Index: lib/Transforms/Scalar/LoopUnrollPass.cpp
===================================================================
--- lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -515,8 +515,13 @@
 
         // Can't properly model a cost of a call.
         // FIXME: With a proper cost model we should be able to do it.
-        if(isa<CallInst>(&I))
-          return None;
+        if (auto *CI = dyn_cast<CallInst>(&I)) {
+          const Function *Callee = CI->getCalledFunction();
+          if (!Callee || TTI.isLoweredToCall(Callee)) {
+            LLVM_DEBUG(dbgs() << "Can't analyze cost of loop with call\n");
+            return None;
+          }
+        }
 
         // If the instruction might have a side-effect recursively account for
         // the cost of it and all the instructions leading up to it.
Index: test/Transforms/LoopUnroll/AMDGPU/unroll-cost-call.ll
===================================================================
--- /dev/null
+++ test/Transforms/LoopUnroll/AMDGPU/unroll-cost-call.ll
@@ -0,0 +1,78 @@
+; RUN: opt -S -mtriple=amdgcn-unknown-amdhsa -mcpu=hawaii -loop-unroll -unroll-threshold=100 -unroll-peel-count=0 -unroll-allow-partial=false -unroll-max-iteration-count-to-analyze=16 < %s | FileCheck %s
+
+; CHECK-LABEL: @test_intrinsic_call_cost(
+; CHECK-NOT: br i1
+define amdgpu_kernel void @test_intrinsic_call_cost(float addrspace(1)* noalias nocapture %out, float addrspace(1)* noalias nocapture %in) #0 {
+entry:
+  br label %for.body
+
+for.body:
+  %indvars.iv = phi i32 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+  %sum.02 = phi float [ %fmul, %for.body ], [ 0.0, %entry ]
+  %arrayidx.in = getelementptr inbounds float, float addrspace(1)* %in, i32 %indvars.iv
+  %arrayidx.out = getelementptr inbounds float, float addrspace(1)* %out, i32 %indvars.iv
+  %load = load float, float addrspace(1)* %arrayidx.in
+  %call = call float @llvm.minnum.f32(float %load, float 1.0);
+  %fmul = fmul float %call, %sum.02
+  store float %fmul, float addrspace(1)* %arrayidx.out
+  %indvars.iv.next = add i32 %indvars.iv, 1
+  %exitcond = icmp eq i32 %indvars.iv.next, 16
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}
+
+; CHECK-LABEL: @test_func_call_cost(
+; CHECK: br i1 %exitcond
+define amdgpu_kernel void @test_func_call_cost(float addrspace(1)* noalias nocapture %out, float addrspace(1)* noalias nocapture %in) #0 {
+entry:
+  br label %for.body
+
+for.body:
+  %indvars.iv = phi i32 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+  %sum.02 = phi float [ %fmul, %for.body ], [ 0.0, %entry ]
+  %arrayidx.in = getelementptr inbounds float, float addrspace(1)* %in, i32 %indvars.iv
+  %arrayidx.out = getelementptr inbounds float, float addrspace(1)* %out, i32 %indvars.iv
+  %load = load float, float addrspace(1)* %arrayidx.in
+  %fptr = load float(float, float)*, float(float, float )* addrspace(4)* null
+  %call = tail call float %fptr(float %load, float 1.0)
+  %fmul = fmul float %call, %sum.02
+  store float %fmul, float addrspace(1)* %arrayidx.out
+  %indvars.iv.next = add i32 %indvars.iv, 1
+  %exitcond = icmp eq i32 %indvars.iv.next, 16
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}
+
+
+; CHECK-LABEL: @test_indirect_call_cost(
+; CHECK: br i1 %exitcond
+define amdgpu_kernel void @test_indirect_call_cost(float addrspace(1)* noalias nocapture %out, float addrspace(1)* noalias nocapture %in) #0 {
+entry:
+  br label %for.body
+
+for.body:
+  %indvars.iv = phi i32 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+  %sum.02 = phi float [ %fmul, %for.body ], [ 0.0, %entry ]
+  %arrayidx.in = getelementptr inbounds float, float addrspace(1)* %in, i32 %indvars.iv
+  %arrayidx.out = getelementptr inbounds float, float addrspace(1)* %out, i32 %indvars.iv
+  %load = load float, float addrspace(1)* %arrayidx.in
+  %min = call float @func(float %load, float 1.0);
+  %fmul = fmul float %min, %sum.02
+  store float %fmul, float addrspace(1)* %arrayidx.out
+  %indvars.iv.next = add i32 %indvars.iv, 1
+  %exitcond = icmp eq i32 %indvars.iv.next, 16
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:
+  ret void
+}
+
+declare float @llvm.minnum.f32(float, float) #1
+declare float @func(float, float) #1
+
+attributes #0 = { nounwind }
+attributes #1 = { nounwind readnone speculatable }