[PATCH] D44277: Avoid creating a Constant for each value in a ConstantDataSequential.

[Alina Sbirlea via Phabricator via llvm-commits]

asbirlea created this revision.
asbirlea added reviewers: bogner, lhames, t.p.northover.
Herald added a subscriber: jlebar.

We create a ConstantDataSequential (ConstantDataArray or ConstantDataVector) to avoid creating a Constant for each element in an array of constants. But them in AsmPrinter, we do create a ConstantFP for each element in the ConstantDataSequential. This triggers excessive memory use when generating large global FP constants.


Repository:
  rL LLVM

https://reviews.llvm.org/D44277

Files:
  lib/CodeGen/AsmPrinter/AsmPrinter.cpp


Index: lib/CodeGen/AsmPrinter/AsmPrinter.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -2127,6 +2127,8 @@
                                    uint64_t Offset = 0);
 
 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
+static void emitGlobalConstantFPFromAPFloat(APFloat APF, Type *ET,
+                                            AsmPrinter &AP);
 
 /// isRepeatedByteSequence - Determine whether the given value is
 /// composed of a repeated sequence of identical bytes and return the
@@ -2204,8 +2206,9 @@
                                    ElementByteSize);
     }
   } else {
+    Type *ET = CDS->getElementType();
     for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I)
-      emitGlobalConstantFP(cast<ConstantFP>(CDS->getElementAsConstant(I)), AP);
+      emitGlobalConstantFPFromAPFloat(CDS->getElementAsAPFloat(I), ET, AP);
   }
 
   unsigned Size = DL.getTypeAllocSize(CDS->getType());
@@ -2274,17 +2277,18 @@
          "Layout of constant struct may be incorrect!");
 }
 
-static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
-  APInt API = CFP->getValueAPF().bitcastToAPInt();
+static void emitGlobalConstantFPFromAPFloat(APFloat APF, Type *ET,
+                                            AsmPrinter &AP) {
+  APInt API = APF.bitcastToAPInt();
 
   // First print a comment with what we think the original floating-point value
   // should have been.
   if (AP.isVerbose()) {
     SmallString<8> StrVal;
-    CFP->getValueAPF().toString(StrVal);
+    APF.toString(StrVal);
 
-    if (CFP->getType())
-      CFP->getType()->print(AP.OutStreamer->GetCommentOS());
+    if (ET)
+      ET->print(AP.OutStreamer->GetCommentOS());
     else
       AP.OutStreamer->GetCommentOS() << "Printing <null> Type";
     AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
@@ -2299,7 +2303,7 @@
 
   // PPC's long double has odd notions of endianness compared to how LLVM
   // handles it: p[0] goes first for *big* endian on PPC.
-  if (AP.getDataLayout().isBigEndian() && !CFP->getType()->isPPC_FP128Ty()) {
+  if (AP.getDataLayout().isBigEndian() && !ET->isPPC_FP128Ty()) {
     int Chunk = API.getNumWords() - 1;
 
     if (TrailingBytes)
@@ -2318,8 +2322,11 @@
 
   // Emit the tail padding for the long double.
   const DataLayout &DL = AP.getDataLayout();
-  AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
-                            DL.getTypeStoreSize(CFP->getType()));
+  AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(ET) - DL.getTypeStoreSize(ET));
+}
+
+static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
+  emitGlobalConstantFPFromAPFloat(CFP->getValueAPF(), CFP->getType(), AP);
 }
 
 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {


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