[PATCH] D91401: [AMDGPU] Mark sin/cos load folding as modifying the function.

[Matthew Dawson via Phabricator via llvm-commits]

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When the load value is folded into the sin/cos operation, the
AMDGPU library calls simplifier could still mark the function
as unmodified.  Instead ensure if there is an early return,
return whether the load was folded into the sin/cos call.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D91401

Files:
  llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp


Index: llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp
+++ llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp
@@ -1288,6 +1288,7 @@
   BasicBlock * const CBB = CI->getParent();
 
   int const MaxScan = 30;
+  bool Changed = false;
 
   { // fold in load value.
     LoadInst *LI = dyn_cast<LoadInst>(CArgVal);
@@ -1295,6 +1296,7 @@
       BasicBlock::iterator BBI = LI->getIterator();
       Value *AvailableVal = FindAvailableLoadedValue(LI, CBB, BBI, MaxScan, AA);
       if (AvailableVal) {
+        Changed = true;
         CArgVal->replaceAllUsesWith(AvailableVal);
         if (CArgVal->getNumUses() == 0)
           LI->eraseFromParent();
@@ -1330,7 +1332,8 @@
     if (UI) break;
   }
 
-  if (!UI) return false;
+  if (!UI)
+    return Changed;
 
   // Merge the sin and cos.
 
@@ -1339,7 +1342,8 @@
   AMDGPULibFunc nf(AMDGPULibFunc::EI_SINCOS, fInfo);
   nf.getLeads()[0].PtrKind = AMDGPULibFunc::getEPtrKindFromAddrSpace(AMDGPUAS::FLAT_ADDRESS);
   FunctionCallee Fsincos = getFunction(M, nf);
-  if (!Fsincos) return false;
+  if (!Fsincos)
+    return Changed;
 
   BasicBlock::iterator ItOld = B.GetInsertPoint();
   AllocaInst *Alloc = insertAlloca(UI, B, "__sincos_");


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