[X86][AVX512] Autoupgrade lossless i32/u32 to f64 conversion intrinsics with generic IR

Both the (V)CVTDQ2PD (i32 to f64) and (V)CVTUDQ2PD (u32 to f64) conversion instructions are lossless and can be safely represented as generic SINT_TO_FP/UINT_TO_FP calls instead of x86 intrinsics without affecting final codegen.

LLVM counterpart to D26686

Differential Revision: https://reviews.llvm.org/D26736

llvm-svn: 287108

1 files changed, 14 insertions, 3 deletions

diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index 3d079ee35f5..18f2c17c7c9 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -295,6 +295,8 @@ static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
          Name.startswith("avx512.mask.padd.") || // Added in 4.0
          Name.startswith("avx512.mask.psub.") || // Added in 4.0
          Name.startswith("avx512.mask.pmull.") || // Added in 4.0
+         Name.startswith("avx512.mask.cvtdq2pd.") || // Added in 4.0
+         Name.startswith("avx512.mask.cvtudq2pd.") || // Added in 4.0
          Name == "avx512.mask.add.pd.128" || // Added in 4.0
          Name == "avx512.mask.add.pd.256" || // Added in 4.0
          Name == "avx512.mask.add.ps.128" || // Added in 4.0
@@ -821,7 +823,9 @@ void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
     } else if (IsX86 && (Name == "sse2.cvtdq2pd" ||
                          Name == "sse2.cvtps2pd" ||
                          Name == "avx.cvtdq2.pd.256" ||
-                         Name == "avx.cvt.ps2.pd.256")) {
+                         Name == "avx.cvt.ps2.pd.256" ||
+                         Name.startswith("avx512.mask.cvtdq2pd.") ||
+                         Name.startswith("avx512.mask.cvtudq2pd."))) {
       // Lossless i32/float to double conversion.
       // Extract the bottom elements if necessary and convert to double vector.
       Value *Src = CI->getArgOperand(0);
@@ -837,11 +841,18 @@ void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
                                           ShuffleMask);
       }
 
-      bool Int2Double = (StringRef::npos != Name.find("cvtdq2"));
-      if (Int2Double)
+      bool SInt2Double = (StringRef::npos != Name.find("cvtdq2"));
+      bool UInt2Double = (StringRef::npos != Name.find("cvtudq2"));
+      if (SInt2Double)
         Rep = Builder.CreateSIToFP(Rep, DstTy, "cvtdq2pd");
+      else if (UInt2Double)
+        Rep = Builder.CreateUIToFP(Rep, DstTy, "cvtudq2pd");
       else
         Rep = Builder.CreateFPExt(Rep, DstTy, "cvtps2pd");
+
+      if (CI->getNumArgOperands() == 3)
+        Rep = EmitX86Select(Builder, CI->getArgOperand(2), Rep,
+                            CI->getArgOperand(1));
     } else if (IsX86 && Name.startswith("sse4a.movnt.")) {
       Module *M = F->getParent();
       SmallVector<Metadata *, 1> Elts;