[llvm] 947374c - [IRTranslator] Simplify fixed vector ConstantAggregateZero handling. NFC (#108667)

[via llvm-commits]

Author: Craig Topper
Date: 2024-09-13T22:02:29-07:00
New Revision: 947374c3933b51f7f3acfe365d6ff9b10fb6cda0

URL: https://github.com/llvm/llvm-project/commit/947374c3933b51f7f3acfe365d6ff9b10fb6cda0
DIFF: https://github.com/llvm/llvm-project/commit/947374c3933b51f7f3acfe365d6ff9b10fb6cda0.diff

LOG: [IRTranslator] Simplify fixed vector ConstantAggregateZero handling. NFC (#108667)

We don't need to loop through the elements, they're all the same zero.
We can get the first element and create a splat build_vector.

Added: 
    

Modified: 
    llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index b85087c23845d5..7fbefd05ae67c7 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -3532,14 +3532,11 @@ bool IRTranslator::translate(const Constant &C, Register Reg) {
       return false;
     // Return the scalar if it is a <1 x Ty> vector.
     unsigned NumElts = CAZ->getElementCount().getFixedValue();
+    Constant &Elt = *CAZ->getElementValue(0u);
     if (NumElts == 1)
-      return translateCopy(C, *CAZ->getElementValue(0u), *EntryBuilder);
-    SmallVector<Register, 4> Ops;
-    for (unsigned I = 0; I < NumElts; ++I) {
-      Constant &Elt = *CAZ->getElementValue(I);
-      Ops.push_back(getOrCreateVReg(Elt));
-    }
-    EntryBuilder->buildBuildVector(Reg, Ops);
+      return translateCopy(C, Elt, *EntryBuilder);
+    // All elements are zero so we can just use the first one.
+    EntryBuilder->buildSplatBuildVector(Reg, getOrCreateVReg(Elt));
   } else if (auto CV = dyn_cast<ConstantDataVector>(&C)) {
     // Return the scalar if it is a <1 x Ty> vector.
     if (CV->getNumElements() == 1)