[llvm] [SimplifyLibCalls] Shrink llvm.sincos.f64 to llvm.sincos.f32 (PR #211218)

[Kito Cheng via llvm-commits]

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@@ -2047,6 +2047,41 @@ static Value *optimizeBinaryDoubleFP(CallInst *CI, IRBuilderBase &B,
   return optimizeDoubleFP(CI, B, true, TLI, isPrecise);
 }
 
+/// Shrink double -> float for llvm.sincos.
+static Value *optimizeSinCosDoubleFP(CallInst *CI, IRBuilderBase &B) {
+  auto *RetTy = dyn_cast<StructType>(CI->getType());
+  if (!RetTy || RetTy->getNumElements() != 2 ||
+      !RetTy->getElementType(0)->isDoubleTy())
+    return nullptr;
+
+  Value *X = valueHasFloatPrecision(CI->getArgOperand(0));
+  if (!X)
+    return nullptr;
+
+  for (User *U : CI->users()) {
+    auto *EV = dyn_cast<ExtractValueInst>(U);
+    if (!EV)
+      return nullptr;
+    for (User *EVU : EV->users()) {
+      auto *Cast = dyn_cast<FPTruncInst>(EVU);
+      if (!Cast || !Cast->getType()->isFloatTy())
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kito-cheng wrote:

I may found some time to handle other `double -> float` together latter 

https://github.com/llvm/llvm-project/pull/211218