ll
@@ -0,0 +1,76 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -instcombine < %s | FileCheck %s
+
+define double @fdiv_pow_ab_a(double %a, double %b)  {
+; CHECK-LABEL: @fdiv_pow_ab_a(
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.pow.f64(double [[A:%.*]], double [[B:%.*]])
+; CHECK-NEXT:    [[DIV:%.*]] = fdiv double [[TMP1]], [[A]]
+; CHECK-NEXT:    ret double [[DIV]]
+;
+  %1 = call double @llvm.pow.f64(double %a, double %b)
+  %div = fdiv double %1, %a
+  ret double %div
+}
+
+define double @fdiv_pow_ab_a_fast(double %a, double %b)  {
+; CHECK-LABEL: @fdiv_pow_ab_a_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = fadd fast double [[B:%.*]], -1.000000e+00
+; CHECK-NEXT:    [[TMP2:%.*]] = call fast double @llvm.pow.f64(double [[A:%.*]], double [[TMP1]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = call fast double @llvm.pow.f64(double %a, double %b)
+  %div = fdiv fast double %1, %a
+  ret double %div
+}
+
+define double @fdiv_pow_ab_pow_cb(double %a, double %b, double %c) {
+; CHECK-LABEL: @fdiv_pow_ab_pow_cb(
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.pow.f64(double [[A:%.*]], double [[B:%.*]])
+; CHECK-NEXT:    [[TMP2:%.*]] = call double @llvm.pow.f64(double [[C:%.*]], double [[B]])
+; CHECK-NEXT:    [[DIV:%.*]] = fdiv double [[TMP1]], [[TMP2]]
+; CHECK-NEXT:    ret double [[DIV]]
+;
+  %1 = call double @llvm.pow.f64(double %a, double %b)
+  %2 = call double @llvm.pow.f64(double %c, double %b)
+  %div = fdiv double %1, %2
+  ret double %div
+}
+
+define double @fdiv_pow_ab_pow_cb_fast(double %a, double %b, double %c) {
+; CHECK-LABEL: @fdiv_pow_ab_pow_cb_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = fdiv fast double [[A:%.*]], [[C:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = call fast double @llvm.pow.f64(double [[TMP1]], double [[B:%.*]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = call fast double @llvm.pow.f64(double %a, double %b)
+  %2 = call fast double @llvm.pow.f64(double %c, double %b)
+  %div = fdiv fast double %1, %2
+  ret double %div
+}
+
+define double @fdiv_pow_ab_pow_ac(double %a, double %b, double %c) {
+; CHECK-LABEL: @fdiv_pow_ab_pow_ac(
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.pow.f64(double [[A:%.*]], double [[B:%.*]])
+; CHECK-NEXT:    [[TMP2:%.*]] = call double @llvm.pow.f64(double [[A]], double [[C:%.*]])
+; CHECK-NEXT:    [[DIV:%.*]] = fdiv double [[TMP1]], [[TMP2]]
+; CHECK-NEXT:    ret double [[DIV]]
+;
+  %1 = call double @llvm.pow.f64(double %a, double %b)
+  %2 = call double @llvm.pow.f64(double %a, double %c)
+  %div = fdiv double %1, %2
+  ret double %div
+}
+
+define double @fdiv_pow_ab_x_pow_ac_fast(double %a, double %b, double %c) {
+; CHECK-LABEL: @fdiv_pow_ab_x_pow_ac_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = fsub fast double [[B:%.*]], [[C:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = call fast double @llvm.pow.f64(double [[A:%.*]], double [[TMP1]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = call fast double @llvm.pow.f64(double %a, double %b)
+  %2 = call fast double @llvm.pow.f64(double %a, double %c)
+  %div = fdiv fast double %1, %2
+  ret double %div
+}
+
+declare double @llvm.pow.f64(double, double)
Index: test/Transforms/InstCombine/fmul-pow.ll
