diff --git a/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h b/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
--- a/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
+++ b/llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h
@@ -198,7 +198,7 @@
   Value *optimizeFMinFMax(CallInst *CI, IRBuilderBase &B);
   Value *optimizeLog(CallInst *CI, IRBuilderBase &B);
   Value *optimizeSqrt(CallInst *CI, IRBuilderBase &B);
-  Value *optimizeSinCosPi(CallInst *CI, IRBuilderBase &B);
+  Value *optimizeSinCosPi(CallInst *CI, bool IsSin, IRBuilderBase &B);
   Value *optimizeTan(CallInst *CI, IRBuilderBase &B);
   // Wrapper for all floating point library call optimizations
   Value *optimizeFloatingPointLibCall(CallInst *CI, LibFunc Func,
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -2588,7 +2588,7 @@
   return true;
 }
 
-Value *LibCallSimplifier::optimizeSinCosPi(CallInst *CI, IRBuilderBase &B) {
+Value *LibCallSimplifier::optimizeSinCosPi(CallInst *CI, bool IsSin, IRBuilderBase &B) {
   // Make sure the prototype is as expected, otherwise the rest of the
   // function is probably invalid and likely to abort.
   if (!isTrigLibCall(CI))
@@ -2627,7 +2627,7 @@
   replaceTrigInsts(CosCalls, Cos);
   replaceTrigInsts(SinCosCalls, SinCos);
 
