[PATCH] D77600: [CallSite Removal] a CallBase is never an IndirectCall for isInlineAsm

[Nick Desaulniers via Phabricator via llvm-commits]

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- simplify function



================
Comment at: llvm/lib/IR/Instructions.cpp:272
+    return false;
   return true;
 }
----------------
eh, could simplify this more, will do.


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()


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D77600

Files:
  llvm/lib/IR/Instructions.cpp
  llvm/test/Transforms/PGOProfile/callbr.ll


Index: llvm/test/Transforms/PGOProfile/callbr.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/PGOProfile/callbr.ll
@@ -0,0 +1,17 @@
+; 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
+}
Index: llvm/lib/IR/Instructions.cpp
===================================================================
--- llvm/lib/IR/Instructions.cpp
+++ llvm/lib/IR/Instructions.cpp
@@ -265,12 +265,7 @@
 
 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 !(isa<Function>(V) || isa<Constant>(V) || isInlineAsm());
 }
 
 /// Tests if this call site must be tail call optimized. Only a CallInst can


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