Fix format, assert and add codegen test for uncalled local functions

Author: JanekvO

llvm/lib/Target/AMDGPU/AMDGPUResourceUsageAnalysis.cpp

@@ -155,8 +155,8 @@ bool AMDGPUResourceUsageAnalysis::runOnModule(Module &M) {
     // machinefunction equivalent. These may not exist as the (codegen) passes
     // prior to this one are run in CGSCC order which will bypass any local
     // functions that aren't called.
-    assert((MF || !TPC->requiresCodeGenSCCOrder()) &&
-            "function must have been generated already");
+    assert((MF || TPC->requiresCodeGenSCCOrder()) &&
+           "function must have been generated already");
     if (MF) {
       Info = analyzeResourceUsage(*MF, TM);
       HasIndirectCall |= Info.HasIndirectCall;

llvm/test/CodeGen/AMDGPU/uncalled-local-functions.ll

@@ -0,0 +1,11 @@
+; RUN: llc -O0 -march=amdgcn < %s | FileCheck %s
+
+; CHECK-NOT: foo
+define internal i32 @foo() {
+  ret i32 0
+}
+
+; CHECK-NOT: bar
+define private i32 @bar() {
+  ret i32 0
+}