Inliner should not add callgraph edges for intrinsic calls (PR22857)

[spatel]

Summary

The CallGraphNode function "addCalledFunction()" asserts that edges are not to intrinsics.

This patch makes sure that the Inliner does not add such an edge to the callgraph.

Fix for clang crash by assertion: https://llvm.org/bugs/show_bug.cgi?id=22857

[chandlerc]

Looks good.

[spatel]

Thanks, Chandler - committed at r231927.

lib/Transforms/Utils/InlineFunction.cpp

for (; I != E; ++I) {
     ValueToValueMapTy::iterator VMI = VMap.find(OrigCall);
     // Only copy the edge if the call was inlined!
     if (VMI == VMap.end() || VMI->second == nullptr)
       continue;
     
     // If the call was inlined, but then constant folded, there is no edge to
     // add.  Check for this case.
     Instruction *NewCall = dyn_cast<Instruction>(VMI->second);
-    if (!NewCall) continue;
+    if (!NewCall)
+      continue;
+
+    // We do not treat intrinsic calls like real function calls because we
+    // expect them to become inline code; do not add an edge for an intrinsic.
+    CallSite CS = CallSite(NewCall);
+    if (CS && CS.getCalledFunction() && CS.getCalledFunction()->isIntrinsic())
+      continue;
     
     // Remember that this call site got inlined for the client of
     // InlineFunction.
     IFI.InlinedCalls.push_back(NewCall);
 
     // It's possible that inlining the callsite will cause it to go from an
     // indirect to a direct call by resolving a function pointer.  If this
     // happens, set the callee of the new call site to a more precise
     // destination.  This can also happen if the call graph node of the caller

test/Transforms/InstCombine/inline_intrinsic_assert.ll

+; RUN: opt < %s -inline -instcombine -S | FileCheck %s
+
+; PR22857: http://llvm.org/bugs/show_bug.cgi?id=22857
+; The inliner should not add an edge to an intrinsic and
+; then assert that it did not add an edge to an intrinsic!
+
+define float @foo(float %f1) #0 {
+  %call = call float @bar(float %f1)
+  ret float %call
+
+; CHECK-LABEL: @foo(
+; CHECK-NEXT: call float @llvm.fabs.f32
+; CHECK-NEXT: ret float
+}
+
+define float @bar(float %f1) #0 {
+  %call = call float @sqr(float %f1)
+  %call1 = call float @sqrtf(float %call) #0
+  ret float %call1
+}
+
+define float @sqr(float %f) #0 {
+  %mul = fmul fast float %f, %f
+  ret float %mul
+}
+
+declare float @sqrtf(float) #0
+
+attributes #0 = { "unsafe-fp-math"="true" }
+