[CallSite Removal] a CallBase is never an IndirectCall for isInlineAsm

[nickdesaulniers]

Summary

Thanks to Bill Wendling (void) for the report and steps to reproduce. It looks
like this was missed during r350508's cleanup of the CallSite split into
CallBase, CallInst, and CallBrInst.

This was exposed by running pgo on a callbr, which was creating a ptrtoint to
the inline asm thinking it was an indirect call. The relevant callchain looks
like:

IndirectCallPromotionPlugin::run()
-> PGOIndirectCallVisitor::findIndirectCalls()
  -> PGOIndirectCallVisitor::visitCallBase()
    -> CallBase::isIndirectCall()

[nickdesaulniers]

llvm/lib/IR/Instructions.cpp

270

eh, could simplify this more, will do.

[nickdesaulniers]

• simplify function

[nickdesaulniers]

• touch fewer lines as per Bill

[nickdesaulniers]

• actually compile test the change...

llvm/lib/IR/Instructions.cpp

unsigned CallBase::getNumSubclassExtraOperandsDynamic() const {
   assert(getOpcode() == Instruction::CallBr && "Unexpected opcode!");
   return cast<CallBrInst>(this)->getNumIndirectDests() + 1;
 }
 
 bool CallBase::isIndirectCall() const {
   const Value *V = getCalledValue();
   if (isa<Function>(V) || isa<Constant>(V))
     return false;
-  if (const CallInst *CI = dyn_cast<CallInst>(this))
-    if (CI->isInlineAsm())
-      return false;
-  return true;
+  return !CI->isInlineAsm();
 }
 
 /// Tests if this call site must be tail call optimized. Only a CallInst can
 /// be tail call optimized.
 bool CallBase::isMustTailCall() const {
   if (auto *CI = dyn_cast<CallInst>(this))
     return CI->isMustTailCall();
   return false;

llvm/test/Transforms/PGOProfile/callbr.ll

+; RUN: opt -pgo-instr-gen -S 2>&1 < %s | FileCheck %s
+
+define i32 @a() {
+entry:
+; CHECK-NOT: ptrtoint void (i8*)* asm sideeffect
+; CHECK: callbr void asm sideeffect
+  %retval = alloca i32, align 4
+  callbr void asm sideeffect "", "X,~{dirflag},~{fpsr},~{flags}"(i8* blockaddress(@a, %b)) #1
+          to label %asm.fallthrough [label %b]
+
+asm.fallthrough:
+  br label %b
+
+b:
+  %0 = load i32, i32* %retval, align 4
+  ret i32 %0
+}