[llvm] 96e0f34 - [X86] Auto upgrade SSE/AVX PABS intrinsics to generic Intrinsic::abs

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2020-09-07T15:07:26+01:00
New Revision: 96e0f34be797ab8bb80526367009495a7eb2118f

URL: https://github.com/llvm/llvm-project/commit/96e0f34be797ab8bb80526367009495a7eb2118f
DIFF: https://github.com/llvm/llvm-project/commit/96e0f34be797ab8bb80526367009495a7eb2118f.diff

LOG: [X86] Auto upgrade SSE/AVX PABS intrinsics to generic Intrinsic::abs

Minor followup to D87101, we were expanding this to a neg+icmp+select pattern like we were in CGBuiltin

Added: 
    

Modified: 
    llvm/lib/IR/AutoUpgrade.cpp

Removed: 
    


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diff  --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index 369dc5089572..5ec3eb85d99d 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -1375,16 +1375,12 @@ static Value *UpgradeMaskedLoad(IRBuilder<> &Builder,
 }
 
 static Value *upgradeAbs(IRBuilder<> &Builder, CallInst &CI) {
+  Type *Ty = CI.getType();
   Value *Op0 = CI.getArgOperand(0);
-  llvm::Type *Ty = Op0->getType();
-  Value *Zero = llvm::Constant::getNullValue(Ty);
-  Value *Cmp = Builder.CreateICmp(ICmpInst::ICMP_SGT, Op0, Zero);
-  Value *Neg = Builder.CreateNeg(Op0);
-  Value *Res = Builder.CreateSelect(Cmp, Op0, Neg);
-
+  Function *F = Intrinsic::getDeclaration(CI.getModule(), Intrinsic::abs, Ty);
+  Value *Res = Builder.CreateCall(F, {Op0, Builder.getInt1(false)});
   if (CI.getNumArgOperands() == 3)
-    Res = EmitX86Select(Builder,CI.getArgOperand(2), Res, CI.getArgOperand(1));
-
+    Res = EmitX86Select(Builder, CI.getArgOperand(2), Res, CI.getArgOperand(1));
   return Res;
 }