-  return nullptr;
+  return IsSin ? Sin : Cos;
 }
 
 void LibCallSimplifier::classifyArgUse(
@@ -3470,9 +3470,10 @@
   switch (Func) {
   case LibFunc_sinpif:
   case LibFunc_sinpi:
+    return optimizeSinCosPi(CI, /*IsSin*/true, Builder);
   case LibFunc_cospif:
   case LibFunc_cospi:
-    return optimizeSinCosPi(CI, Builder);
+    return optimizeSinCosPi(CI, /*IsSin*/false, Builder);
   case LibFunc_powf:
   case LibFunc_pow:
   case LibFunc_powl:
diff --git a/llvm/test/Transforms/InstCombine/sincospi.ll b/llvm/test/Transforms/InstCombine/sincospi.ll
--- a/llvm/test/Transforms/InstCombine/sincospi.ll
+++ b/llvm/test/Transforms/InstCombine/sincospi.ll
@@ -24,8 +24,7 @@
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[SINCOSPI:%.*]] = call <2 x float> @__sincospif_stret(float [[VAL]])
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[SINPI:%.*]] = extractelement <2 x float> [[SINCOSPI]], i64 0
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[COSPI:%.*]] = extractelement <2 x float> [[SINCOSPI]], i64 1
-; CHECK-FLOAT-IN-VEC-NEXT:    [[SIN:%.*]] = call float @__sinpif(float [[VAL]]) #[[ATTR0:[0-9]+]]
-; CHECK-FLOAT-IN-VEC-NEXT:    [[COS:%.*]] = call float @__cospif(float [[VAL]]) #[[ATTR0]]
+; CHECK-FLOAT-IN-VEC-NEXT:    [[COS:%.*]] = call float @__cospif(float [[VAL]]) #[[ATTR0:[0-9]+]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[RES:%.*]] = fadd float [[SINPI]], [[COSPI]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    ret float [[RES]]
 ;
@@ -34,8 +33,7 @@
 ; CHECK-NEXT:    [[SINCOSPI:%.*]] = call { float, float } @__sincospif_stret(float [[VAL]])
 ; CHECK-NEXT:    [[SINPI:%.*]] = extractvalue { float, float } [[SINCOSPI]], 0
 ; CHECK-NEXT:    [[COSPI:%.*]] = extractvalue { float, float } [[SINCOSPI]], 1
-; CHECK-NEXT:    [[SIN:%.*]] = call float @__sinpif(float [[VAL]]) #[[ATTR0:[0-9]+]]
-; CHECK-NEXT:    [[COS:%.*]] = call float @__cospif(float [[VAL]]) #[[ATTR0]]
+; CHECK-NEXT:    [[COS:%.*]] = call float @__cospif(float [[VAL]]) #[[ATTR0:[0-9]+]]
 ; CHECK-NEXT:    [[RES:%.*]] = fadd float [[SINPI]], [[COSPI]]
 ; CHECK-NEXT:    ret float [[RES]]
 ;
@@ -60,7 +58,6 @@
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[SINPI:%.*]] = extractelement <2 x float> [[SINCOSPI]], i64 0
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[COSPI:%.*]] = extractelement <2 x float> [[SINCOSPI]], i64 1
 ; CHECK-FLOAT-IN-VEC-NEXT:    store float [[VAL]], ptr [[PTR:%.*]], align 4
-; CHECK-FLOAT-IN-VEC-NEXT:    [[SIN:%.*]] = call float @__sinpif(float [[VAL]]) #[[ATTR0]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[COS:%.*]] = call float @__cospif(float [[VAL]]) #[[ATTR0]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[RES:%.*]] = fadd float [[SINPI]], [[COSPI]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    ret float [[RES]]
@@ -71,7 +68,6 @@
 ; CHECK-NEXT:    [[SINPI:%.*]] = extractvalue { float, float } [[SINCOSPI]], 0
 ; CHECK-NEXT:    [[COSPI:%.*]] = extractvalue { float, float } [[SINCOSPI]], 1
 ; CHECK-NEXT:    store float [[VAL]], ptr [[PTR:%.*]], align 4
-; CHECK-NEXT:    [[SIN:%.*]] = call float @__sinpif(float [[VAL]]) #[[ATTR0]]
 ; CHECK-NEXT:    [[COS:%.*]] = call float @__cospif(float [[VAL]]) #[[ATTR0]]
 ; CHECK-NEXT:    [[RES:%.*]] = fadd float [[SINPI]], [[COSPI]]
 ; CHECK-NEXT:    ret float [[RES]]
@@ -97,7 +93,6 @@
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[SINCOSPI:%.*]] = call <2 x float> @__sincospif_stret(float 1.000000e+00)
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[SINPI:%.*]] = extractelement <2 x float> [[SINCOSPI]], i64 0
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[COSPI:%.*]] = extractelement <2 x float> [[SINCOSPI]], i64 1
-; CHECK-FLOAT-IN-VEC-NEXT:    [[SIN:%.*]] = call float @__sinpif(float 1.000000e+00) #[[ATTR0]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[COS:%.*]] = call float @__cospif(float 1.000000e+00) #[[ATTR0]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[RES:%.*]] = fadd float [[SINPI]], [[COSPI]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    ret float [[RES]]
@@ -106,7 +101,6 @@
 ; CHECK-NEXT:    [[SINCOSPI:%.*]] = call { float, float } @__sincospif_stret(float 1.000000e+00)
 ; CHECK-NEXT:    [[SINPI:%.*]] = extractvalue { float, float } [[SINCOSPI]], 0
 ; CHECK-NEXT:    [[COSPI:%.*]] = extractvalue { float, float } [[SINCOSPI]], 1
-; CHECK-NEXT:    [[SIN:%.*]] = call float @__sinpif(float 1.000000e+00) #[[ATTR0]]
 ; CHECK-NEXT:    [[COS:%.*]] = call float @__cospif(float 1.000000e+00) #[[ATTR0]]
 ; CHECK-NEXT:    [[RES:%.*]] = fadd float [[SINPI]], [[COSPI]]
 ; CHECK-NEXT:    ret float [[RES]]
@@ -131,7 +125,6 @@
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[SINCOSPI:%.*]] = call { double, double } @__sincospi_stret(double [[VAL]])
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[SINPI:%.*]] = extractvalue { double, double } [[SINCOSPI]], 0
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[COSPI:%.*]] = extractvalue { double, double } [[SINCOSPI]], 1
-; CHECK-FLOAT-IN-VEC-NEXT:    [[SIN:%.*]] = call double @__sinpi(double [[VAL]]) #[[ATTR0]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[COS:%.*]] = call double @__cospi(double [[VAL]]) #[[ATTR0]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[RES:%.*]] = fadd double [[SINPI]], [[COSPI]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    ret double [[RES]]
@@ -141,7 +134,6 @@
 ; CHECK-NEXT:    [[SINCOSPI:%.*]] = call { double, double } @__sincospi_stret(double [[VAL]])
 ; CHECK-NEXT:    [[SINPI:%.*]] = extractvalue { double, double } [[SINCOSPI]], 0
 ; CHECK-NEXT:    [[COSPI:%.*]] = extractvalue { double, double } [[SINCOSPI]], 1
-; CHECK-NEXT:    [[SIN:%.*]] = call double @__sinpi(double [[VAL]]) #[[ATTR0]]
 ; CHECK-NEXT:    [[COS:%.*]] = call double @__cospi(double [[VAL]]) #[[ATTR0]]
 ; CHECK-NEXT:    [[RES:%.*]] = fadd double [[SINPI]], [[COSPI]]
 ; CHECK-NEXT:    ret double [[RES]]
@@ -167,7 +159,6 @@
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[SINCOSPI:%.*]] = call { double, double } @__sincospi_stret(double 1.000000e+00)
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[SINPI:%.*]] = extractvalue { double, double } [[SINCOSPI]], 0
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[COSPI:%.*]] = extractvalue { double, double } [[SINCOSPI]], 1
-; CHECK-FLOAT-IN-VEC-NEXT:    [[SIN:%.*]] = call double @__sinpi(double 1.000000e+00) #[[ATTR0]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[COS:%.*]] = call double @__cospi(double 1.000000e+00) #[[ATTR0]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    [[RES:%.*]] = fadd double [[SINPI]], [[COSPI]]
 ; CHECK-FLOAT-IN-VEC-NEXT:    ret double [[RES]]
@@ -176,7 +167,6 @@
 ; CHECK-NEXT:    [[SINCOSPI:%.*]] = call { double, double } @__sincospi_stret(double 1.000000e+00)
 ; CHECK-NEXT:    [[SINPI:%.*]] = extractvalue { double, double } [[SINCOSPI]], 0
 ; CHECK-NEXT:    [[COSPI:%.*]] = extractvalue { double, double } [[SINCOSPI]], 1
-; CHECK-NEXT:    [[SIN:%.*]] = call double @__sinpi(double 1.000000e+00) #[[ATTR0]]
 ; CHECK-NEXT:    [[COS:%.*]] = call double @__cospi(double 1.000000e+00) #[[ATTR0]]
 ; CHECK-NEXT:    [[RES:%.*]] = fadd double [[SINPI]], [[COSPI]]
 ; CHECK-NEXT:    ret double [[RES]]