===================================================================
--- /dev/null
+++ test/Transforms/InstCombine/fmul-pow.ll
@@ -0,0 +1,76 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -instcombine < %s | FileCheck %s
+
+define double @pow_ab_x_a(double %a, double %b)  {
+; CHECK-LABEL: @pow_ab_x_a(
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.pow.f64(double [[A:%.*]], double [[B:%.*]])
+; CHECK-NEXT:    [[MUL:%.*]] = fmul double [[TMP1]], [[A]]
+; CHECK-NEXT:    ret double [[MUL]]
+;
+  %1 = call double @llvm.pow.f64(double %a, double %b)
+  %mul = fmul double %1, %a
+  ret double %mul
+}
+
+define double @pow_ab_x_a_fast(double %a, double %b)  {
+; CHECK-LABEL: @pow_ab_x_a_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = fadd fast double [[B:%.*]], 1.000000e+00
+; CHECK-NEXT:    [[TMP2:%.*]] = call fast double @llvm.pow.f64(double [[A:%.*]], double [[TMP1]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = call fast double @llvm.pow.f64(double %a, double %b)
+  %mul = fmul fast double %1, %a
+  ret double %mul
+}
+
+define double @pow_ab_x_pow_cb(double %a, double %b, double %c) {
+; CHECK-LABEL: @pow_ab_x_pow_cb(
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.pow.f64(double [[A:%.*]], double [[B:%.*]])
+; CHECK-NEXT:    [[TMP2:%.*]] = call double @llvm.pow.f64(double [[C:%.*]], double [[B]])
+; CHECK-NEXT:    [[MUL:%.*]] = fmul double [[TMP2]], [[TMP1]]
+; CHECK-NEXT:    ret double [[MUL]]
+;
+  %1 = call double @llvm.pow.f64(double %a, double %b)
+  %2 = call double @llvm.pow.f64(double %c, double %b)
+  %mul = fmul double %2, %1
+  ret double %mul
+}
+
+define double @pow_ab_x_pow_cb_fast(double %a, double %b, double %c) {
+; CHECK-LABEL: @pow_ab_x_pow_cb_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = fmul fast double [[C:%.*]], [[A:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = call fast double @llvm.pow.f64(double [[TMP1]], double [[B:%.*]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = call fast double @llvm.pow.f64(double %a, double %b)
+  %2 = call fast double @llvm.pow.f64(double %c, double %b)
+  %mul = fmul fast double %2, %1
+  ret double %mul
+}
+
+define double @pow_ab_x_pow_ac(double %a, double %b, double %c) {
+; CHECK-LABEL: @pow_ab_x_pow_ac(
+; CHECK-NEXT:    [[TMP1:%.*]] = call double @llvm.pow.f64(double [[A:%.*]], double [[B:%.*]])
+; CHECK-NEXT:    [[TMP2:%.*]] = call double @llvm.pow.f64(double [[A]], double [[C:%.*]])
+; CHECK-NEXT:    [[MUL:%.*]] = fmul double [[TMP2]], [[TMP1]]
+; CHECK-NEXT:    ret double [[MUL]]
+;
+  %1 = call double @llvm.pow.f64(double %a, double %b)
+  %2 = call double @llvm.pow.f64(double %a, double %c)
+  %mul = fmul double %2, %1
+  ret double %mul
+}
+
+define double @pow_ab_x_pow_ac_fast(double %a, double %b, double %c) {
+; CHECK-LABEL: @pow_ab_x_pow_ac_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = fadd fast double [[C:%.*]], [[B:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = call fast double @llvm.pow.f64(double [[A:%.*]], double [[TMP1]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %1 = call fast double @llvm.pow.f64(double %a, double %b)
+  %2 = call fast double @llvm.pow.f64(double %a, double %c)
+  %mul = fmul fast double %2, %1
+  ret double %mul
+}
+
+declare double @llvm.pow.f64(double, double)